TY - CONF A1 - Askar, Enis T1 - Competence centre h2safety@bam N2 - In this presentation the current focus areas of the competence centre H2Safety@BAM are shown. The fields of competence include “Material properties and compatibility”, “Process and plant safety”, “Component testing, component safety and approval” as well as “Sensors, analytics and certified reference Materials. Moreover, the cross-cutting activities regarding “Education and training” and the testing possibilities and planed test facilities at the Test Site for Technical Safety (BAM TTS) are presented. T2 - VDMA P2X4A: P2X Technik-Treffen CY - Online meeting DA - 14.09.2023 KW - Hydrogen KW - Test area hydrogen safety KW - ModuH2Pipe PY - 2023 AN - OPUS4-58333 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Asna Ashari, Parsa T1 - Exploring the Technological Innovation System for Hydrogen Technologies - Four Essays on the Roles of Research, Innovation, and Safety N2 - Presentation of the doctoral thesis held at the PhD Colloquium of the Chair of Innovation Management, Freie Universität Berlin. Hydrogen has recently come into political and industrial focus due to its potential to advance the transition to a net-zero economy. Despite this recognized potential, the market ramp-up of hydrogen technologies has not yet been realized at large. Therefore, this thesis attempts to investigate how advances in hydrogen research, innovation, and safety link up to market formation using the Technological Innovation Systems (TIS) and Quality Infrastructure (QI) frameworks. Thereupon, the thesis formulates several recommendations for transitioning to a hydrogen economy. T2 - PhD Colloquium of the Chair of Innovation Management (Freie Universität Berlin) CY - Berlin, Germany DA - 09.01.2024 KW - Hydrogen KW - Research and innovation KW - Innovation system KW - Safety PY - 2024 AN - OPUS4-59400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernardy, Christopher T1 - Thermal Radiation Investigations of Real-Scale Hydrogen Jet Flames at High Pressure N2 - In order to reduce global warming, the use of hydrogen as a renewable energy source is becoming more important. To enable this transition, unprecedently large amounts of hydrogen need to be safely transported and stored. Since hydrogen is usually stored and transported under pressure, one scenario to be considered is the release of hydrogen from a leakage with subsequent ignition. The resulting jet flame must be characterized with respect to the thermal radiation emitted into the environment to define safety distances. Various models that characterize the resulting flame shape and radiation already exist in the literature, but these are mainly based on empirical data from hydrocarbon jet flames. To verify the applicability of these models to hydrogen, real-scale tests are carried out at the BAM Test Site for Technical Safety (BAM-TTS) with the aim to assess the flame geometry and the emitted thermal radiation. Parameters such as leakage diameter (currently up to 30 mm), pressure (currently up to max. 250 bar) and mass flow (up to max. 0.5 kg/s) are varied. In particular, the focus will be laid on the measurement and modelling of the thermal radiation. The challenge here is the characterization of the flame geometry in an open environment and its impact on the thermal radiation. Existing heat radiation data from literature are mostly based on unsteady outflow conditions. The experimental setup used here allows for the generation of a steady-state outflow for several minutes and thus a direct comparability with existing (steady-state) models. Furthermore, stationary outflow tests with hydrocarbons (methane) were also carried out, which are intended to serve as reference tests for checking flame models based on hydrocarbon data. Following from the experimental investigations, modelling parameters such as the Surface Emissive Power (SEP) and the radiant heat fraction for hydrogen and methane will be compared to literature data. T2 - Center for Hydrogen Safety Americas Conference, American Institute of Chemical Engineers CY - Las Vegas, NV, USA DA - 21.05.2024 KW - Thermal radiation KW - Hydrogen KW - Release KW - Jet flame PY - 2024 AN - OPUS4-60195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernardy, Christopher T1 - Real scale safety investigations of hydrogen jet flames at high pressure N2 - In order to reduce the human footprint of CO2 emissions and limit global warming effects hydrogen combustion is becoming increasingly important. To enable fuel cells and gas turbines to operates this carbon free fuel, unprecedently large amounts of hydrogen need to be produced and safely transported and stored. The investigation of the effects of accidents involving hydrogen is therefore becoming of outmost importance. Since hydrogen is usually stored and transported under pressure, one scenario to be considered is the release of hydrogen from a leakage with subsequent ignition. The resulting jet flame must be characterized with respect to the thermal radiation emitted into the environment to define safety regulations. Various models that characterize the resulting flame shape and radiation already exist in the literature, but these are mainly based on empirical data from hydrocarbon jet flames.[1-4] To verify these models, a H2 Jet Flame project conducted at BAM, is investigating the safety of momentum driven hydrogen jet flames. For this purpose, large-scale tests are carried out at the Test Site Technical Safety (BAM-TTS). The object of the investigations is to assess the effects of real scale release scenarios regarding flame geometry and the thermal radiation emitted. Parameters such as release angle, leakage diameter (currently 1 mm to 10 mm), pressure (currently up to max. 250 bar) and mass flow (up to max. 0.5 kg/s) are varied. In addition, influences such as the type of ignition, ignition location as well as delayed ignition can also be investigated. The gained knowledge will be compared with existing jet flame models, to validate these and identify a possible need for further development. In particular, the focus will be laid on the thermal radiation of hydrogen flames. The challenge here is the visualization and characterization of the flame geometry in an open environment. Visualization is performed using infrared (IR) camera systems from at least two viewing angles. Measurements of the heat radiation of jet flames, which can be found in the literature, are mostly based on unsteady outflow conditions.The experimental setup used here allows for the generation of a steady-state outflow for several minutes and thus a direct comparability with existing (steady-state) models. Furthermore, the tests can be carried out for comparative measurements with hydrocarbons (methane, etc.) as well as mixtures of hydrogen and hydrocarbons. T2 - European PhD Hydrogen Conference 2024 (EPHyC2024) CY - Gent, Belgium DA - 20.03.2024 KW - Hydrogen KW - Release KW - Jet flame KW - Thermal radiation PY - 2024 AN - OPUS4-59908 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernardy, Christopher T1 - Investigation of the thermal radiation from hydrogen jet flames N2 - For industrial applications dealing with hydrogen, the definition of safety distances and the assessment of possible hazards emanating from releases is mandatory. Since hydrogen is usually stored and transported under pressure, one scenario to be considered is the momentum driven release of hydrogen from a leakage with subsequent ignition. In this scenario, the emitted heat radiation from the resulting jet flame to the surroundings has to be determined to define adequate safety distances. For hydrocarbon flames, different jet flame models are available to assess the hazards resulting from an ignited jet release. Since hydrogen flames differ from hydrocarbon flames in their combustion behavior, it has to be checked if these models are also applicable for hydrogen. To evaluate the accuracy of these models for hydrogen jet flames, tests at real-scale are carried out at the BAM Test Site for Technical Safety (BAM-TTS). Herein, the flame geometry and the heat radiation at defined locations in the surroundings are recorded for varying release parameters such as leakage diameter (currently up to 30 mm), release pressure (currently up to max. 250 bar) and mass flow (up to max. 0.5 kg/s). The challenge here is the characterization of the flame geometry in an open environment and its impact on the thermal radiation. Existing heat radiation data from the literature are mostly based on unsteady outflow conditions. For a better comparability with the steady state jet flame models, the experiments presented here are focused on ensuring a constant mass flow over the release duration to obtain a (quasi) stationary jet flame. In addition, stationary outflow tests with hydrocarbons (methane) were also carried out, which are intended to serve as reference tests for checking flame models based on hydrocarbon data. T2 - 15th International Symposium on Hazards, Prevention and Mitigation of Industrial Explosions (ISHPMIE) CY - Naples, Italy DA - 10.06.2024 KW - Hydrogen KW - Release KW - Jet flame KW - Thermal radiation PY - 2024 AN - OPUS4-60512 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernardy, Christopher T1 - Large scale safety investigations of hydrogen jet flames N2 - For industrial applications dealing with hydrogen, the definition of safety distances and the assessment of possible hazards emanating from releases is mandatory. Since hydrogen is usually stored and transported under pressure, one scenario to be considered is the momentum driven release of hydrogen from a leakage with subsequent ignition. In this scenario, the emitted heat radiation from the resulting jet flame to the surroundings has to be determined to define adequate safety distances. For hydrocarbon flames, different jet flame models are available to assess the hazards resulting from an ignited jet release. Since hydrogen flames differ from hydrocarbon flames in their combustion behavior, it has to be checked if these models are also applicable for hydrogen. To evaluate the accuracy of these models for hydrogen jet flames, tests with a horizontal outlet at large-scale are carried out at the BAM Test Site for Technical Safety (BAM-TTS). Herein, the flame geometry and the heat radiation at defined locations in the surroundings are recorded for varying release parameters such as release pressure (currently up to max. 250 bar), mass flow (up to max. 0.175 kg/s) at an outlet diameter of 30 mm. The challenge here is the characterization of the flame geometry in an open environment and its impact on the thermal radiation. Existing heat radiation data from the literature are mostly based on unsteady outflow conditions. For a better comparability with the steady state jet flame models, the experiments presented here are focused on ensuring a constant mass flow over the release duration (currently 120 s) to obtain a stationary jet flame. In addition, stationary outflow tests with hydrocarbons (methane) were also carried out, which are intended to serve as reference tests for checking flame models based on hydrocarbon data. The comparison of the flame geometry shows that hydrogen jet flames with the same outlet mass flow have a greater flame length (average deviation of 15 %) but a smaller flame diameter than methane jet flames (average deviation of 17 %). Conclusions regarding thermal radiation show that the proportion of total combustion energy emitted as thermal radiation is lower for hydrogen (xrad = 0.04–0.08) than for methane (xrad = 0.05–0.1). A comparison of the surface emissive power (SEP) of the jet flame shows a SEP range of 7 kW/m²-15 kW/m² for hydrogen and 3 kW/m² - 9,5 kW/m² for methane. T2 - H2 Safety - Colloquium - Process and Plant Safety CY - Online meeting DA - 19.02.2025 KW - Hydrogen KW - Release KW - Radiant heat fraction KW - Jet flame KW - Thermal radiation PY - 2025 AN - OPUS4-62779 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernardy, Christopher T1 - Experimental investigation of large scale hydrogen diffusion jet flames N2 - Hydrogen is a promising alternative to natural gas in industrial energy applications which would serve the goal of limiting global warming. However, wide application of hydrogen requires specific safety considerations taking into account that hydrogen is stored and transported under much higher pressure than natural gas. Thus, one scenario to be considered for hazard assessment is a sudden release of hydrogen from a leakage or safety valve and its subsequent ignition. For hydrocarbon flames, various jet flame models are available. However, hydrogen flames significantly differ from hydrocarbon flames in their combustion behavior, so that the applicability of these models to hydrogen has to be investigated. For that purpose, reals scale tests were carried out at the BAM Test Site Technical Safety. In addition, hydrocarbon jet flames (methane) were investigated. In these tests, the flame geometry and the thermal heat radiation were investigated for a release angle of 90°, for different release pressures (up to 220 bar) and mass flows (up to 0.175 kg/s). While existing heat radiation data from the literature are mostly based on unsteady outflow conditions and/or releases in still air, the experiments presented here are focused on ensuring a constant mass flow over the release duration under realistic free field conditions (with wind influence). This allows a better comparability with the stationary jet flame models and assessment of wind influence on model predictions. A number of parameters such as the surface emissive power of the jet flame and the radiant heat fraction were determined. A detailed comparison of the obtained experimental results with literature radiation models was performed. Good agreement between experimental and literature data was found for hydrogen whereas significant differences were identified for methane. Based on the investigations, empirical equations for modelling jet flames could be derived. T2 - American Society of Mechanical Engineers - Turbomachinery Technical Conference & Exposition CY - Memphis, TN, USA DA - 15.06.2025 KW - Hydrogen KW - Release KW - Thermal radiation KW - Diffusion jet flame PY - 2025 AN - OPUS4-63454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bühling, Benjamin T1 - Recent Developments of Fluidic Ultrasonic Transducers at BAM N2 - Ultrasonic measurement technology has become indispensable in NDT. In order to reduce measurement time and extend the application to other materials, contactless ultrasound is the subject of many different research groups. Department 8 has been researching successfully in this field for years. A novel approach is based on so-called fluidic devices. These devices can be used to perform binary logic operations with the help of natural flow instabilities. Hence the abbreviated name, Fluidic (FLUID+LogIC). Only a pressure reservoir of the used fluid is required as energy supply. This enables the production of very robust actuators that generate ultrasonic signals in an extremely energy efficient way. The presentation includes the research results of the ZIM innovation project OsciCheck. The original idea will be presented and its application on different building materials is validated. Beyond this, the possible application areas are much larger and a detailed outlook is given to discuss the future potential of fluidic ultrasonic actuators. T2 - Abteilungsseminar Abteilung 8 CY - Berlin, Germany DA - 23.09.2021 KW - Uultrasound KW - Non-destructive testing KW - Fluidic devices KW - Hydrogen KW - Ranging KW - Harsh environments PY - 2021 AN - OPUS4-53356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chulvi Iborra, Katherine T1 - Pd(II)-LMOF based material for the sensing of molecular hydrogen in gas phase N2 - Current interest in hydrogen gas as an energy source is growing due to its attractive properties such as high chemical energy density and the fact that its combustion produces water as by-product, qualifying this gas as an appealing clean energy source. In particular, the use of molecular hydrogen in automotive applications such as the hydrogen internal combustion engine (HICE) or hydrogen fuel cells is an excellent clean alternative. Despite these promising opportunities, hydrogen gas has a distinct disadvantage as an everyday energy medium, that is, it is highly flammable. Hydrogen processing apparatuses should therefore be constantly monitored so that leaks are immediately detected. The implementation of direct sensing systems for H2(g) is thus a decisive factor for its application and acceptance as a clean energy source. Because the automotive market alone is already a mass market, these sensors do not only have to be reliable, robust and dimensionally small, but operation has to be simple and the device itself cost-effective. In addition, very low detection limits are a must as already escape of small quantities of H2(g) is directly related to public health and safety. Besides electrochemical or semiconductor sensors, optical sensors are especially appealing because the equipment is usually simple and accessible, easily miniaturized and measurements can be performed in situ and in real time. If one cannot rely for instance on metallic palladium as interacting matrix, a major challenge for optochemical hydrogen sensors is to find a suitable material that fulfils all the requirements mentioned above and undergoes a dedicated indication reaction with H2(g). One such alternative can be Metal-Organic Frameworks (MOFs) which constitute a predefined, organized, mesoporous structure built up from metal ions and organic bridging ligands. With a myriad of building blocks being available, MOFs can be equipped with internal H2 reception sites that shall allow for selective and sensitive indication. For instance, if Pd ions are implemented in such a way that they express open metal sites (OMS), these OMS shall possess a strong affinity for hydrogen. If light absorbing and emitting organic ligands are additionally chosen, luminescent MOFs (LMOFs) can result that are perfect candidates for optical sensors, as changes at the analyte reception site can be effectively transduced into a measurable signal. In this contribution, we intended to discuss the development of a new luminescent sensor material for the detection of the highly flammable H2(g). This sensor material is based on an LMOF assembled from Pd(II) and aromatic bridging ligands, the advent of hydrogen at the OMS in the LMOF producing distinct variations in the material’s optical properties. T2 - 24th Congress and General Assembly of the International Union of Crystallography CY - Hyderabad, India DA - 21.08.2017 KW - Optical sensor KW - Hydrogen KW - LMOF PY - 2017 UR - http://www.iucr2017.org/abstract/myaccount/pdf/iucr2017-abstract-0b61b4c101d7bf652ae5b0dffd66e5fd.pdf AN - OPUS4-42362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Prestressed Concrete Structures with ConcentratedTendons- Structural Damage due to Hydrogen-Induced Stress Corrosin Cracking N2 - In the course of the deconstruction of the "Bridge of the 20th anniversary of the GDR" at the Altstädter Bahnhof in Brandenburg a. d. Havel, new information on the initiation of hydrogen-induced stress cracks was obtained. BAM was commissioned by the Brandenburg State Road Administration to participate in a corresponding joint project which is financed by the Federal Ministry for Digital and Transport. The added value of the new information gained in this project goes beyond the specific structure. It describes unexpected new damage patterns that can be transferred to other structures with concentrated tendons (tendon block method and Baur-Leonhardt method) and were previously unknown in this form. These should be made known to other developers to enable them to initiate any necessary actions. T2 - Consec 2024 CY - Chennai, India DA - 24.09.2024 KW - Corrosion KW - Spannstahl KW - Hydrogen KW - Korrosion PY - 2024 AN - OPUS4-61305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Prestressed Concrete Structures with Concentrated Tendons - Structural Damage due to Hydrogen-Induced Stress Corrosion Cracking N2 - In the course of the deconstruction of the "Bridge of the 20th anniversary of the GDR" at the Altstädter Bahnhof in Brandenburg a. d. Havel, new information on the initiation of hydrogen-induced stress cracks was obtained. BAM was commissioned by the Brandenburg State Road Administration to participate in a corresponding joint project which is financed by the Federal Ministry for Digital and Transport. The added value of the new information gained in this project goes beyond the specific structure. It describes unexpected new damage patterns that can be transferred to other structures with concentrated tendons (tendon block method and Baur-Leonhardt method) and were previously unknown in this form. These should be made known to other developers to enable them to initiate any necessary actions. T2 - Eurocorr 2022 CY - Berlin, Gemany DA - 29.08.2022 KW - Korrosion KW - Corrosion KW - Hydrogen KW - Stress Cracking PY - 2022 AN - OPUS4-55613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Einfluss von Korrosionsprozessen auf die Verbundfestigkeit Feuerverzinkter Betonstähle in der Erstarrungsphase von Beton N2 - Die Wechselwirkung von hoher Alkalität und feuerverzinktem Betonstahl in der Frischbetonphase generiert einen Störung in der Verbundzone. diese Störung basiert sowohl auf der Wasserstoffentwicklung in der Frischbetonphase bis zur diffusionskontrollierten Decksschichtbildung als auch auf die erstarrungsverzögernde Wirkung von Zinkionen auf die CSH-Phasenbildung. Diese werden zwangsläufig infolge anfänglicher starker Korrosionsprozesse frei, und reichern sich in der Verbundzone an. Hier kann es beim normgerechten Ausschalen nach 24h zu weiteren Störungen des Haftverbundes kommen das davon Auszugehen ist das die Erstarrung der CSH-Phasen in der Verbundzone noch nicht begonnen hat. T2 - Forschungsbeiratssitzung der Forschungsvereinigung Feuerverzinkung CY - Darmstadt, Germany DA - 04.12.2025 KW - Korrosion KW - Verzinkter Betonstahl KW - Hydrogen PY - 2025 AN - OPUS4-65054 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Inhibition of hydrogen evolution on galvanized reinforcement in fresh concrete by addition of potassium permangante N2 - Due to the EUdirective53/2003/EEC,which has been in force since 17th January, 2005, restricts the soluble chromate content in cements to amaximum value of 2ppm. This ammount is to low to inhibit the hydrogen evolutuion by the cathodic partial reaction in fresh concrete. T2 - Eurocorr 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Corrosion KW - Galvanized reinforcement KW - Hydrogen PY - 2019 AN - OPUS4-48934 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino A1 - Seifert, Lando A1 - Müller, Thoralf T1 - Stress corrosion test in thiocyanate solution with galvanostatic current N2 - Prüfung von Spannstählen hinsichtlich ihrer Anfälligkeit gegenüber wasserstoffinduzierter Spannungsrisskorrosion in kürzeren Zeiträumen. Gewährleistung der Dauerhaftigkeit mittels neuartiger elektrochemischer Prüfverfahren und galvanostatischer Kontrolle und Wasserstoffbeladung T2 - Meeting ISO TC17 SC16 WG8 CY - Online meeting DA - 11.01.2023 KW - Hydrogen KW - Corrosion PY - 2023 AN - OPUS4-56854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ekici, Nilsah T1 - Introduction of The SHIMMER Database for Safe Hydrogen Injection in The European Natural Gas Infrastructure N2 - An important step in the transportation strategy for hydrogen is its injection into the existing natural gas grid, which allows accelerating the transition to a low-carbon economy, in other words, hydrogen economy. The European Commission has established hydrogen roadmaps and strategies that emphasize the safe and efficient integration of hydrogen into the natural gas network to support this transition. In line with the objectives of the road map, several funded projects have been established, among others – the Safe Hydrogen Injection Modelling and Management for European Gas Network Resilience (SHIMMER) project. One of the main goals of this project is establishing a database containing a comprehensive repository of information regarding materials, standards, European pilot projects, and operational conditions parameters for the European gas network gathered from open sources as well as transmission and distribution system operators participating in the project. The SHIMMER database has an extensive structure consisting of 262 pipeline entries, each with details such as length, design pressure, inner diameter, and installation year and more. The following contribution elaborates on how the SHIMMER database was established as reliable source of information to be available for the public. The database allows consistent assessments of hydrogen compatibility across different countries, offering a structured framework to help overcome the challenges inherent to the assessments of the components for the injection of hydrogen across Europe. Further, the SHIMMER database provides a valuable information source for future research on the European gas networks. T2 - ICHS 2025 CY - Seoul, South Korea DA - 22.09.2025 KW - Database KW - Hydrogen KW - Gas Grid KW - Low-carbon KW - Pipeline Steel PY - 2025 AN - OPUS4-64288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - El Harrab, Hayat A1 - Askar, Enis A1 - Franken, T. A1 - Mauss, F. T1 - Experimental and Reaction Kinetic Study of Hydrogen Ignition Behavior at Ignition Limits N2 - The paper presents the results of the experimental and reaction kinetic investigation of hydrogen ignition at different pressures, highlighting its non-linear behaviour and effects of radical wall termination. The reaction kinetic simulation predicts the three characteristic ignition limits caused by radical and thermal auto-ignition and is in close agreement with the experimental measurements. The introduction of radical wall termination in the reaction mechanism allowed us to investigate the effect of the autoclave wall and vessel size on the hydrogen ignition behaviour. The first ignition limit is determined by the chain initiation reaction H_2+O_2→2 OH and shows a strong sensitivity towards wall termination of O, H and OH radicals. The third ignition limit is dominated by the reaction paths HO_2+HO_2→H_2 O_2+O_2 and H_2 O_2+M→2 OH+M which is why it shows a strong sensitivity towards wall termination of HO₂ and H₂O₂ radicals. The second ignition limit is influenced by the wall termination of O, H, OH, HO2 and H2O2 radicals. Increasing the radical wall termination rate by increasing the adsorption rate of the radicals at the wall leads to an increase of the auto-ignition temperature at the same pressure. T2 - 13th Mediterranean Combustion Symposium CY - Corfu, Greece DA - 01.06.2025 KW - Hydrogen KW - Auto-ignition Temperature KW - Radical Wall Termination Reaction KW - Ignition Limit PY - 2025 AN - OPUS4-64762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erxleben, Kjell T1 - Component test for the assessment of in-service welding on/onto pressurized hydrogen pipelines N2 - Hydrogen is seen as the energy carrier of the future. Therefore a reliable infrastructure to transport hydrogen in a large scale is needed. A so called European hydrogen backbone out of long distance transmission pipelines is planned by European countries to create a hydrogen transport infrastructure. Due to economic reasons this will be achieved by new build pipelines such as repurposed natural Gas (NG) pipelines, converted to hydrogen useage. A general suitability for hydrogen service of low alloyed pipeline steel, as it is used for NG service today, is given. But in case of necessary in-service welding procedures in terms of e.g. hot-tapping and stoppling, the risk of a critical hydrogen uptake into the pipe materials due to much higher temeperatures while welding and the possibility of hydrogen embrittlement (HE) needs to be closely investigated. The presentation gives an overview of the current H2-SuD project, investigating the feasability of in-service welding on future hydrogen pipelines. Therefore, component-like demonstrators were developed to test (I) the additional hydrogen uptake due to in-service welding under hydrogen pressure and (II) to measure the temperature field due to different welding parameters and demonstrator geometries, especially on the inner pipe wall surface. Collected data will be used to validate a numerical simulation of the thermal field and additionally the hydrogen diffusion in the pipeline material. T2 - Presentation at The University of Manchester CY - Manchester, United Kingdom DA - 12.09.2025 KW - In-service KW - Hydrogen KW - Pipeline KW - Welding PY - 2025 AN - OPUS4-64129 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erxleben, Kjell T1 - Hydrogen determination in welded metallic materials: Necessity and challenges N2 - In the course of tomorrow's hydrogen-based energy transition, the construction of the corresponding infrastructure will play a central role. The majority of materials used to date are typically welded for component fabrication. In that context, steels are widely applied and can be prone to hydrogen embrittlement. For the evaluation of any hydrogen effect on, for example, the mechanical properties of a welded metallic material, the hydrogen content must be precisely determined. According to ISO 3690, carrier gas hot extraction (CGHE) can be used. In addition to the pure quantification of hydrogen, thermal desorption analysis (TDA) with varied heating rates can be used to determine and evaluate the bonding state at microstructural defects in the material. For both techniques, experimental and measurement influences have to be considered, which have a great effect on the result. For CGHE, for example, ISO 3690 suggests different sample geometries as well as minimum extraction times. The present study summarizes results and experiences of numerous investigations with different sample temperatures and geometries (ISO 3690 type B and cylindrical TDA samples) regarding: the influence of the sample surface (polished/welded), measurement accuracies depending on the sample volume. In particular, a deviating extraction temperature to the set temperature, can significantly falsify the measurement results. Based on the results, methods are shown to quickly reach the desired extraction temperature without having to physically interfere with the measurement equipment. This serves to substantially improve the reliability of hydrogen measurement through increased signal stability and accelerated hydrogen desorption. In general, an independent temperature measurement with dummy samples for the selected heating procedure is advisable to exclude possible unwanted temperature influences already before the measurement. In addition (and way more important), the methods described can be transferred directly to industrial applications. T2 - Eurocorr 2023 - The European Corrosion Congress CY - Brussels, Belgium DA - 27.08.2023 KW - Hydrogen KW - Carrier gas hot extraction KW - Welding KW - ISO 3690 KW - Measurement PY - 2023 AN - OPUS4-58305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erxleben, Kjell T1 - Repair welding of in service hydrogen pipelines N2 - In the course of tomorrow's hydrogen-based energy transition, the construction of the corresponding infrastructure will play a central role. In that context, large diameter long-distance transmission pipelines for hydrogen will be the backbone in the European Union with service pressures from 70 to 90 bar (e.g., depending on national regulations). It is a major goal to rededicate the existing LNG infrastructure despite the necessity of new pipelines. From that point of view repairing of such transmissions pipelines via welding can be necessary. For the LNG infrastructure, it is state of the art that repair welding is conducted at pipelines under service, i.e., the LNG is still flowing as pressurized gas in the steel pipes. The reason is that a shut-down of large diameter pipelines is not so easy or sometimes impossible. In fact, as long no oxygen enters the pipeline, there would be any combustion or (in the worst case) explosion. At the moment, it is entirely open if current repair welding procedures for LNG pipelines can be transferred to pure hydrogen pipelines. In opposite to LNG, hydrogen can be way easier absorbed to the pipeline steels and diffuses through the material. If it accumulates in susceptible regions, i.e., in the welded joint, hydrogen assisted embrittlement could occur. The planned welding procedure requires a so-called preheating and maintenance of the weld joint of up to 300°C for several hours. This temperature is way higher compared to the typical service temperature of max. 40 to 50°C at operational pressures of 100 bar. In accordance to API 941, these low-alloyed pipeline steels are subjected to short-term service loads, which they are not designed for. For that reason, a collaborative project between BAM and DVGW (German Association for Gas and Water professions) was initiated in 2022 to answer the following questions by experiments and numerical simulation of: (1) How many hydrogen is additionally absorbed during the heating of the material to max. 300°C under remaining operational pressures? (2) Is the hydrogen concentration sufficient to reach a critical condition? (3) Which material and weld microstructure is the most susceptible? (4) Is there a significant difference in the repair welding behavior of LNG pipelines that had been already in use for long-term? (5) Which welding parameters and joint dimensions must be ensured for safe repair welding repair of typical pipelines? For that reason, the present study gives an overview on the current practice in repair welding of in-service pipelines, the industrial importance of this topic for the hydrogen-based energy transition and summarizes first results. T2 - Eurocorr 2023 - The European Corrosion Congress CY - Brussels, Belgium DA - 27.08.2023 KW - Hydrogen KW - Repair Welding KW - Pipeline KW - In-service KW - High-pressure PY - 2023 AN - OPUS4-58334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erxleben, Kjell T1 - Component test for safety assessment of in-service welding on / onto pressurized hydrogen pipelines N2 - Hydrogen is the energy carrier of tomorrow for a fossil-free future. This requires a reliable transport infrastructure capable of transporting large quantities of hydrogen, e.g. for the steel and chemical industries. In addition to the construction of new pipelines, the conversion of existing natural gas (NG) networks is an essential part of global hydrogen strategies. The transport of hydrogen is fundamentally different from that of NG, as hydrogen can be absorbed into the pipeline material. Given the known effects of hydrogen embrittlement, the compatibility of the materials for the proposed pipelines (typically low alloy steels in a wide range of strengths and thicknesses) must be investigated. However, pipelines require frequent maintenance, repair, or the need to install additional outlets. In some cases, it is necessary to perform welding on or to the pipelines while they are still in service, i.e. with active gas flow under high pressure, such as the well-known "hot tapping". This in-service welding poses challenges for hydrogen operations in terms of additional hydrogen absorption during welding and material compatibility. The challenge can be roughly divided into the possible austenitization of the inner pipe material exposed to hydrogen, which can lead to sufficient hydrogen absorption, and the welding itself, which causes an increased temperature range. Both lead to a significant increase in hydrogen solubility and diffusivity of the respective materials compared to room temperature. In this context, knowledge about hot tapping on hydrogen pipelines is scarce due to the lack of operational experience. Fundamental experimental investigations are required to investigate the transferability from natural gas to hydrogen pipeline networks. For this reason, the present study presents a specially designed mock-up / demonstrator concept for the realistic assessment of the welding process conditions. T2 - Materials Week 2025 CY - Frankfurt am Main, Germany DA - 02.04.2025 KW - In-service KW - Hydrogen KW - Pipeline KW - Repair welding PY - 2025 AN - OPUS4-62874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erxleben, Kjell T1 - Challenges in repair welding of in-service h2-pipelines N2 - Hydrogen will be one of the most important energy carriers of tomorrow. For the necessary large-scale and long-distance transportation, a reliable pipeline infrastructure is required. It is meanwhile in the most countries accepted to follow a two-way strategy by (I) repurposing the existing natural gas (NG) grid combined with (II) the installation of new pipelines. For example, in Europe a so-called European Hydrogen Backbone (EHB) is planned for 2040. Currently, 28 countries work together to establish a hydrogen pipeline grid of several thousands of kilometers. In that connection, a wide number of materials are used with different thicknesses, strength levels, chemical composition, surface conditions and so on. Worldwide research projects suggest the general compatibility of the currently applied pipeline steels e.g., in Germany the “SysWestH2” project. Nonetheless, the hydrogen gas grid will require regular inspections, repair, and maintenance. In addition, sometimes pipeline tees are required to connect new grids or pipelines the existing infrastructure. From that point of view, existing concepts from NG-grids must be investigated in terms of the transferability to hydrogen service. An overview on occurring challenges for this hydrogen transition, especially for in-service weld repair procedures is given in this presentation. T2 - AMPP 2024 - The Association for Materials Protection and Performance CY - Genoa, Italy DA - 09.06.2024 KW - In-service KW - Pipeline KW - Repair welding KW - High-pressure KW - Hydrogen PY - 2024 AN - OPUS4-60327 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erxleben, Kjell T1 - Component test to simulate critical conditions of hydrogen assisted cracking in submerged arc welded offshore steel N2 - Offshore Wind Turbines (OWT) are a key factor in tomorrow's sustainable energy generation. The ever� increasing installation depth and weight of OWTs require suitable foundation concepts such as monopiles or tripods. Typically, mild steels such as S420ML are used with plate thicknesses of up to several hundred mm, resulting in high restraints in the welded joints. The large plate thickness requires high-efficiency welding processes such as submerged arc welding (SAW) with multiple wires. Due to the very high stiffness and plate thickness of the large-scale offshore structure, a susceptibility to time� delayed hydrogen assisted cracking (HAC) may occur. For this reason, a minimum waiting time (MWT) of up to 48 h must be considered before NDT is conducted. The evaluation of the crack susceptibility is complex due to the component size and stiffness of real offshore structures. For this purpose, a near-component test geometry has been developed to transfer the real stiffness conditions to laboratory (i.e. workshop) scale. The 350 kg mock-up consisted of heavy plates (thickness 50 mm, seam length 1,000 m) joined by a 22-pass submerged-arc weld. Additional stiffeners simulated the effect of high restraint or shrinkage restraint of the weld. Extreme scenarios of hydrogen absorption during welding were simulated by using flux in dry (HD < 5 ml/100g Fe) and wet (HD > 15 ml/100g Fe) conditions. Weld residual stresses were determined using a robotic X-ray diffractometer. Areas of critical tensile residual stress (at the yield strength level) were found in the weld metal and in the heat affected zone, suggesting that these weld subzones are the most critical in the case of hydrogen ingress. To identify possible delayed cracking, the welds were inspected by phased array ultrasonic testing (PAUT) after welding, 6 h, 12 h, 24 h, and a maximum of 48 h. Summarized, no significant occurrence of HAC was detected, indicating the high crack resistance of the welded joint, i.e., a suitable combination of base material, welding consumable and parameters. T2 - Materials Week/Steel Innovation CY - Frankfurt am Main, Germany DA - 02.04.2025 KW - Cold cracking KW - Component test KW - Hydrogen KW - Minimum waiting time KW - Offshore steel grade PY - 2025 AN - OPUS4-62873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erxleben, Kjell T1 - Component test concept for evaluation of in-service welding on pressurized hydrogen pipelines N2 - Hydrogen is set as the energy carrier of tomorrow and most countries will achieve large-scale hydrogen transport through the conversion of the natural gas (NG) grid and the construction of new pipelines. The interaction between hydrogen and the pipeline materials differs fundamentally from that of NG, as hydrogen is readily absorbed into the material. Considering the possible hydrogen embrittlement (HE), the compatibility of the pipeline materials (low-alloyed steels with a wide strength/thickness range) must be investigated. However, pipelines require intervention for maintenance, repair, or grid expansion with welding on/onto the pipelines while in service, i.e. the well-known "hot tapping" and "plugging" or “stoppling”. The challenges compared to NG can be broadly divided into the possible austenitization of the inner pipe material exposed to hydrogen and the welding itself. Both result in a significant increase in hydrogen solubility and could potentially pose challenges in terms of HE. Emphasis is placed on the word "could" because knowledge of "hot tapping" on hydrogen pipelines is scarce due a lack of service experience. To this end, this study proposes a concept for a component-like demonstrator with the objectives: (1) safe feasibility of "hot tapping" on pressurized model hydrogen pipeline sections, (2) facilitate ex-post sample extraction for the purpose of quantifying the absorbed hydrogen concentrations, and (3) ensure in-situ temperature measurement during welding to monitor the pipeline surface temperature. For safety reasons in the event of an unintentional "burn-through", a solid cylinder was inserted in the demonstrator to restrict the hydrogen gas volume to a small, pressurized layer. Reference pipeline surface temperature measurements were ensured on comparable, unpressurized geometries. The investigated range of welding conditions was investigated for representative material/thickness combinations (DN50 to DN200), suggesting the feasibility of the demonstrator for the determination of reliable in-service welding conditions for both installed and new pipelines for hydrogen service. T2 - 20th Pipeline Technology Conference ptc2025 CY - Berlin, Germany DA - 06.05.2025 KW - In-service KW - Hydrogen KW - Pipeline KW - Repair welding KW - Component test PY - 2025 AN - OPUS4-63170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erxleben, Kjell T1 - Quantification of hydrogen uptake during in-service hydrogen pipeline welding N2 - Hydrogen must be transported on a large scale from producers to consumers to ensure the energy transition. The necessary pipeline grid is achieved by conversion of the natural gas (NG) grid and building new pipelines. Welding during service as part e.g. of “hot-tapping” is unavoidable for maintenance/repair/expansion. Based on existing studies, the basic material compatibility of (low-alloyed) pipeline steels with hydrogen is postulated. However, this cannot be assumed for the case of in-service welding on pipelines in pressurized condition. The reason is the increased temperature e.g. by preheating and (in particular) during welding of the single passes. As a result, the inner pipeline surface undergoes multiple short-term heating but to high temperatures. In particular, the first passes can result in a temperature close to the austenitic transformation of the material for small wall thicknesses. Both increase the hydrogen uptake into the welded joint. If hydrogen embrittlement is likely to occur, depends on the hydrogen uptake, which must be quantified. For this purpose, welding experiments on pressurized demonstrators were conducted. The hydrogen uptake at 100 bar was compared to reference experiments with nitrogen. A new sample extraction routine for the quantification of the weld-zone specific hydrogen uptake was established. Comprehensive experiments with different steels (P235, L360, L485), wall thicknesses (4.1 mm to 7.8 mm) and diameters (DN50 and DN200) were conducted. In addition, the influence of the welding layer sequence on the hydrogen uptake between single- and multi-layer welds was investigated. Analytical approaches were used to approximate the hydrogen uptake in the respective weld zones. The main findings were that the layer sequence and especially the wall thickness have a large influence on the hydrogen uptake. T2 - 20th Pipeline Technology Conference ptc2025 CY - Berlin, Germany DA - 06.05.2025 KW - In-service KW - Hydrogen KW - Pipeline KW - Repair welding KW - Component test PY - 2025 AN - OPUS4-63165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erxleben, Kjell T1 - Challenges and difficulties in repair welding procedures on in-service hydrogen pipelines N2 - Hydrogen as an energy carrier plays a key role in tomorrow's energy transition. For effective use of hydro-gen as energy carrier the construction of the corresponding infrastructure is of utmost importance. In that context, large diameter long-distance transmission pipelines will form the so-called hydrogen backbone in the European Union with service pressures up to 100 bar (e.g., depending on national regulations). From an economically and ecologically point of view, a major goal is to repurpose the existing natural gas (NG) infra-structure to minimize the need to install new pipelines. To ensure the safety, reliability and integrity of this future hydrogen infrastructure repair welding or further welding of branch pipes etc. can be necessary at in-service conditions, meaning a permanent flow of pressurized hydrogen while executing the repair procedure. The reason is that a shut-down of large diameter pipelines is not easy or sometimes merely impossible. In fact, as long, as no oxygen enters the pipeline, there will neither be any combustion nor (in the worst-case scenario) explosion. The special techniques like hot tapping or stoppling are state-of-the-art for NG and oil pipeline grids. Currently, it is not finally clarified if repair welding procedures for NG pipelines can be trans-ferred to pure hydrogen pipelines. In opposite to NG, hydrogen can be way easier absorbed to the pipeline steels and diffuses through the material. If it accumulates in susceptible regions, i.e., in the welded joint or heat affected zone, hydrogen assisted embrittlement could occur and lead to loss of integrity or even cata-strophic failure of the pipeline. For example, requires the planned welding procedure a preheating and maintenance of the weld joint of up to 300°C for up to several hours at the outer. This temperature is way higher compared to the typical service temperature of max. 60°C at operational pressures of up to 100 bar. In accordance to API 941, these low-alloyed pipeline steels are subjected to short-term service loads, which they are not designed for. Another considerable fact is that if the weld seam is attached to the pipeline, the temperature especially for small wall thickness can be easily above the austenitization temperature. It is well known that austenite has a way higher hydrogen solubility compared e.g. to ferrite/bainite microstructure of the low-alloyed steel. Current studies indicate a remarkable increase of the hydrogen ingress dur-ing the austenitization from the inner pipe wall. It must be answered if a critical material degradation because of increased hydrogen uptake due to in-service welding procedures is likely to occur. T2 - MPA Seminar 2024 CY - Stuttgart, Germany DA - 08.10.2024 KW - In-service KW - Pipeline KW - Hydrogen KW - Welding KW - Repair PY - 2024 AN - OPUS4-61468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feldkamp, Martin T1 - R&D Activities by BAM Related to Transport Package Fire Testing N2 - Packages for the transport of radioactive material shall meet the mechanical and thermal test requirements of the International Atomic Energy Agency (IAEA) regulations for package design approval. Besides mechanical testing, the Federal Institute for Materials Research and Testing (BAM) performs thermal tests in accordance with the IAEA regulations. The thermal test includes a 30-minute 800°C fully engulfing fire. BAM continuously performs various thermal experiments for the investigation of the thermal response of packages with respect to the IAEA fire. The purpose of this paper is to give an overview of the already performed, ongoing and future physical tests and experiments of BAM in the field of thermal investigations. These research and development works shall support our competencies for the authority package design assessment. BAM operates a propane gas fire test facility. To be able to carry out comparative investigations and validity between the propane fire and the in detail prescribed pool fire test in the regulations, BAM carries out various calorimetric tests and investigates the boundary conditions of the fire with the help of fire reference packages. At the same time, we are conducting various fire scenarios with wood-filled impact limiters. Large-scale fire tests of impact limiters are carried out on a full scale as well as on a small scale. Influencing variables are investigated in particular by means of geometric changes and the consideration of artificial damages, in particular holes. In addition to propane fire as a heat source, thermal scenarios are also investigated with hydrogen as heat source and an infrared radiator system to ignite test specimens. For these numerous test arrangements, the transferability to existing and newly developed transport package designs is essential and fruitful within the review of design approvals, especially for Dual Purpose casks with a long-lasting operation time. T2 - 20th International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 22) CY - Juan-les-Pins, France DA - 11.06.2023 KW - Fire Testing KW - Wood KW - Hydrogen KW - Fire Reference Test PY - 2023 AN - OPUS4-57722 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gleim, Tobias T1 - Potential Effects of Battery and Hydrogen Fires regarding Regulatory Requirements N2 - Introduction and Necessity of the Investigation The IAEA regulations for the safe transport of radioactive material (IAEA SSR-6) define the safety requirements for different package types and consider different transport conditions. The accident conditions of transport specify different mechanical and thermal tests based on investigations of real accident scenarios. Considering the rapid development of new boundary conditions of transport such as electric mobility and the use of hydrogen as energy source for trucks and other kind of vehicles, potential effects of battery and hydrogen fires in transport accidents should be investigated. The aim is to evaluate the existing test requirements developed and derived decades ago, whether they are covering the current transport situation. This concept paper will briefly present the reasons for detailed investigations as bases for a coordinated research project under the roof of the IAEA. T2 - Technical Exchange IRSN – BAM Transport & Storage of Packages for Radioactive Material CY - Berlin, Germany DA - 04.06.2024 KW - Fire KW - Battery KW - Hydrogen KW - IAEA Regulations PY - 2024 AN - OPUS4-60338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gradt, Thomas T1 - Influence of cryogenic hydrogen environment on the tribological properties of materials N2 - The presentation gives an overview over the LH2-activities during 20 years of tribological research in cryogenic environments at BAM. T2 - 2019 Hydrogenius & I2CNER Tribology Symposium CY - Fukuoka, Japan DA - 30.01.2019 KW - Friction KW - Wear KW - Hydrogen KW - Cryogenic Engineering KW - Hydrogen Embrittlement PY - 2019 AN - OPUS4-47339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Griesche, Axel A1 - Schaupp, Thomas T1 - Hydrogen in steel visualized by neutron imaging N2 - Neutron cameras allow visualizing hydrogen distributions with radiographic or tomographic imaging methods in iron and steel. The necessary contrast between hydrogen and iron stems from the high difference in the total neutron cross section of both elements. This allows e.g. the in situ measurement of hydrogen mass flow inside cm thick steel samples with a temporal resolution of 20 s using neutron radiography as well as the quantitative measurement of hydrogen accumulations at the crack’s inner surfaces in hydrogen embrittled iron samples with neutron tomography. We could detect directly gaseous hydrogen in the crack cavities and we measured the gas pressure. This new quality of the information on a micrometer scale allows new insights for the analysis of hydrogen-induced damage mechanisms. Further, this method is non-destructive and provides local information in situ and in three dimensions with a spatial resolution of 20-30 μm. In this contribution, we show examples that demonstrate the spatial and temporal resolution of the neutron radiography and tomography methods in order to visualize and quantify hydrogen accumulations at cracks. The measurements were performed at the research reactor BER II of the HZB in Berlin and at the FRM II reactor of the neutron source Heinz Maier-Leibnitz in Garching. T2 - 3rd international conference on metals & hydrogen CY - Ghent, Belgium DA - 29.05.2018 KW - Hydrogen KW - Neutron KW - Radiography KW - Tomography KW - Steel PY - 2018 AN - OPUS4-45074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grimault de Freitas, Tomás T1 - Utilization of the Tubular Specimen Technique for the Qualification of Metallic Materials for Hydrogen Technologies N2 - As the world shifts to a decarbonized economy, the demand for hydrogen-based technologies is rapidly increasing. In order to make optimal use of hydrogen as an energy carrier, the infrastructure for hydrogen storage and transport in particular, must meet high technical safety standards. The indispensable basis for such safety assessments are the material properties, which must be evaluated under operating conditions that are as real as possible. The conventional method for the assessment of the material properties in gaseous hydrogen is conducted by testing materials in high-pressure hydrogen gas in a pressure vessel (autoclave). It is an established method that allows to perform common standardized tests such as tensile, fatigue and crack growth tests under varying hydrogen conditions. However, this method is complex and entails high costs due to extensive safety regulations. The hollow specimen technique is a more efficient test method, which can be used to assess the mechanical properties of materials under high-pressure hydrogen gas. The procedure is conducted by enclosing high-pressure gas into a hole along the axis of the tensile test specimen. Recently, this method has been successfully performed at pressures up to 1000 bar and over a wide range of temperatures. Due to the low hydrogen volume needed, this method requires minimal safety regulation; therefore, the costs are reduced when compared to the conventional autoclave technique. This method is now in a standardization process, which has been initiated by Japan as a new working package in ISO (TC 164/SC 1/WG 9). The following contribution presents preliminary results obtained testing common grades of metastable austenitic stainless steel. For this purpose, the mechanical properties and fracture surface of solid and tubular specimens were assessed and compared using slow strain rate tensile (SSRT) test as part of the preliminary work at the Fraunhofer IWM. In a similar way, pipeline steels evaluated under hydrogen atmospheres using the geometry adapted by BAM will be presented. Within the framework of the TransHyDE flagship project, more results with the goal of supporting the standardization of the hollow specimen technique are expected to be obtained. T2 - ZwickRoell Forum for High-Temperature Testing CY - Fürstenfeld, Austria DA - 03.05.2023 KW - Hydrogen KW - H2Hohlzug KW - TransHyDE KW - Tubular specimen technique KW - Innovation PY - 2023 AN - OPUS4-57417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grimault de Freitas, Tomás T1 - State of the Art in the Qualification of Metallic Materials for Hydrogen Technologies N2 - The hydrogen economy is one of the main solutions for achieving climate neutrality in Europe. Metallic materials, predominantly steels, are the most common structural materials in the various components along the hydrogen supply chain. Ensuring their sustainable and safe use in hydrogen technologies is a key factor in the ramp-up of the hydrogen economy. This requires extensive materials qualification, however, most of the accepted, and standardised test methods for determining the influence of gaseous hydrogen on metallic materials describe complex and costly procedures that are only available to a very limited extent worldwide (e.g., autoclave technique). The hollow specimen technique is presented as an alternative method that can overcome the limitations of current techniques and complement them. To standardise the technique, a process has been initiated by ISO in 2021. Knowledge gaps for tests with the technique in hydrogen have been identified by DIN. The H2HohlZug project, which falls under the umbrella of TransHyDE, aims to address the identified knowledge gaps and provide a foundation for a comprehensive standardisation of the hollow specimen technique. T2 - E-World Energy & Water CY - Essen, Germany DA - 20.02.2024 KW - Hydrogen KW - Hydrogen Embrittlement KW - Hollow Specimen Technique KW - High-Pressure Gaseous Hydrogen KW - Standardisation KW - H2HohlZug KW - TransHyDE PY - 2024 AN - OPUS4-59564 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grimault de Freitas, Tomás T1 - Closing the gaps towards the Standardisation of the Hollow Specimen Method for Tests in High-Pressure Hydrogen Gas N2 - Metallic materials, mainly steels, are the most commonly used structural materials in various components throughout the hydrogen supply chain. Ensuring their sustainable and safe use in hydrogen technologies is a crucial factor in the development of the hydrogen economy. This is particularly important since hydrogen can promote crack formation and ultimately lead to premature failure in these materials when combined with mechanical load. This process is commonly known as Hydrogen Embrittlement and can occur in a large number of steels used for the hydrogen technologies.[1] Extensive materials qualification is required for the rapid implementation of hydrogen technologies, however, most accepted, and standardised test methods for determining the effect of gaseous hydrogen on metallic materials describe complex and costly procedures (e.g. in-situ autoclave technique) that are only available to a very limited extent worldwide. The hollow specimen technique is a simple and economical method that has the potential to overcome the limitations of the current methods and complement them for qualifying metallic materials under high-pressure hydrogen gas. Unlike the conventional autoclave technique, this method requires significantly lower amounts of hydrogen, resulting in fewer safety measures and no need for complex equipment or a specialised laboratory. The technique's low investment and testing costs, simple operation, and shorter testing time make it an optimal for widespread use around the world, thereby increasing the output of results. Initial studies have demonstrated the feasibility of assessing hydrogen effects in metallic materials using the hollow specimen technique. This led to the establishment of an ISO committee to standardise the method, however, there are open questions that currently prevent the technique from being standardised for hydrogen testing. These open questions relate to specimen geometry, inner hole surface and gas quality and are being addressed in the TransHyDE - H2HohlZug project. The aim of the project is to systematically address and close the gaps towards the standardisation of this technique for tests in hydrogen. The project is divided into four work packages. First, the elastic-plastic behaviour of a hollow tensile specimen is compared with that of a conventional solid tensile specimen of identical external dimensions using finite element methods (3D-FEM) and subsequently validated by experimental results. In the second, the influence of the inner hole surface quality of the specimen on the hydrogen effects is evaluated. Five different methods of producing the inner axial hole were chosen to ensure different average roughness values and residual stresses (drilling vs. EDM), and also to ensure a good representation of the more common and easily accessible processes (drilling and reaming) to the more complex ones (EDM and honing). Next, the influence of gas purity (different compositions) and purging process (different routines) is evaluated. Finally, an optimal specimen geometry, inner hole production process, gas quality and purging process are proposed from each working package and its reproducibility and repeatability is evaluated in a round robin with national and international partners. This contribution presents the structure and milestones of the project, followed by initial results regarding the influence of different manufacturing and finishing processes on the inner hole surface of the hollow specimen and its response to hydrogen effects. T2 - MPA Seminar 2024 - Materials, Processes, Applications CY - Stuttgart, Germany DA - 08.10.2024 KW - Hydrogen KW - Hydrogen Embrittlement KW - Tensile Test KW - High-Pressure Gaseous Hydrogen KW - Hollow Specimen Technique KW - Standardisation KW - TransHyDE KW - H2HohlZug PY - 2024 AN - OPUS4-61286 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grimault de Freitas, Tomás T1 - Repair Welding on Future Pressurized Hydrogen Pipelines N2 - Hydrogen is the energy carrier for a sustainable future without fossil fuels. This requires a reliable transport infrastructure. In this context, the conversion of existing natural gas (NG) grids is an essential part of the worldwide hydrogen strategies, in addition to the construction of new pipelines. Given the known effects of hydrogen embrittlement, the compatibility of the materials already in use (typically low alloy steels in a wide range of strengths and thicknesses) must be investigated. Initial comprehensive studies of the hydrogen compatibility of pipeline materials indicate that these materials can be used to a certain extent. However, pipelines require frequent maintenance and repair. In some cases, it is necessary to perform welding on pipelines while they are under pressure, such as the well-known tapping of natural gas grids. This in-service welding presents additional challenges for hydrogen operations in terms of additional hydrogen absorption during welding and material compatibility. The challenge can be roughly divided into the possible austenitization of the inner pipe material exposed to hydrogen, which can lead to sufficient hydro- gen absorption, and the welding itself, which causes an increased temperature range. Both lead to a significant increase in hydrogen solubility and diffusivity of the respective materials compared to room temperature. In this context, knowledge about hot tapping on hydrogen pipelines is scarce due to the lack of operating experience. Fundamental experimental investigations are required to investigate the possibility of transferring the state-of-the-art concepts from natural gas to hydrogen pipeline grids to ensure that no critical material degradation occurs due to the potentially increased hydrogen uptake. For this reason, the presentation will present the state of the art in hydrogen pipeline hot tapping, including current research projects and their solution strategies in terms of pressurized mock-ups and basic testing scenarios. T2 - ASTM Conference on Hydrogen Materials CY - La Rochelle, France DA - 03.06.2025 KW - Component Test KW - Hydrogen KW - In-service welding KW - Pipeline PY - 2025 AN - OPUS4-63332 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grimault de Freitas, Tomás T1 - From Research to a Standard: The Hollow Specimen Technique for High-Pressure Hydrogen Gas Testing N2 - As the world moves towards a decarbonised economy, the demand for sustainable and low-carbon alternatives is growing rapidly. Hydrogen has an important role to play in this transition, but in order to make the most of hydrogen as an energy carrier, a comprehensive understanding of its impact on the integrity of structural materials is necessary. Metallic materials, mainly steels, are the most commonly used structural materials in various components throughout the hydrogen supply chain. Ensuring their sustainable and safe use in hydrogen technologies is a crucial factor in the development of the hydrogen economy. This is particularly important since hydrogen can promote crack formation and ultimately lead to premature failure in these materials when combined with mechanical load. This process is commonly known as Hydrogen Embrittlement and can occur in almost all the steels used for the hydrogen technologies. Extensive materials qualification is required for the rapid implementation of hydrogen technologies, however, most accepted, and standardised test methods for determining the effect of gaseous hydrogen on metallic materials describe complex and costly procedures that are only available to a very limited extent worldwide. The hollow specimen technique is a simple and economical method that has the potential to overcome the limitations of the current methods and complement them for qualifying metallic materials under high-pressure hydrogen gas. Unlike the conventional autoclave technique, this method requires significantly lower amounts of hydrogen, resulting in fewer safety measures and no need for complex equipment or a specialised laboratory. The technique's low investment and testing costs, simple operation, and shorter testing time make it an optimal for widespread use around the world, thereby increasing the output of results. Initial studies have demonstrated the feasibility of assessing hydrogen effects in metallic materials using the hollow specimen technique. This led to the establishment of an ISO committee to standardise the method. However, there are open questions that currently prevent the technique from being standardised for hydrogen testing. These open questions relate to specimen geometry, inner hole surface and gas quality and are being addressed in the H2HohlZug project, of which the overall aim is to systematically close the gaps towards a standard. This contribution presents the structure and milestones of the project, followed by initial results. T2 - CETIM Workshop Technique H2 CY - Nantes, France DA - 11.12.2025 KW - Hydrogen KW - Hydrogen Embrittlement KW - Hollow Specimen Technique KW - High-Pressure Gaseous Hydrogen KW - TransHyDE KW - H2HohlZug KW - Standardisation PY - 2025 AN - OPUS4-65103 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grimault de Freitas, Tomás T1 - Hollow Specimen Method for Tests in High-Pressure Hydrogen Gas: The Role of Strain-Rate and Surface Quality N2 - As the world moves towards a decarbonised economy, the demand for sustainable and low-carbon alternatives is growing rapidly. Hydrogen has an important role to play in this transition, but in order to make the most of hydrogen as an energy carrier, a comprehensive understanding of its impact on the integrity of structural materials is necessary. Metallic materials, mainly steels, are the most commonly used structural materials in various components throughout the hydrogen supply chain. Ensuring their sustainable and safe use in hydrogen technologies is a crucial factor in the development of the hydrogen economy. This is particularly important since hydrogen can promote crack formation and ultimately lead to premature failure in these materials when combined with mechanical load. This process is commonly known as Hydrogen Embrittlement and can occur in almost all the steels used for the hydrogen technologies. Extensive materials qualification is required for the rapid implementation of hydrogen technologies, however, most accepted, and standardised test methods for determining the effect of gaseous hydrogen on metallic materials describe complex and costly procedures that are only available to a very limited extent worldwide. The hollow specimen technique is a simple and economical method that has the potential to overcome the limitations of the current methods and complement them for qualifying metallic materials under high-pressure hydrogen gas. Unlike the conventional autoclave technique, this method requires significantly lower amounts of hydrogen, resulting in fewer safety measures and no need for complex equipment or a specialised laboratory. The technique's low investment and testing costs, simple operation, and shorter testing time make it an optimal for widespread use around the world, thereby increasing the output of results. Initial studies have demonstrated the feasibility of assessing hydrogen effects in metallic materials using the hollow specimen technique. This led to the establishment of an ISO committee to standardise the method. However, there are open questions that currently prevent the technique from being standardised for hydrogen testing. These open questions relate to specimen geometry, inner hole surface and gas quality and are being addressed in the H2HohlZug project, of which the overall aim is to systematically close the gaps towards a standard. This contribution presents the structure and milestones of the project, followed by initial results. T2 - HyLab | HyTalks CY - Online meeting DA - 12.11.2025 KW - Hydrogen KW - Hydrogen Embrittlement KW - Hollow Specimen Technique KW - High-Pressure Gaseous Hydrogen KW - TransHyDE KW - H2HohlZug PY - 2025 AN - OPUS4-64749 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grimault de Freitas, Tomás T1 - Comprehensive standardization of the hollow specimen method for tests in high pressure hydrogen gas N2 - As the world moves towards a decarbonised economy, the demand for sustainable and low-carbon alternatives is rapidly increasing. Hydrogen plays an important role in this transition, but in order to make the most of hydrogen as an energy carrier, a comprehensive understanding of its impact on the integrity of structural materials is necessary. Metallic materials, mostly steels, are the most regularly used structural materials in various components throughout the hydrogen supply chain. Ensuring their sustainable and safe use in hydrogen technologies is a crucial factor in the development of the hydrogen economy. This is particularly important since hydrogen can promote crack formation and ultimately lead to premature failure in these materials when combined with mechanical load. This process is commonly known as Hydrogen Embrittlement and can occur in almost all the steels used for the hydrogen technologies. Extensive materials qualification is needed for the rapid implementation of hydrogen technologies, however, most accepted, and standardised test methods for determining the effect of gaseous hydrogen on metallic materials describe complex and costly procedures that are only available to a very limited extent worldwide. The hollow specimen technique is a simple and economical method that has the potential to overcome the limitations of the current methods and complement them for qualifying metallic materials under high-pressure hydrogen gas. In this method, an axial hole is drilled in a tensile specimen, which is then filled with hydrogen gas, sealed, and placed in a standard testing machine. This method requires significantly lower amounts of hydrogen, resulting in fewer safety measures and no need for complex equipment or a specialised laboratory, unlike the conventional autoclave technique. The technique's low investment and testing costs, simple operation, and shorter testing time make it optimal for widespread use around the world, thereby increasing the output of results. Initial studies have demonstrated the feasibility of assessing hydrogen effects in metallic materials using the hollow specimen technique. This led to the establishment of the committee ISO/TC 164/SC 1/WG 9 “Tensile testing, method in high-pressure hydrogen environment“ to standardise the method, however, there are open questions that currently prevent the technique from being standardised for hydrogen testing. These open questions relate to specimen geometry, inner hole surface and gas quality and are being addressed in the H2HohlZug project. Here, the aim is to systematically address and close the gaps towards the standardisation of this technique for tests with hydrogen. This contribution presents the structure and milestones of the project, followed by initial results regarding the optimisation of the specimen geometry, as well as the influence of different manufacturing and finishing processes on the inner hole surface of the hollow specimen and its response to hydrogen effects. T2 - TestXpo | 32nd International Expo for Materials Testing CY - Ulm, Germany DA - 21.10.2024 KW - Hydrogen KW - Hydrogen Embrittlement KW - High-Pressure Gaseous Gas KW - Hollow Specimen Technique KW - H2HohlZug KW - TransHyDE KW - Standardisation KW - Tensile Test PY - 2024 AN - OPUS4-61453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grimault de Freitas, Tomás T1 - Hollow Specimen Technique for Tests in High-Pressure Hydrogen Gas: The Path Towards Standardisation and the Case Study of a Pipeline Steel and its Weld N2 - The hollow specimen technique is a simple method that has the potential to make material qualification with gaseous pressurized hydrogen widely applicable for the hydrogen industry at low cost. The feasibility of this method has been demonstrated in several studies, leading to the establishment of an ISO committee for its standardization. Questions have emerged during this process, that currently prevent the method from being standardized for hydrogen testing. These questions relate to specimen geometry, specimen manufacturing and gas quality and are being systematically addressed in the TransHyDE-H2HohlZug project. The aim is to close the identified gaps towards the standardization of this method for hydrogen testing. This contribution presents the structure and milestones of the project, followed by the results regarding the influence of specimen production and its response to hydrogen effects. Depending on the production method, different roughness and residual stresses can be expected on the inner hole surface of the specimens. This is of importance since an increase in stress concentration sites have been found to be associated to a higher severity of hydrogen effects. This influence has been investigated after applying the following machining processes: a) drilled only; b) drilled and reamed; c) drilled and honed; d) electro-discharge machining (EDM) and honed; e) EDM and reamed. Roughness measurements using a profilometer, electron back-scatter diffraction (EBSD) analysis and microhardness tests have been performed previous to mechanical testing to infer on the effect of the different production methods on the surface of the inner hole. Next, the specimens were mechanically tested via slow strain rate tensile tests in a argon and in hydrogen, both at 150 bar and room temperature. Here, a strain-rate sensibility analysis was also performed to identify an optimal strain-rate for the mechanical tests. Based on the results an optimal production method is identified and proposed. T2 - ASTM Conference on Hydrogen Materials CY - La Rochelle, France DA - 03.06.2025 KW - Hydrogen KW - Hydrogen Embrittlement KW - Hollow Specimen Technique KW - High-Pressure Gaseous Hydrogen KW - Austenitic Stainless Steel KW - H2HohlZug KW - TransHyDE KW - Tensile Test KW - Pipeline Steel PY - 2025 AN - OPUS4-63329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günzel, Stephan T1 - Safety aspects of hydrogen transportation N2 - In this presentation safety aspects of hydrogen transportation are discussed. At first, the regulatory background and level of safety are presented. In the second part, the modelling of consequence due to sudden rupture of pressure receptacles is explained. Finally, the results are used to define a limit for consequence to enable an acceptable and safe transport of hydrogen. T2 - 3rd Germany-Korea Hydrogen Conference CY - Berlin, Germany DA - 27.09.2022 KW - Safety KW - Hydrogen KW - Wasserstoff KW - Gefahrgut KW - Consequence PY - 2022 AN - OPUS4-59902 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günzel, Stephan T1 - Safety assessment of hydrogen gas storage systems N2 - In this lecture, the safety assessment of hydrogen gas storage systems is presented using the example of composite pressure vessels. The main element is a probabilistic approval approach based on five steps. Firstly, the testing and evaluation of properties at the beginning of life are shown. Secondly, methods for artificial aging and the effect on the residual strength are presented. Thirdly, testing against dedicated accidents is introduced. Fourthly, effects on the surveillance of production quality are discussed. Finally, degradation and the end of life are estimated. Background information and examples are given for each step. The assessment presented is a method applicable for many safety-related systems. T2 - Masterstudiengang Wasserstofftechnologie - Modul 8: Safety and Public Acceptance – Sicherheitsaspekte, Akzeptanz und werkstofftechnische Herausforderungen des Wasserstoffs CY - Online meeting DA - 25.08.2023 KW - Safety KW - Hydrogen KW - Wasserstoff KW - Bewertung KW - Assessment PY - 2023 AN - OPUS4-59899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günzel, Stephan T1 - Safety assessment of hydrogen gas storage systems N2 - In this lecture, the safety assessment of hydrogen gas storage systems is presented using the example of composite pressure vessels. The main element is a probabilistic approval approach based on five steps. Firstly, the testing and evaluation of properties at the beginning of life are shown. Secondly, methods for artificial aging and the effect on the residual strength are presented. Thirdly, testing against dedicated accidents is introduced. Fourthly, effects on the surveillance of production quality are discussed. Finally, degradation and the end of life are estimated. Background information and examples are given for each step. The assessment presented is a method applicable for many safety-related systems. T2 - Joint European Summer School 2021 on Fuel Cell, Electrolyser, and Battery Technologies CY - Online meeting DA - 12.09.2021 KW - Safety KW - Hydrogen KW - Wasserstoff KW - Bewertung KW - Assessment PY - 2021 AN - OPUS4-59905 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günzel, Stephan T1 - Safety assessment of hydrogen gas storage systems N2 - In this lecture, the safety assessment of hydrogen gas storage systems is presented using the example of composite pressure vessels. The main element is a probabilistic approval approach based on five steps. Firstly, the testing and evaluation of properties at the beginning of life are shown. Secondly, methods for artificial aging and the effect on the residual strength are presented. Thirdly, testing against dedicated accidents is introduced. Fourthly, effects on the surveillance of production quality are discussed. Finally, degradation and the end of life are estimated. Background information and examples are given for each step. The assessment presented is a method applicable for many safety-related systems. T2 - Joint European Summer School 2023, Hydrogen Safety CY - Online meeting DA - 17.09.2023 KW - Safety KW - Hydrogen KW - Wasserstoff KW - Bewertung KW - Assessment PY - 2023 AN - OPUS4-59903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günzel, Stephan T1 - Safety assessment of hydrogen gas storage systems N2 - In this lecture, the safety assessment of hydrogen gas storage systems is presented using the example of composite pressure vessels. The main element is a probabilistic approval approach based on five steps. Firstly, the testing and evaluation of properties at the beginning of life are shown. Secondly, methods for artificial aging and the effect on the residual strength are presented. Thirdly, testing against dedicated accidents is introduced. Fourthly, effects on the surveillance of production quality are discussed. Finally, degradation and the end of life are estimated. Background information and examples are given for each step. The assessment presented is a method applicable for many safety-related systems. T2 - Joint European Summer School 2022, Hydrogen Safety CY - Athens, Greece DA - 18.09.2022 KW - Safety KW - Hydrogen KW - Wasserstoff KW - Bewertung KW - Assessment PY - 2022 AN - OPUS4-59904 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habib, Abdel Karim T1 - P2X: From production to application Safety issues around hydrogen N2 - For hazard Assessment purposes we need models to predict what would happen in case of an accident. The challenge in hazard assessment consists not only in choosing the right model, but beforehand to define the correct scenario. For hydrogen applications the validity of the models has to be checked, as well as the kind of scenario to assume for accidental releases of hydrogen. Open questions on these topics will be adressed and the newly founded competecne centre for Hydrogen Saftey at BAM will be presented. T2 - VDMA Webinar P2X: From production to application CY - Online Meeting DA - 18.05.2021 KW - Hydrogen KW - Hasard assessment KW - Modeling PY - 2021 AN - OPUS4-52678 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habib, Abdel Karim T1 - Heat radiation emanating from hydrogen and methane jet fires N2 - Modelling the heat radiation emanating from jet flames for hazard assessment purposes, is generally done using simple, steady-state approaches that give a quick result and estimation of the consequences to account for. Although nowadays computational fluid dynamics can be used to simulate this phenomenon in detail, it is still very demanding in computational power and time and generally not all required boundary conditions to achieve a reliable result are known. Therefore, even today the simpler approaches as for example the Model of Chamberlain or Johnson (mainly developed for hydrocarbon flames) are still widely used for consequence analysis. Hydrogen is becoming increasingly important as renewable energy carrier resulting in an increasing demand of “hydrogen approved” models. Since the aforenamed jet flame models were mainly developed based on data from hydrocarbon jet flame experiments, it is to be verified, that they also apply to hydrogen jet flames. To this purpose real-scale tests are carried out at the BAM Test Site Technical Safety (BAM-TTS) with the aim to assess the flame geometry and the emitted thermal radiation of hydrogen and methane jet flames. Parameters such as leakage diameter (ranging from 1 mm to 10 mm), pressure (up to max. 250 bar), release orientation (vertical or horizontal) and mass flow (up to max. 0.5 kg/s) are varied. In particular, the focus is laid on the measurement and modelling of the thermal radiation. The challenge here is the characterization of the flame geometry in an open environment and its impact on the thermal radiation. Existing heat radiation data from the literature are mostly based on unsteady outflow conditions. The experimental setup used here allows for the generation of a steady-state outflow for several minutes and thus a direct comparability with existing (steady-state) models. From these data, an assessment of the applicability of jet flame models to hydrogen jet flames is carried out not only accounting for their accuracy in predicting the heat radiation but also with regard to possible needs of further development of the models. T2 - 18th EFCE International Symposium on Loss Prevention and Safety Promotion in the Process Industries CY - Bologna, Italy DA - 08.06.2025 KW - Jet Fire KW - Hydrogen KW - Methane KW - Heat radiation PY - 2025 AN - OPUS4-63696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heimann, Jan A1 - Yilmaz, Bengisu A1 - Charmi, Amir A1 - Duffner, Eric A1 - Schukar, Marcus A1 - Prager, Jens T1 - Structural Health Monitoring (SHM) for continuous monitoring of hydrogen pressure vessels N2 - While hydrogen is one of the most promising energy carriers, the safety of hydrogen storage technology remains one of the most important factors for technological and societal approval. While the engineering safety factors of the pressure vessels are kept high, the periodic inspection and the limited lifetime are making the application very costly considering manpower, time, money, and material waste. The development of an integrated structural health monitoring system can allow an easy transition from the current situation to cost-effective predictive maintenance. Hence, we propose to integrate three different SHM systems into hydrogen pressure vessels, namely guided wave ultrasonics, acoustic emission, and fibre optic sensing, to continuously monitor the condition and integrity. In this work, we evaluated the condition of a Type IV composite overwrapped pressure vessel using ultrasonic guided wave propagation. We mounted fifteen piezo-electric wafers on the composite cylinder by shaping three rings containing five sensors each. We acquired data from the sensor network following different boundary conditions with artificial damages on the selected locations. The data were evaluated with guided wave tomography techniques using ultrasonic features (amplitude, frequency, etc.) as well as artificial intelligence (AI). The results suggest that both traditional guided wave fusion techniques and AI-based characterization methods can detect artificial damages. In future work, it is planned to integrate acoustic emission and fibre optic sensing. Moreover, the measurement and the test results will be implemented into a digital twin to derive trends and make predictions on the damage propagation as well as the remaining useful lifetime. This work has received funding from German Ministry of Economic Affairs and Climate Actions within the QI-Digital initiative (www.qi-digital.de). T2 - SCHALL 23 CY - Wetzlar, Germany DA - 21.03.2023 KW - Structural Health Monitoring KW - Ultrasonic Guided Waves KW - Composite Overwrapped Pressure Vessel KW - Hydrogen PY - 2023 AN - OPUS4-58026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hickel, Tilmann T1 - Data driven research on hydrogen in metals N2 - The talk gives an overview on data-driven research on hydrogen in metals performed at BAM. The focus is on a ab-initio based high-throughput study on the hydrogen solubility in metals and metallic alloys. Furthermore, the redistribution of hydrogen in transforming microstructures is addressed. The talk ends with an explanation of participant projects in NFDI-MatWerk, motivating the formation of a new project connected to hydrogen technology. T2 - DGM Fachausschuss “Wasserstoffeffekte in Werkstoffen" CY - Saarbrücken, Germany DA - 05.05.2024 KW - Hydrogen KW - Solubility KW - High-throughput study KW - Ab initio simulation KW - NFDI-MatWerk PY - 2024 AN - OPUS4-62721 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hickel, Tilmann T1 - Hydrogen redistribution during electrochemical charging and mechanical testing: insights from a combined ab initio and finite element method N2 - In advanced high strength steels the mechanisms of hydrogen embrittlement are expected to be strongly connected to the amount of retained austenite (RA) contained in the microstructure and its transformation upon deformation. We have developed a multi-scale model for the hydrogen redistribution during hydrogen charging and tensile loading within martensitic/austenitic microstructure. Ab initio simulations have been used to resolve the complex energy profile of hydrogen in the martensite/austenite interface. Representative microstructures with different amounts of RA have been converted form experimental SEM-EBSD measurements. Simulations with the finite element method (FEM) have been used to analyse H concentration profiles within the microstructure. The simulations confirm an accumulation of H within the austenitic phase during charging, which undergoes a phase transformation under applied mechanical load during tensile testing and releases accumulated H into the martensite matrix. As a result, there is a pronounced H segregation to the microstructure regions subjected to high hydrostatic tensile stresses and plastic strains, which has a strong impact on the embrittlement behaviour. T2 - DPG Frühjahrstagung Sektion SKM CY - Berlin, Germany DA - 17.03.2024 KW - Hydrogen KW - Steel KW - Structural transformation KW - Ab initio simulation KW - Multiscale simulation PY - 2024 AN - OPUS4-62726 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hickel, Tilmann T1 - Effect of Hydrogen on the Phase Stability of Steels N2 - In this work, we studied the role of extreme hydrogen concentrations on the relative stability of the fcc/bcc/hcp phases using the ab initio thermodynamics. The results indicate that at low hydrogen chemical potentials the stability of the fcc phase, which can be representative of retained austenite (RA) in steels, is slightly enhanced by the presence of H atoms. In contrast, at high hydrogen chemical potentials the bcc phase is stabilized by H. Moreover, since the excess volume of the hydrogen-rich bcc phase is significantly larger than that of the fcc phase, the presence of a stress field can change the relative stability of these phases in the coexistence regions of the phase diagram. This feature is particularly important for cyclic loading conditions: during loading cycles forward and reverse phase transformations occur and the H released by these transformations can damage the material. T2 - TMS Annual Meeting 2024 CY - Orlando, FL, USA DA - 03.03.2024 KW - Hydrogen KW - Ab initio thermodynamics KW - Multiscale simulation KW - Hydride formation KW - Workflow PY - 2024 AN - OPUS4-62730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hickel, Tilmann T1 - Fundamental insights into the mechanism of hydrogen embrittlement N2 - The talks starts with a study on H trapping and embrittlement in high-strength Al alloys. Then the phase stability and transformation between different Fe-H phases is discussed, together with implications on crack nucleation. In the last part MD-MC simulation of hydride formation at crack tips in Al alloys are shown. T2 - Integrated Computational Materials, Process and Product Engineering Conference, IC-MPPE CY - Leoben, Austria DA - 06.06.2024 KW - Hydrogen KW - Ab initio thermodynamics KW - Multiscale simulation KW - Hydride formation KW - Cracks PY - 2024 AN - OPUS4-62727 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holtappels, Kai T1 - Hydrogen - Trust through safety N2 - In den Virtual Talks der DECHEMA wurden allgemeine Aspekte der Sicherheit und Akzeptanz von Wasserstofftechnologien vorgestellt. Wie kann Vertrauen in neue Technologien geschaffen werden, wenn Unfälle aus der Vergangenheit zu Mythen und Märchen führten? Der Vortrag räumt mit allgemeinen Vorurteilen auf und zeigt, dass der Umgang mit Wasserstoff weder unsicherer, noch sicherer ist als der Umgang mit anderen Brenngasen. Basis für den sicheren Umgang mit Wasserstoff ist immer eine Risikoanalyse. N2 - In the DECHEMA Virtual Talks, general aspects of the safety and acceptance of hydrogen technologies were presented. How can trust in new technologies be built when past accidents led to myths and fairy tales? The presentation does away with general prejudices and shows that handling hydrogen is neither more unsafe nor safer than handling other fuel gases. The basis for the safe handling of hydrogen is always a risk analysis. T2 - DECHEMA Virtual Talks CY - Online meeting DA - 23.11.2020 KW - Hydrogen KW - Wasserstoff KW - Safety KW - Sicherer Umgang KW - Sicherheit PY - 2020 AN - OPUS4-52082 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -