TY - CONF A1 - Rethmeier, Michael T1 - Anwendung einer Kombination aus Laserhybrid- und Unterpulverschweißen zum Fügen dicker Bleche aus Schiffbaustahl EH36 N2 - In diesem Beitrag wird ein Schweißverfahren vorgestellt, mit dem 30 mm dicke Bleche aus Schiffbaustahl EH36 effizient und werkstoffgerecht gefügt werden können. Die wirtschaftlichen Vorteile des Verfahrens ergeben sich aus dem Wegfall der aufwendigen Kantenvorbereitung und der Reduzierung des Schweißzusatzbedarfs. Die Stumpfschweißnähte werden in einer Lagen-/Gegenlage-Technik durch Laserhybridschweißen und Unterpulverschweißen ausgeführt. Dabei erfolgt die Laserhybridschweißung als Einschweißung mit einer Tiefe von etwa 25 mm, während die Unterpulvernaht als zweiter Durchgang auf der gegenüberliegenden Seite des Bauteils mit einer Einschweißtiefe von 8 mm aufgebracht wird. Die Überlappung der beiden Lagen gewährleistet einen geschlossenen Nahtquerschnitt. Dank der partiellen Durchschweißung der Laserhybridnaht entfällt die Notwendigkeit zur Wurzelformierung. Darüber hinaus bietet die Prozesskombination eine höhere Toleranz gegenüber Ungenauigkeiten in der Kantenvorbereitung, was die Prozesskomplexität reduziert. Der Einsatz dieses robusteren Verfahrens, das weniger von einer präzisen Kantenvorbereitung abhängig ist, erleichtert die Produktionsvorbereitung, minimiert die Fehleranfälligkeit und senkt die Nachbearbeitungskosten. Dies macht das Laserhybridschweißen besonders attraktiv für Anwendungen im Schiffbau. T2 - 22. Tagung Schweißen in der maritimen Technik und im Ingenieurbau CY - Hamburg, Germany DA - 13.05.2025 KW - Kerbschlagbiegeversuch KW - Laserhybridschweißen KW - Unterpulverschweißen PY - 2025 AN - OPUS4-65073 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine T1 - Tribologische Untersuchungen unter GH2 und LH2-Bedingungen N2 - In diesem Beitrag werden Untersuchungen an Polymerwerkstoffen auf ihre Eignung für Reibsysteme in gasförmigem und flüssigem Wasserstoff vorgestellt. Dabei wird der Einfluss der Wasserstoffumgebung in Bezug auf die Materialzusammensetzung diskutiert. Weiterhin zeigen die Experimente in LH2 einen deutlichen Einfluss der Temperatur, der jedoch bei den verschiedenen Polymerverbundwerkstoffen unterschiedlich stark ausgeprägt ist. T2 - DKV Tagung CY - Hannover, Germany DA - 23.11.2023 KW - Polymerwerkstoffe KW - Reibung KW - Verschleiß KW - Gasförmiger Wasserstoff KW - Flüssiger Wasserstoff PY - 2023 AN - OPUS4-61963 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine T1 - Toward sustainable and hydrogen compatible sealing materials N2 - Materialien auf PTFE-Basis werden in der Regel als Kolbenringe in Hochdruck- und/oder kryogenem Wasserstoff verwendet. In diesem Projekt werden neu formulierte und nachhaltigere Polymerwerkstoffe mit herkömmlichen Materialien verglichen. Auf Grundlage der tribologischen Ergebnisse werden vielversprechende Kandidaten zusammen mit Reibungsmechanismen sowohl bei Hochdruck- als auch bei Niedrigtemperatur-Wasserstoff vorgeschlagen. T2 - 66. Tribologie-Fachtagung 2025 CY - Wernigerode, Germany DA - 29.09.2025 KW - Wasserstoff KW - Reibung KW - Verschleiß KW - Kolbenring KW - Dynamische Dichtung PY - 2025 AN - OPUS4-64313 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine T1 - Fretting wear of elastomer materials in hydrogen N2 - This paper presents an experimental study on the fretting wear behavior of two types of cross-linked hydrogenated acrylonitrile butadiene rubbers against 316L steel ball in hydrogen environment. Furthermore, aging experiments were conducted for 7 days under static conditions in 100 MPa hydrogen. The influences of hydrogen pressure as well as the aging exposure on the fretting behavior are discussed by means of surface analyses and well as material properties. T2 - WHEC-2022, 23rd World Hydrogen Energy Conference CY - Istanbul, Turkey DA - 26.06.2022 KW - Rubbers KW - Hydrogen KW - Fretting PY - 2022 AN - OPUS4-62086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine T1 - Polymer tribology in cryogenic hydrogen N2 - In this presentation, an overview of polymer tribology in cryogenic hydrogen is given along comparison with other environments. T2 - Hydrogenius Symposium 2024 CY - Kyushu University Ito Campus, Japan DA - 12.09.2024 KW - Hydrogen KW - Friction KW - Wear KW - Polymer materials KW - Cryogenic PY - 2024 AN - OPUS4-61426 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scharf-Wildenhain, R. T1 - Influence of build up height on residual stresses in additive repair and modification using DED Arc N2 - Directed Energy Deposition (DED)-Arc is suitable for the hybrid additive manufacturing, modification and repair of large metal components with high deposition rates. Residual stresses and distortion are of central importance when characterizing the manufactured components and the sensitive transition area between AM component and semi-finished product. Residual stresses caused by the thermal cycles during the manufacturing process can impair the mechanical properties of the manufactured parts and can lead component failure. Therefore, understanding and controlling residual stresses, especially when combining different base and filler materials, is critical to improving the quality and efficiency of the hybrid DED-Arc process. This article deals with the influence of the build-up height on the residual stress distribution of additively manufactured components with a selected base and filler material combination. Using a robot-assisted DEDsystem and a controlled short arc, systematic step cancellation tests were carried out at a selected working temperature (200 C°) and heat input (600 kJ/m). In a 5-stage termination experiment, straight walls were produced using a one bead per layer strategy and selected increasing component heights between 15 mm and 300 mm. The influence of the build height on the longitudinal residual stress in the process direction was analyzed and discussed. All experiments showed a comparable stress distribution in the area of the substrate plate up to the heat-affected zone (HAZ) and the transition zone, regardless of the buliding height. However, the height showed a significant influence on the of residual stress distribution of the deposited AM-component. High positive stress gradients with a maximum range between 300 MPa to 400 MPa were always found in the last approx. 18 component layers (upper 40 mm), which can be explained by the shrinkage of the nonheat- treated top layer. Underlying layers, where present, showed a homogeneous residual stress distribution characterized by low compressive stresses. This can be explained by the process related tempering during the deposition of the upper layers. A constant boundary layer number was determined for all specimens. Once this number was exceeded, the distribution of residual stresses no longer changed, but merely shifted with the increasing height of the component in the direction of build-up. These correlations contribute to the understanding of residual stress development with increasing structure height. This study is part of a running research project on the properties of hybrid additive components and processes. It aims the stress optimized hybrid additive manufacturing of high-strength components and the necessary recommendations for application. T2 - 78th IIW Annual Assembly and International Conference on Welding and Joining CY - Genoa, Italy DA - 22.06.2025 KW - DED-Arc KW - Additive manufacturing KW - Residual stress PY - 2025 AN - OPUS4-65192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröpfer, Dirk T1 - Wear resistance of modified Ni based claddings in relation to the resulting machinability via ultrasonic-assisted milling N2 - In the field of plastics processing, extruder screws are subjected to significant wear stresses. The extruder screw is the main wear component in those production machines and is usually coated with intermetallic wear protection alloys composed of Ni-based alloys, specifically Colmonoy C56 PTA (NiMoCrSi). There is a growing demand for providing an economic machinability of these alloys to achieve defined contours with a sufficient surface integrity. Recent investigations exhibit promising results applying ultrasonic milling for such hard-to-cut materials. The Colmonoy C56 is modified by various alloying additions Ti, Nb, Mo, Hf, and Al, and then cladded on a steel S355 via Plasma Transferred Arc process. The effect of alloying additions on the microstructure is analyzed regarding their resistance to abrasive and adhesive wear. With Miller test ASTM G75 the influence of alloying elements on resistance to abrasive wear for two abrasive materials is investigated (high-grade corundum F220 and quartz powder). The wear loss is not increased for additions of Nb and Ti compared to the base material C56. Modifications with Hf or Al reduces the resistance to abrasive wear and significantly increases material loss. The extruder screw is also subject to adhesive wear, which can be quantified by means of the pin-roll test. It is demonstrated that the addition of Hf, for example, contributes to a reduction in wear loss. Aim of the investigations is to find suitable modifications for the wear claddings of C56 for a sufficient machineability, without compemising the wear resistant. The machinability is considerably affected by the alloy additions, and is determined using ultrasonic-assisted milling. The addition of hafnium reduces machinability, i.e. significantly increases cutting forces. The incorporation of Nb exhibits a significant reduction of cutting forces, and results in reduced tool wear and an enhanced of surface integrity (roughness, density of defects, residual stresses). T2 - Wear of Materials 2025 CY - Sitges, Spain DA - 13.04.2025 KW - Abrasive wear KW - Adhesive wear KW - Colmonoy C56 KW - PTA welding KW - Service life and efficiency KW - Substitution of critical raw materials KW - Surface integrity KW - Ultrasonic-assisted milling process PY - 2025 AN - OPUS4-65189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drexler, A.-K. A1 - Konert, Florian A1 - Nietzke, Jonathan A1 - Hodžić, E. A1 - Pastore, S. A1 - Domitner, J. A1 - Rhode, Michael A1 - Sommitsch, C. A1 - Böllinghaus, Thomas T1 - Effect of Tensile Loading and Temperature on the Hydrogen Solubility of Steels at High Gas Pressure N2 - The hydrogen solubility in ferritic and martensitic steels is affected by hydrostatic stress, pressure, and temperature. In general, compressive stresses decrease but tensile stresses increase the hydrogen solubility. This important aspect must be considered when qualifying materials for high‐pressure hydrogen applications (e.g., for pipelines or tanks) by using autoclave systems. In this work, a pressure equivalent for compensating the effect of compressive stresses on the hydrogen solubility inside of closed autoclaves is proposed to achieve solubilities that are equivalent to those in pipelines and tanks subjected to tensile stresses. Moreover, it is shown that the temperature effect becomes critical at low temperatures (e.g., under cryogenic conditions for storing liquid hydrogen). Trapping of hydrogen in the microstructure can increase the hydrogen solubility with decreasing temperature, having a solubility minimum at about room temperature. To demonstrate this effect, the generalized law of the hydrogen solubility is parameterized for different steels using measured contents of gaseous hydrogen. The constant parameter sets are verified and critically discussed with respect to the high‐pressure hydrogen experiments. KW - Hydrogen KW - Solubility KW - Temperature KW - Tensile loading KW - Analytical calculation PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-586701 DO - https://doi.org/10.1002/srin.202300493 SN - 1611-3683 SP - 1 EP - 9 PB - Wiley AN - OPUS4-58670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drexler, A A1 - Konert, Florian A1 - Sobol, Oded A1 - Rhode, Michael A1 - Domitner, J A1 - Sommitsch, C A1 - Böllinghaus, Thomas T1 - Enhanced gaseous hydrogen solubility in ferritic and martensitic steels at low temperatures N2 - Metals that are exposed to high pressure hydrogen gas may undergo detrimental failure by embrittlement. Understanding the mechanisms and driving forces of hydrogen absorption on the surface of metals is crucial for avoiding hydrogen embrittlement. In this study, the effect of stress-enhanced gaseous hydrogen uptake in bulk metals is investigated in detail. For that purpose, a generalized form of Sievert's law is derived from thermodynamic potentials considering the effect of microstructural trapping sites and multiaxial stresses. This new equation is parametrized and verified using experimental data for carbon steels, which were charged under gaseous hydrogen atmosphere at pressures up to 1000 bar. The role of microstructural trapping sites on the parameter identification is critically discussed. KW - Hydrogen KW - Thermodynamic modelling KW - Pressure-dependent solubility KW - Steel KW - Trapping PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559307 DO - https://doi.org/10.1016/j.ijhydene.2022.09.109 SN - 0360-3199 VL - 47 IS - 93 SP - 39639 EP - 39653 PB - Elsevier Ltd. AN - OPUS4-55930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Campari, Alessandro A1 - Konert, Florian A1 - Sobol, Oded A1 - Alvaro, Antonio T1 - A comparison of vintage and modern X65 pipeline steel using hollow specimen technique for in-situ hydrogen testing N2 - The transition toward a hydrogen-based economy requires a widespread transport and distribution network, and repurposed natural gas pipelines are a viable option. An assessment of the hydrogen-induced degradation of pipeline steels is needed to inject H2 gas into the existing infrastructure safely. The conservative and standardized method consists of in-situ tensile tests in an autoclave filled with high-pressure hydrogen gas. A proposed alternative method involves using a hollow specimen as containment volume and applying the gas pressure in the inner cavity. This technique has lower costs and shorter test preparation time but is not standardized yet. This study aims to evaluate and compare the tensile properties of API 5L X65 pipeline steel in two states: vintage and modern. The influence of the surface roughness is investigated through parallel tests with drilled and reamed specimens. Hydrogen tests are compared with reference tests in an inert environment. A significant hydrogen-induced decrease in tensile properties is observed, and no significant difference between vintage and modern X65 can be drawn. The reduction in tensile properties is more significant in specimens with higher inner surface roughness. The evaluation of surface conditions appears crucial when assessing the HE susceptibility of hydrogen transport and storage equipment. KW - Hydrogen embrittlement KW - Hollow specimen technique KW - Pipeline steel KW - SSRT PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603013 DO - https://doi.org/10.1016/j.engfailanal.2024.108530 VL - 163 SP - 1 EP - 15 PB - Elsevier Ltd. AN - OPUS4-60301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nietzke, Jonathan A1 - Konert, Florian A1 - Poka, Konstantin A1 - Merz, Benjamin A1 - Sobol, Oded A1 - Böllinghaus, Thomas T1 - Comparison of hydrogen effects on additively manufactured and conventional austenitic steels N2 - Hydrogen and its derivatives are promising energy carriers for future renewable energy supplies. Austenitic stainless steels, such as AISI 316L, are commonly used in hydrogen transportation systems. While often thought to be resistant to hydrogen embrittlement, studies have shown that 316L is susceptible under certain conditions. As demand for hydrogen applications grows, additive manufacturing (AM) technologies offer design flexibility and customisation benefits. However, data on AM parts behaviour in hydrogen environments is lacking. This study investigates the influence of hydrogen on mechanical properties using slow strain rate testing (SSRT) on conventional AISI 304L, 316L and AM 316L specimens. The results indicate a greater effect of hydrogen on 304L compared to 316L, with AM 316L showing increased susceptibility. However, the ductility of AM 316L remains comparable to conventional 316L due to its initial ductility. The study provides insights into the performance of conventional and AM austenitic stainless steels in gaseous hydrogen environments. KW - Slow strain rate testing KW - Hollow specimen KW - Hydrogen embrittlement KW - Additive manufacturing KW - Austenitic steel PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615919 DO - https://doi.org/10.1016/j.engfailanal.2024.109042 SN - 1350-6307 VL - 167 SP - 1 PB - Elsevier B.V. AN - OPUS4-61591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grimault de Freitas, Tomás A1 - Konert, Florian A1 - Nietzke, Jonathan A1 - Krzysch, Zephanja A1 - Böllinghaus, Thomas A1 - Michler, Thorsten A1 - Wackermann, Ken A1 - Oesterlin, Heiner A1 - Tlili, Mohamed A1 - Ruchti, Peter A1 - Beitelschmidt, Denise A1 - Elsen-Humberg, Stephan A1 - Koenigs, Timo A1 - Systermans, Thomas A1 - Sobol, Oded T1 - Tensile testing in high-pressure gaseous hydrogen using the hollow specimen method N2 - 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 standardized 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. The hollow specimen technique is a simple, rapid, and economical method designed to overcome the limitations of the current methods for the qualification of metallic materials under high-pressure hydrogen gas. However, this technique is not yet standardized. The TransHyDE-H2Hohlzug project is presented in this article, along with the main steps required to optimize the hollow specimen technique. This includes closing knowledge gaps related to the specimen geometry, surface quality, and gas purity in dedicated working packages, thus contributing to a comprehensive standardization of the technique for tests in high-pressure hydrogen gas. KW - High-pressure Gaseous Hydrogen KW - Hydrogen Embrittlement KW - Tensile Testing KW - Hollow Specimen Technique PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610557 DO - https://doi.org/10.1557/s43577-024-00776-9 VL - 49 SP - 1 EP - 9 PB - Springer Nature AN - OPUS4-61055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Konert, Florian A1 - Nietzke, Jonathan A1 - Grimault de Freitas, Tomás A1 - Rhode, Michael A1 - Sobol, Oded A1 - Böllinghaus, Thomas T1 - Investigation of resistance to gaseous hydrogen of a longitudinal weld seam in a X65 pipeline using the hollow specimen technique N2 - The constantly increasing demand for renewable energy sources leads to the necessity of transporting large amounts of hydrogen. Since pipelines enable a cost-effective way for the distribution of gaseous hydrogen, the interaction of hydrogen and the pipeline materials must be carefully investigated as hydrogen can cause a degradation of the mechanical properties under certain conditions. Especially welds, which are assumed to be more susceptible to the degradation enhanced by hydrogen, are of great interest. The aim of this study is to investigate the effect of gaseous hydrogen on the mechanical properties of an X65 pipeline, and the longitudinal submerged arc welding (SAW) welded joint. The tests are conducted using the hollow specimen technique on two types of specimens: one extracted from the base material (BM) and the other extracted as a cross-weld (CW) specimen consisting of BM and weld seam. The specimens are charged in situ under a pressure of 60 bar and tested using slow strain rate (SSR) tensile tests with a nominal strain rate of 10−5 s−1. The properties obtained of specimens tested in hydrogen atmosphere are compared to the properties of comparable specimen in inert argon atmosphere as a reference. The performed tests showed a decrease of the reduction of area (RA) from 72% in inert atmosphere to 52% in hydrogen atmosphere for the CW specimen and a decrease from 73% in inert atmosphere to 51% for the BM. Metallographic analyses showed the crack initiation between fine-grained heat-affected zone (FGHAZ) and BM for the specimens tested in hydrogen atmosphere as well as for the reference specimens. This leads to the conclusion that the location of the crack initiation does not change due to the presence of gaseous hydrogen. KW - Hydrogen KW - Hollow specimen technique KW - Pipeline KW - SSRT KW - Hydrogen embrittlement KW - Cross-weld specimen PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624658 DO - https://doi.org/10.1007/s40194-025-01953-3 SN - 0043-2288 SN - 1878-6669 VL - 69 IS - 3 SP - 861 EP - 870 PB - Springer CY - Berlin AN - OPUS4-62465 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 - The hollow specimen technique is a simple and economical technique that has the potential to make materials qualification with pressurised gaseous hydrogen widely accessible to academia and industry. This contribution focuses on the results obtained from assessing the influence of the 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 relevant because an increase in stress concentration sites, e.g. notches, has been found to be associated with increased severity of hydrogen effects. The presence of strain-induced martensite caused by mechanical stress may also be detrimental and accelerate the embrittlement. To assess this influence, the inner hole of the hollow specimens was manufactured in two different ways: 1) only drilling; 2) EDM followed by honing. A representative steel widely used in hydrogen technologies was assessed, X5CrNi18-10 (AISI 304). Roughness measurements, and electron back-scatter diffraction (EBSD) analysis 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 argon and in hydrogen, both at 150 bar and room temperature. Here, a strain-rate sensibility analysis was performed to investigate the influence of strain-rate on hydrogen degradation. T2 - International Conference on Hydrogen Safety 2025 CY - Seoul, South Korea DA - 22.09.2025 KW - Tensile Testing KW - Hollow Specimen Technique KW - High-Pressure Hydrogen Gas KW - Hydrogen Embrittlement KW - Surface Condition KW - Strain Rate PY - 2025 AN - OPUS4-64286 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 TransHyDE - H2HohlZug Project 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 - TransHyDE Vollversammlung 2025 CY - Leipzig, Germany DA - 26.11.2025 KW - Hydrogen KW - Hydrogen Embrittlement KW - Hollow Specimen Technique KW - High-Pressure Gaseous Hydrogen KW - TransHyDE KW - H2HohlZug KW - Standardisation PY - 2025 AN - OPUS4-64938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Konert, Florian T1 - Evaluation of hydrogen effect on hardened and annealed 100Cr6 steel N2 - The use of hydrogen demands high safety requirements, since hydrogen can be absorbed by metallic materials and may cause hydrogen embrittlement (HE) under certain conditions. Slow strain rate (SSR) tensile testing is a widespread method to quantify the hydrogen-induced ductility loss of alloys. Here, the hollow specimen technique was used to evaluate the effect of 150 bar hydrogen on the tensile properties of solution annealed and hardened 100Cr6 steel, which is a common material for bearing systems. This technique reduces the required amount of hydrogen and minimizes the duration and costs of the tests performed compared to in-situ tensile tests in autoclaves. T2 - EPRI Workshop on Hydrogen Embrittlement 2024 CY - Oxford, UK DA - 23.06.2024 KW - Hydrogen KW - Hydrogen Embrittlement KW - Hollow Specimen Technique KW - 100Cr6 PY - 2024 AN - OPUS4-60476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nietzke, Jonathan T1 - Influence of strain rate on the effect of hydrogen in pre-charged 316L stainless steel: A comparison of conventional and hollow specimen testing N2 - The growing demand for hydrogen requires an expansion of testing capabilities to assess the performance of metallic materials under hydrogen exposure. Considering only gaseous atmospheres, there is a variety of in-situ and ex-situ methods used to investigate the material behavior while or after exposed to hydrogen, respectively. Among these methods, a more conservative one is the in-situ testing at slow strain rates (SSRT) using conventional tensile specimens. While results obtained by a conservative procedure may be more applicable in many cases than those of ex-situ experiments, the tests are quite demanding, leading to limited testing capacities and high costs, especially for very slow strain rates. A possible solution that can enable in-situ testing at relatively low cost is the hollow specimen technique which gained increasing interest in the last decade. The main reasons are the minimal volume of hydrogen required and the elimination of a high-pressure hydrogen autoclave leading to significantly lower costs and enabling more laboratories worldwide to perform these tests. However, interpreting results from hollow specimens, especially when compared to conventional ones, remains a significant challenge. To address this, an experimental study was conducted using conventional and hollow specimens, both uncharged and pre-charged. Pre-charging was achieved using pure hydrogen (5.0, i.e. 99.999 %) at 100 bar and 300 °C for around 21 days. In order to obtain suitable reference specimens, other specimens were stored in argon at 100 bar and 300 °C for the same period of time. The tests were performed at various strain rates, down to 1E-6 1/s. While these ex-situ experiments are not directly comparable to in-situ tests with both types of specimens, they do provide some insights into the differences between the results of hollow and conventional specimens. Therefore, the elongation at fracture and reduction of area (RA) were compared, among other aspects. In addition, fractographical analyses were carried out using SEM images. Elongation at fracture was not significantly affected by hydrogen in conventional specimens, but it was slightly reduced in hollow specimens. RA, on the other hand, was lower for tests with hydrogen in both types of specimens across all strain rates. Moreover, the strain rate did not appear to influence hydrogen embrittlement in conventional specimens whereas in hollow specimens, tests conducted at higher strain rates (1E-4 1/s) showed a greater impact of hydrogen on elongation at fracture than those at lower strain rates (1E-6 1/s), which is contrary to the typical expectation. These findings suggest that the influence of hydrogen differs between conventional and hollow specimens, possibly due to factors such as surface roughness and differing stress states. However, further experiments are needed to fully understand these differences, including in-situ experiments to understand potential differences in hydrogen absorption between the two specimen types. T2 - EPRI Workshop on Hydrogen Embrittlement CY - Oxford, England, United Kingdom DA - 23.06.2024 KW - Stainless steel KW - Hollow specimen KW - Pre-charging KW - Hydrogen PY - 2024 AN - OPUS4-60494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shikomba, Nikanor A1 - Böllinghaus, Thomas A1 - Konert, Florian A1 - Sobol, Oded A1 - Blasón Gonzalez, Sergio A1 - Ohijeagbon, Idehai Olayemi A1 - Krafft, Eike A1 - Staudt, Thorsten T1 - Resistance of welded low-alloyed pressure vessel and pipeline steels in gaseous hydrogen N2 - Green hydrogen has become an essential energy carrier to achieve a climate-neutral economy. The production, storage, transport and usage of green hydrogen require safe and sustainable facilities and systems. The present contribution provides a procedure guideline to investigate the compatibility of steel welds for pressurised gaseous hydrogen applications under quasi-static mechanical loads, utilising the slow strain rate test and hollow specimen technique. Exemplarily, a weld of the low-alloyed steel P355NL1 was investigated and compared to an X65 weld. The results indicate that the base metal exhibits a higher ductility than the weld metal for both steels. Generally, hydrogen-exposed specimens exhibited a reduced strain, as compared to reference specimens. The hydrogen degradation, evaluated by the hydrogen embrittlement index, was more pronounced in the weld metal compared to the base P355NL1 material, whereas the X65 exhibited a larger hydrogen degradation of the base material than in the weld metal. Fractographic analysis of the test specimens revealed that hydrogen causes a transition from ductile to brittle features. Generally, the results of this study indicate a mild but significant degradation of the mechanical properties in terms of the ductility of the welds in the respective pressurised hydrogen atmosphere. KW - Hydrogen-assisted cracking KW - Welded joint KW - Slow strain rate test KW - Hollow Specimen KW - Structural steel PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634138 DO - https://doi.org/10.1007/s40194-025-02074-7 SN - 0043-2288 SP - 1 EP - 15 PB - Springer CY - Berlin AN - OPUS4-63413 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kromm, Arne T1 - Werkstoffsichere Dickblechschweißung und KI N2 - Der Vortrag zeigt, welche Herausforderungen beim Schweißen sogenannter Dickblechverbindungen bestehen und welche Strategien zur Lösung genutzt werden können. Ansätze zur Fehlerprävention werden vorgestellt. Es wird dargestellt, wie KI-basierte Methoden die Fehlererkennung erleichtern. Letztlich werden Potentiale zur effizienten Fehlerbeseitigung aufgezeigt und der Anwendernutzen herausgestellt. T2 - Mitgliederversammlung der Forschungsvereinigung Stahlanwendung e. V. CY - Essen, Germany DA - 17.12.2025 KW - UP-Schweißen KW - Eigenspannungen KW - Künstliche Intelligenz KW - Reparatur PY - 2025 AN - OPUS4-65210 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröpfer, Dirk T1 - Residual stress evaluation using the contour method of an additive manufactured high-strength steel solid cuboid N2 - Direct Energy Deposition with Arc (DED-Arc) enables the weight-optimized and near-net-shape manufacturing of complex structures. Lightweight construction principles allow a reduction of CO2 emissions by saving time, costs, and resources. Further optimisations can be achieved by using high-strength steel. This allows for a reduction in wall thickness and optimisation of weight. However, manufacturing intricate geometries using high-strength steels poses challenges in managing residual stresses (RS), which are essential for ensuring the structural integrity of welded components. High residual stresses can increase the risk of cold cracking, arising from the complex interactions between material properties, process conditions, and component design. Despite the availability of suitable filler metals, the lack of comprehensive knowledge and guidelines on residual stress formation limits the industrial application. Therefore, in the present study, the contour method (CM) was used to analyse the full field longitudinal residual stresses in an solid cuboid component (dimensions: 120 × 50 × 35 mm³) manufactured by DED-Arc. The CM enables the analysis of the two-dimensional map of residual stresses normal to a cutting plane using a finite element model. For this purpose, a solid cuboid component was welded fully automatically with a high-strength solid wire specially adapted for DED-Arc (yield strength > 790 MPa) onto conventionally manufactured substrates made of S690QL. The residual stresses from CM in the volume are compared with residual stress analyses using X-Ray diffraction on the surface. Additionally, comparative data from previous studies on hollow cuboid structures was included in order to identify similarities and differences in the resulting stress state, and to complement and validate the CM results. These results demonstrate the significant influence of the geometry on the residual stress profiles within the solid cuboid in relation to the open hollow. T2 - 4th International Conference on Advanced Joining Processes 2026 CY - Coimbra, Portugal DA - 16.10.2025 KW - Residual stress KW - Contour method KW - DED-Arc/M KW - High-strength steel KW - Filler metals KW - Neutron diffraction PY - 2025 AN - OPUS4-65209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -