TY - CONF A1 - Gumenyuk, Andrey T1 - Reducing Noise Impact on Strain Accuracy Measurement by Optical Flow and DIC for Laser Welding Applications N2 - In recent years, non-contact methods for in situ local strain measurement during welding processes have gained increasing importance. This trend is driven by advancements in both measurement technology—such as improved camera systems, illumination sources, and X-ray techniques—and in image processing algorithms for strain evaluation. Laser beam welding poses specific challenges for optical strain measurement due to various types of process-related emissions that impair measurement accuracy. In this study, two different algorithms were applied to analyze the local strain field in the solidification zone during laser welding of AISI 310S stainless steel: the inverse compositional Gauss-Newton algorithm for Digital Image Correlation (DIC) and the Lucas-Kanade method for optical flow analysis [1]. Video sequences were recorded under Controlled Tensile Weldability Test (CTW) conditions, in which the specimens were subjected to a defined external tensile load during welding. This setup consistently induced solidification cracking at the material surface, which could be observed in the video recordings. To enhance the robustness and accuracy of the strain evaluation, various noise reduction techniques were implemented. These included identification and mitigation of erroneous frames caused by process emissions and dynamic disturbances. The resulting strain distributions showed high repeatability across multiple experiments and were in good qualitative agreement with predictions from high-fidelity finite element simulations. [2]. T2 - AJP 2025 CY - Coimbra, Portugal DA - 16.10.2025 KW - Laser beam welding KW - Solidification cracking KW - Optical measurement PY - 2025 AN - OPUS4-64428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Thiel, Erik A1 - Altenburg, Simon A1 - Mohr, Gunther A1 - Thiede, Tobias A1 - Mishurova, Tatiana A1 - Paul, Andrea A1 - Kranzmann, Axel A1 - Hilgenberg, Kai A1 - Pittner, Andreas A1 - Bruno, Giovanni A1 - Sommer, Konstantin A1 - Gumenyuk, Andrey T1 - Quality control in additive manufacturing via in-situ monitoring and non-destructive testing N2 - More than 80 representatives of SMEs, industrial companies and research institutes met on September 12 at the workshop "Challenges in Additive Manufacturing: Innovative Materials and Quality Control" at BAM in Adlershof to discuss the latest developments in materials and quality control in additive manufacturing. In special lectures, researchers, users and equipment manufacturers reported on the latest and future developments in additive manufacturing. Furthermore, funding opportunities for projects between SMEs and research institutions on a national and European level were presented. T2 - Challenges in Additive Manufacturing: Innovative Materials and Quality Control CY - Berlin, Germany DA - 12.09.2018 KW - Additive manufacturing KW - Quality control KW - Non-destructive testing KW - In-situ monitoring PY - 2018 AN - OPUS4-46072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rethmeier, Michael A1 - Gumenyuk, Andrey A1 - Quiroz Penaranda, Vanessa T1 - Investigation on laser beam welding of high-manganese austenitic and austenitic-ferritic stainless steels PY - 2012 SN - 0005-111x SN - 0005-2302 VL - 1 IS - 705 SP - 12 EP - 17 CY - Kiev, Ukraine AN - OPUS4-27209 LA - rus AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Quiroz Penaranda, Vanessa A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Investigation of the hot cracking susceptibility of laser welds with the controlled tensile weldability test N2 - Due to significant developments over the last decades, laser beam welding has become a well-established industrial process offering high processing speeds and causing low component distortions. But an important issue currently preventing its intense use, especially in the energy or plant construction sector where high alloy steels are applied, concerns hot crack formation. Although considerable advances in understanding hot cracking mechanisms have been made, most of the known influencing factors are metallurgical in character. The thermo-mechanical effects are barely considered or quantified. Up to the present, there exist numerous hot cracking tests that were however conceived for welding methods other than laser beam welding. Considering the special features of the laser welding process, such as high cooling rates and the narrow process zone, results obtained with other welding techniques and test procedures cannot be transferred to laser beam welding. In this study, the laser beam weldability of various stainless steels was examined in terms of their susceptibility to hot cracking by means of the controlled tensile weldability test, which was proven to be suitable for use in conjunction with CO2 laser welding. This test allows the application of tensile strain at a variable fixed cross-head speed transverse to the welding direction. Full and partial penetration bead-on-plate welds were produced. In a first attempt to determine the impact of the applied external strain on the local transient strains and strain rates near the weld pool, an optical system was used to measure the backside surface of partial penetration welds. The results showed the influence of the strain and the strain rates on hot crack formation. Furthermore, a classification of the studied austenitic, duplex and ferritic stainless steels according to the established test criteria (critical strain and cross-head speed) was conducted. KW - Laser beam welding KW - CO2 laser KW - Hot cracking KW - Stainless steels KW - Critical strains KW - Strain rates KW - Hot cracking test KW - Controlled tensile weldability test PY - 2012 DO - https://doi.org/10.1177/0309324712462120 SN - 0309-3247 SN - 2041-3130 VL - 47 IS - 8 SP - 587 EP - 599 PB - Sage CY - London AN - OPUS4-27281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rethmeier, Michael A1 - Gook, Sergej A1 - Gumenyuk, Andrey ED - Turichin, G. T1 - Prospects of application of laser-GMA hybrid welding for manufacturing of large diameter longitudinal welded high strength steel pipes N2 - To a large extend, longitudinally welded large-diameter pipes are used for modern oil- und gas-pipelines. Thereby the mostly applied base materials are made from the API-steels X65 and X70. Constantly increasing natural gas and oil delivery rates demand advancements of the assigned materials. Wall thickness minimization or operating pressure increase is achieved by material Substitution, e.g. employment of a high strength Steel grade API-X80, API-X100 or API-X120. For the production of such pipes a large plate is first formed to an open ring. Subsequent, it is continuously tacked along its longitudinal gap by means of a GMA-process. In the further process, the remaining double-sided joint gaps are filled up by cost-intensive multiple-wire submerged arc welding (SAW) processes. The GMA-tack weld is being completely remelted in the process. The maximal root face is dependent on the welding process and which is currently 8 mm. The innovative laser hybrid welding technology offers a significant increase in the full penetrated root face and welding speed, compared to conventional wielding technologies. It means for the pipe production, that the amount of SAW filier layers will be reduced and, parallel to that, the increased welding speed will led to the shortening of the production cycle for the longitudinal welded pipes. T2 - VII. International scientific and technical conference 'Beam technologies & laser application' CY - Saint-Petersburg, Russia DA - 18.09.2012 KW - High strength steel KW - Laser hybrid welding KW - Modified spray arc KW - Longitudinal weld KW - Pipeline PY - 2013 SP - 130 EP - 140 PB - Publishing house SPbSPU AN - OPUS4-28040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reisgen, U. A1 - Olschok, S. A1 - Backhaus, A. A1 - Rethmeier, Michael A1 - Gumenyuk, Andrey A1 - Tölle, Florian T1 - Reduction of weld residual stresses with the electron beam N2 - High weiding residual stresses can cause Service life reducing consequences. Even though many processes have been developed to reduce these stresses, they are only applicable for wider welds and simple component geometries or are cost-intensive, respectively. This work introduces a possibility to reduce the weid residual stresses by means of the electron beam. The same tool is used for the production of the welded seam and the weid residual stresses are reduced touchless, in a multiple-process technique or in a second working step. Other process steps, spanning orshifting of the component or even additional machines are no longer required when this rnethod is used. Via beam oscillation and multiple-process technique, the defocused electron beam produces thermal fields in transversal and lateral distance to the welded seam which impose compressive stress on the ambient material. With the help of adjusted heating fields in defined distance from the weid seam, the residual stresses in the weld seam are, e.g. in the case of ferritic Steel, reduced by up to 73%. In this work, the basic mechanism for stress relief is introduced and also the influence of different process Parameters, e.g. beam power, deflection parameters, diameter of the defocused electron beam and work distances between thermal fields and welded seams exert on the reduction of residual stresses. Moreover, different results made with ferritic and austenitic Steel are presented in the form of linear and circumferential welds. T2 - 2nd International electron beam welding conference (IEBW) CY - Aachen, Germany DA - 26.03.2012 PY - 2012 SN - 978-3-87155-299-1 N1 - Serientitel: DVS-Berichte – Series title: DVS-Berichte VL - 285 SP - 128 EP - 132 PB - DVS Media GmbH CY - Düsseldorf AN - OPUS4-26110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fritzsche, André A1 - Avilov, Vjaceslav A1 - Gumenyuk, Andrey A1 - Hilgenberg, Kai A1 - Rethmeier, Michael T1 - High power laser beam welding of thick-walled ferromagnetic steels with electromagnetic weld pool support N2 - The paper describes an experimental investigation of high power laser beam welding with an electromagnetic weld pool support for up to 20 mm thick plates made of duplex steel (AISI 2205) and mild steel (S235JR). The results of the welding tests show a successful application of this technology at ferromagnetic metals. Irregular sagging was suppressed successfully. An ac-power of less than 2 kW at oscillation frequencies between 800 Hz and 1.7 kHz is necessary for a full compasation of the hydrostatic pressure. Thus, it was demonstrated that the electromagnetic weld pool support is not only limited to non-ferromagnetic metals like austenitic steels. For future studies with duplex steel, the use of filler material has to take into account with regard to the balance of the mixed austenitic and ferritic phases. KW - Laser beam welding KW - Thick-walled steel KW - Ferromagnetic steel KW - Weld pool support PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-377593 DO - https://doi.org/10.1016/j.phpro.2016.08.038 SN - 1875-3892 VL - 83 SP - 362 EP - 372 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-37759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Böllinghaus, Thomas A1 - Gumenyuk, Andrey A1 - Quiroz Penaranda, Vanessa ED - Lippold, J. ED - Böllinghaus, Thomas ED - Cross, C.E. ED - et al., T1 - Short Term Metallurgy and Hot Cracking During Laser Beam Welding of Austenitic Stainless Steels N2 - Industrial application of high alloyed austenitic stainless steel laser welding has grown significantly in the recent time due to the continuous improvement of compact and high power density lasers systems. The application of such processes meanwhile ranges from pipeline or railway car body manufacturing to the production of household wares. The largest advantages of the laser application to welding production are much higher welding speeds, reduction or complete exclusion of welding consumables, easy design of the weld joints, decrease of thermal distortions and thus, costs saving. In contrast to arc welding, laser beam welding might particularly be associated with metallurgical defects, like the formation of hot cracks. Such phenomena are related to an order of magnitude higher temperature gradients and cooling rates in the solidification zone, providing rapid solidification kinetics which may cause significant segregation of alloying elements such as Ni and Cr and respective undercooling of the solute at the solidification front. In specific metastable austenitic stainless steels alloys in vicinity of the so called eutectic rim of the Fe-Cr-Ni constitutional diagram, such effects might entail a change of solidification mode from primary ferrite to austenite, providing an increased risk of solidification cracking. Previous studies has shown that the primary solidification mode change during laser beam welding of Cr-Ni austenitic stainless steels such alloys could be effectively influenced by nitrogen absorption as well as by the laser plasma type and also proved the occurrence of metastable primary ferritic solidification. In the present contribution, such results are compared to recent investigations of laser welding newer austenitic Fe-Cr-Mn-Ni steel grades by identification of respective hot cracking critical welding parameter intervals and strain rates in the Controlled Thermal Weldability (CTW) Test. PY - 2011 SN - 978-3-642-16863-5 DO - https://doi.org/10.1007/978-3-642-16864-2_7 IS - Part 2 SP - 103 EP - 129 PB - Springer CY - Berlin, Heidelberg AN - OPUS4-24348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Stelling, Karen A1 - Lammers, Marco A1 - Gumenyuk, Andrey A1 - Böllinghaus, Thomas A1 - Rethmeier, Michael T1 - Laser Plasma Hybrid Welding of Austenitic Stainless Steels - Phenomena of Process Instability N2 - Laser plasma hybrid welding has been proved to be a very stable hybrid welding process and welds of high quality can be produced, especially if high surface quality and low spattering is demanded such as in welding fabrication of high alloyed austenitic stainless steels. In particular cases, even though welds display high outer quality, X-ray examinations revealed weld defects which may range from low porosity to blowhole-like cavities. The phenomena and the main influencing parameters such as arc current, welding speed and focal point position are discussed. Parameter fields will be suggested for welding plates of different austenitic stainless steel grades with thicknesses ranging from 3 to 8 mm. The results are based on welding experiments carried out using a 4.4 kW diode pumped Nd:YAGlaser. Thus, also the influence of the feeding fibre diameter has been investigated and it was found that the resulting beam shape has a major effect on the welding performance. T2 - 60th IIW Annual Assembly CY - Dubrovnik, Croatia DA - 2007-07-01 KW - Laser KW - Plasma KW - Hybrid welding KW - Pores KW - Cavities KW - Root dropping KW - Austenitic steel PY - 2007 IS - IV-933-07 SP - 1 EP - 14 PB - International Institute of Welding CY - Paris AN - OPUS4-18677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gook, Sergej A1 - Biegler, Max A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Integration of hybrid laser-arc and narrow gap submerged arc welding for cost-effective joining of 80 mm thick S355ML steel plates N2 - This paper presents the results of developing a cost-effective, robust process for welding thick steel plates. Welding trials were performed on S355ML structural steel plates with a thickness of 80 mm. A specially designed U-shaped joint preparation with a 45 mm root face was proposed to enable thick welds to be welded using a combined technique. In the developed process, a hybrid laser arc weld (HLAW) is performed as the first pass. Subsequently, narrow-gap submerged arc welding (NG-SAW) is applied to the opposite side using a multi-layer technique. The weld cross-section is completed using a reliable overlap of both the HLAW and NG-SAW welds. This method achieves a 2.9-fold reduction in weld volume and filler material consumption, as well as shorter production times for thick-walled welds. Further advantages of the process combination include eliminating the need to form the root of the HLAW weld and the absence of a backing support. The applied process parameters ensure that the maximum heat input does not exceed 5 kJ/mm, leading to uniform hardness across the weld metal and heat-affected zone (HAZ). Impact toughness testing at −40 °C demonstrated excellent performance, with Charpy V-notch energies of 138 ± 45 J in the arc-dominated region and 65 ± 12 J in the critical laser-dominated zone of the HLAW weld. In addition, the NG-SAW weld exhibited an average Charpy V-notch energy of 274 ± 5 J, confirming excellent low-temperature toughness of the fill passes. Owing to its high process stability and practical applicability, the proposed welding approach shows high potential for integration into the fabrication of thick-walled offshore constructions. KW - Hybrid laser arc welding KW - Narrow gap submerged arc welding KW - Low carbon structural steel KW - Fusion zone size KW - Microstructure KW - Impact absorbed energy KW - Hardness PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655627 DO - https://doi.org/10.1016/j.optlastec.2026.114796 SN - 0030-3992 VL - 197 SP - 1 EP - 12 PB - Elsevier Ltd. AN - OPUS4-65562 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -