TY - CONF A1 - Launert, B. A1 - Rhode, Michael A1 - Pasternak, H. A1 - Kannengießer, Thomas ED - Dubina, D. ED - Ungureanu, V. T1 - Welding Residual Stresses in High-strength Steel. Experimental Results T2 - SDSS 2016 - The International Colloquium on Stability and Ductility of Steel Structures N2 - This article presents the latest results of an ongoing national research project on improved models for the prediction of welding residual stresses of thick-plated welded I-girders. The experimental program is presented and the importance of different influencing factors on the residual stresses is discussed in detail. All results are compared for mild (S355J2+N) and high strength (S690QL) steel. Finally, conclusions for further works are drawn. T2 - SDSS 2016 - The International Colloquium on Stability and Ductility of Steel Structures - SDSS 2016 CY - Timisoara, Romania DA - 30.05.2016 KW - Residual Stresses KW - Welding KW - High-Strength Steel KW - I-Girder KW - Component Test PY - 2016 SN - 978-92-9147-133-1 VL - 2016 SP - 517 EP - 524 PB - Ernst & Sohn AN - OPUS4-37890 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Schröpfer, Dirk A1 - Kromm, Arne A1 - Kannengießer, Thomas T1 - Adaption of Heat Control Concepts for Welding Stress Optimization in High-strength Steel Components N2 - High-strength structural steels from 690 MPa are increasingly applied at present. Major reasons are lightweight design trends and potential cost reductions. The structural design of welds and their manufacturing become more challenging with increasing material strength. By reasons of a higher yield ratio of these steels, the development of high residual stresses has to be avoided, since they are detrimental to the components safety and performance. Local restraint stresses and welding loads due to external shrinkage restraints occur. Frequently, this leads to critical tensile residual stresses in the weld and HAZ. In this study, influences of welding process parameters and restraint conditions on the residual stress state in welded components of high-strength steels were investigated. Multilayer GMAW tests under free shrinkage and experiments under well-defined restraints in special in-house developed testing facilities were accomplished. The tests permitted analyses of the resulting local residual stresses measured by means of X-ray diffraction and global reaction stress build-up while welding and cooling. Significant effects were found for heat control, seam configuration and restraint condition. Besides high restraints, elevated preheating and interpass temperatures lead to increased welding stresses. An adaption of welding parameters considering heat control, weld run sequence and seam configuration proved to be beneficial. T2 - 10th Conference on Trends in Welding Research CY - Tokyo, Japan DA - 11.10.2016 KW - Weld heat input KW - Residual Stress KW - High-strength Steel KW - Welding KW - Component Test PY - 2016 AN - OPUS4-37828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -