Experimental and numerical investigations on residual stresses in a multi-pass butt-welded high strength SM570-TMCP steel plate

During fusion welding process, complex thermal stresses are inevitably generated. The presence of residual stresses can be detrimental to the integrity and the service behavior of the welded part. In this study, both an experiment and a finite element (FE) method were utilized to investigate residual stress distribution in high strength SM570-TMCP (thermo-mechanical controlled process) steel weldment, which was constructed using a multi-pass butt welding process. Firstly, experiments which included a tensile test at elevated temperatures, an observation of the microstructures and a residual stress measurement were carried out to examine characteristics of residual stresses in the weldment. Secondly, a three-dimensional thermo-mechanical FE model was developed to simulate the temperature field and the residual stress field incorporating the experimental results. The thermo-mechanical model used as well as the experimental procedure is described in detail, and the results obtained from the FE model are compared with the experimental measurements and discussed.