Residual Stresses in Multi-pass Butt-welded Tubular Joints

In this study, the mechanics of the residual stress development in multi-pass butt-welded joints of ferritic-pearlitic steel pipes are investigated. Therefore, the effects of the welding process and its parameters, as well as the impact of the preheating temperature on the residual stress state are studied by determining the temperature profile during welding and performing X-ray diffraction measurements on the pipes' inner and outer surfaces. Additionally, residual stress depth distributions are determined using the incremental hole-drilling method. The residual stress distributions can be explained by phase transformations and thermal shrinkage, the latter being the governing mechanism in the tubular geometry of the welds.