Numerical and experimental investigation of residual stress distribution in a dissimilar ferritic-austenitic weld

In this study, a model considering an asymmetric power heat distribution, temperature-dependent material properties, strain hardening, and phase transformation was developed to predict the temperature field and residual stress distribution in a gas tungsten arc (GTA) dissimilar weld between austenitic stainless steel (AISI 304) and low-carbon steel (AISI 1018). The effect of martensite formation on the longitudinal and transverse residual stress distributions were investigated using both finite element (FE) model and neutron diffraction measurements. The results indicated that the martensitic phase had a significant influence on the transverse and longitudinal residual stress components. The martensitic phase does not only change the distribution of residual stresses near the weld centerline but can also alter the peak value of the residual stress. The calculated temperature and weld zone (WZ) profile were in agreement with the experimental results from thermocouples and a macrograph of the weld. Favorable agreement was also found between the calculated residual stress distribution from the FE model and residual stress measurements obtained by neutron diffraction.