Finite Element Modeling and Validation of Residual Stresses in 304L Girth Welds

摘要

Three dimensional finite element simulations of thermal and mechanical response of a 304L stainless steel pipe subjected to a circumferential autogenous gas tungsten arc weld were used to predict residual stresses in the pipe. Energy is input into the thermal model using a volumetric heat source. Temperature histories from the thermal analysis are used as loads in the mechanical analyses. In the mechanical analyses, a state variable constitutive model was used to describe the material behavior. The model accounts for strain rate, temperature, and load path histories. The predicted stresses are compared with X-ray diffraction determinations of residual stress in the hoop and axial directions on the outside surface of the pipe. Calculated stress profiles fell within the measured data. Reasons for the observed scatter in the measured stresses are discussed.