Thermo-mechanical analysis in SAE-AISI 1524 carbon steel gas tungsten arc welds

A thermo-mechanical analysis was conducted in SAE-AISI 1524 carbon steel gas tungsten arc welds. The sequentially coupled thermal-mechanical finite element modelling approach was used to simulate the thermal and stress evolution during the GTAW process. The analysis procedure was divided into two major steps. First, a 3D transient nonlinear heat flow analysis was performed to determine the temperature distribution for the entire welding and cooling cycle of the process. In the second step, the thermal history from the heat flow model was included into the mechanical elasto-plastic calculation of the stress and deformation in the weldment. Temperature-dependent material properties and the effect of forced convection due to the flow of the shielding gas were included in the model. It is encouraging to note that the model is sufficiently accurate to predict the FZ and HAZ weld profiles as evidenced for the good agreement observed between numerical cross-sectional and metallographic temperature profiles. The successful in the results can be attributed greatly to the characteristic heat distribution parameter C selected from the complementary experimental work. For further experimental comparison purposes, numerically predicted residual stresses obtained in three different locations of two different weld situations are presented.