Prediction of asymmetric transient temperature and longitudinal residual stress in friction stir welding of 304L stainless steel

•This study considers all of the heat generation components and factors affecting on FSW process.•This study can predict the asymmetric distribution of temperature and residual stress accurately.•This study considers all of the heat transfer and mechanical boundary conditions on FSW process.•This study presents a time saving and accurate method for parametric study of FSW process.

This paper presents a thermo-mechanical model to predict the thermal histories and the longitudinal residual stress difference at two sides of the butting surfaces using a factor named advancing retreating factor. This model allows taking into account of frictional heating dependent on both the temperature and the velocity of the tool, as well as heat generation due to plastic deformation dependent on temperature. The mechanical loads caused by the tool are added to the model for the mechanical analysis and the uncoupled thermo-mechanically equations are solved using a nonlinear finite element code ABAQUS. The numerical results showed that the longitudinal residual tensile stresses are asymmetrically distributed at different sides of the weld line due to the effect of the unsymmetrical temperature distribution and the tool forces. The calculated results have good agreement with experimental data that are presented in the literature.