Comparison of Residual Stress Between MIG Welding and Friction Stir Welding

Abstract

Residual stress distribution plays a very important role in welded structures, the aim of present work is to find out the effect of different welding methods on the residual stress distribution by means of neutron diffraction measurements and FE models simulation. 4 mm thick DH-36 steel plates were butt welded by MIG welding process and 5 mm thick AA 2024 aluminium alloy plates were butt welded by friction stir welding process. Results show that residual stresses of MIG welding process are higher than those of friction stir welding process. The peak residual stress of MIG weld is close to the room temperature uniaxial yield strength of DH-36 while the peak residual stress of friction stir weld is just about 50% of the room temperature uniaxial yield strength of AA2024. The size effect of MIG welded and effect of welding speeds of friction stir welded on the residual stress distribution have also been studied in the paper.