Effect of simulated post-weld heat treatment temperature on welding residual stress and mechanical properties of Q345R steel plate welded joint

Through heat treatment test,residual stress test,tensile test,bending test,hardness test and other methods,the effect of simulated post-weld heat treatment temperature on the welding residual stress and mechanical properties of Q345R steel plate welded joint was analyzed.The results showed that as the simulated post-weld heat treatment temperature increased from 400℃ to 620℃,the welding residual stress of Q345R steel plate welded joint gradually decreased,and the welding residual stress could be basically eliminated after heat treatment at 620℃.With the increase of post-heat treatment temperature,the tensile strength and hardness of Q345R steel plate welded joint decreased.The hardness of the heat-affected zone decreased most obviously,followed by the hardness of the weld,and the hardness of the base metal remained basically unchanged.