摘要
30CrMnSi, one kind of the medium-carbon quenching and tempering steel（ MCQTT） , has been widely utilized in some industrial fields. However, just like some other MCQTT, this kind of steel also faces such problem as delayed cracking in its welded joints. In this paper, the delayed cracking and microstructure of the joints of 30CrMnSi steel were researched by SEM. Moreover, a method called welding with trailing impacting and rolling （WTIR） was utilized to solve the delayed cracking problem by decreasing the residual welding stress in the joint of 30CrMnSi. The crack-free joints of 30CrMnSi steel were obtained by using optimized parameters.
30CrMnSi, one kind of the medium-carbon quenching and tempering steel（ MCQTT） , has been widely utilized in some industrial fields. However, just like some other MCQTT, this kind of steel also faces such problem as delayed cracking in its welded joints. In this paper, the delayed cracking and microstructure of the joints of 30CrMnSi steel were researched by SEM. Moreover, a method called welding with trailing impacting and rolling （WTIR） was utilized to solve the delayed cracking problem by decreasing the residual welding stress in the joint of 30CrMnSi. The crack-free joints of 30CrMnSi steel were obtained by using optimized parameters.
