Influence of welding trailing with peening on microstructure of LY12CZ joints

Welding with trailing peening, a new welding technique, is proposed for prevention of welding hot cracking from the viewpoint of mechanism. With LY12CZ sheet, a material highly susceptible to hot cracking, using as the subject of study, welding experiments were made on test clamp with self-made variable restraints, and the microstructure of welded joints was studied under different process conditions. Test results show that welding with trailing peening can effectively reduce the welding cracking tendency, obviously refine the grains in the welded joints, and greatly improve the microstructure of LY12CZ welded joints. Better test results can be obtained if strong restraints are imposed on welded parts to reduce the excessive vibration of welding pool once welding with trailing peening begins.