Structure Investigation of Shielded Metal Arc Welding of 316L Stainless Steel

Double-sided shielded metal arc welding method was used to weld 6mm thickness 316Lstainless steel,the micro-structures of weld zone,fusion zone and heat affected zone and micro-hardness were investigated.The result of structure analysis showed the microstructure of the weld zone was equiaxed grain within Austenite and a large amount ofδ-ferrite,and the gain size of the prior weld was finer than the later weld;fusion zone and heat affected zone were dendritic crystal which had the characteristics of cogenetic crystallization,and the microstructure of them were Austenite and a small amount ofδ-ferrite;micro-hardness test showed the hardness of weld zone was higher than the base metal but lower than the dendritic crystal of fusion zone.