Research on welding process and microstructure and properties of welded joint of 09CuPCrNi-A and 316L dissimilar steel
ZHOU Fangming;CHENG Ruiqiang;WU Xingxiang;ZHU Zhengxiang;Jiangsu Province Key Lab of Advanced Welding Technology,Jiangsu University of Science and Technology;Shanghai Hulin Heavy Industry Co.Ltd;
The dissimilar steel( 09 Cu PCr Ni- A and 316L) of SCR device of the marine diesel engine was welded by FCAW method. When the dissimilar steel is welded,there are the following problems: the welded metal easily produces hot crack during the process of welding because of the different thermal conductivity and linear expansion coefficient; the hardness of the weld increases and the toughness of the weld decreases which is caused by carburization; during the face bend test,the crack appears at the fusion area of low alloy steel due to decarburization; flux cored wire welding due to the groove design is not appropriate,easy to cause the slag. The inappropriate groove design is easy to cause the slag problem when it is welded by FCAW. In this paper,a reasonable welding process plan which is designed based on the analysis of weldability of weathering steel 09 Cu PCr Ni-A and stainless steel 316 L,has made the joint qualified. The mechanical properties and microstructure analysis show that the welding process can meet the requirements of products and the welding procedure has been applied to practical production.