04Cr13Ni5Mo/20MnMoNb异种钢焊接接头微观组织及性能研究OA北大核心CSTPCD

In order to improve the welding efficiency and welding mechanism of 04Cr13Ni5Mo super martensitic stainless steel and 20MnMoNb high-strength steel,manual tungsten inert gas arc welding(TIG)+electrode arc welding(SMAW)was used to weld two different materials of the same thickness.The microstructure and mechanical properties of the welded joint of 04Cr13Ni5Mo/20MnMoNb dissimilar metals were studied using metallographic microscopy,scanning electron microscopy,energy dispersive spectroscopy,X-ray analyzer,and hardness tester.The results show that TIG+SMAW welding can effectively bond 04Cr13Ni5Mo and 20MnMoNb dissimilar steels;The microstructure of the weld seam area is γ growing from the bottom perpendicular to the fusion line,the contents of Ni,Cr,Mo,and Fe show a clear gradient distribution from 04Cr13Ni5Mo to 20MnMoNb;The tensile strength of the joint is slightly lower than that of the base metal on both sides,reaching 92%of the 04Cr13Ni5Mo super martensitic stainless steel and 98.2%of the 20MnMoNb base metal.The fracture type is a mixture of cleavage fracture and ductile fracture;The hardness of the weld area is higher than that of the base metal on both sides,and the impact absorption energy ranges from 76.3 J to 84.9 J.This study lays a certain foundation for the promotion and application of TIG+SMAW combination welding in the field of super martensite and high-strength steel welding.