Laser Welding Of Disimilar Steels

In this paper, research on laser welding of dissimilar steels of 20G steel and 20Cr2Ni4A was made.In the research, welding technics parameters such as the laser power, welding travel speed, defocus distance and velocity of protection gas, which affect welding quality were verified and optimized, stretching stress of laser welded zone between 20G steel and 20Cr2Ni4A steel is surpassed that of 20G steel, which is verified by mechanical testing. After being focused, laser is with high energy density, so that it can form tiny melted cavity in the process of welding, In stretching testing, the welded seal is with little latitude transition while the welding zone is with more deformation, thus lead to the result of welding seal is with great strength as to the primary materials. Analyzing of the seal structure of welded dissimilar steels between 20G and 20Cr2Ni4A indicate that it is mainly of martensite, which is with great hardness.