Research on Laser Full Penetration Welding of 42CrMo Alloy Steel Plate and 45# Carbon Steel Plate
Chengyun Cui, Jiandong Hu, Shulai Pang, Yue Yang and Zuoxing Guo
Experiments of laser full penetration welding of the alloy steel 42CrMo with 3mm thickness and 45# carbon steel plates with 6mm thickness were carried out using a 5kW continuous wave (CW)CO2 laser. The microstructure of the welded was characterized by scanning electron microscopy (SEM). The results showed that a high quality, full penetration laser weld could be obtained by optimizing the welding process parameters. The laser weld showed non-equilibrium solidified dendritic microstructures and the HAZ consisted of a solid solution of martensite as the dominant component with a very small amount of retained austenite. The micro-hardness of the laser weld was close to the base metal but lower than that of the HAZregion.
Keywords: Laser full penetration welding, welded melt, microstructure, microhardness.