Research on Laser Full Penetration Welding of 42CrMo Alloy Steel Plate and 45# Carbon Steel Plate

摘要

Experiments of laser full penetration welding of the alloy steel 42CrMo with 3 mm thickness and 45# carbon steel plates with 6 mm thickness were carried out using a 5 kW continuous wave (CW) CO{sub}2 laser. The microstruc-ture 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 HAZ region.