Interface Structure of Laser Welding 42CrMo Alloy Steel and 45# Carbon Steel with Al and Cu as Interlayer

摘要

The interface structure of laser welding 42CrMo and 45# carbon steel with Al and Cu as the interlayer was investigated. Cracks did not arise in the most critical region when Al and Cu were used as the interlayer. And cracks arose when no such layers existed. The cooling rates in laser welding were responsible for the formation of relatively fine dendritic structures in the weld fusion zone. Mechanical tests showed that the micro-hardness of the weld increased compared to that of the base metal due to the formation of intermetallic compounds.