Laser Deposition of Precipitation Hardening Carbon-Free Tool Steel Powder

摘要

Laser deposition is an effective way to modify metallic surfaces, e.g. to improve the hardness and wear resistance. In the present work, carbon-free tool steel layers of the general composition Fe-Co-Mo(-W) were produced on structural steel surfaces by laser depositing gas atomized spherical powders. It showed that these precipitation hardenable tool steel grades are particularly well suited for laser deposition since they are fairly soft and ductile as-deposited, this avoiding the cracking problems common with standard carbidic tool steels and also enabling soft machining. After a subsequent isothermal aging process at about 600°C the full hardness of about 65 HRC is obtained, the isothermal treatment resulting in virtually distortion-free hardening.