Laser cladding of a martensitic stainless steel on a tool steel substrate

The improvement of surface quality of a tool steel by laser cladding has been investigated by using a stainless steel as the coating material. Microstructural analysis indicated a significant modification in the laser remelted zone with secondary dendrite arm spacings of about 2 mu m and corresponding cooling rates of the order of 10(3) K/s. The microhardness achieved in the coating (800 HV) is about four times the hardness of the substrate, which is high compared to a value of 530 HV normally attained in conventional treatments of the same tool steel. The processing conditions used yield a 700 mu m coating depth with a uniform chromium distribution and without porosity.9322923