The Microstructural Evolution and Wear of Weld Deposited M2 Steel Coating After Laser Spot Melting

Abstract

This paper is devoted to studying the microstructural evolution and wear of the laser pulse remelted spot patterns on the weld deposited M2 steel coating. The energy of laser pulse was changed by changing the pulse parameters to obtain optimal structure of the irradiated spot. As shown, the remelted metal macroscopically consists of fusion and heat-affected zones each of them containing different phases and structures. The fusion zone is composed of two structural components so that one of which (A) has a dendrite-cellular type of structure and contains δ-iron, retained austenite, and carbides. The other one (B) is composed of austenite, martensite, and eutectic carbides. The microstructure of laser-irradiated spot obtained at pulse duration 10 ms was optimal from the viewpoint of wear. Sliding wear tests showed high wear resistance of laser-irradiated pattern as compared to that of as-deposited metal.