Effects of Process Parameters on Microstructure and Wear Resistance of Laser Cladding A-100 Ultra-High-Strength Steel Coatings

Abstract

To improve the hardness and wear resistance of mild steel, A-100 ultra-high-strength steel cladding coatings were prepared on the surface of mild steel by laser cladding. In this study, the effects of laser cladding process parameters on the forming quality, phase composition, microstructure, microhardness and wear resistance of the A-100 ultra-high-strength steel cladding coatings were researched. The results show that the main phase of the coating is martensite and a small amount of austenite. The microstructures of the upper part of the cladding coatings are mainly equiaxed grains, while those of the lower part are mainly columnar grains. With an increase in laser specific energy, the microstructures of the cladding coatings become coarse. When the laser specific energy is 70.8 J/mm2, the microhardness of the cladding coating is the highest, and the maximum average microhardness of the cladding coatings is 548.3 HV. When the laser specific energy is low, the wear of the cladding coatings is mainly pitting, while when the laser specific energy is high, the wear type of the cladding coatings is mainly adhesive wear. Moreover, the microhardness and wear resistance of the cladding coatings are reduced if the laser specific energy is too high.