Study on ductile iron surface laser cladding austenitic stainless steel coating heat treatment to enhance wear resistance

In this paper, laser cladding technology coated the ductile iron surface with austenitic stainless steel. To improve the wear resistance of the coating, consider a heat treatment way to strengthen it. The effects of temperature and time on microstructure, hardness, and wear resistance of austenitic stainless steel coating were investigated. The results show that the martensitic phase was added to the samples at different times of 950℃, and the carbide precipitated phase was the main change in the microstructure. At 1050℃, the samples also changed from austenite to martensite at different deal times, and the microstructure mainly changed between dendrites. The hardness and abrasion resistance of the 1050°C/2 h process improved with a hardness of 40.6 HRC, an increase of 26.1%, and a maximum relative abrasion resistance improvement of 84.63%. Which strengthening mechanism was mainly coating dendrites coarse and uniform diffusion occurs, martensite uniform phase transition presented on the surface, coating austenite grain size 9.08 μm smaller, martensite recrystallization and larger grain size of 28.57 μm, the coating as a whole in the uniform phase transition and dendritic crystal strengthening synergistic effect, hardness increased, resistance to wear became stronger.