Wear resistance of laser cladding Fe50Cr40Si10 coating on AISI 1045 steel in elevated temperature

Abstract

To improve the high-temperature wear resistance of a substrate, in this study, Fe50Cr40Si10 coating was prepared on AISI 1045 steel by the laser cladding technique and the microstructure was characterized by using an optical microscope (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results show that the coating with a fine and uniform microstructure has a good metallurgical bond with the AISI 1045 steel substrate. The upper layer of the coating is composed of typical equiaxed grains, and the bottom layer has columnar grains. The XRD pattern shows that the phase compositions are Fe-based solid solution (α phase) with Cr and Si and Fe-Cr intermetallics (α′ phase). The average microhardness of the coating is approximately 530 ± 37.5 HV0.5. The elevated-temperature dry sliding wear resistance of laser cladding Fe50Cr40Si10 coating was carried out on a pin-on-disk mode machine at different temperatures and loads. Under the same wear test conditions, the elevated-temperature wear rates of Fe50Cr40Si10 coating were much lower than those of AISI 1045 steel. When the load was 30 N, it was found that the wear mechanism of Fe50Cr40Si10 coating changed from abrasive wear and adhesive wear to oxidation wear with the increase in temperature. At the wear test temperature of 300 °C, the wear mechanism of the coating changed from oxidation wear to abrasive wear and adhesive wear with the increase in loads.