Microstructure and Wear Resistance of High-Chromium Cast Iron with Multicomponent Carbide Coating via Laser Cladding

Abstract

High-chromium cast iron (HCCI) coatings with multicomponent carbides were prepared on low-alloy steel substrates using a laser cladding technique in this work. The microstructure and wear resistance of the coatings were characterized via optical microscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, X-ray diffraction and block-on-ring wear testing. Multicomponent carbides (Ti, Nb, Mo, W, V)C with an FCC structure and multicomponent compounds (Nb, Mo, W, V) (B,C) with an FCC structure were found in the microstructures of coatings after multielement doping. In addition, (Cr, Mo, W, V)23C6 compounds could be obtained by heat treatment. These multicomponent compounds were beneficial for obtaining coatings with an excellent hardness (60 HRC) and high wear resistance. This multielement doping method provides an effective modified method for preparing high-wear-resistance laser cladding coatings.