Effect of Cr 3 C 2 on Microstructure and Mechanical Properties of CoCrW/Cr 3 C 2 Deposited Layers on 42CrMoA Steel by Laser Deposition

CoCrW/Cr 3 C 2 deposited layers of various Cr 3 C 2 contents (0 wt%, 10 wt%) are created on the 42CrMoA steel substrate by laser deposition technology to improve the wear resistance of the steel used in crankshafts. The study investigates the effect of Cr 3 C 2 on the microstructure, microhardness, and friction‐wear properties of deposited layers. The results indicate that the CoCrW/Cr 3 C 2 deposited layer is primarily composed of M 7 C 3 , M 23 C 6 , and γ‐Co phases. The addition of Cr 3 C 2 significantly increases the content of phases such as M 23 C 6 within the deposited layer. The microstructure of the deposited layer primarily consists of columnar crystals and equiaxed grains. The addition of Cr 3 C 2 refines the overall microstructure and promotes the columnar‐to‐equiaxed transition. Compared to the deposited layer without Cr 3 C 2 addition, the average microhardness of the CoCrW/Cr 3 C 2 deposited layer increases by 24.01%, from 561.4 HV 0.2 to 696.1 HV 0.2 . Similarly, the average coefficient of friction decreases by 18.92%, from 0.37 to 0.30. Furthermore, the wear mechanism of the CoCrW/Cr 3 C 2 deposited layer shifts from a combination of abrasive wear and minor adhesive wear to purely abrasive wear after Cr 3 C 2 is added.