Microstructure And Wear Property Of Fe901/WC Composite Coating Prepared By Laser Cladding On 40Cr Surface

40Cr steel is often used in the manufacture of shaft parts such as gears,connecting rods and rolls,it has excellent overall mechanical properties after modulated treatment.The working conditions of these parts are more severe,often subject to shock,alternating,vibration and other load effects,with serious surface wear and low service life.Due to the controlled heat input and small heat affected zone,laser cladding technology can be used to prepare wear resistant coatings with good metallurgical bonding on 40 Cr surfaces.It is able to retain the better strength and toughness of the 40 Cr substrate,while enhancing the surface wear resistance of the substrate.As single alloy coatings such as Fe and Ni are limited in enhancing the wear resistance of 40 Cr surfaces,in this paper,using WC ceramic particles as the reinforcing phase,iron-based composite coatings with WC mass fractions of 0%,10%,20% and 30% are prepared on the surface of 40 Cr steel.The main research works of the paper are as follows:(1)The single-factor controlled variable method is used to investigate the effect of variations in laser cladding process parameters on the macroscopic morphology of Fe901 cladding.Orthogonal experiments are carried out using the dilution rate of the cladding layer and the forming factor as comprehensive criteria to obtain the optimum process parameters for the preparation of single cladding.Based on the optimal single cladding process parameters,the optimization of overlap rate are carried out to obtain a better combination of process parameters for the preparation of coatings without microscopic defects and with good morphology.(2)Fe901/ WC composite powders with different blending ratios(WC mass fraction: 0%,10%,20%,30%)are configured and Laser cladding tests are carried out based on the optimised process parameters.OM,XRD,SEM and EDS are used to observe the effects of changes in WC content on the macroscopic morphology,physical phase,microstructure and tissue composition of Fe901/WC coatings.Analysing the intrinsic link between the partial melting of WC and the formation of high hardness carbides from other elements in the melt pool and macroscopic properties.To investigate the effect of different WC ratios on the microstructure of the coating.(3)Analysis of the effect of variations in WC content on the wear resistance of Fe901/WC coatings.The effect of the variation of WC content on the microhardness,average friction coefficient and wear scar morphology of Fe901/WC composite coatings are investigated by means of microhardness tester,friction and wear tester and Ultra-deep field microscope.Elucidate the wear mechanism of Fe901/WC composite coatings.