Effect of WC Contents on the Microstructure and Mechanical Properties of Laser Cladding Cr17Ni2MoSiB/WC Coatings

Cr17Ni2MoSiB/WC composite coatings are fabricated on UNS N08367 stainless steel substrates by laser cladding. The effects of WC contents on the microstructure, phase composition, elemental distribution, microhardness, and wear resistance of the coatings are investigated. The coatings are composed of austenite, martensite, and WC particles. The microstructure exhibits a combination of cellular, columnar, and equiaxed grains. The proportion of martensite decreases from 32% to 0.3% as the WC content increased from 0% to 10%, while the average grain size increases from 3.93 μm to 53.27 μm. WC addition coarsens the grain size and inhibits the formation of martensite, thus reducing the matrix microhardness in the cladding layer. The microhardness of the WC‐free coating decreases with increasing WC content, which is opposite of the WC‐containing coatings. The wear resistance first increases and then decreases with increasing WC content. The 5% WC coating exhibits the highest microhardness and wear resistance, with an average friction coefficient of 0.430 and a wear volume loss of 0.02 mm 3 . The 5% WC coating achieves optimal mechanical properties through a balance between the second‐phase strengthening effect induced by WC particles and the coating matrix softening effect caused by the combined factors of reduced martensite fraction and grain coarsening.