Research On Wear Resistance And Corrosive-wear Resistance Of WC-Co Coating Prepared By Plasma Spraying

The mud pump liners work in a corrosive-wear condition of mixed mortar, so the materials used on mud pump liners have low service life. In order to improve the service life and cost performance of mud pump liners, WC-12 Co coating and WC-10Co-4Cr coating were prepared on Q235 by plasma spraying techniques. By comparing with the wear resistant cast iron which was often used in mud pump liners, the paper provides a reference for WC-10Co-4Cr coating which is likely to be used in mud pump liners in the future.In this paper, phase identification, microstructure, morphology of WC-12 Co coating and WC-10Co-4Cr coating were investigated by XRD, SEM, super depth-of-field 3D system, etc. Vickers hardness tester was used to determine the hardness of WC-12 Co coating, WC-10Co-4Cr coating and Km TBCr8 after heat treatment. Besides, friction and wear performance of all three of these materials was investigated using a ball-on-disk tribometer under different loads. Also, wear-corrosion resistance of these three kinds of materials was detailed analysised under different conditions by using a corrosive-wear experimental tester which was made by ourselves. The experiment results are listed as follows:(1) The thickness of the coatings was about 400 μm and they combined well with the substrate by machine function;(2) The coatings were both composed of fully melted, partially melted and unmelted powers and no large holes were found on the surface of the coatings. The WC powers decomposed slightly in both two coatings.(3) Both the two coatings had higher hardness and better abrasion resistance than the Km TBCr8 under different loads.(4) The mass loss of all the three materials decreased with the increase of PH value of the slurry, but it increased significantly with the increase of corrosive-wear speed. The Cr element can improve the corrosion potential of the WC-Co coating and was beneficial to the corrosive-wear resistance.(5) The WC-10Co-4Cr coating possessed better corrosive-wear resistance than Km TBCr8 and WC-12 Co coating after comprehensive analysis, indicating WC-10Co-4Cr coating had some potential advantages in the application of mud pump liner.