Research On Preparation And Application Of Wear Resistance Additive With WC

Aiming at the problem of short service life of abrasion resistance material, which isalways used in extreme working conditions such as high strength, high hardness, high wear,the method of adding ceramic particle like nano-sized WC particulates as wear-resistancephase is used to improve abrasion properties of wear parts like cutting pick body. Consideringthe segregation phenomenon caused by high density of WC (15.63g/cm3) during the smeltingprocess, the wear-resistance additive consisting of nano-sized WC powder and other metalpowders is prepared through mixing, press forming and high temperature sintering processes.The ability of the additive in solving the problem of segregation phenomenon effectivelydepends on the quality of the samples after melting and casting. The additive is added intomolten steel to be casted into samples in the experiment. After different heat treatment process,wear test, hardness test and tensile test are carried out on the samples. The distribution of WCphase and sintering product of the wear resistance additive in cast steel is examined by XRD,SEM with EDS and FESEM. After many experiments, analyzes and summarizes, theexperimental results are obtained as follows: the weight loss of the casting sample of40CrNi2Mo matrix adding5%~8%wear-resistance additive is12.8%lower than that of thecutting pick serving in mine. That means the composite has better wear-resistance. Detectionand analysis of microstructure show that wear-resistance phase of WC distributing mainly inthe microstructure of steel matrix plays a crucial role in improving the wear resistance. Whiteareas are mainly consisting of the oxide of Fe and Si element together with a small amount ofWC and other metal mixed phase. Fewer oxides are observed in black areas. It is easy for WCto become the core of the solidification during the smelting process and to be coated by themolten steel nearby since the excellent wettability between WC and molten steel can lead toeffective grain refinement. In the wear test, WC particulates coated firmly by the steel matrixare difficult to peel off, and perform good wear resistance. Such organization plays animportant role to improve the wear resistance. The high density wear-resistance phase WCdistributes evenly in the steel matrix without any segregation. The method of addinghigh-density component by means of additive to avoid segregation phenomenon has beenproved to be successful. In this project, the additive is creatively applied to the study of the cutting pick body and gains effective results. The traditional idea of surface hardening oncutting pick body has been changed.