The steel surface processed by sand blasting and shot blasting in Dalian shall be free of visible attachments such as grease, dirt, oxide scale, rust and paint coating, and any residual trace shall be only slight spot or strip color spots. The blasting dent formed after shot blasting shall be evenly arranged on the steel surface. Silicon carbide has stable chemical properties, high thermal conductivity, low thermal expansion coefficient and good wear resistance. In addition to being used as abrasive, it also has many other uses. For example, coating silicon carbide powder on the inner wall of water turbine impeller or cylinder block with special process can improve its wear resistance and prolong its service life by 1 ~ 2 times; The high-grade refractory material made of it has the advantages of heat shock resistance, small volume, light weight, high strength and good energy-saving effect.