High chromium section and low chromium section are widely used in powder preparation and ultra-fine deep processing in cement, building materials, metal mines, coal slurry thermoelectricity, chemical industry, ceramic coatings, light industry, papermaking, magnetic materials and other industries. The high chromium part has lower wear, better toughness and less fracture than the low grid part. In the process of use, the surface hardness will be further improved and the wear resistance will be improved. At the same time, the production capacity of the mill can be improved, and the specific surface area of cement and concentrate recovery can be improved. With the rapid development of the national economy, resource industries such as cement, metallurgy and mining have developed vigorously, and application manufacturers in the field of iron and steel are also increasing. The appearance of high chromium section not only improves the grinding efficiency, reduces the time of stopping and replenishing the ball, reduces the opening and closing times, but also prolongs the cleaning time and reduces the labor intensity of workers.