The centrifugal casting process of the bainite was obtained by centrifugal casting, and the roller was obtained directly under the casting state. Because of the added alloy element such as manganese, chromium, nickel molybdenum, the metallurgical properties of the outer layer is rather high, the work layer of roller almost no change in the depth direction, the number of graphite and working layer with high strength, good toughness and high hardness and degree of hardness drop small features. The hardness of rollers mainly depends on the type of collective organization, the bainite or martensite, the bainite ductile iron rollers have good wear resistance and accident resistance, and the inner layer is the high strength ball iron.