Roll is divided into cast iron roll, cast steel roll and forged steel roll according to material. The carbon content of cast iron roller is 2. 50 / 0 ~ 3.5% , according to the main materials can be divided into four categories: chilled cast iron rolls, infinitely chilled cast iron rolls, high chromium cast iron rolls and nodular cast iron rolls. The common structure of cast iron roll can be divided into Matrix, cementite and graphite. The Matrix structure mainly includes austenite, ferritic, pearlite, Bainite and martensite, graphite in cast iron in the form of general sheet and two kinds of spherical. CAST steel rolls can be divided into two categories: steel rolls (0.4% ~ 114% carbon) and semi-steel rolls (1.4% ~2.40 / 0 carbon) , the carbon content of steel roll is low, so the hardness is low. The microstructure of steel roll is generally composed of ferrite and pearlite.

         To improve the hardness, chromium, nickel, manganese, molybdenum, vanadium and other alloy elements can be added, or for special heat treatment. Due to its high tensile strength and toughness, steel rolls are suitable for open mills or blooming mills with high rolling temperature and heavy rolling load, and can also be used as backup rolls. If special heat treatment is carried out and high hardness above HS90 is obtained, it can also be used as

cold rolling work roll.
      The carbon content of semi-steel roll is between cast steel roll and cast iron roll, and its hardness is higher than that of cast steel roll and lower than that of cast iron roll. The main characteristic of semi-steel roller is that the internal hardness drops very little, so it is especially suitable for making deep pass roller. If the silicon content in semi-steel roll material is increased, it has high resistance to hot cracking and strength and toughness through graphitization treatment. It is used as roughing roll of blooming mill, roughing roll of large section steel, roughing roll of blooming mill and vertical roll of hot strip mill, good rolling effect can be obtained. Through smelting, forging and heat treatment, the working layer of forged steel roll body has high hardness, high wear resistance and excellent accident resistance, and the roll neck and core have certain strength and high toughness. Forging Steel Roll has this unique performance, making it in cold rolling and non-ferrous rolling, casting roll has irreplaceable advantages. Roller bearing grease, roller, rolling mill