Cast steel rolls

Cast steel rolls can be divided into two categories: steel rolls (carbon content of 0.4-1.4%) and semi-steel rolls (carbon content of 1.4-2.4) steel rolls with low carbon content, so the hardness is low, its organization is generally composed of ferrite and pearlite, with the increase in carbon content, the amount of ferrite decreases, the amount of pearlite increases. In order to improve the hardness, Cr, Ni, Mo and other alloying elements can be added, or special heat treatment, due to the high tensile strength and toughness of the steel rolls, suitable for high rolling temperatures, high rolling loads of open billet mill or primary mill, can also be used as a support roll. Such as special heat treatment, to get HS90 above the high hardness, can also be used as cold rolling work roll.
Semi-steel rolls in the carbon content of cast steel rolls and cast iron rolls, its organization is mainly composed of pearlite, and contains a certain carbide, therefore, its strength is slightly higher than the cast steel rolls, lower than the cast iron rolls, its hardness is higher than the general cast steel rolls Semi-steel rolls, the most important feature of the internal hardness of the rolls landing is very small, therefore, is particularly suitable for the manufacture of deep-hole rolls, and is widely used in the roughing and finishing mill stands for section mills, hot rolls, and the steel strip mill roughing and finishing mill stands. Strip mill roughing and finishing front work rolls. Semi-steel roll material if you increase the silicon content, through the graphitization process, with high resistance to thermal cracking and toughness, as the initial rolling mill billet rolls, large section steel roughing rolls, billet rolling mill rolls and hot strip mill stand rolls, you can get good rolling results.
1, alloy cast steel rolls according to its chemical composition and heat treatment process, so that the roll body of the outer matrix organization for pearlite and bainite. Pearlitic can be flaky or spherical, or the type of Soxhlet tempered Soxhlet not only has a high toughness, but also has excellent resistance to thermal cracking, especially with the phase of the tempered Soxhlet organization also has excellent resistance to wear and tear, so when used in the early rolling mill, rolling results are good.

2, cast high chrome steel rolls
High-chromium steel roll is its high-chromium steel (C: 0.5-1.5%, Cr: 8-15%) for the roll body outer material, ductile cast iron for the core material, using centrifugal composite casting process production, due to the outer layer of the roll body has a more chromium-rich matrix than the high-chromium composite cast iron material organization, wear resistance is very good. In addition, due to the high chromium steel roll body work layer matrix organization of carbide content is low, so that it has excellent resistance to thermal cracking, based on this, high chromium steel roll is currently the development trend of the selection of roughing roll of hot rolling mill.
3, centrifugal composite high-speed steel rolls high-speed steel rolls not only has a high resistance to thermal cracking, at the same time, its high wear resistance and red hardness can greatly extend the life of the rolls, improve the quality of rolled material, can be used for hot strip mill finishing mill before the work roll.

4, semi-steel rolls
Semi-steel rolls containing carbon is usually 1.4-2.4%, the mechanical properties are in the cast steel and cast iron, with a small hardness landing, high wear resistance, widely used in section steel mill roughing and rolling mill stand, hot strip mill roughing and finishing mill before the work rolls, when the semi-steel carbon content is greater than 1.9%, known as the high carbon semi-steel, high-carbon steel, high-carbon semi-steel, high carbon content, the existence of the matrix organization has eutectic Carbide and pseudo eutectic carbide in the matrix organization, is used for open billet continuous rolling stand with rolls, section steel mill intermediate stand and finishing mill stand with rolls. Semi-steel rolls used as hot rolls, in order to improve crack resistance, the composition of the increased silicon content, become graphite cast steel rolls, concentrated cast steel and cast iron the advantages of both, a large number of billet hot rolling mill rolls and section steel mill rolls.

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