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Roll by roll material consists of cast iron, cast steel and forged steel roll roll three categories. In which the carbon content of cast iron rolls in 2.50 / 0 ~ 3.5%, according to the main material can be divided into chilled cast iron rolls, indefinite chill cast iron rolls, cast iron and ductile iron roll roll four categories. Cast Iron Roll common organization can be divided into the matrix, cementite, graphite three categories, mainly austenitic matrix, cable, pearlite, bainite and martensite, the form of graphite in cast iron generally Two sheets and spherical.
Cast steel roller can be divided into two categories: steel roller (carbon content 0.4% ~ 114%) and semi-steel roller (carbon content 1.4% ~ 2.40 / 0), the carbon content of steel roll low, low hardness, The organization generally composed of ferrite and pearlite, with the increase of carbon content, reduced ferrite, pearlite increased. In order to improve hardness, can be added to chromium, nickel, manganese, molybdenum, vanadium and other alloying elements, or for special treatment. Because the steel roll has a high tensile strength and toughness, high temperature for rolling, rolling loads or large blooming mill blooming mill, but also can be used as backup roll. In case of special treatment, get more than HS90 high hardness, cold work rolls can also be used.
Roll half the carbon content of steel rolls and cast steel rolls between the hardness higher than steel rollers, lower than the cast iron rolls. Semi-steel roller is characterized by the internal hardness of the main land is very small, therefore, particularly suitable for the manufacture of deep hole-type roll. Semi-steel roll material in the If the increase in silicon content, through the graphite treatment, with a high thermal crack resistance and toughness, as the first mill breakdown roller, a large steel rough roll, blooming mill rolls and hot strip mill Vertical roll, get a good rolling effect.
Forged roll through smelting, forging, heat treatment, so that the work roll body layer has high hardness, high wear resistance and excellent anti-accident ability, while ensuring the roll neck and roll the body of the core has a certain strength and high toughness. Forged steel roll has unique properties that make it well in cold rolled non-ferrous, has a casting roll irreplaceable advantages. |
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