| 摘要 |
PROBLEM TO BE SOLVED: To provide a composite roll provided with an external layer excellent in wear resistance and composed of a uniform material preventing the generation of the unevenness of wear and the unevenness of surface roughness caused by macrosegregation in the roll surface. SOLUTION: In a composite roll composed of an external layer 1 formed of a wear resistant cast iron material, an intermediate layer 3 welded on the inner circumferential face of the external layer and an internal layer 2 welded on the inner circumferential face of the intermediate layer, in which, also, the external layer and the intermediate layer are centrifugally cast, the external layer has a chemical compsn. composed of, by weight, 1.0 to 3.0% C, 0.1 to 2.0% Si, 0.1 to 2.0% Mn, 0.1 to 4.5% Ni, 3.0 to 10.0% Cr, 0.1 to 9.0% Mo, 1.5 to 10.0% W, 0.01 to 0.50% Al, 0.01 to 0.5% Ti, one or two kinds of V and Nb by 3.0 to 10.0% in total, and the balance substantial Fe. The external layer can be incorporated with 0.01 to 0.50% Ti, Zr and B in addition to the alloy components. |
