| 摘要 |
PURPOSE:To permit production of an outside layer material of a roll having excellent wear resistance and crack resistance by heating an Fe-Ni cast iron roll material having a specific compsn. to a specific temp., then subjecting the material to controlled cooling and holding the same in an adequate temp. range to cause the isothermal transformation thereof. CONSTITUTION:The outside layer material of the rolling roll having the compsn. consisting of 3.0-4.0wt% C, 1.0-2.0% Si, 0.8-2.5% Mn, 1.5-4.0% Cr, 4.1-5.5% Ni, 0.2-8.0% Mo, 0.020-0.050% Ti, <=0.040% P, <=0.030% S, and the balance Fe and unavoidable impurities is cast. The cast iron roll material is heated and held to and at 800-950 deg.C; thereafter, the material is cooled at 100-500 deg.C/H cooling rate. The material is in succession held for 5-50hr at 350-500 deg.C to cause the isothermal transformation. Since such outside layer material of the roll has the excellent wear resistance without impairing the crack resistance, the material is usable for a work roll for the final stage of finishing of a hot rolling mill, etc.
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