Centrifugally cast composite roll for rolling and its production method

A method for producing a centrifugally cast composite roll for rolling comprising an outer layer and an inner layer, which are integrally fused to each other, said outer layer being made of an Fe-based alloy comprising by mass 1.70-2.70% of C, 0.3-3% of Si, 0.1-3% of Mn, 1.1-3.0% of Ni, 4.0-10% of Cr, 2.0-7.5% of Mo, 3-6.0% of V, 0.1-2% of W, 0.2-2% of Nb, 0.01-0.2% of B, and 0.01-0.1% of N, the balance being Fe and inevitable impurities, and said inner layer being made of ductile cast iron, comprising the steps of centrifugally casting said outer layer in a rotating centrifugally casting cylindrical mold;

• casting a melt for said inner layer into a cavity of said outer layer;
• reheating said outer layer at an austenization temperature or higher after or during casting said inner layer;
• and
• cooling the resultant composite roll at a cooling rate of 10-60° C./hr between the reheating temperature and 600° C.