| 摘要 |
PURPOSE:To reduce the residual stress of the entire roll, and to improve the material quality of the inner shell, by restricting the carbon content of the molten metal of high class cast iron to be poured for casting the inner shell of the roll to a specified carbon equivalent in order to regulate the C and Si contents of the composition of the inner shell after being cast. CONSTITUTION:The carbon equivalent of the molten metal of the high class cast iron to be poured for casting the composite roll's inner shell is regulated to 3.6-4.1. After casting the molten metal, the composition of the inner shell, under the condition that a part of the inner surface of the outer shell diffuses and mingles, is restricted so as to contain 3.35-3.6% C and 1.0-1.4% Si. Even if a thermal stress is added to this composite roll during the roll is working, the stress generated in the inner shell of the roll drum is small, and the troubles like as the breakage of the drum, the peeling of large piece of the outer shell, etc., are reduced. Accordingly, the durable life of the roll is extended, so that the roll becomes desirable as the rolling roll. |
