| 摘要 |
PURPOSE:To prevent the stripping of an intermediate layer by interposing a Ca-alloy between the outer and inner layers of a composite roll and forming an intermediate layer of vermicular cast iron having a vermicular graphite form. CONSTITUTION:A hard-alloy cast iron, such as a high-alloy grain cast iron or a high chromium steel, is used for the outer layer of a composite roll. For the inner layer 3, a well-known nodular graphite cast iron is used. An intermediate layer 2 of vermicular cast iron is interposed between the outer and inner layers 1, 3. The casting components of vermicular cast iron are, by wt. percent; 2.5-4.0% C, 2.0-3.5% Si, >0.03% S, about 0.003-0.020% Ca and the balance Fe. In this way, the intermediate layer 2 is formed into a vermicular graphite form; and the strength thereof has an intermediate value between those of the outer and inner layers 1 and 3 to prevent the stripping phenomenon from the intermediate layer 2. |
