| 摘要 |
PURPOSE:To improve both of performance and life, by fitting to outside of the shaft the three-layer composite sleeve consisting of the outer layer, the intermediate layer and the inner layer respectively constituted of a specified material. CONSTITUTION:The molten metal for forming the outer layer 3 is first poured into the centrifugal casting mold; while this molten metal is still unsolidified, or after completing the solidification, the molten metal for forming the intermediate layer 4 is poured into the mold. Similarly, the inner layer 5 is formed, and the three-layer composite sleeve, in which the outer layer 3, the intermediate layer 4 and the inner layer 5 are integrally joined into one body, is formed. Since the outer layer 3 is the part to contact with the rolled material as the working layer, it is required the sufficient abrasion-resistance and the thermal-fatigue durability, so that the high hard adamite is employed for the inner layer 5, it is especially required the tougheness for reinforcing the sleeve, and besides, it is required the castability, so that so called graphite steel is employed for the inner layer 5. The intermediate layer 4, being interposed between the outer layer 3 and the inner layer 5, is made from the adamite or the graphite steel, containing carbon in almost middle percentage between the outer layer 3 and the inner layer 5. |
