| 摘要 |
PURPOSE:To obviate generation of crazes and cracks of a roll occuring in the difference in the cooling rate of a molten metal by providing a boundary part mold having an intermediate heat extracting power to the neck part between a cylindrical metallic mold and end metallic molds and changing gradually the heat extracting power. CONSTITUTION:A mold for casting a composite roll is constituted by disposing a boundary part mold 12 having the heat extracting power smaller than that of a cylindrical metallic mold 2 and larger than that of sand molds 3, 4 for the end parts having the heat extracting power smaller than that of the mold 2 between the mold 2 and the molds 3, 4. The mold 12 is formed of a metallic mold 12a and a refractory sand layer 12b. The difference in the cooling rate when the molten metal charged into the casting mold is cooled to solidify is decreased and the concentration of the internal stress generated during cooling of the molten metal is prevented by the above-mentioned casting mold. The crazes and cracks of the roll are thus prevented. |
