| 摘要 |
PURPOSE:To prevent the generation of cold cracks and to perform stable casting by supporting a solidified columnar cast ingot and pulling down the same onto a vertically movable bottom mold wherein a bulging curved surface peaking at the axial center of an annular mold is formed on the top surface. CONSTITUTION:In a semi-continuous casting device constituted of a force-cooled annular casting mold 1 provided with a water cooling jacket and a freely vertically movable bottom mold 2 fitted to the inside wall thereof, molten Al or Al alloy is charged continuously from above into the mold 1. A sump 3 is cooled and solidified by the mold 1 and spray devices 14 right under the mold, whereby a solid cast ingot part 5 is produced. As the part 5 is formed, the bottom mold 2 descends. If in this case the top surface of the mold 2 is formed to a bulging curved surface peaking at the axial center of the mold 1 and to a shape wherein the solidification interface of the cast ingot 5 is substantially inverted, the shape of the solidification interface of the cast ingot in the initial period of casting is flat and the generation of cold cracks is difficult. |
