| 摘要 |
PURPOSE:To break growing columnar crystals, to form the fine isometric structure from the surface of a alloy steel or high alloy steel ingot down to the axial center and to save a hot forging stage in casting of said ingot by electromagnetically agitating the unsolidified part from the period of starting casting of the molten steel into a mold of a nonmagnetic material. CONSTITUTION:Right after the start of casting by using a mold 1 of a nonmagnetic material, an electromagnetic agitating coil 2 provided on the outside surface of the mold 1 is moved upward in conformity with the ascending speed of the level of molten metal. Thence, the coil 2 is moved upward and downward along the mold 1 since the end of casting until the fine equiaxes crystal is grown on the surface of the steel ingot. Thereby, the need for hot forging of the steel ingot is eliminated in the case of making a pipe or the like from the ingot of alloy steel or high alloy steel vulnerable to formation of columnar crystal structure. |
