| 摘要 |
PROBLEM TO BE SOLVED: To cast an ingot having a casting surface in a favorable state by reducing component segregation, and to elongate a life of a plasma torch by preventing mutual intervention of plasma torches.SOLUTION: When the radius of the molten metal surface of a molten metal 12 is R, plasma torches 7a, 7b are moved on an orbit which connects an inner peripheral arc the center of which has a radius of 0<r1<R/2 from the center of the molten metal surface with an outer peripheral arc the center of which has a radius of R/2<r2<R by means of a straight line. The plasma torches 7a, 7b are moved in such a manner that when one of the plasma torches 7a, 7b is located above a vicinity of cast mold 2 end, the other of the plasma torches 7a, 7b is located in a vicinity of the cast mold 2 center. The plasma output of the plasma torches 7a, 7b are controlled in such a manner that the plasma output of the plasma torches 7a, 7b during movement on the inner peripheral arc is lower than the plasma output of the plasma torches 7a, 7b during movement on the outer peripheral arc. |
