Patent ID: 11925979
Assignee: INDUCTOTHERM, CORP.
Field: Materials, metallurgy (Chemistry)
Classification: CPC B  Y | IPC B

Claim 17:
18. A method of producing a large steel ingot by solidifying a molten steel supplied to a casting mold, the molten steel forming an upper riser part of the molten steel over a lower main part of the molten steel, the method comprising:
positioning an electric induction heating coil over a top surface area of the molten steel;
supplying continuously a variable power magnitude and a variable frequency to the electric induction heating coil;
initially adjusting a supplied voltage and a supplied current to the electric induction heating coil by a scale of a multiple of 10 kilowatts per square meter of the top surface area of the molten steel; and
adjusting simultaneously the variable power magnitude and the variable frequency supplied to the electric induction heating coil coordinately to maintain an induced power from the electric induction heating coil at a nominal induced power level from when the molten steel in the main part is in a molten state until at least the main part has solidified and such that the molten steel in the riser part is maintained in the molten state until after a lower main body part has solidified.