Heating magnetic metal workpieces
AssigneePark-Ohio Industries, Inc.
InventorsNorbert R. Balzer, David R. Soworowski
Life of this patent
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Abstract
Method and apparatus for heating a billet of magnetic metal material to a forging or other elevated processing temperature above the Curie point temperature of the workpiece metal by first inductively preheating the billet in an induction heating coil to a preheat temperature not appreciably higher than the Curie point temperature of the workpiece metal, and then conveying the preheated billet from the induction heating coil into, and post-heating it to the elevated processing temperature within, the heating chamber of a slot-type high efficiency electric radiant heat electric furnace.
Claims8
The method of heating a workpiece of magnetic metal from about ambient temperature to a selective elevated processing temperature above the Curie point temperature of said workpiece metal comprising the steps of:
- (a) initially inductively preheating the said workpiece from about ambient temperature to a preheat temperature of about the Curie point temperature of the workpiece metal in an induction heating coil energized by an electric power source;
- and,
- (b) then immediately radiantly post-heating said workpiece to said processing temperature in the heating chamber of an electric radiant heat furnace.
The method of heating a workpiece of magnetic metal from about ambient temperature to a selective elevated processing temperature above the temperature at which said metal is converted into a nonmagnetic state comprising the steps of:
- (a) initially inductively preheating the said workpiece from about ambient temperature to a preheat temperature of about the said temperature at which the metal of the workpiece is converted into a nonmagnetic state;
- and,
- (b) then post-heating the said preheated nonmagnetic state workpiece to the said elevated processing temperature in the heating chamber of an electric radiant heat furnace.
The method of heating an end length portion only of an elongated workpiece of magnetic metal from about ambient temperature to a selective processing temperature above the Curie point temperature of said workpiece metal comprising the steps of:
- (a) initially inductively preheating the said end length portion only of the workpiece in an induction heating coil from about ambient temperature to a preheat temperature of about the said Curie point temperature of the workpiece metal;
- and,
- (b) then post-heating the said preheated end length portion only of the workpiece to the said elevated processing temperature in the heating chamber of an electric radiant heat furnace.
Dependencies are inferred from the claim text.