US 12,305,248 B2 · Heat treatment method and heat treatment furnace

Abstract

The present disclosure relates to a heat treatment method and a heat treatment furnace that enable characteristics on an equal level to those when bluing processing is performed to be obtained without the bluing processing being performed in stress-relief annealing of a motor core. A heat treatment method according to one aspect is a heat treatment method in stress-relief annealing of a motor core. The heat treatment method includes an annealing step of annealing the motor core by using an exothermic converted gas as a furnace atmospheric gas, and a cooling step of cooling the motor core obtained in the annealing step, by using an exothermic converted gas as a furnace atmospheric gas, in a temperature range from a temperature in the annealing step to 500° C. at a cooling rate exceeding 600° C. per hour.

Claims4

Dependent claims

A heat treatment furnace comprising:

a heating chamber configured to be supplied with an exothermic converted gas as a furnace atmospheric gas and to anneal a motor core, the heating chamber comprising a heater configured to control a temperature of the heating chamber to become a target temperature in annealing;
and
a cooling chamber on a downstream side of the heating chamber communicating directly with the heating chamber, the cooling chamber being configured to be supplied with an exothermic converted gas as a furnace atmospheric gas, wherein
the cooling chamber comprises cooling means configured to cool the motor core passed through the heating chamber, in a temperature range from the temperature in annealing to 500° C. at a cooling rate which is a rate in a range equal to or higher than 650° C. per hour and equal to or lower than 700° C. per hour.

1 more element

Dependencies are inferred from the claim text.

Heat treatment method and heat treatment furnace

Life of this patent

Heat treatment method and heat treatment furnace

Life of this patent

Abstract

Claims4