HEAT TREATMENT METHOD AND METHOD OF MANUFACTURING MACHINE PART

摘要

A heat treatment method includes the steps of: measuring a hot section temperature; measuring a cold section temperature; adjusting a temperature of a workpiece; and determining quenching timing for the workpiece. The step of adjusting a temperature includes the steps of: heating the workpiece by high energy heating; and controlling heating based on the hot section temperature. In the step of determining quenching timing, the quenching timing is determined based on the hot section temperature and the cold section temperature so as to achieve a predetermined solid-dissolved state of carbon on a TTA diagram in the entire workpiece. The TTA diagram is derived by a calculation formula obtained by conducting a regression analysis of a result of an experiment performed for examining a relation between the solid-dissolved state of carbon and each of a heating temperature and a heating time of steel.

主权项

1. A high-energy heat treatment method of heating a surface layer of a workpiece made of steel for implementing quench-hardening, said heat treatment method comprising the steps of:
measuring a hot section temperature corresponding to a temperature of a portion in which the temperature rises most in said workpiece; measuring a cold section temperature corresponding to a temperature of a portion in which the temperature rises least in said workpiece; adjusting the temperature of said workpiece; and determining quenching timing for said workpiece, said step of adjusting the temperature of said workpiece including the steps of
heating said workpiece by high energy heating, andcontrolling heating of said workpiece by said high energy heating based on said hot section temperature, in said step of determining quenching timing for said workpiece, said quenching timing being determined based on said hot section temperature and said cold section temperature such that said steel forming said workpiece exhibits a predetermined solid-dissolved state of carbon on a TTA diagram in entire said workpiece, and said TTA diagram being derived by a calculation formula obtained by conducting a regression analysis of a result of an experiment performed in advance for examining a relation between said solid-dissolved state of carbon in said steel and each of a heating temperature and a heating time of said steel.