METHOD OF HIGH-FREQUENCY QUENCHING, HIGH-FREQUENCY QUENCHING APPARATUS, AND PRODUCT OF HIGH-FREQUENCY QUENCHING

摘要

A method of high-frequency quenching (10) in which temperature control is possible, quenching can be easily and efficiently conducted, and a desired heat-treatment quality can be imparted to a wide range in a work. It comprises a temperature control step (20) and a quenching control step (30). The temperature control step (20) comprises a temperature measurement step (23) for temperature control, a temperature regulation step (24), and a heating step (22). The quenching control step (30) comprises a temperature measurement step (35) for quenching in which the temperatures of a high-temperature part and low-temperature part of the work are measured, a cooling timing regulation step (36), and a cooling step (37). In the cooling timing regulation step (36), the heating time is regulated so that the temperature history in the high-temperature part satisfies a temperature history requirement resulting in a residual austenite amount not larger than a desired upper limit and that the temperature history in the low-temperature part satisfies a requirement resulting in a hardness not lower than a desired lower limit, and a cooling start signal is output accordingly.