HEAT TREATMENT METHOD FOR RING-SHAPED MEMBER AND HEAT TREATMENT EQUIPMENT FOR RING-SHAPED MEMBER

摘要

In a heating step (S1) of inductively heating a steel outer ring (OR) to a target temperature, a plurality of outer rings (OR) retained coaxially by a retaining unit (3) are caused to sequentially pass through an opposing region of a pre-heating coil (22) having a variable output, and through an opposing region of a heating coil (21) having a constant output and being arranged coaxially with the pre-heating coil (22) on an exit side of the pre-heating coil (22). Thus, the plurality of outer rings (OR) are sequentially and inductively heated to the target temperature.