METHOD FOR PRODUCING SPRING, AND ELECTRICAL HEATING DEVICE

摘要

A method of producing a spring which reduces time required for a heat treatment step of eliminating a machining strain generated by a forming step is provided. This production method is provided with a forming step (S10) of forming a spring steel material into a spring shape and a heat treatment step (S12) of eliminating a machining strain generated in the spring steel material by the forming step. The heat treatment step is executed by electrically heating the spring steel material by applying a current thereto. The heat treatment step has a first step of heating the spring steel material to a predetermined set temperature and a second step of keeping the spring steel material at the set temperature for a predetermined set time period subsequent to the first step. The set temperature is set to be higher than 430° C. but not higher than 500° C.