What is the tempering temperature of spring steel?
1) Spring steel is mainly silico-manganese steel. Silicon can promote decarburization, and manganese can promote grain growth. Surface decarburization and grain growth greatly reduce the fatigue strength of military rigidity. Therefore, the selection and control of heating temperature, heating time and heating medium must be prudent. Such as using a salt furnace for rapid heating and heating in a protective atmosphere. After quenching, it should be tempered as soon as possible to prevent delayed fracture.
2) Spring steel has a high silicon content and is easy to graphitize during the drawing process, so attention must be paid. Generally, the graphite content of steel needs to be checked when it enters the factory.
3) The tempering temperature is generally 350 ~ 450℃. If the steel surface is in good condition (such as after grinding), a lower limit temperature should be used for tempering; in addition, the upper limit temperature can be used for tempering to improve the toughness of the steel and reduce the sensitivity to surface defects.