1. Avoid spring tempering by increasing the temperature and shortening the time.
2. Hardness: With the increase of tempering temperature, the hardness decreases after a slight increase. The temperature at which the fatigue performance is best is slightly lower than the temperature at which the hardness is at its greatest.
3. Reduced diameter: The outer diameter of the carbon steel spring will be reduced when it is tempered, so some dimensions should be reserved when the spring is coiled.
4. Spring tempering color: The tempering color is related to the temperature and the residue on the surface of the steel wire, and the uneven color is related to the temperature distribution or the airflow in the furnace.
5. If the color is expected to be uniform, the furnace and the charging method should be managed well; if there is oil or fingerprints locally, it will change color after tempering.
6. Tempering temperature: The tempering temperature generally used is 250-280 °C. If the steel wire is treated at 200-250 °C, although the strength can be improved, the plasticity and toughness will also be lost, which can cause the tension spring to be bent as a hook or torsion spring. Broken leg.
7. Compression spring: mild low temperature tempering after hammering can reduce deformation.
8. Tension spring: the initial stress will be lost after tempering, and the allowable loss should be considered when setting the deviation.
9. Torsion spring: Tempering at 280℃ after coiling the spring, if reprocessing after coiling the spring, the low temperature tempering temperature is 250℃.
10. The hook of the tension spring and the arm of the torsion spring: the position will change after tempering. If there is an exact position requirement, the amount of change should be grasped.
