Spring relaxation treatment-the spring works under the action of external force for a long time, and the result of stress relaxation will produce a small amount of permanent (plastic) deformation, especially the spring working at high temperature, the stress relaxation phenomenon is more serious at high temperature, making the spring The accuracy is reduced, which is not allowed for general precision springs.
Therefore, this type of spring should be relaxed after quenching and tempering-pre-load the spring so that its deformation exceeds the deformation that may occur when the spring is working. Then it is heated and kept at a temperature higher than 20C. 8-24h.