Precision spring heat treatment refers to a process of heating precision springs in a certain environment to a certain temperature, holding them for a certain period of time, and cooling them at the same speed.
Precision spring heat treatment is the most important process in production. During heat treatment, the shape and overall chemical composition of the precision spring are not changed. By changing the microstructure inside the precision spring or the chemical composition on the surface of the precision spring, the performance of the precision spring is endowed or improved. The main characteristic is to change the internal quality of the spring.
1. The reason for decarburization is that the occurrence of this situation can lead to a decrease in service life, which is often due to the lack of protective gas during air furnace heating and quenching or incomplete salt bath deoxidation. During production, during hot quenching in an air furnace, protective gas or dripping solution should be used for protection. During heating in a salt bath furnace, the salt bath should be deoxygenated, and the mass fraction of impurities should be less than 0.2%. The surface of the raw materials should also be inspected.
2. Overheating, this situation is mainly due to the high quenching heating temperature and the high hot forming temperature. When processing, heat according to the correct experimental temperature, reduce the hot forming temperature, strengthen instrument calibration to ensure accurate temperature measurement.
3. Cracking is mainly caused by surface decarburization, untimely tempering, high heating temperature, or strong cooling ability of the quenching medium. When dealing with this situation, the heating temperature should be strictly controlled, using isothermal quenching or martensitic graded fire, cooling in the fire medium to 250-300 degrees Celsius before removing it for air cooling. After quenching, tempering should be carried out immediately.
