The compression spring is a kind of hardware accessory with spiral geometry formed by line. Therefore, it is more difficult to strengthen the compression spring than the plane hardware parts (such as stamping parts). In addition, the hardening effect of the cross section of the compression spring should be strictly controlled, so as to fully understand the anti fatigue fracture resistance of the compression spring after use.
Generally, the pressure spring is hardened by shot peening and heat treatment.
Shot peening and hard spring pressing treatment: to process a batch of pressure springs, the compressed springs can be transported to the shot blasting chamber by a single conveyor belt. A group of parallel roller paths are installed in the shot blasting area, which can be strengthened and rolled at the same time, It drives the edge of the compression spring to rotate forward. In this way, the high-speed shot flow can pass through the middle of each coil of the pressure spring and hit the metal surface of the inner ring. That is exactly where the stress of the spring is most concentrated. Shot peening is the best strengthening method for suspension spring. After proper shot peening, the fatigue life of high stress spring can be increased by more than 4 times.