The shot peening process of torsion springs can be divided into the following three types:
1) Combined shot peening technology. Combined shot peening is generally called multiple shot peening. Most economical processes use secondary shot peening. This is achieved by using shot peening with different diameters. Large pellets to obtain residual compressive stress and surface finish.
2) Stress shot peening process. The stress shot peening process is also a relatively classic shot peening process, just because it is difficult to apply to mass production, but in recent years, due to the rapid development of stress shot peening equipment, the torsion spring of high-stress automobile suspension Large-scale production has been greatly developed. Especially the combined application of stress-strengthened shot peening and other shot peening processes has a good strengthening effect. The prestress of stress shot peening is generally set at (700~800) MPa, and the stress After shot blasting, the peak value of residual stress can reach (1200~1500) MPa, thereby obtaining high fatigue strength.
3) The hot pressure process of torsion springs. The hot pressure process is mainly applied to spiral torsion springs that require high permanent deformation resistance. It is used as an advanced anti-permanent deformation stabilization process. The heat pressure process can significantly improve the resistance to permanent deformation. In addition to deformation, it can also improve fatigue life.