The shot peening process of torsion springs can be divided into the following three types:
1). Combination shot peening technology. Combination shot peening is generally called multiple shot peening. Most economical processes use secondary shot peening. This is achieved by using different diameters of shot peening. The first use Larger 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, but it is difficult to apply to mass production. However, due to the rapid development of stress shot peening equipment in recent years, it has been Spring has been greatly developed in mass production. Especially the combined application of stress-strengthened shot peening and other shot-peening processes has a good strengthening effect. The pre-stress of stress shot peening is generally set at (700~800) MPa, after After stress 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 resistance to permanent deformation. It is used as an advanced anti-permanent deformation stabilization process. The heat-pressure process can significantly improve the resistance In addition to permanent deformation, it can also improve fatigue life.