Two strengthening technologies of Datong spring

(1) The heat treatment strengthening technology of Datong spring

1) Heat treatment of protective atmosphere. In China, the heat treatment of Datong spring, oil quenched tempered steel wire and toughened steel with wire less than 15mm has been treated by protective atmosphere. The heat treatment of protective atmosphere can eliminate the surface decarbonization and oxidation and improve the surface quality of the material.

2) Induction heating or protective atmosphere induction heating heat treatment. This process is usually carried out on the wire before the forming of the spiral Datong spring. Some Datong spring factories put the heat treatment of the wire material together with the Datong spring production to reduce the cost. Induction heating has good strengthening effect, and the induction heating speed is fast, which helps to refine the grain and reduce the surface decarbonization, and can give full play to and improve the strength and toughness of the material.

3) Surface nitriding heat treatment technology. In recent years, in order to achieve reliable fatigue life, surface nitriding technology has been adopted for high stress valve Datong spring or other high stress clutch Datong spring. Now, the advanced technology is low temperature gas nitriding technology, with the general nitriding temperature of (450-470) ℃, and gas nitriding time of (5-20) H.

(2) Shot peening strengthening technology of Datong spring

1) Combined shot peening technology. Combined shot peening, also known as multiple shot peening process. Most economical processes are secondary shot peening. It is realized by shot peening with different diameter. For the first time, the larger pellets were used to obtain residual compressive stress and surface finish.

2) Stress peening process. Stress peening is also a classic shot peening process, but it is difficult to be applied to mass production. However, due to the rapid development of stress peening equipment in recent years, it has been greatly developed in the mass production of high stress automobile suspension Datong spring. Especially, the combination of stress strengthening shot peening and other shot peening processes has a good effect. The stress shot blasting prestress is generally set at (700-800) MPa. After stress shot blasting, the peak value of residual stress can reach (1200-1500) MPa, thus obtaining high fatigue resistance strength.

(3) The hot pressing technology of Datong spring is mainly applied to the high demand of anti permanent deformation of the coil Datong spring, which is a high-level stabilization treatment technology to prevent permanent deformation. The hot pressing technology can not only improve the anti permanent deformation, but also improve the fatigue life.

More news about Datong spring“ www.qzspring.com ”