How to extend spring life
Rubber spring used for a long time, there will be no high elasticity. Break the problem. How can we extend the life of rubber springs?
A. Shot Peening: Shot peening is one of the most widely used methods to improve the surface quality of springs. The spring requires a high surface quality, scratches, folding, oxidative decarburization and other surface defects tend to become the spring when the stress concentration of work and fatigue fracture source. If the use of small steel shot high-speed spray spring surface, shot peening, not only to improve the surface quality of the spring, improve the surface strength, so that the surface in a compressive stress state, thereby enhancing the spring fatigue strength and service life.
B. Isothermal Quenching of Springs: Isothermal quenching for springs with a small diameter or sufficient hardenability can not only reduce the center of change, but also improve the strength and toughness. After the isothermal quenching is best followed by a tempering, can improve the elastic limit, tempering temperature and isothermal quenching the same temperature.
C. Deformation heat treatment: deformation heat treatment is the steel deformation and heat treatment to strengthen the combination of the two, to further improve the strength and toughness of steel. Deformation heat treatment has high temperature, medium temperature and low temperature of the points. High temperature deformation heat treatment is stable in the austenitic state after the deformation immediately after quenching, but also with forging or hot rolling together, that is, immediately after the hot forming quenching. 60Si2Mn steel plate spring, the high temperature deformation heat treatment (930 ℃ + thermal variable 18%, oil quenching), the use of 650 ℃ × 3.25min high temperature rapid tempering, its strength and fatigue life have been greatly improved.
D. spring relaxation treatment: the spring for a long time under the action of external force, due to stress relaxation, will produce a trace of permanent (plastic) deformation, especially the work of high temperature springs, stress relaxation at high temperatures more serious, so that the spring Accuracy is reduced, which is not allowed for general precision springs. Therefore, such springs in the quenching, tempering should be relaxed after treatment. Heat treatment process: the spring pre-load, so that the amount of deformation than the spring may produce the amount of deformation. And then higher than the operating temperature of 20 ℃ under the conditions of heating, heat 8 ~ 24h.
E. low temperature carbonitriding: for the coil spring using tempering and low temperature carbonitriding (soft nitriding) combined process, can significantly improve the spring fatigue life and corrosion resistance.