What are the ways to improve the customized service life of springs?
1. Isothermal quenching of non-magnetic spring
The spring manufacturer believes that for springs with small diameter or sufficient cutting performance, isothermal process quenching can be selected, which can not only reduce the transformation of the core, but also improve the compressive strength and ductility. After the isothermal process quenching, it is better to carry out another tempering to improve the ductility limit. The tempering temperature is the same as the isothermal process quenching.
2. Thermal mechanical equipment solution
The solution of thermomechanical equipment is the close combination of deformation strengthening and heat treatment process strengthening to further improve the hardness and ductility of steel. Thermal mechanical equipment solution can be divided into high temperature Medium soft ultra low temperature. The solution of high-temperature thermomechanical equipment is to quench immediately after deformation under the condition of stable martensite. It can also be closely combined with forging or hot rolling, that is, quench immediately after hot forming. After high-temperature thermomechanical treatment, the non-magnetic spring can be rapidly tempered at 650 ℃, and the compressive strength and fatigue service life can be greatly improved.
3. Non magnetic spring relaxation solution
When the spring works for a long time under the action of external force, a small amount of permanent deformation will be caused due to stress relaxation. Rectangular die springs, especially those working under high temperature. The stress relaxation is more serious under high temperature, which reduces the precision of the spring, which is not allowed by general high-precision springs. Therefore, the spring manufacturer thinks that this type of spring should release pressure after heat treatment. Heat treatment method: preload the spring to make its deformation exceed the deformation that may be caused when the non-magnetic spring is working, and then heat it at an ambient temperature 20 ℃ higher than the operating temperature for 8-24 hours.
4. Shot blasting
Shot peening is one of the common methods to improve the surface quality of non-magnetic spring. It is used to compress the spring scratch, stretch and air oxidation Surface defects such as carburization are often the root cause of stress location and fatigue cracking. Selecting fast small steel balls to carry out shot peening treatment on the spring surface can improve the surface quality of the spring, improve the surface compressive strength of the spring, make the spring surface in the stress state, and then improve the fatigue limit and service life of the spring.
