Chemical Composition & Mechanical Properties

The spring wire rod  is used in the elastic range, and should be returned to the original position after unloading. It is hoped that the smaller the plastic deformation is, the better, so the steel wire should have a high elastic limit, yield strength and tensile strength. The higher the flexure ratio, the closer the elastic limit is to the tensile strength, so the better the strength utilization rate can be improved, and the stronger the spring elasticity will be.

Spring depends on elastic deformation to absorb the impact energy, so the spring steel wire does not have to have high plasticity, but at least it should be able to withstand the plasticity of the spring forming, and enough toughness to withstand the impact energy.

Springs usually work under alternating stress for a long time, so they should have a high fatigue limit, as well as good resistance to creep and relaxation.

Spring used in a specific environment, there will be some special requirements for steel wire, such as: spring used in corrosive media, must have good corrosion resistance. The spring used in precision instruments should have long-term stability and sensitivity. The temperature coefficient should be low, the quality factor should be high, the after-effect should be small, and the elastic modulus should be constant. Springs working at high temperature are required to maintain sufficient elastic limit and good creep resistance at high temperature.