The operating temperature of the battery spring increases and the elastic modulus of the spring material decreases, resulting in a decrease in stiffness and a smaller carrying capacity. Therefore, the spring working at high temperature must understand the rate of change (value) of elastic modulus and calculate the effect of the reduction of spring carrying capacity on the performance of use. According to GB1239, when the operating temperature of the ordinary coil spring exceeds 60 degrees C, the shear modulus shall be corrected, and the formula is: The elastic modulus at The G-Normal temperature in the Gt-KtG type; Gt -the amount of shear and die at the operating temperature t; Kt – temperature correction coefficient is selected according to table 2-98.
Spring materials used at low temperatures should have good low temperature toughness. Carbon spring wire, piano wire and 1Cr18Ni9, such as Aostainless stainless steel spring wire, copper alloy, nickel alloy has better low temperature toughness and strength.
At low temperature, the brittleness of the material is very sensitive to surface defects, so the surface quality of the material should be strictly required.
At low temperatures, the environmental medium corrodes the material much less than it does under the greenhouse, while cadmium plating and galvanizing are prone to cold and brittleness.
At low temperature, the elastic modulus and expansion coefficient of the material do not change much and can not be considered in the design.
Spring steel production of spring, hardness (i.e. strength) should be based on the load nature of the spring and stress size. However, the hardness and plane strain fracture toughness are greatly related.