What are the principles of spring selection

What are the principles of spring selection:

The principle of spring selection is: first to meet the functional requirements, then strength requirements, and finally to consider economics.

Carbon spring steel is a widely used and the largest amount of steel in spring steel. Steel contains 0.60% to 0.90% carbon and 0.3% to 1.20% manganese, no longer add other alloy elements, the cost of use is relatively low.

Carbon spring wire by proper processing or heat treatment, can obtain a high tensile strength, adequate toughness and good fatigue life.

However, the clamofability of carbon wire is low, anti-relaxation and corrosion resistance is poor, the temperature coefficient of elastic modulus is larger (up to 300 x 10-6/ degrees C), suitable for the manufacture of small cross-section, low operating temperature (120 degrees C) of the spring.

Metal spring steel generally contains 0.45% to 0.70% carbon and a certain amount of Si, Mn, Cr, V, W and B alloy elements. The addition of alloyelements improves the anti-relaxation properties of spring steel, improves the toughness of the steel, while significantly improving the quenchability and use temperature of the steel, and is suitable for the manufacture of larger cross-sections and the use of springs at higher temperatures.