According to GB / T 13304 standards, spring steel according to its chemical composition is divided into non-alloy spring steel (carbon spring steel) and alloy spring steel.
1. Carbon spring steel
Carbon steel spring carbon content (mass fraction) is generally 0.62% ~ 0.90%. According to its manganese content is divided into general manganese content (mass fraction) (0.50% ~ 0.80%) such as 65,70,85 and higher manganese content (mass fraction) (0.90 ~ 1.20%), such as 65Mn two types.
2 alloy spring steel
Alloy spring steel is based on carbon steel, by adding one or more of the appropriate alloy elements to improve the mechanical properties of steel, hardenability and other properties to meet the performance required for the manufacture of various steel springs.
Alloy spring steel basic series, silicon-manganese spring steel, silicon-chromium spring steel, chrome-manganese spring steel, chrome-vanadium spring steel, tungsten-chromium-vanadium spring steel. Based on these series, some grades have added alloying elements such as molybdenum, vanadium or boron in order to improve their performance in some aspects.
In addition, select some grades from other types of steel, such as high-quality carbon structural steel, carbon tool steel, high-speed tool steel, stainless steel.