55CrMnA Features and application: to highlight the advantages of good hardenability, while thermal processing properties, mechanical properties, good resistance to decarburization performance is also a large section of a variety of important springs, such as cars, motorcycles large spring, spiral spring. 55CrMnA spring steel with high strength, ductility and toughness, good hardenability, heat-sensitive than the low-manganese, silico-manganese steel decarburization tendency than the small, temper brittleness.
55CrMnA spring steel used for cars, tractors and industrial production of heavy load, stress and a larger spring diameter larger coil spring.

Chemical composition:


Carbon C: 0.52 ~ 0.60


Si Si: 0.17 ~ 0.37


Manganese Mn: 0.65 ~ 0.95


Sulfur S: ≤ 0.030


Phosphorus P: ≤ 0.030


Chromium Cr: 0.65 ~ 0.95


Ni-Ni: ≤ 0.35


Copper Cu: ≤ 0.25


Vanadium V: 0.10 ~ 0.20 [1]


● Mechanical Properties:


Tensile strength σb (MPa): ≥ 1225 (125)


Conditions yield strength σ0.2 (MPa): ≥ 1080 (110)


Elongation δ5 (%): ≥ 9 (for reference)


Reduction of area ψ (%): ≥ 20


Hardness: hot, ≤ 321HB;


Cold Drawn + heat treatment, ≤ 321HB