Composition and properties of superior carbon steel 50Mn

50Mn is a high-quality carbon structural steel, the implementation standard is GB/T 699.

Carbon steel 50Mn has high strength, elasticity and hardness, and is mostly used after quenching and tempering, resulting in poor welding performance. 50Mn round steel is used to manufacture heat-treated parts with high wear resistance requirements, such as gears, gear shafts and mandrels with a cross-section below 80mm, and its performance is close to that of No. 50 steel. But it has higher hardenability. After heat treatment, the hardness, strength and elasticity are higher than those of No. 50 steel. Carbon steel 50Mn has overheating sensitivity and a tendency to become fire brittle. 50Mn steel is used as stress-bearing parts, high wear-resistant parts, high-stress parts, such as mandrels with a diameter of less than 80 mm. It can also manufacture train shafts, worms, connecting rods and automobile crankshafts, such as gears, gear shafts, friction discs, mandrels, flat springs, etc.

Carbon steel 50Mn chemical composition:
Carbon C: 0.48-0.56
Silicon Si: 0.17-0.37
Manganese Mn: 0.70-1.00
Sulfur S: ≤0.035
Phosphorus P: ≤0.035
Chromium Cr: ≤0.25
Nickel Ni: ≤0.30
Copper Cu: ≤0.25

Mechanical properties of carbon steel 50Mn:
Tensile strength σb (MPa): ≥645(66)
Yield strength σs (MPa): ≥390(40)
Elongation δ5 (%): ≥13
Area shrinkage ψ (%): ≥40
Impact energy Akv (J): ≥31
Impact toughness value αkv (J/cm2): ≥39(4)

50Mn carbon steel hardness
Unheated≤255HB; Annealed Steel≤217HB
Heat treatment: 830℃ normalizing, 830℃ quenching, Tempering at 600℃