Name: high-quality carbon structural steel
Grade: 50Mn
Standard: GB / T 699-1988

Features:

     50Mn strength, flexibility and hardness were higher than in the quenched and tempered use, welding performance is poor. 50Mn demanding round for the manufacture of wear resistance, high heat load under the action of parts such as gears, gear shaft and the cross section below the spindle in 80mm and so on. Performance with 50 similar, but its high hardenability, strength after heat treatment. Hardness elasticity are slightly higher than the 50 steel. Poor welding, heat-sensitive and has a tendency to temper brittleness. Withstand the stress components for High wear parts such as gears. Gear shaft friction disc. Spindles. Flat springs.

Chemical composition:

     Carbon C: 0.48 ~ 0.56

Si Si: 0.17 ~ 0.37

Manganese Mn: 0.70 ~ 1.00

Sulfur S: ≤ 0.035

Phosphorus P: ≤ 0.035

Chromium Cr: ≤ 0.25

Ni-Ni: ≤ 0.30

Copper Cu: ≤ 0.25

Mechanical properties:

     Tensile strength σb (MPa): ≥ 645 (66)

Yield strength σs (MPa): ≥ 390 (40)

Elongation δ5 (%): ≥ 13

Reduction of area ψ (%): ≥ 40

Impact energy Akv (J): ≥ 31

Impact toughness αkv (J/cm2): ≥ 39 (4)

Hardness:

     Without heat treatment ≤ 255HB; annealed steel ≤ 217HB

Heat treatment

830 ℃ normalizing

830 ℃ quenching

600 ℃ tempering