Chemical composition:
Chemical Composition
C Si Mn P S Ni Cr Cu
≤
15Mn 0.12 ~ 0.18 0.17 ~ 0.37 0.70 ~ 1.00 0.035 0.035 0.30 0.25 0.25
20Mn 0.17 ~ 0.23 0.17 ~ 0.37 0.70 ~ 1.00 0.035 0.035 0.30 0.25 0.25

Mechanical properties:
Grades blank sample
Size
/ mm heat treatment process of the mechanical properties of the steel hardness delivery status
/ HBS
Normalizing quenching and tempering σb / MPa σs / MPa δ5 (%) ψ (%) Ak / J ≤
≥ No heat annealed steel
15Mn 25 920 410 245 26 55 163
20Mn 25 910 450 175 24 50 197

Characteristics and Uses:
15Mn is a high manganese carbon hardened steel, its performance and the 15th of steel similar, but hardenability, strength and ductility than the 15th of steel are higher. After carburizing steel or cyanide can be a hard surface and toughness unchanged, the center has a high strength, soft spots during carburizing and hardening steel less formed on the 15th, cutting performance is also better than the 15th of steel than welding good performance. Mechanical properties for demanding manufacturing center part, and the need carburizing parts.
20Mn is a high manganese carbon hardened steel, and its performance is similar with 15Mn steel, hardenability, strength and ductility than the 20th of steel is good, also improved machinability, good low temperature impact toughness and weldability. Used in the manufacture camshafts, gears, couplings, hinges, pins, tow bars, crank shaft, bearing rings and so on.