Material Name: high quality carbon structural steel
Grade: 30Mn
Standard: GB / T 699-1988
● Features and application:
Strength and hardenability steel more than 30 high, medium welding, cold deformation, the plastic medium, good machinability, usually used in normalizing the state, for the manufacture of bolts, nuts, leverage, and high-stress work in small parts.
Manganese (W mn 0.70% -1.00%) higher carbon-hardened steel, high manganese because it is their strength plastic. Can be cut and hardenability slightly higher than 15 steel, carburizing and quenching surface soft point less, should be cementite. carbonitriding treatment, surface wear and heart to get a good overall performance of the Ministry of toughness. Hot-rolled or normalized after treatment toughness. For gear crank shaft, frame the longer chain screws. Nuts. Welding structural parts, sheet metal for manufacturing tanks and so on. Tools in cold regions, such as butter cans.

     ● Chemical Composition:

Carbon C: 0.27 ~ 0.34

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): ≥ 540 (55)

Yield strength σs (MPa): ≥ 315 (32)

Elongation δ5 (%): ≥ 20

Reduction of area ψ (%): ≥ 45

Impact energy Akv (J): ≥ 63

Impact toughness αkv (J/cm2): ≥ 78 (8)

Hardness: no heat treatment ≤ 217HB; annealed steel ≤ 187HB

Sample Size: Sample size is 25mm

● Heat treatment and microstructure specifications:

Heat treatment specifications: normalizing, 880 ℃; quenching, 860 ℃; tempering, 600 ℃.

● Delivery status: no heat treatment or heat treatment (annealing, normalizing or tempering) the status of delivery. Demands heat treatment delivery should be specified in the contract, not indicated by no heat treatment delivery.