Material Name: Grade: 40Mn standard: GB / T 699-1988

Features and application:
40Mn carbon steel can be used in a normalized state, but also in the quenched and tempered condition to use. Cutting performance, cold plastic deformation of the medium, poor welding performance. Withstand fatigue loads used in the manufacture of parts, such as the roller shaft to work under high stress and screws, nuts and so on.

Hardenability slightly higher than the 40 steel. After heat treatment, strength, hardness. Toughness slightly higher than the 40 steel, cold plastic deformation of the middle, can be good cutting, welding low, with a thermal sensitivity and temper brittleness, water quenched easy to crack. Components for fatigue crank. Rollers. Axis. Link.

     ● Chemical Composition:

Carbon C: 0.37 ~ 0.45

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): ≥ 590 (60)

Yield strength σs (MPa): ≥ 355 (36)

Elongation δ5 (%): ≥ 17

Reduction of area ψ (%): ≥ 45

Impact energy Akv (J): ≥ 47

Impact toughness αkv (J/cm2): ≥ 59 (6)

Hardness: no heat treatment ≤ 229HB; annealed steel ≤ 207HB

Sample Size: Sample size is 25mm

     Heat treatment specifications:
Normalizing, 860 ℃; quenching, 840 ℃; tempering, 600 ℃.

     Delivery status:
With 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.