Military Steel: 12CrNi3

Standard: GB / T 3077-1988

● Features and application:

The wider use of advanced carburizing steel with 15Cr, 20Cr steel compared to its strength, ductility, hardenability are high. Mainly used to produce heavy-duty conditions requiring high strength, high hardness and high toughness requirements of central spindle and high toughness or shock loading, surface wear, heat deformation of the shaft, rod, and the impact of high-speed and work load a variety of gear, adjust the screw, camshaft

● Chemical Composition:

Carbon C: 0.10 ~ 0.17

Si Si: 0.17 ~ 0.37

Manganese Mn: 0.30 ~ 0.60

Sulfur S: to allow the residual content of ≤ 0.035

Phosphorus P: allow the residual content ≤ 0.035

Chromium Cr: 0.60 ~ 0.90

Ni-Ni: 2.75 ~ 3.15

Copper Cu: to allow the residual content ≤ 0.030

● Mechanical Properties:

Tensile strength σb (MPa): ≥ 930 (95)

Yield strength σs (MPa): ≥ 685 (70)

Elongation δ5 (%): ≥ 11

Reduction of area ψ (%): ≥ 50

Impact energy Akv (J): ≥ 71

Impact toughness αkv (J/cm2): ≥ 88 (9)

Hardness: ≤ 217HB

Sample size: Sample size is 15mm rough

● Heat treatment and microstructure specifications:

Standard heat treatment: quenching: the first 860 ℃, the second 780 ℃, oil cooling; tempering 200 ℃, water, air-cooled.

● Delivery status: to heat treatment (normalizing, annealing, or tempering) or heat treatment delivery, delivery status should be indicated in the contract.

● processing performance: When the hardness HB260 ~ 320, the relative machinability of 60% to 70%