30CrMnSiNi2A alloy structural steel. High strength, good ductility and toughness can be obtained after heat treatment. Good fatigue resistance and fracture toughness. Low fatigue cracks growth rate.


Chemical Composition

%0.27-0.340.90-1.201.00-1.300.020 MAX0.020 MAX0.90-1.201.40-1.80

Mechanical Properties

Tensile strength σb (MPa): 1) 1767; 2) 1627
Elongation δ5 (%): 1) 12; 2) 13
Reduction of ψ (%): 50
Impact toughness αku (J / cm2): 1) 79; 2) 90
Sample size: bar

Physical properties

The critical temperature of 30CrMnSiNi2A Steel

Critical piontAc1Ac3Ms
Temperature/℃705 705800 815321 314

Elastic modulus of 30CrMnSiNi2A Steel

Elastic modulus E/MPa211000208000204000202000

Linear Expansion Coefficient of 30CrMnSiNi2A Steel:

Linear Expansion Coefficient /C10.5511.3711.6712.6812.913.5513.813.911.1512.1

Thermal conductivity of 30CrMnSiNi2A Steel:

Thermal conductivity λ/W·(m·K)25.728.029.329.929.328.227.025.724.022.3

Mass constant pressure heat capacity of 30CrMnSiNi2A Steel:

Mass constant pressure heat capacitycp/J·(kg·K)472.3526.6518.0639.5698.0752.4831.8

Heat treatment

1) 890 ~ 900 ℃ oil quenching, 200 ~ 300 ℃ tempering, air-cooled;

2) 890 ~ 900 ℃ heated, quenched into 210 ~ 280 ℃ nitrate bath isothermal 1h, air-cooled, and then at 200 ~ 300 ℃ tempering, air-cooled.


High hardenability. Machinability and weldability are good. But sensitive to notch and hydrogen embrittlement (including environmental hydrogen embrittlement).

30CrMnSiNi2A is suitable for important stress-bearing structural components. Such as high-strength connectors and shaft parts.

Available Size

Round BarDiameter(mm): 6-800mm ,Length: 1000-9000mm or custom size
Plate/Flat/BlockThickness: 6mm-500mm , Width: 20mm-1000mm or custom size
Tolerance±1%,Thickness: +/-0.02mm, Width:+/-2mm