EN 10085 Grade 31CrMo12 surface hardened
EN 10085 Grade 31CrMo12 surface hardened introduction
The nitriding steel 31 CrMo 12 can undergo quenchhardening and is used for heavy machine parts that are subjected to wear, have a high surface hardness and have a dimension of up to 250 mm. With parts for hot steam fittings such as valve spindles, it is used for dimensions of up to 100 mm and under highest pressure, the same with grinder valves and milling machine spindles.
The steel contains a nitride agent (Cr) which contributes through the nitriding process or the nitro-carburization process with N or N and C to a higher:
- case hardness
- abrasion resistance
- fatigue strength
and
- corrosion resistance.
It is used for forged construction components: quench-hardened, mechanically processed and treated thermo-chemically (for example nitriding).
Equivalent material: NBN 31CrMo12, AFNOR 30CD12, BS 722M24, ISO 31CrMo12, UNI 31CrMo12, SS 2240, UNE F.1712-31CrMo12, DIN 1.8515, EN 31CrMo12, EN 1.8515
EN 10085 Grade 31CrMo12 surface hardened general
| Property |
Temperature |
Value |
| Density |
20.0 °C |
Density of 7.83 - 7.85 g/cm³ |
EN 10085 Grade 31CrMo12 surface hardened thermal
| Property |
Temperature |
Value |
| Coefficient of thermal expansion |
-100.0 °C |
Coefficient of thermal expansion of 1.05E-5 1/K |
| - |
20.0 °C |
Coefficient of thermal expansion of 1.15E-5 1/K |
| - |
100.0 °C |
Coefficient of thermal expansion of 1.1E-5 - 1.21E-5 1/K |
| - |
200.0 °C |
Coefficient of thermal expansion of 1.2E-5 - 1.27E-5 1/K |
| - |
300.0 °C |
Coefficient of thermal expansion of 1.3E-5 - 1.32E-5 1/K |
| - |
400.0 °C |
Coefficient of thermal expansion of 1.36E-5 - 1.4E-5 1/K |
| - |
500.0 °C |
Coefficient of thermal expansion of 1.4E-5 1/K |
| - |
600.0 °C |
Coefficient of thermal expansion of 1.44E-5 1/K |
| Specific heat capacity |
-100.0 °C |
Specific heat capacity of 423 J/(kg·K) |
| - |
20.0 °C |
Specific heat capacity of 440 - 461 J/(kg·K) |
| - |
100.0 °C |
Specific heat capacity of 479 J/(kg·K) |
| - |
200.0 °C |
Specific heat capacity of 499 J/(kg·K) |
| - |
300.0 °C |
Specific heat capacity of 517 J/(kg·K) |
| - |
400.0 °C |
Specific heat capacity of 536 J/(kg·K) |
| - |
500.0 °C |
Specific heat capacity of 558 J/(kg·K) |
| - |
600.0 °C |
Specific heat capacity of 587 J/(kg·K) |
| Thermal conductivity |
20.0 °C |
Thermal conductivity of 25.7 - 36 W/(m·K) |
| - |
100.0 °C |
Thermal conductivity of 27.4 W/(m·K) |
| - |
200.0 °C |
Thermal conductivity of 28.5 W/(m·K) |
| - |
300.0 °C |
Thermal conductivity of 28.9 W/(m·K) |
| - |
400.0 °C |
Thermal conductivity of 28.5 W/(m·K) |
| - |
500.0 °C |
Thermal conductivity of 27.7 W/(m·K) |
| - |
600.0 °C |
Thermal conductivity of 26.8 W/(m·K) |
| Thermal diffusivity |
20.0 °C |
Thermal diffusivity of 7.1 mm²/s |
| - |
100.0 °C |
Thermal diffusivity of 7.1 mm²/s |
| - |
200.0 °C |
Thermal diffusivity of 6.9 mm²/s |
| - |
300.0 °C |
Thermal diffusivity of 6.6 mm²/s |
| - |
400.0 °C |
Thermal diffusivity of 6.1 mm²/s |
| - |
500.0 °C |
Thermal diffusivity of 5.3 mm²/s |
| - |
600.0 °C |
Thermal diffusivity of 4.5 mm²/s |
EN 10085 Grade 31CrMo12 surface hardened chemical
| Property |
Value |
| Carbon |
Carbon of 0.28 - 0.35 % |
| Chromium |
Chromium of 2.8 - 3.3 % |
| Manganese |
Manganese of 0.4 - 0.7 % |
| Molybdenum |
Molybdenum of 0.3 - 0.5 % |
| Nickel |
Nickel of 0.3 % |
| Phosphorus |
Phosphorus of 0.03 % |
| Silicon |
Silicon of 0.4 % |
| Sulfur |
Sulfur of 0.03 % |
EN 10085 Grade 31CrMo12 surface hardened electrical
| Property |
Temperature |
Value |
| Electrical resistivity |
20.0 °C |
Electrical resistivity of 1.8E-7 - 4.05E-7 Ω·m |
| - |
100.0 °C |
Electrical resistivity of 4.67E-7 Ω·m |
| - |
200.0 °C |
Electrical resistivity of 5.53E-7 Ω·m |
| - |
300.0 °C |
Electrical resistivity of 6.5E-7 Ω·m |
| - |
400.0 °C |
Electrical resistivity of 7.62E-7 Ω·m |
| - |
500.0 °C |
Electrical resistivity of 8.92E-7 Ω·m |
| - |
600.0 °C |
Electrical resistivity of 1.03E-6 Ω·m |
EN 10085 Grade 31CrMo12 surface hardened mechanical
| Property |
Temperature |
Value |
Comment |
| Elastic modulus |
-100.0 °C |
Elastic modulus of 217 GPa |
- |
| - |
20.0 °C |
Elastic modulus of 210 - 212 GPa |
- |
| - |
100.0 °C |
Elastic modulus of 205 - 207 GPa |
- |
| - |
200.0 °C |
Elastic modulus of 195 - 199 GPa |
- |
| - |
300.0 °C |
Elastic modulus of 185 - 192 GPa |
- |
| - |
400.0 °C |
Elastic modulus of 184 GPa |
- |
| - |
500.0 °C |
Elastic modulus of 175 GPa |
- |
| - |
600.0 °C |
Elastic modulus of 164 GPa |
- |
| Poisson's ratio |
23.0 °C |
Poisson's ratio of 0.3 [-] |
Typical for Steel |
Discover innovative solutions at every stage of your project journey with our steel expertise.
-- Our promise
Similar or equivalent steel materials
Get a quote