Description
30CrNiMo8 Alloy Steel Introduction
30CrNiMo8 is a high-quality alloy steel known for its excellent combination of strength, toughness, and wear resistance. It is particularly valued for its use in demanding applications where high fatigue resistance, impact strength, and hardenability are required. This steel is commonly utilized in the automotive, aerospace, and engineering industries for manufacturing components that undergo significant stress and strain.
The alloy composition of 30CrNiMo8 includes chromium, nickel, and molybdenum, which contribute to its superior mechanical properties. The steel is typically supplied in the normalized or quenched and tempered condition, providing an optimal balance of hardness and toughness.
30CrNiMo8 Alloy Steel Application
30CrNiMo8 alloy steel is employed in various high-stress and high-wear applications. Its unique properties make it suitable for:
- Automotive Industry: Gear wheels, drive shafts, and crankshafts that require high strength and durability.
- Aerospace Industry: Aircraft components like landing gear, structural parts, and turbine blades.
- Engineering: Components such as couplings, spindles, and heavy-duty machinery parts.
- Oil and Gas: Drilling equipment, valve bodies, and high-pressure parts.
- Tooling: Molds and dies subjected to high loads and thermal stress.
30CrNiMo8 Alloy Steel Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| DIN | 1.6580 |
| BS | 817M40 |
| AISI/SAE | 4340 |
| UNS | G43400 |
| JIS | SNCM439 |
30CrNiMo8 Alloy Steel Chemical Composition
The following table outlines the chemical composition of 30CrNiMo8 alloy steel:
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.30 – 0.38 |
| Silicon (Si) | 0.10 – 0.35 |
| Manganese (Mn) | 0.40 – 0.70 |
| Nickel (Ni) | 1.30 – 1.70 |
| Chromium (Cr) | 0.90 – 1.20 |
| Molybdenum (Mo) | 0.15 – 0.30 |
| Phosphorus (P) | 0.035 max |
| Sulfur (S) | 0.035 max |
30CrNiMo8 Alloy Steel Mechanical Properties
The mechanical properties of 30CrNiMo8 alloy steel, as detailed below, make it suitable for various high-stress applications:
| Property | Value (Typical) |
|---|---|
| Tensile Strength (MPa) | 930 – 1080 |
| Yield Strength (MPa) | 780 |
| Elongation (%) | 12 |
| Impact Toughness (J) | 40 (at 20°C) |
| Hardness (HB) | 248 – 302 |
30CrNiMo8 Alloy Steel Heat Treatment
30CrNiMo8 alloy steel can be heat-treated to achieve specific mechanical properties:
- Annealing: Heat to 830-870°C, hold until uniform, then cool slowly in the furnace to relieve internal stresses and refine the grain structure.
- Hardening: Heat to 830-870°C, followed by quenching in oil or water to achieve high hardness.
- Tempering: After hardening, temper at 500-650°C to adjust hardness and improve toughness.
30CrNiMo8 Alloy Steel Hardness
The hardness of 30CrNiMo8 in the hardened and tempered condition typically ranges between 248 – 302 HB. This range allows for a balance between strength and ductility, suitable for demanding applications.
30CrNiMo8 Alloy Steel Physical Properties
The physical properties of 30CrNiMo8 are important for understanding its behavior under various conditions:
| Property | Value |
|---|---|
| Density (g/cm³) | 7.85 |
| Melting Point (°C) | 1425 |
| Thermal Conductivity (W/m·K) | 45 |
| Specific Heat Capacity (J/kg·K) | 460 |
30CrNiMo8 Alloy Steel Forging Properties
30CrNiMo8 can be forged at temperatures between 850 – 1150°C. After forging, it is crucial to cool the material slowly to avoid the development of internal stresses and potential cracking.
30CrNiMo8 Alloy Steel Stress Relieving
For components that have undergone heavy machining or significant deformation, stress relieving should be performed by heating to 550 – 650°C, holding for a sufficient period, and then cooling slowly. This process helps to reduce residual stresses and improve dimensional stability.
30CrNiMo8 Alloy Steel Normalizing
Normalizing of 30CrNiMo8 is conducted by heating to 830 – 870°C and then air cooling. This process refines the grain structure and enhances the material’s mechanical properties.
30CrNiMo8 Alloy Steel Annealing
Annealing involves heating 30CrNiMo8 to 830 – 870°C, holding it at this temperature, and then slowly cooling it in the furnace. This treatment reduces hardness, improves machinability, and relieves internal stresses.
30CrNiMo8 Alloy Steel Machinability
30CrNiMo8 exhibits good machinability in the annealed or normalized condition. It is recommended to use sharp cutting tools and appropriate machining parameters to achieve optimal results and extend tool life.
30CrNiMo8 Alloy Steel Welding
Welding of 30CrNiMo8 is feasible but requires preheating to 150 – 250°C to prevent cracking. Post-weld heat treatment is often necessary to ensure the integrity of the weld and avoid residual stresses.
Supply Cities:
Mumbai Ahmedabad, Amaravathi, Ambattur, Bangalore, Belgaum, Chennai, Chittoor, Coimbatore, Dindigul, Mysore, Nellore, Hyderabad, Kochi, Mangalore, Tirupur, Tuticorin, Madurai, Andhra Pradesh, Karnataka, Puducherry, Kerala, Tamil Nadu, Telangana, Visakhapatnam, Kochi, Kerala, Hubli-Dharwad, Karnataka, Ghaziabad Kolkata.
