Description
35CrMo Steel Introduction:
35CrMo is a high-strength, low-alloy steel with excellent toughness, high hardenability, and good resistance to wear and fatigue. The alloying elements chromium (Cr) and molybdenum (Mo) enhance the material’s strength, hardness, and resistance to impact, particularly at high temperatures. This steel is typically used for manufacturing parts subjected to high stresses, such as components in the aerospace, automotive, and energy sectors.
35CrMo Grade Applications:
35CrMo steel is used for parts that require high toughness, wear resistance, and strength, including:
- Gears
- Shafts
- High-strength bolts and fasteners
- Axles
- Drill collars and other components in oil field applications
- Pressure vessels
It is commonly used in structural applications and in environments with high static or dynamic loads.
Equivalent Grades:
- GB: 35CrMo
- DIN: 1.7220 (42CrMo4 similar but with slight differences in carbon content)
- AISI/SAE: 4135 (similar but with slight differences)
- JIS: SCM435
Chemical Composition:
| Element | Content (%) |
|---|---|
| C | 0.32-0.40 |
| Mn | 0.40-0.70 |
| P | ≤ 0.035 |
| S | ≤ 0.035 |
| Cr | 0.80-1.10 |
| Mo | 0.15-0.25 |
| Si | 0.17-0.37 |
Mechanical Properties:
| Property | Value |
|---|---|
| Tensile strength (MPa) | ≥ 980 |
| Yield strength (MPa) | ≥ 835 |
| Elongation rate (%) | ≥ 12 |
| Reduction of area (%) | ≥ 55 |
| Impact energy (J) | ≥ 47 |
| Hardness (HB) | 217-241 (annealed) |
35CrMo Hardness:
When annealed, the hardness is typically between 217-241 HB, and it can be further increased through heat treatment to achieve greater wear resistance and mechanical strength.
Heat Treatment:
35CrMo can be hardened, tempered, and normalized to achieve specific mechanical properties.
Hardening Process:
- Heating: Heat to 880-920°C, then quench in oil or water to achieve full hardening.
- Tempering: After quenching, tempering is performed at temperatures between 500-650°C, which enhances toughness and reduces brittleness.
Physical Properties:
| Property | Value |
|---|---|
| Modulus of Elasticity (N/mm²) | 210 × 10³ |
| Density (g/cm³) | 7.85 |
| Thermal Conductivity (W/m.K) | 37.0 |
Thermal Properties:
- Thermal conductivity: 37.0 W/m.K at room temperature.
- Specific heat: 460 J/kg-K.
Forging Properties:
Forging temperatures range between 1100°C and 850°C. After forging, the material should be cooled slowly to prevent the formation of undesirable microstructures.
Normalizing:
Normalize the steel by heating it to 870-900°C followed by air cooling. This process refines the grain structure and improves mechanical properties.
Annealing:
Annealing is typically conducted at 850°C, followed by slow cooling in the furnace, making the material easier to machine and improving ductility.
Welding:
35CrMo has good weldability, but preheating and post-weld heat treatment are recommended for thick sections to minimize the risk of cracking.
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.
