Description
21CrMoV5-7 Alloy Steel Overview
21CrMoV5-7 is a high-quality alloy steel known for its exceptional strength, toughness, and heat resistance. It is a chromium-molybdenum-vanadium steel that offers superior performance in high-stress applications and demanding environments. The steel is particularly well-suited for use in components requiring high mechanical properties and resistance to wear and fatigue. Its alloying elements contribute to its excellent hardenability and thermal stability, making it ideal for heavy-duty applications in various industries.
Key Features of 21CrMoV5-7:
- High Strength: Offers excellent tensile and yield strength, making it suitable for load-bearing applications.
- Wear Resistance: Enhanced by the alloying elements, providing durability in abrasive conditions.
- Heat Resistance: Good performance at elevated temperatures due to the presence of chromium and molybdenum.
- Toughness: High impact resistance, which is critical for components subjected to dynamic loads.
Applications of 21CrMoV5-7 Alloy Steel
21CrMoV5-7 is widely used in industries where high strength and durability are required. Its applications include:
- Automotive Industry: Components such as gears, crankshafts, and camshafts.
- Engineering: Heavy machinery parts, structural components, and high-load bearings.
- Aerospace: Parts that require high-temperature strength and resistance to fatigue.
- Energy Sector: Components for power generation equipment, including turbines and compressors.
Equivalent Grades for 21CrMoV5-7
To ensure compatibility across various standards and regions, 21CrMoV5-7 is equivalent to several other grades:
| Standard | Equivalent Grade |
|---|---|
| DIN | 1.7709 |
| BS | 708M40 |
| AISI/SAE | 4140V |
| UNS | G41400 |
| JIS | SCM440 |
Chemical Composition of 21CrMoV5-7
The chemical composition of 21CrMoV5-7 defines its mechanical properties and performance. The typical composition is as follows:
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.18 – 0.23 |
| Silicon (Si) | 0.20 – 0.40 |
| Manganese (Mn) | 0.50 – 0.80 |
| Chromium (Cr) | 1.00 – 1.30 |
| Molybdenum (Mo) | 0.30 – 0.40 |
| Vanadium (V) | 0.10 – 0.15 |
| Phosphorus (P) | 0.025 max |
| Sulfur (S) | 0.025 max |
Mechanical Properties of 21CrMoV5-7
The mechanical properties of 21CrMoV5-7 are crucial for its performance in high-stress applications:
| Property | Value (Typical) |
|---|---|
| Tensile Strength (MPa) | 850 – 1000 |
| Yield Strength (MPa) | 650 – 850 |
| Elongation (%) | 10 – 15 |
| Impact Toughness (J) | 35 – 50 (at 20°C) |
| Hardness (HB) | 220 – 270 |
Heat Treatment of 21CrMoV5-7
Heat treatment processes are essential for achieving the desired mechanical properties of 21CrMoV5-7:
- Annealing: Heat to 850-900°C, hold until uniform, and cool slowly to improve machinability and relieve internal stresses.
- Hardening: Heat to 850-880°C, followed by quenching in oil or water to increase hardness and strength.
- Tempering: After hardening, temper at 500-600°C to reduce brittleness and enhance toughness.
Hardness of 21CrMoV5-7
In its hardened and tempered condition, 21CrMoV5-7 typically exhibits a hardness range of 220 – 270 HB. This range provides a balance between hardness and toughness, suitable for demanding applications.
Physical Properties of 21CrMoV5-7
The physical properties of 21CrMoV5-7 contribute to its performance in various environments:
| Property | Value |
|---|---|
| Density (g/cm³) | 7.85 |
| Melting Point (°C) | 1450 |
| Thermal Conductivity (W/m·K) | 43 |
| Specific Heat Capacity (J/kg·K) | 460 |
Forging Properties of 21CrMoV5-7
21CrMoV5-7 can be forged at temperatures between 850 – 1150°C. After forging, components should be cooled slowly to avoid internal stresses and potential cracking.
Stress Relieving for 21CrMoV5-7
To remove residual stresses from machining or deformation, stress relieving should be performed by heating to 550 – 650°C, holding for a sufficient period, and then cooling slowly.
Normalizing 21CrMoV5-7
Normalizing involves heating to 850 – 880°C and air cooling. This process refines the grain structure and improves mechanical properties.
Annealing 21CrMoV5-7
Annealing requires heating to 850 – 900°C, holding at this temperature, and then slowly cooling in the furnace. This treatment improves machinability and relieves internal stresses.
Machinability of 21CrMoV5-7
21CrMoV5-7 exhibits good machinability in the normalized or annealed condition. For optimal results, use sharp cutting tools and appropriate machining parameters to enhance tool life and surface finish.
Welding of 21CrMoV5-7
Welding of 21CrMoV5-7 is feasible but requires careful handling to avoid potential issues. Preheat to 150 – 250°C to prevent cracking, and consider post-weld heat treatment to ensure the integrity of the weld.
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.
