Description
24CrNiMo7 Alloy Steel Overview
24CrNiMo7 is a high-quality alloy steel known for its excellent strength, toughness, and hardenability. This steel grade is primarily used in applications that require high wear resistance and superior mechanical properties. Its composition includes chromium, nickel, and molybdenum, which collectively enhance its performance under high-stress conditions. Due to its robust characteristics, 24CrNiMo7 is widely used in the automotive, aerospace, and heavy machinery industries.
Key Features of 24CrNiMo7 Alloy Steel:
- High Hardenability: Achieves high hardness and strength after appropriate heat treatment.
- Excellent Toughness: Provides good impact resistance and ductility, suitable for dynamic loads.
- Superior Wear Resistance: Enhanced resistance to wear and abrasion, making it ideal for demanding applications.
- Good Machinability: Suitable for machining into complex shapes with standard tools.
Applications of 24CrNiMo7 Alloy Steel
24CrNiMo7 alloy steel is utilized in a variety of high-performance applications where strength and durability are critical. Its properties make it suitable for components that undergo significant stress and wear.
Typical Applications Include:
- Automotive Industry: Gear shafts, crankshafts, and differential gears.
- Aerospace Industry: Structural components and landing gear.
- Engineering Machinery: Gearboxes, heavy-duty shafts, and hydraulic cylinders.
- Oil and Gas Industry: Drilling equipment and high-pressure fittings.
Equivalent Grades of 24CrNiMo7 Alloy Steel
24CrNiMo7 alloy steel has equivalents in various international standards, ensuring compatibility and ease of sourcing across different regions.
| Standard | Equivalent Grade |
|---|---|
| DIN | 24CrNiMo7 |
| EN | 1.6587 |
| AISI/SAE | 9317 |
| BS | 817M40 |
| UNS | G93170 |
Chemical Composition of 24CrNiMo7 Alloy Steel
The chemical composition of 24CrNiMo7 is optimized to provide a balance of strength, toughness, and hardenability. The following table outlines the typical composition of 24CrNiMo7 alloy steel:
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.22 – 0.28 |
| Silicon (Si) | 0.15 – 0.35 |
| Manganese (Mn) | 0.40 – 0.70 |
| Phosphorus (P) | ≤ 0.035 |
| Sulfur (S) | ≤ 0.035 |
| Chromium (Cr) | 1.50 – 1.80 |
| Nickel (Ni) | 1.50 – 2.00 |
| Molybdenum (Mo) | 0.20 – 0.35 |
This composition ensures that 24CrNiMo7 alloy steel offers high strength, durability, and resistance to wear.
Mechanical Properties of 24CrNiMo7 Alloy Steel
The mechanical properties of 24CrNiMo7 are crucial for its performance in high-stress applications. The following table summarizes the typical mechanical properties:
| Property | Value (Typical) |
|---|---|
| Tensile Strength (MPa) | 850 – 1000 |
| Yield Strength (MPa) | 600 – 750 |
| Elongation (%) | ≥ 10 |
| Impact Toughness (J) | ≥ 40 (at room temperature) |
| Hardness (HB) | 200 – 250 |
These properties indicate that 24CrNiMo7 maintains good strength and toughness even under high stress, making it suitable for critical engineering components.
Heat Treatment of 24CrNiMo7 Alloy Steel
Proper heat treatment is essential to achieve the desired mechanical properties in 24CrNiMo7 alloy steel. The typical heat treatment processes include:
- Hardening: Heat to 830 – 870°C and quench in oil or water. This process increases hardness and strength.
- Tempering: Heat to 150 – 200°C after hardening to reduce brittleness and improve toughness.
- Normalizing: Heat to 850 – 900°C and air cool to refine the grain structure and enhance toughness.
These heat treatment processes help optimize the steel’s performance for various applications.
Hardness of 24CrNiMo7 Alloy Steel
The hardness of 24CrNiMo7 alloy steel is affected by the heat treatment processes it undergoes. Typical hardness values are as follows:
- Annealed Condition: 200 – 250 HB
- After Hardening and Tempering: Up to 60 HRC
This range of hardness ensures that 24CrNiMo7 alloy steel can achieve high wear resistance and strength while maintaining adequate toughness.
Physical Properties of 24CrNiMo7 Alloy Steel
The physical properties of 24CrNiMo7 provide stability and reliability in various operating conditions. The following table summarizes these properties:
| Property | Value |
|---|---|
| Density (g/cm³) | 7.85 |
| Melting Point (°C) | 1420 – 1450 |
| Thermal Conductivity (W/m·K) | 30 – 35 |
| Specific Heat Capacity (J/kg·K) | 460 – 480 |
These properties help ensure that 24CrNiMo7 alloy steel maintains its performance in different temperature and load conditions.
Forging Properties of 24CrNiMo7 Alloy Steel
24CrNiMo7 alloy steel is forgeable within the temperature range of 1100 – 1200°C. Forging should be followed by controlled cooling to prevent cracking and internal stresses.
Stress Relieving for 24CrNiMo7 Alloy Steel
Stress relieving involves heating the steel to 600 – 650°C to reduce residual stresses from machining or forming, followed by slow cooling. This process improves dimensional stability and reduces the risk of warping.
Normalizing 24CrNiMo7 Alloy Steel
Normalizing is performed by heating the steel to 850 – 900°C and allowing it to cool in air. This process refines the grain structure and enhances toughness.
Annealing 24CrNiMo7 Alloy Steel
Annealing is carried out by heating the steel to 680 – 720°C and cooling it slowly in the furnace. This process improves machinability and prepares the steel for further heat treatments.
Machinability of 24CrNiMo7 Alloy Steel
24CrNiMo7 alloy steel offers good machinability, particularly in its annealed condition. It can be machined into complex shapes with standard cutting tools, although care should be taken to manage tool wear during high-hardness operations.
Welding of 24CrNiMo7 Alloy Steel
Welding of 24CrNiMo7 alloy steel is feasible with appropriate preheating (to about 150 – 200°C) and post-weld heat treatment. Proper procedures must be followed to avoid issues such as cracking or reduced toughness.
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.
