1.6511/AISI 4340/SNCM439 Alloy Steel Overview:
1.6511 is a chromium-molybdenum alloy steel known for its high tensile strength, toughness, and wear resistance. Also known as 36CrNiMo4 or ASTM 4340, it is widely used in various industries such as automotive, aerospace, and machinery manufacturing due to its excellent mechanical properties and versatility.
Chemical Composition:
| Element |
Composition (%) |
| Carbon (C) |
0.32-0.40 |
| Silicon (Si) |
0.15-0.40 |
| Manganese (Mn) |
0.50-0.80 |
| Phosphorus (P) |
≤0.035 |
| Sulfur (S) |
≤0.035 |
| Chromium (Cr) |
0.90-1.20 |
| Nickel (Ni) |
≤0.70 |
| Molybdenum (Mo) |
0.15-0.30 |
Properties:
- High Tensile Strength: 1.6511 steel exhibits high tensile strength, making it suitable for applications requiring load-bearing components and structural parts subjected to high mechanical stress.
- Good Toughness: It offers good toughness and impact resistance, ensuring durability and reliability in demanding operating conditions.
- Excellent Wear Resistance: With its alloying elements, 1.6511 steel provides excellent wear resistance, making it suitable for gears, shafts, and other components subjected to friction and wear.
- Good Hardenability: It has good hardenability, allowing for uniform hardness throughout the cross-section of components during heat treatment, resulting in improved mechanical properties.
- Versatility: 1.6511 steel is versatile and can be used in various applications such as gears, crankshafts, axles, and connecting rods in automotive and machinery industries.
- Machinability: It has good machinability in the annealed or normalized condition, facilitating machining operations such as milling, drilling, and turning.
Heat Treatment:
1.6511 steel can be heat-treated to achieve desired mechanical properties. Common heat treatment processes include:
- Annealing: Heating to 800-850°C followed by slow cooling in the furnace to relieve internal stresses and improve machinability.
- Normalizing: Heating to 870-920°C followed by air cooling to refine the grain structure and improve mechanical properties.
- Quenching and Tempering: Heating to 850-880°C followed by oil quenching and tempering at 550-650°C to achieve desired hardness and toughness.
Surface Treatment:
Surface treatments such as carburizing, nitriding, or black oxide coating can be applied to enhance the surface hardness, wear resistance, and corrosion resistance of 1.6511 steel components in specific applications.
Applications:
- Automotive Industry: Used in the production of automotive components such as gears, crankshafts, axles, and transmission parts due to its high strength and wear resistance.
- Aerospace Industry: Utilized in aircraft components like landing gear, engine parts, and structural elements requiring high tensile strength and toughness.
- Machinery Manufacturing: Widely used for manufacturing gears, shafts, spindles, and other machine components subjected to heavy loads and wear.
Quality Assurance:
1.6511 steel is manufactured according to national and international standards such as DIN EN 10083-3 and ASTM A29/A29M. Quality assurance measures ensure consistency in chemical composition, mechanical properties, and dimensional accuracy of the material.
Environmental Considerations:
In the production and processing of 1.6511 steel, environmental considerations such as waste management, energy efficiency, and emissions control should be addressed to minimize environmental impact and promote sustainability in the industry.
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