SAE 4140, 42CrMo4, Material Number: 1.7225 Forged Steels
PRODUCT DESCRIPTION
42CrMo4 is a steel that provides high strength and hardness for automotive, aerospace, and heavy machinery applications. It is machinable and weldable, suitable for high-stress components.PRODUCT TYPES
- Round Shape Steels between 10 mm and 1300 mm
- SAE 4140 Square Shape Steel Plates
- SAE 4140 Sheet Metals
- SAE 4140 Steel Pipes
42CrMo4: Overview
42CrMo4 is a high-strength, low-alloy steel that is widely used in industries requiring durable and tough materials. It offers excellent hardness, machinability, and weldability, making it ideal for applications in the automotive, machine building, and aerospace industries. 42CrMo4 is commonly used in the production of gears, shafts, and other mechanical components that are exposed to high loads and stresses.
Chemical Composition (in %)
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.38 – 0.45 |
| Silicon (Si) | 0.10 – 0.35 |
| Manganese (Mn) | 0.60 – 0.90 |
| Phosphorus (P) | 0.025 max |
| Sulfur (S) | 0.025 max |
| Chromium (Cr) | 0.90 – 1.20 |
| Nickel (Ni) | 0.30 max |
| Molybdenum (Mo) | 0.15 – 0.30 |
| Copper (Cu) | 0.35 max |
Physical Properties
- Density: 7.85 g/cm³ (or 7850 kg/m³)
- Tensile Strength (Rm): 850–1000 MPa
- Yield Strength (Rp0.2): 700 MPa (min)
- Elongation (A): ≥ 12% (for thickness up to 20 mm)
- Hardness (HB): 190–235
Machinability
42CrMo4 is known for its good machinability, especially in the normalized and tempered state. The steel's alloy content allows for efficient machining into complex parts and components. It is suitable for processes like turning, drilling, milling, and grinding.
Tips for Machining:
- Use carbide tools to achieve high surface quality and prevent wear.
- Maintain moderate cutting speeds to optimize tool life.
- Lubrication or cutting fluids should be used to reduce friction and heat during machining.
Weldability
42CrMo4 exhibits good weldability, but preheating is generally recommended for thicker sections. It can be welded using conventional methods like MIG, TIG, and arc welding. Post-weld heat treatment (PWHT) may be necessary to relieve stresses and avoid cracking.
Welding Guidelines:
- Preheating is recommended for sections thicker than 30 mm.
- Use low-hydrogen electrodes for optimal weld quality.
- Post-weld heat treatment may be required to restore mechanical properties.
Usage Areas
42CrMo4 is used in industries requiring high-strength materials capable of withstanding high mechanical loads, such as:
- Automotive Industry: Gears, shafts, axle parts, and crankshafts.
- Aerospace Industry: Aircraft landing gear components, structural parts.
- Machine Building: Gearboxes, shafts, crankshafts, and components for heavy machinery.
- Tool Manufacturing: Tools subjected to high stresses and wear.
- Energy Sector: Components in turbines, compressors, and drilling equipment.
Industries Using 42CrMo4 Steel
- Automotive Industry: Components like gears, drives, and shafts in engines and transmissions.
- Aerospace: Critical parts like landing gear and structural components.
- Energy Sector: Parts for turbines, generators, and compressors.
- Machine Building: Heavy-duty components such as shafts, gears, and crankshafts.
- Heavy Equipment: Structural components for excavators, cranes, and other machinery.
Key Advantages of 42CrMo4
- High Tensile Strength: Suitable for heavy-duty and load-bearing applications.
- Good Weldability: Can be welded using standard welding techniques.
- High Hardness: Achieves high hardness after heat treatment, ideal for wear-resistant components.
- Durability and Toughness: Ideal for components subjected to high mechanical stress.
- Versatility: Used across various industries, including automotive, aerospace, and heavy machinery.