Composition and characteristics of 4140 alloy steel

Composition of 4140 alloy steel: 4140 alloy steel is a medium carbon alloy steel. Its main chemical components include: carbon (C) is about 0.38-0.43%, silicon (Si) is about 0.15-0.35%, and manganese (Mn) is about 0.75-1.00%, phosphorus (P) is up to 0.035%, sulfur (S) is up to 0.040%, chromium (Cr) is about 0.80-1.10%, nickel (Ni) is about 0.25%, and molybdenum (Mo) is about 0.15 -0.25%.

4140 alloy steel characteristics:
1. High strength: It has high yield strength and tensile strength, and is suitable for withstanding high loads or high stress environments.

2. Good toughness: After proper heat treatment, it has good toughness and impact toughness, and can resist impact and vibration.

3. Excellent wear resistance: 4140 alloy steel shows good wear resistance after heat treatment and is suitable for parts that require long-term use.

4. Good heat treatment plasticity: It is sensitive to heat treatment and its performance can be adjusted through appropriate heat treatment processes, such as quenching and tempering.

5. Ease of welding: It is relatively easy to weld, but you need to pay attention to selecting appropriate welding materials and processes during welding to avoid cracks or reduced performance.

6. Widely used: often used to manufacture parts that require high strength, high wear resistance and high toughness, such as crankshafts, connecting rods, bearings, etc., as well as mechanical parts and shaft applications.