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Chemical composition and mechanical properties of 18Cr2Ni4WA
**Chemical Composition and Mechanical Properties of 18Cr2Ni4WA Steel: Main Applications**
**Material Name:** Alloy Structural Steel
**Grade:** 18Cr2Ni4WA
**Standard:** GB/T 3077-1999
18Cr2Ni4WA is a high-strength medium-alloy carburizing steel, commonly used in the manufacturing of critical mechanical components that require excellent toughness, strength, and wear resistance. This steel is designed to achieve high surface hardness through carburization, while maintaining a tough core. The carbon and austenite content are carefully controlled to ensure optimal performance during heat treatment.
The steel can be carburized at temperatures between 900–920°C, followed by tempering at 600–650°C. After oil quenching, the hardness typically reaches around 48 HRC, but for applications requiring higher hardness (HRC 58–63), surface carburizing is essential. In addition to carburizing, it can also be quenched and tempered without carburization, making it suitable for larger cross-section parts that demand high load-bearing capacity and low notch sensitivity.
**Chemical Composition (Weight %):**
- Carbon (C): 0.13–0.19
- Silicon (Si): 0.17–0.37
- Manganese (Mn): 0.30–0.60
- Sulfur (S): ≤0.025
- Phosphorus (P): ≤0.025
- Chromium (Cr): 1.35–1.65
- Nickel (Ni): 4.00–4.50
- Copper (Cu): ≤0.025
- Tungsten (W): 0.80–1.20
**Mechanical Properties:**
- Tensile Strength (σb): ≥1175 MPa (≈120 kg/mm²)
- Yield Strength (σs): ≥1029 MPa (≈105 kg/mm²)
- Elongation (δ5): ≥10%
- Reduction of Area (ψ): ≥45%
- Impact Work (Akv): ≥78 J
- Impact Toughness (αkv): ≥98 J/cm²
- Hardness: ≤269 HB
- Sample Size: 15 mm diameter
**Heat Treatment Specifications:**
- Quenching: First at 950°C, second at 850°C, air-cooled
- Tempering: 200°C, water-cooled, then air-cooled
**Delivery Condition:**
The steel can be delivered in various conditions, including normalized, annealed, or high-temperature tempered, or in an untreated state. The specific delivery condition should be clearly stated in the contract.
**Main Applications:**
18Cr2Ni4WA is widely used in heavy-duty mechanical systems such as gears, shafts, and other components that require high strength, good fatigue resistance, and excellent impact properties. It is especially suitable for large sections where uniform hardening and toughness are required.
This alloy is ideal for industries like automotive, aerospace, and heavy machinery, where reliability and durability are crucial. Its combination of high strength, good machinability, and excellent hardenability makes it a popular choice for demanding engineering applications.
Editor: Hardware Business Network Information Center
Source: [http://news.chinawj.com.cn](http://news.chinawj.com.cn)