Views: 0 Author: Site Editor Publish Time: 2025-12-10 Origin: Site
Chemical Composition Comparison (Weight %)
Element | AISI 304 (Basic Grade) | AISI 316 (Molybdenum Grade) | UNS S32205 / S31803 (Duplex 2205) |
Carbon (C) | ≤ 0.08% | ≤ 0.08% | ≤ 0.030% |
Manganese (Mn) | ≤ 2.0% | ≤ 2.0% | ≤ 2.0% |
Phosphorus (P) | ≤ 0.045% | ≤ 0.045% | ≤ 0.030% |
Sulfur (S) | ≤ 0.030% | ≤ 0.030% | ≤ 0.020% |
Silicon (Si) | ≤ 1.0% | ≤ 1.0% | ≤ 1.0% |
Chromium (Cr) | 18.0 - 20.0% | 16.0 - 18.0% | 22.0 - 23.0% |
Nickel (Ni) | 8.0 - 11.0% | 10.0 - 14.0% | 4.5 - 6.5% |
Molybdenum (Mo) | - | 2.0 - 3.0% | 3.0 - 3.5% |
Nitrogen (N) | - | - | 0.14 - 0.20% |
Iron (Fe) | Balance | Balance | Balance |
Key Takeaways from the Composition:
304 Stainless Steel: The most common austenitic grade. It has excellent corrosion resistance in general atmospheres but is susceptible to chloride attack. The key elements are Chromium (18-20%) and Nickel (8-11%).
316 Stainless Steel: The main difference from 304 is the addition of Molybdenum (2-3%). This significantly increases corrosion resistance, particularly against chlorides and acids, making it ideal for marine and chemical processing environments. It also has slightly higher Nickel content.
2205 Stainless Steel (Duplex): This is a "duplex" stainless steel, meaning it has a mixed microstructure of austenite and ferrite. This gives it a unique set of properties:
High Chromium (22-23%) and Molybdenum (3-3.5%) content for excellent pitting and crevice corrosion resistance.
Lower Nickel content compared to 316.
The addition of Nitrogen enhances strength and corrosion resistance.
It offers roughly twice the yield strength of 304 and 316 and superior resistance to stress corrosion cracking.
