Stress Corrosion Cracking of Duplex Stainless Steel
SCC Stress Corrosion Cracking is a form of corrosion which occurs with a particular combination of factors:
- Tensile stress
- Corrosive environment
- Sufficiently high temperature. Normally 50 deg C but can occur at lower temperatures around 25 deg C in specific environments, notably swimming pools.
Unfortunately, the standard austenitic steel like 304 (1.4301) and 316 (1.4401) are the most susceptible to SCC. The following materials are much less prone to SCC:
The resistance to SCC makes duplex steels suitable materials for many processes which operate at higher temperature, notably:
- Hot water boilers
- Brewing tanks
- Desalination
Stainless steel structures in swimming pools are known to be prone to SCC. The use of standard austenitic stainless steel like 304 and 316 is forbidden in this application. The best steels to use for this purpose are the high nickel austenitic steel such as the 6% Mo grades. However, in some cases, duplex steel such as S32205 (1.4462) and the superduplex grades can be considered.
Related References:
1. Duplex Stainless Steel Pipe
2. Duplex Stainless Steel
3. Super-Duplex Stainless Steel
4. Principle of Duplex Stainless Steel
5. How the Austenite Ferrite Balance Achieved
6. Corrosion Resistance of Duplex Stainless Steel
7. Stress Corrosion Cracking SCC of Duplex Stainless Steel
8. Barrier to Using Duplex Stainless Steel
9. Duplex Stainless Steel Grades Comparison Table
10. S32101 | S32205/S31803 | S32304 | S32750 | S32760
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