Stress Corrosion Cracking in Stainless Steel Alloys: What You Need to Know

What stainless steel alloys are susceptible to stress corrosion cracking under insulation?

A. Duplex SS, Low alloys B. 300 Series SS, Duplex SS C. Duplex SS, 300 Series SS D. None of the above

Answer:

The correct answer is C. Duplex SS, 300 Series SS

In the context of corrosion under insulation, it's crucial to understand the susceptibility of different stainless steel (SS) grades. Duplex SS and 300 Series SS are both subject to pitting and localized corrosion under insulation. However, when it comes to stress corrosion cracking (SCC) in the presence of chlorides, Duplex SS is more vulnerable compared to 300 Series SS.

Duplex stainless steels are a combination of austenitic and ferritic stainless steels, known for their high corrosion resistance. However, they can still be susceptible to SCC if chlorides are present. On the other hand, 300 Series SS, which includes austenitic stainless steels like 304 and 316, are generally less susceptible to stress corrosion cracking.

Stress Corrosion Cracking (SCC) is a form of corrosion that occurs under tensile stress in a corrosive environment. It can lead to catastrophic failures in materials, making it a critical concern in engineering and material science. Understanding the susceptibility of different alloys to SCC is crucial in designing structures and components for long-term reliability.