Which material is subject to stress corrosion cracking in sensitized form?

Which material is subject to stress corrosion cracking in sensitized form?

• A. Sensitized 300 SS
• B. 304 SS
• C. 316 SS
• D. 500 Series Stainless

Answer: (A)

Stress corrosion cracking in stainless steels occurs most riskily when austenitic grades become sensitized. Sensitization happens when chromium carbides precipitate at grain boundaries due to exposure to elevated temperatures, which depletes chromium at the boundaries and makes the material prone to intergranular cracking under tensile stress in corrosive environments. The material that fits this condition is the sensitized 300-series stainless steel, because in its sensitized state it is susceptible to intergranular stress corrosion cracking. The other options either refer to stainless grades not typically prone to this mode of cracking in sensitized form (ferritic/martensitic types) or are not specified as sensitized, so they don’t describe the same failure mechanism.

Stress corrosion cracking in stainless steels occurs most riskily when austenitic grades become sensitized. Sensitization happens when chromium carbides precipitate at grain boundaries due to exposure to elevated temperatures, which depletes chromium at the boundaries and makes the material prone to intergranular cracking under tensile stress in corrosive environments. The material that fits this condition is the sensitized 300-series stainless steel, because in its sensitized state it is susceptible to intergranular stress corrosion cracking. The other options either refer to stainless grades not typically prone to this mode of cracking in sensitized form (ferritic/martensitic types) or are not specified as sensitized, so they don’t describe the same failure mechanism.