Ferritic stainless steels tend to be resistant to chlorine stress corrosion cracking, but they may suffer which type of cracking in hot concentrated caustic?

• A. Intergranular cracking
• B. Environmental cracking
• C. Transgranular cracking
• D. No cracking

Answer: (B)

In hot concentrated caustic, cracking is driven by the chemical environment itself, not by a specific fracture path. Ferritic stainless steels may resist chlorine stress corrosion cracking, but the caustic surroundings can still promote cracking through environmental cracking. This term broadly describes cracking caused by the environment (here, hot concentrated NaOH), regardless of whether the crack propagates along grain boundaries (intergranular) or through the grains (transgranular). The other options point to a particular crack path or to no cracking, but the key idea is that the environment enables the crack, which is best described as environmental cracking.