API 571 Certification (Corrosion & Materials) Practice Test

Which of the following is a key factor in preventing caustic corrosion?

1. Regular inspections

2. Ensuring passivity of stainless steel surfaces

3. Using high alloy materials exclusively

4. Minimizing exposure to high temperatures

The correct answer is: Ensuring passivity of stainless steel surfaces

Ensuring passivity of stainless steel surfaces is crucial in preventing caustic corrosion because it enhances the protective oxide layer that naturally forms on stainless steel. When this passivity is intact, the material is more resistant to aggressive environments, including highly alkaline situations where caustic corrosion may occur. The passive layer acts as a barrier to corrosive agents, significantly reducing the likelihood of localized attack and degradation of the metal. In caustic environments, if the passive layer is compromised, the underlying metal can become vulnerable to significant corrosion processes. Therefore, maintaining and ensuring the integrity of the passive oxide film is fundamental in mitigating caustic corrosion risks. Other methods may help manage caustic corrosion, but ensuring passivity directly affects the material's resilience against corrosion in alkaline conditions, making it a key factor in prevention.