API 571 Certification (Corrosion & Materials) Practice Test

In terms of sensitivity to cavitation, which material is more frequently used?

1. Nickel-based alloys

2. Low alloy steels

3. 300 series stainless steel

4. Pure copper

The correct answer is: 300 series stainless steel

The 300 series stainless steel is frequently used in applications sensitive to cavitation due to its excellent resistance to corrosion and good mechanical properties. This stainless steel category, particularly austenitic grades, is known for its strong toughness, which helps mitigate the impacts from cavitation, a phenomenon where vapor bubbles form and collapse in a liquid, leading to significant localized forces that can cause erosion and material degradation. The austenitic structure of 300 series stainless steels contributes to their ability to absorb energy and resist cracking, which is critical in environments where cavitation is a concern. Their composition, which includes nickel and chromium, enhances their ductility, providing a buffer against the forces generated during cavitation events. Other materials, such as nickel-based alloys, low alloy steels, and pure copper, while they may possess certain advantageous properties, typically do not match the overall performance of 300 series stainless steel in cavitation-sensitive applications. For example, although nickel-based alloys can also resist corrosion and perform well under extreme conditions, they may not excel in all cavitation applications. Low alloy steels often suffer from lower corrosion resistance and might not withstand the conditions as effectively as the 300 series. Pure copper can experience significant degradation due to cavitation because it lacks the necessary strength