API 571 Certification (Corrosion & Materials) Practice Test

What is generally affected by oxidation?

1. Only stainless steels

2. Carbon steels, LAS, and nickel-based alloys

3. Copper and aluminum alloys

4. All types of plastics

The correct answer is: Carbon steels, LAS, and nickel-based alloys

Oxidation refers to a chemical reaction in which a material reacts with oxygen, often resulting in a loss of electrons and a corresponding increase in the oxidation state of the material. This process can lead to significant degradation and damage, particularly in metals. Carbon steels, Low Alloy Steels (LAS), and nickel-based alloys are all susceptible to oxidation due to their metallic nature. In carbon steels, oxidation can lead to rust formation, which is a common issue that can weaken the material over time. Low-Alloy Steels can also experience oxidation, especially in high-temperature or corrosive environments, leading to potential failures in structural integrity. Nickel-based alloys, while generally more resistant to oxidation compared to carbon steels, can still undergo oxidation at elevated temperatures, particularly in the presence of corrosive elements. In contrast, while stainless steels are generally more resistant to oxidation due to the presence of chromium that forms a protective oxide layer, they are not completely immune. Copper and aluminum alloys can experience oxidation as well, but typically, they do not fall into the same categories of corrosion concerns as those presented with carbon and low-alloy steels. Plastics, while they can degrade by processes such as photodegradation or hydrolysis, are not typically classified under oxidation in the same