API 571 Certification (Corrosion & Materials) Practice Test

What type of steel shows better resistance in low pressure oxygen environments?

1. Carbon Steel

2. Low Alloy Steel

3. Stainless Steel

4. Nodular Cast Iron

The correct answer is: Stainless Steel

Stainless steel is known for its excellent resistance to corrosion, particularly in environments where oxygen is present, including low-pressure oxygen atmospheres. The inherent properties of stainless steel, such as its chromium content, lead to the formation of a passive oxide layer that protects the underlying metal from oxidation and other forms of corrosion. This makes stainless steel particularly suitable for applications involving oxygen exposure. Moreover, stainless steel's ability to resist localized corrosion, such as pitting and crevice corrosion, enhances its performance in situations where oxygen is present, compared to other types of steel. This characteristic is especially valuable in processes involving oxygen-rich conditions, as the integrity of components is crucial for safety and operational reliability. While other materials like carbon steel, low alloy steel, and nodular cast iron can be susceptible to oxidation and corrosion in oxygen environments, they do not possess the same level of protective properties as stainless steel. This distinction makes stainless steel the preferred choice for low-pressure oxygen applications.