API 571 Certification Practice Test 2026 – Comprehensive All-in-One Guide to Master Corrosion & Materials!

Alloy B-2 is known for its exceptional resistance to sulfuric acid corrosion due to its unique composition and properties. This alloy contains a high percentage of nickel, molybdenum, and chromium, which enhance its corrosion resistance, particularly in highly aggressive environments like those containing sulfuric acid. The combination of these elements aids in forming a protective passive film over the alloy's surface, minimizing the corrosive effects of sulfuric acid.

In contrast, while Alloy 20 and different forms of cast iron offer some level of resistance to sulfuric acid, they do not possess the same degree of protection against it as Alloy B-2. Alloy 20, although it has good corrosion resistance, may not perform as well under certain concentrations of sulfuric acid compared to Alloy B-2. High Nickel Cast Iron and High Silicon Cast Iron, while capable of withstanding some corrosive environments, typically show lesser performance in strong acids like sulfuric acid.

Therefore, Alloy B-2's formulation and resistance characteristics make it the superior choice for applications exposed to sulfuric acid, ensuring longer life and improved performance in corrosive environments.