Question

Which of the following materials exhibits poor corrosion resistance to phosphoric acid?

(a) Aluminum and brass

(b) Aluminum, brass, steel, cast iron, ferritic and martensitic stainless steels

(c) Steel and cast iron

(d) Ferritic and martensitic stainless steels

This question was posed to me in examination.

I want to ask this question from Mineral Acids in division Mineral Acids of Corrosion Engineering

Answer 1

Correct choice is (b) Aluminum, brass, steel, cast iron, ferritic and martensitic stainless steels

Easiest explanation: Metals such as aluminum, brass, steel, cast iron, ferritic, and martensitic stainless steels exhibit poor corrosion resistance to phosphoric acid. Whereas 316 stainless steel and Durimet 20 are widely used for phosphoric acid.