Question

Variation in solubility of gases can cause the generation of gases in metal castings.

(a) True

(b) False

I had been asked this question during an internship interview.

Origin of the question is Gases in Metals in section Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I

Answer 1

Correct choice is (a) True

Explanation: At different temperatures and phases, the gases may be generated due to the variation in their solubility. And chemical reactions also lead to a generation of gases in metal castings. The gases most generally present are hydrogen and nitrogen, in which removal of hydrogen from the melt is very necessary for better castings.