Question

Which of the following formulas show the Sievert’s law of percent of hydrogen (H) present in a melt?

(a) H = K(pHa)^2

(b) H = K*pHa

(c) H = K/pHa

(d) H = K√pHa

I had been asked this question in a national level competition.

This interesting question is from Gases in Metals in portion Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I

Answer 1

Right answer is (d) H = K√pHa

The best explanation: Sievert’s law states that the amount of hydrogen dissolved in a melt varies as % hydrogen present (H) = K√pHa, where pHa is the partial pressure of hydrogen in the atmosphere over the melt, and K is a constant.