Experimental Investigation on the Evolution of Hydrogen in Steel during the Electroslag Remelting Process

Hydrogen, which is a harmful element, has a great effect on the mechanical properties of steel, should be removed during the steel manufacture process. The evolution of hydrogen content in steel during electroslag remelting process is experimentally investigated. The results show that during the electroslag remelting process, the hydrogen content in steel firstly increases steeply to maximum, then decreases to minimum and reaches the equilibrium. For a prefixed slag composition, the final hydrogen content in steel depends on the initial hydrogen content and the atmospheric moisture. When the electroslag remelting is operated under the argon protected atmosphere, the hydrogen in steel increased slightly. With the increase of the atmospheric moisture, the hydrogen content in steel increased significantly, and the larger atmospheric moisture is, the more significant influence on the hydrogen content in steel is. Moreover the mathematical formula to predict the hydrogen content in steel from the initial hydrogen content and the atmospheric moisture is derived: $\mathit{w}{\left[\%H\right]}_{\mathit{e}}=0.359\mathit{w}{\left[\%H\right]}_{\mathit{S}}+0.016\sqrt{{\mathit{p}}_{{\mathit{H}}_2\mathit{O}}/{\mathit{p}}^{\Theta }}+0.525$ It could be used to forecast the final hydrogen content in ESR ingot.

Keywords:
Electroslag remelting; hydrogen content; slag/metal interface reaction; protective atmosphere.