Fundamental Study on Vacuum Melting of Pure Iron and Stainless Steel I : On the Crucibles, Ingotism and the Recovery of Alloy Additions

Abstract

The relations between vacuum melting practices and the behavior of gases, the magnesia crucibles, ingotism, the recovery of alloy additions etc. were studied. It was found that the B´ type magnesia crucibley was most satisfactory in view of its resistance to oxygen contamination. The refining practice using hydrogen gas showed somewhat higher content of hydrogen, while that utilizing immersion of a graphite rod was found to offer difficulties in regard to control of the dissolved carbon content. A sound ingot was obtained by appropriate modifications of the mold assembly. The vacuum melting practices for controlling the compositions of some kinds of stainless steels were confirmed.