| 摘要 |
<p>A carbon-containing metallic melt particularly alloyed steel is degassed and refined by blowing first an inert gas such as argon then a mixture of an inert gas and oxygen against the melt surface, the amount of oxygen being limited to such quantity that only C and elements easier to oxidize than C such as Si and Mn will be oxidized to avoid the loss of other alloying elements such as Cr, Fe, Ni, Co more difficult to oxidize and minimize red iron oxide fume formation. Inert gas is also blown against the components of the melt being melted; subsequently oxygen is added followed by a final blowing again with inert gas only. The refining may be effected by using commercial grade argon containing 2% by volume oxygen, the initial and final degassing with pure argon being effected by leading this argon through layers of iron chips and titanium sponge at 875 DEG C. Oxidation may be made in several steps alternating with degassing blowings. The process may also be applied to the re-melting of scrap while adjusting its composition. In manufacturing alloy steels, e.g. austenitic steels of composition 0.05% C, 15% Cr, 25% Ni, 0.4% Si, 0.3% Mn, 0.3% V, 0.3% Mo, 2% active Ti, balance Fe, Ti may be added to the degassed and refined steel melt at 1650 DEG C. in the form of a Ti-Ni alloy.</p> |
