| 摘要 |
<p>1,188,680. Refining molten metal. KAYSER INDUSTRIES CORP. Nov.22, 1967 [Nov. 25, 1966], No.53250/67. Heading C7D. Molten metal, particularly steel, is deoxidized in a furnace chamber by passing a H 2 - containing atmosphere into contact with the metal surface to react with the O 2 in the metal to form water vapour, and stripping water vapour from the atmosphere, e. g. by circulating over water-cooled condensing coils at the chamber walls or through gettering or stripping columns, to maintain the volume percentage ratio of H 2 O:H 2 in the atmosphere not more than 0À14. When the O 2 content of the molten metal is reduced to the desired level, the H 2 content of the atmosphere may be lowered to not more than 4% by volume and the water vapour content lowered to not more than 0À1% by volume to reduce the H 2 content of the metal to not more than 0À0005% by weight. A metallic deoxidizer such as Al may be passed below the metal surface to complete deoxidation. The atmosphere may be pure H 2 or a gas mixture of H 2 and an innocuous gas such as an inert gas, CO and CO 2 or steam and partly burned natural gas. The melting furnace may be induction heated.</p> |
