| 摘要 |
<p>545,481. Treating molten metals. UDY, M. J. Feb. 11, 1941, No. 1877. Convention date, May 28, 1940. [Classes 72 and 82 (i)] [Also in Group XXII] Molten metals, particularly iron and steel, are purified and protected against oxidation by means of a slag formed from an exothermic reaction mixture, preferably finely divided, comprising slag-forming materials such as lime silica, iron oxide, blast furnace slag &c. a reducing agent such as silicon or aluminium or alloys containing them, and an oxidizing agent such as sodium nitrate or chlorate. The components of the mixture may be agglomerated by means of the oxidizing material. The molten metal may be poured through a layer of the slag resulting from the ignition of the exothermic mixture, or the mixture may be placed in a mould or ladle in which it is ignited by the . first addition of metal. Casting is preferably so conducted that the mould is only partly filled, the slag layer remaining to protect the upper surface of the metal and a thin film of slag being formed between the surface of the mould and the' casting which protects the casting from pitting.</p> |
