| 摘要 |
<p>1304640 Casting processes INLAND STEEL CO 19 April 1971 [12 March 1970] 22585/71 Heading B3F [Also in Division C7] A method of casting rimming steel ingots in a bottle-top mould, which includes adding to the ingot a substance which produces noxious fumes, comprises partially filling a bottle-top ingot mould 12 (e.g. to a level 15), leaving the mould neck 13 empty and allowing the steel to rim to the extent desired, adding the fumeproducing substance to the rimming metal in the mould and filling the mould neck 13 with a further charge of rimming steel, or effecting addition of the fume-producing agent and the further rimming steel charge concurrently, and immediately placing a cap 20 on top of the mould neck 13 to depend into and freeze the surface of the further rimming steel charge. In order that the upper surface of the first rimming steel charge does not rise into the mould neck 13, no addition of deoxidizing agent should be made to the steel in the ladle or mould. Specific fume-producing agents mentioned are As and P as well as the machinability improving elements, Te, Se, S, Bi. The method cannot be advantageously employed for Pb addition.</p> |
