| 摘要 |
In an injection-metallurgical process for the desulphurisation of steel, lime (CaO), opt. together with fluorspar (CaF2) is injected by means of a neutral carrier gas such as argon or nitrogen beneath the surface of the melt. The amt. of calcium injected is sufficient to remove the major part of the sulphur in a melt. A cpd. comprising non-oxidically combined calcium, such as calcium-silicon, calcium carbide or calcium cyanamide is then injected which acts as a source of elementary calcium which dissolves in the melt and/or with any remaining inclusions to render these harmless and to improve the flowability of the steel. The process is economical and is esp. useful in the treatment of low carbon and low silicon aluminium-treated steels. Good desulphurisation is achieved together with morphological conversion of remaining inclusions, esp. the transformation of aluminium oxides into spheroidal complex calcium aluminates which to not have the same tendency as Al2O3 to combine to form large aggregates. The process is esp. useful for the prodn. of aluminium treated deep-drawing steels, e.g. of the type used in the prodn. of car bodies. |
