Compositions and method for the deoxidation of steel
OwnerArmando Villarrealinventor
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Abstract
Deoxidizing compositions and two-stage methods for deoxidizing molten steel produce purer steel products, at lower cost, than traditional aluminum and silicon-based deoxidation technologies. A first deoxidizing composition is free from elemental aluminum and reduces oxygen content primarily by the conversion of carbon to carbon monoxide, along with the conversion of silicon to silica. A subsequently-added second deoxidizing composition lowers the oxygen content to a highly desirable level, with the production of substantially less alumina impurities than the prior art technologies.
Claims20
A method of deoxidizing molten steel, comprising:
- a first deoxidation step comprising adding to molten steel an amount of carbon and silicon effective to substantially lower the reactive oxygen content in the absence of elemental aluminum, whereby said carbon is converted to carbon monoxide and said silicon is converted to silica, followed by
- a second deoxidation step comprising adding elemental aluminum to the molten steel to further lower the reactive oxygen content of the molten steel.
A first deoxidation composition for deoxidizing molten steel, comprised of on a weight basis, from about 38 to about 42% CaO, about 38 to 42% Al2O3, about 4 to about 6% MgO, about 14 to 17% C, and about 0 to about 5% Si.
A second deoxidation composition for deoxidizing molten steel, comprised of on a weight basis, from about 68 to about 72% CaO, about 4 to about 6% MgO, and about 24 to 27% Al.
A first deoxidation composition for deoxidizing molten steel, comprised of on a weight basis,
- 3 Calcium aluminate 70% Lime 12% Coke 14% Silicon carbide 4%.
A second deoxidation composition for deoxidizing molten steel, comprised of on a weight basis,
- 4 Lime 62% Dolomitic lime 12% Aluminum 26%.
Dependencies are inferred from the claim text.