Method of scavenging steel
OwnerEdward J. Dunn, Jr.inventor
Life of this patent
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Abstract
The present invention relates to a more efficient method for adding lighter-than steel, low solubility, volatile, active scavenging agents into molten steel that reduces or eliminates the smoke that accompanies other methods of adding these agents.
Claims20
A method of refining steel characterized by a safer more effective and efficient adding of an active elemental or alloyed substance capable of combining with the dissolved impurities for the primary purpose of reducing or eliminating the voluminous polluting smoke that is normally associated with such additions which method comprises the placement upon the end of a refractory covered vertical rod, a consummable solid body of a pressed together mixture of materials comprising an active substance which has a limited solubility in the steel and an inactive material or mixtures of inactive material selected from the group consisting of iron, aluminum, elements which will alloy with the steel and oxides thereof, so that upon effecting an immersion of the subsequent assembly into a deep molten steel pool and the holding in place thereof, the pressed together shape dissolves, with the rate of dissolution being controlled to within desired limits by the appropriate choice of the composition and dimensional shape of the solid body, resulting in the composition and the shape of the solid body providing a means by which a given amount of active substance can be added to the molten steel at a rate that does not allow the active substance to exceed its solubility limit in the steel and thus prevent any active substance from reaching the surface to react with the air to cause air pollution.
A method for adding calcium into molten steel via a safe, simple, efficient, smoke eliminating, submersion technique, comprising submersing and holding submerged until dissolved, a consummable, solid body of pressed together material consisting of active calcium and at least one inactive material, with the surface area of the solid body being chosen to meet a desired finite dissolution time, and the calcium percentage of the body being adjusted, beforehand, such as to allow a desired amount of calcium to become available to the steel as the body of pressed together calcium and inactive material dissolves, the surface area of the solid body, and, the calcium percentage of the body, being selected to provide the maximum rate at which calcium can be made available to the molten steel, that will:
- (1) on a continuing bases, replace the calcium that is being consumed by the impurities in the steel;
- while, at the same time, (2) not allow the concentration of calcium in the steel bath to exceed its solubility limit at any time to provide a more smoke-free, efficient calcium addition.
A method of reducing impurities in steel by a more efficient adding of an elemental or alloyed material capable of combining with the dissolved impurities in the steel for (1) lowering the impurities such as oxygen, sulfur, and the like, and (2) reducing or eliminating the smoke that normally accompanies such additions which comprises adding to molten steel by submersing a consummable solid body of a pressed together mixture of materials comprising an active material which has a limited solubility in the steel and an inactive material or mixtures of inactive materials selected from the group consisting of iron, elements which will alloy with the steel, and oxides thereof, the composition of the solid body being adjusted to allow a precalculated controlled release of the active material into the liquid steel as the solid body dissolves providing a means by which a given amount of active material can be added to the molten steel at a rate that does not allow the active material to exceed its solubility limit in the steel.
Dependencies are inferred from the claim text.