With Addition Of Solid Elemental Carbon(c) Or Employing Elemental Carbon Furnace Lining Patents (Class 75/517)
  • Patent number: 6527877
    Abstract: An alloy having two constituents: a crystal structure of orderly solid iron-based solution; a non-metallic phase at least partially soluble in iron including particles which are uniformly dispersed in the volume of the first phase and are of suitable size. In a preferred embodiment, the alloy contains iron with dissolved and bonded carbon as the first phase, which forms the crystal structure, and material partially soluble in iron, for example structurally free molecular carbon, is taken as the second non-metallic phase. The alloy preferably contains the components at the following ratios, % by mass: carbon in a dissolved and in a bonded state: 0.01-1.00; free carbon: 0.01-2.24; iron: balance. The ratio of free carbon to that of carbon in a dissolved and in a bonded state ranges from 0.01 to 20. The alloy Is preferably produced by melting out low carbon semi-product, overheating the semi-product above a liquidus temperature, for example by 20-70° C.
    Type: Grant
    Filed: April 22, 1999
    Date of Patent: March 4, 2003
    Assignee: Limited Liability Company “SKM”
    Inventor: Genrikh Alexeevich Dorofeev
  • Patent number: 4891063
    Abstract: A killed steel is stirred in a ladle with the aid of gaseous carbon dioxide. Before the beginning of the stirring in the ladle, there is added to the quantity of deoxidizer usually employed, a supplementary quantity of deoxidizer in the molten metal, the rate of supply of carbon dioxide, bearing in mind the capacity of the ladle and the duration of the stirring, remaining less than or equal to the maximum rate of supply corresponding to the oxidation of the supplementary quantity of deoxidizer at the end of the stirring.
    Type: Grant
    Filed: August 8, 1988
    Date of Patent: January 2, 1990
    Assignee: L'Air Liquide
    Inventor: Francois Weisang
  • Patent number: 4808220
    Abstract: The invention relates to a process for the preparation of low-carbon and low-silicon ferromanganese (refined ferromanganese) by blowing with pure oxygen in a converter ferromanganese of high carbon content (high-carbon ferromanganese) produced in a blast furnace. The characterizing feature of the invention is that in an oxidation phase oxygen is blown from above with a top blowing lance on to the melt of high-carbon ferromanganese melt, while at the same time an inert stirring gas is blown through tuyeres into the melt below its level, and on termination of oxygen top blowing, in an immediately following reduction phase, solid reducing agents and lumps of lime are added to the melt to recover the slagged manganese.
    Type: Grant
    Filed: March 1, 1988
    Date of Patent: February 28, 1989
    Assignee: Thyssen Stahl AG
    Inventors: Hans Litterscheidt, Manfred Rahder, Carl-Heinz Schutz, Richard A. Weber
  • Patent number: 4762555
    Abstract: A process for the production of nodular cast iron is disclosed. The process comprises adding magnesium to molten iron and then desulphurizing the melt. Next, the melt is after-treated with a neutral gas. The neutral gas which is introduced into the melt may be Ar, N.sub.2, CO.sub.2, or any combination thereof. The after-treatment with the neutral gas scavenges the melt for nonmetallic inclusions. The after-treatment may be performed by blowing the gas into the melt in a known manner using blowing lances or through a porous plug. In a preferred embodiment, the melt is also carburized by treatment with a gaseous hydrocarbon.
    Type: Grant
    Filed: December 22, 1986
    Date of Patent: August 9, 1988
    Assignee: Georg Fischer Aktiengesellschaft
    Inventors: Ivo Henych, Karl Gut
  • Patent number: 4746361
    Abstract: The dissolved oxygen content in a bath of molten steel is controlled, in one embodiment, by diluting a slag layer atop the bath with an oxide such as lime (CaO), to reduce the percentage of MnO and FeO in the slag, and stirring the bath of molten steel. In another embodiment, a gaseous mixture of an inert gas and carbon monoxide is disequilibrium with the carbon and dissolved oxygen content is bubbled through the bath.
    Type: Grant
    Filed: April 3, 1987
    Date of Patent: May 24, 1988
    Assignee: Inland Steel Company
    Inventors: Howard M. Pielet, Larry A. Frank, William Edgar, Milan Alavanja
  • Patent number: 4740241
    Abstract: A method of introducing and mixing a refining agent into molten metal in a ladle using a lance having a refractory body shaped to facilitate the positioning of the lance in the ladle is disclosed. Several tubular members are positioned within the lance and communicate with vertically spaced openings in a common plane in a lower side wall thereof communicating with the interior of the ladle and the molten metal therein. Some of the openings are plugged with porous material and others form passageways for the refining agent such as an alloy wire or powder. Gas, such as argon, is introduced through the tubular members having porous plugs and delivered through the porous plugs so as to bubble upwardly through the molten metal around the other openings and the refining agent delivered therethrough in a stirring and mixing action beginning adjacent the bottom of the ladle.
    Type: Grant
    Filed: May 22, 1987
    Date of Patent: April 26, 1988
    Inventor: Micheal D. LaBate
  • Patent number: 4666511
    Abstract: The process for producing killed steel having a low content of nitrogen comprises pouring an effervescent steel from a converter into a ladle in which there are added to the molten steel contained in the ladle, in the course of the pouring operation, additives for killing the steel, such as aluminium, silicon, etc. . . . The invention comprises pouring the effervescent steel into the ladle before introducing the killing additives, and prior to the introduction of the killing additives carbon dioxide in the form of carbon dioxide snow in the vicinity of the lower part of the pouring jet and on the surface of the bath of steel in the ladle in a quantity sufficient to protect the surface of the molten metal from the surrounding air upon the introduction of the killing additives into the ladle.
    Type: Grant
    Filed: March 25, 1986
    Date of Patent: May 19, 1987
    Assignee: L'Air Liquide
    Inventor: Jean-Michael Naud
  • Patent number: 4564390
    Abstract: A process is disclosed for reducing the carbon content of a melt of metal or metal alloy, carbon, and at least one strong oxide forming metallic alloying element from an initial value of about 0.1 wt % carbon to a final value of not less than about 0.003 wt % carbon. The process consists of contacting the melt with a reactive oxide of the metallic alloying element and simultaneously stirring the melt with an inert gas.
    Type: Grant
    Filed: December 21, 1984
    Date of Patent: January 14, 1986
    Assignee: Olin Corporation
    Inventors: Debabrata Gupta, John C. Yarwood
  • Patent number: 4551173
    Abstract: Molten steel is refined in a converter and is poured from the converter to a ladle. A ferro-alloy containing a component to be adjusted is added to the molten steel as needed. An amount of the alloy to be added to the molten steel in the ladle is calculated from a composition analysis value of the molten steel in the converter, and the amount of the alloy which is added when the molten steel is poured from the converter. The thus calculated amount of the alloy is added to the molten steel in the ladle. Electrodes are submerged in a slag layer on the molten steel so as to be arranged a predetermined distance from the molten steel. Power is supplied to the electrodes so as to generate electric arcs between the electrodes and the molten steel, thereby, arc-heating the molten steel. Simultaneously, a lance is submerged in the molten steel, and an Ar gas is injected in the molten steel therethrough, thus strirring the molten steel.
    Type: Grant
    Filed: November 28, 1984
    Date of Patent: November 5, 1985
    Assignee: Nippon Kokan Kabushiki Kaisha
    Inventors: Hirohisa Nakashima, Yoshimi Komatsu, Masafumi Ikeda, Tsuneo Kondo
  • Patent number: 4511396
    Abstract: This invention uses a dual basicity (DB) flux during the refining of steel which comprises the use of one or more flux components with high basicity/activity, for example sodium carbonate and/or barium oxide, with one or more normal fluxes having a lower basicity/activity such as calcium or magnesium oxides or dolomite. It has been found that it is only necessary to use a small percentage of the said high basicity fluxes in the total flux, for example 10%. The use of the said DB type of flux is particularly apt when the total amount of flux used is reduced to give a slag with a low Vee Ratio (CaO:SiO.sub.2), of the order of 1.0 to 2.0, and when magnesia is present in the slag formed preferably derived from an added lower basicity (MgO) flux component or partly from the furnace refractory lining.
    Type: Grant
    Filed: August 24, 1983
    Date of Patent: April 16, 1985
    Inventor: Ivor G. Nixon