Patent classifications
C21C5/5211
Method and apparatus for the production of cast iron, cast iron produced according to said method
A method for the production of cast iron starting from pre-reduced iron ore (DRI) with an electric arc furnace includes the steps of preparing a charge of pre-reduced iron ore DRI having a metallization higher than 90% and containing over 2.8% by weight of carbon, wherein at least 80% of the carbon is combined with the iron to form iron carbide Fe.sub.3C; charging the charge of pre-reduced iron ore into the electric arc furnace; and melting the DRI charge to form liquid cast iron having at least 80% by weight of actual carbon content deriving from the carbon in the charge of pre-reduced iron ore, the melting step being in a reducing atmosphere and in a melting chamber of the electric arc furnace subjected to a positive internal pressure generated by the gases produced by reduction reactions that develop during melting.
Rail
A rail according to an aspect of the present invention is manufactured by melting steel using an electric furnace, satisfies a predetermined range as a chemical composition and particularly includes Pb: 0.0003% to 0.0020%, 95 area % or more of a region from an outer surface of a head portion to a depth of 20 mm is a pearlite structure, and a hardness in the region from the outer surface of the head portion to the depth of 20 mm is in a range of Hv 300 to Hv 500.
SENSING AND CONTROL OF POSITION OF AN ELECTRICAL DISCHARGE
Sensors measure magnetic field components, and the measured fields are used to calculate and estimated transverse position of a longitudinal electric current flowing as an electric discharge across a discharge gap. Based on the estimated position, and according to a selected transverse trajectory or distribution of the estimated discharge position, magnetic fields are applied transversely across the discharge gap so as to control or alter the estimated discharge position. Inventive apparatus and methods can be employed, inter alia, during operation of a vacuum arc furnace.
MOLTEN MANGANESE-CONTAINING STEEL PRODUCTION METHOD, HOLDING FURNACE, AND MOLTEN MANGANESE-CONTAINING STEEL PRODUCTION EQUIPMENT USING HOLDING FURNACE
When storing a molten ferroalloy or molten nonferrous metal, the molten ferroalloy or molten nonferrous metal is denitrified or prevented from absorbing nitrogen, and thus post processing such as a denitrification process may not be performed. For this, there is provided a method of producing molten manganese-containing steel, the method including: preparing a molten ferroalloy or a molten nonferrous metal; maintaining the molten ferroalloy or the molten nonferrous metal at a temperature equal to or higher than a melting point thereof; and pouring the molten ferroalloy or the molten nonferrous metal into prepared molten steel, wherein in the maintaining of the molten ferroalloy or the molten nonferrous metal, the molten ferroalloy or the molten nonferrous metal is subjected to a nitrogen-absorption prevention process or a denitrification process.
METAL PRODUCT MANUFACTURING DEVICE AND METAL PRODUCT MANUFACTURING METHOD
A metal product manufacturing device is provided to remove, with higher accuracy, impurities from a molten metal of a non-ferrous metal or another metal containing the impurities, obtain the molten metal having higher purity, and obtain a high-purity non-metal product or another metal product from the high-purity molten metal.
Sidewall with buckstay for a metallurgical furnace
A sidewall for a metallurgical furnace and a metallurgical furnace having the same are described herein. In one example, a sidewall of a metallurgical furnace is provided that includes an outer wall, a hot plate and a buckstay. The hot plate is coupled in a spaced apart relation to the outer wall. The buckstay is mechanically coupled to the outer wall and the hot plate. The buckstay includes a buckstay web extending from a buckstay flange. The buckstay web includes a first end coupled to the buckstay flange, and a second end mechanically and movably coupled to the hot plate.
Sensing and control of position of an electrical discharge
Sensors measure magnetic field components, and the measured fields are used to calculate and estimated transverse position of a longitudinal electric current flowing as an electric discharge across a discharge gap. Based on the estimated position, and according to a selected transverse trajectory or distribution of the estimated discharge position, magnetic fields are applied transversely across the discharge gap so as to control or alter the estimated discharge position. Inventive apparatus and methods can be employed, inter alia, during operation of a vacuum arc furnace.
METHODS OF PROTECTING FURNACE ELECTRODES WITH COOLING LIQUID THAT CONTAINS AN ADDITIVE
A method for forming a protective antioxidative barrier on the furnace electrodes using a chemically altered cooling liquid containing an antioxidant additive. This method can be applied to electrodes used in electric arc furnaces and ladle metallurgy furnaces. The method can involve spraying the cooling liquid onto the electrode, thereby forming the protective antioxidative barrier and reducing the oxidation of the electrode.
ESTIMATION OF ARC LOCATION IN THREE DIMENSIONS
Multiple magnetic field sensors are arranged around a current-containing volume at multiple longitudinal and circumferential positions. Each sensor measures multiple magnetic field components and is characterized by one or more calibration parameters. A longitudinal primary current flows through two end-to-end electrical conductors that are separated by an arc gap, and flows as at least one longitudinal primary electric arc that spans the arc gap and that moves transversely within the arc gap. Estimated transverse position of the primary electric arc is calculated, based on the longitudinal position of the arc gap, and two or more of the measured magnetic field components along with one or more corresponding sensor positions or calibration parameters. In addition, estimated occurrence, position, and magnitude of a transverse secondary current (i.e., a side arc) can be calculated based on those quantities.
Methods of protecting furnace electrodes with cooling liquid that contains an additive
A method for forming a protective antioxidative barrier on the furnace electrodes using a chemically altered cooling liquid containing an antioxidant additive. This method can be applied to electrodes used in electric arc furnaces and ladle metallurgy furnaces. The method can involve spraying the cooling liquid onto the electrode, thereby forming the protective antioxidative barrier and reducing the oxidation of the electrode.