Abstract: A surface-treated sheet for fuel tanks includes a cold-rolled steel sheet with a low carbon content, a zinc or zinc-based alloy plating layer formed on the steel sheet, and a chromate film coated on the zinc or zinc-based alloy plating layer. The chromate film is formed from a chromate solution. The chromate solution includes a subject solution and an aqueous silane solution in an amount ranging from 5 to 50% by weight of the subject solution. The subject solution contains a chrome aqueous solution where the concentration of chrome is in the range of 5-50 g/l and the ratio of trivalent chrome to the chrome content is in the range of 0.4 to 0.8.

Abstract: In a method for producing a hot CO- and H2-containing reducing gas serving for the reduction of fine-grained metal ore, in particular iron ore, the reducing gas is formed in a gasification zone by a gasification of carbon carriers, in particular coal, taking place under the supply of oxygen and subsequently is cooled down to a reducing-gas temperature favorable to the reduction process. In order to produce a thermodynamically more stable reducing gas, the reducing gas by the addition of H2O and/or CO2—in order to prevent the Boudouard and heterogeneous water-gas reaction and a resultant heating of the reducing gas—is converted to a reducing gas that is thermodynamically more stable at the reducing-gas temperature.

Abstract: A converter includes a side wall, and a tapping hole placed at the side wall to allow passage of molten steel. A refractory plug is axially spaced apart from the tapping hole with a predetermined distance. The distance between the refractory plug and the tapping hole is in the range of 3-5 d where d indicates the inner diameter of the tapping hole. The refractory plug has one or more heat resisting steel tubes. When the molten steel is discharged through the tapping hole of the converter to the ladle, 0.1-0.4 Nm3/min of inert gas is introduced into the converter through the refractory plug to prevent leakage of the carried over slag.

Abstract: In a method of producing molten metal (8) from at least partially fine-particulate metal carriers in a melter gasifier (2) in which under supply of carbon-containing material and oxygen or an oxygen-containing gas under simultaneous formation of a reducing gas in a bed (11) formed of solid carbon carriers (4) the metal carriers are melted, the supplied fine-particulate metal carriers in order to avoid discharging thereof are charged to a high-temperature combustion zone (13) maintained by a combustion process and there are melted at least for the most part or completely, wherein the high-temperature combustion zone (13) is spatially isolated from the freeboard (12) of the melter gasifier (2) located above the bed (11) and extends into the bed (11), wherein the offgases formed in the high-temperature combustion zone (13) exit the same passing through at least a portion of the bed (11) and wherein furthermore the offgases are cooled in the bed (11) and are withdrawn from the melter gasifier (2) along with the r

Abstract: A pulverized coal injecting apparatus includes a cylindrical inner pipe for feeding pulverized coal into a tuyere of a blast furnace. A cylindrical outer pipe coaxially surrounds the inner pipe. A spiral swirler is formed on the surface of the inner pipe and the pulverized coal is supplied through the inner pipe, while a combustible fluid is supplied through a space defined between the outer and inner pipes. The pulverized coal injecting apparatus further includes a plurality of dimples formed on a surface of a leading end portion of the inner pipe for reducing fluid flow resistance so as to improve the mixing of the pulverized coal with the combustible fluid. The fluid flow becomes efficient so as to improve the combustion efficiency of the pulverized coal. Thus, the oxygen enrichment cost and fuel costs are reduced.

Abstract: A continuous casting method, and a device for use in the casting method, are disclosed. The flow state of the discharged molten metal is properly controlled, and thus, the amounts of residual non-metallic inclusions and gas bubbles within the molten metal are decreased, so that continuously cast slabs of a good quality can be produced. The continuous casting device includes a mould with a submerged nozzle installed therein, the submerged nozzle having a pair of discharge holes directed toward narrow faces of the mould. Further, an electromagnetic brake ruler is included for establishing a magnetic field within the mould. The electromagnetic brake ruler includes a base frame surrounding the mould, and iron cores projecting from near the wide faces of the mould, while the iron cores are wound with induction coils.

Abstract: In a method of producing molten metal (8) from at least partially fine-particulate metal carriers in a melter gasifier (2) in which under supply of carbon-containing material and oxygen or an oxygen-containing gas under simultaneous formation of a reducing gas in a bed (11) formed of solid carbon carriers (4) the metal carriers are melted, the supplied fine-particulate metal carriers in order to avoid discharging thereof are charged to a high-temperature combustion zone (13) maintained by a combustion process and there are melted at least for the most part or completely, wherein the high-temperature combustion zone (13) is spatially isolated from the freeboard (12) of the melter gasifier (2) located above the bed (11) and extends into the bed (11), wherein the offgases formed in the high-temperature combustion zone (13) exit the same passing through at least a portion of the bed (11) and wherein furthermore the offgases are cooled in the bed (11) and are withdrawn from the melter gasifier (2) along with the r

Abstract: An edge dam position control method and device in a twin roll strip casting process calculates the reduction ratio and rolling force of rolls to obtain the height of a solidification point, and adjusting the height of an edge dam during casting to correspond to the obtained height of the solidification point. It minimizes the force applied to the edge dam during casting, reduces the degree of wear of the edge dam, and improves the quality of edge portions of both sides of the strip.

Abstract: An upper shearing blade 3 equipped with a protrusion 30 of a triangle-columnar shape and a lower shearing blade 4 equipped with a protrusion 40 of the same shape are applied onto the overlapped portion of metal plates 1 and 2 to be bonded, and then pressed into the metal plates 1 and 2 in an oblique direction inclined with respect to the thickness direction by a stroke in such a range that the metal plates 1 and 2 are not completely cut off. The operating loci of the upper shearing blade 3 and the lower shearing blade 4 are overlapped each other so that one falls inside the other, and the sheared surfaces of the metal plates 1 and 2 are formed into a bonded portion by plastic flow deformation. Therein, since a compressive force is applied onto the portions to be bonded, the portion being defined by the amount of overlap, and the portions are compressed to form a compressed portion after completion of bonding, the bonding strength enhances.

Abstract: An apparatus and a method for manufacturing molten pig iron by using a fine iron ore are disclosed. Coal is used to produce a reducing gas, and a fine iron ore is used to produce a molten iron and a reduced iron in a simple and efficient manner. The apparatus for manufacturing a molten iron by directly using coal as the fuel is as follows. A high temperature reducing gas is sent from a melter-gasifier to a fluidized bed lime stone calcining furnace to calcine the lime stone. The reducing gas is supplied to a second fluidized bed reducing furnace so as to manufacture a reduced iron directly. An off-gas from the second fluidized bed reducing furnace is supplied to a first fluidized bed reducing furnace (disposed above the second fluidized bed reducing furnace) to pre-heat and pre-reduce the fine iron ore. The calcined lime stone and the finally reduced iron are supplied to a melter-gasifier to manufacture a molten pig iron.

Abstract: In a method of charging metal carriers which contain a portion of fines and are at least partially reduced and carbon carriers to a melter gasifier (10) in which a melt-down gasifying zone (11) is maintained, the metal carriers and the carbon carriers are fed into the melter gasifier (10) above the level of the melt-down gasifying zone (11) and descend to the melt-down gasifying zone (11) and travel through the same forming a metal melt and producing a reducing gas by coal gasification. In order to prevent a partial discharge of the metal carriers from the melter gasifier (10) during the charging of the same and to be able to achieve uniform distribution of the carbon carriers and the metal carriers, both the carbon carriers and the metal carriers are introduced into the melter gasifier centrally above the melt-down gasifying zone (11), preferably gravitationally, with a central strand (32) of metal carriers being formed which is peripherally surrounded by a jacket strand (37) formed by the carbon carriers.

Abstract: According to a process for injecting metal-oxide-containing fine particles into a reducing gas, a central material stream formed by the fine particles and a carrier gas is introduced into the reducing gas and at least one gas stream formed by a secondary gas is directed against the material stream to ensure an optimum contact of the fine particles with the reducing gas, the gas stream atomizing the material stream and the fine particles being evenly distributed within the reducing gas.

Abstract: A method for manufacturing wire rods and steel wire for use in making bead wires, wire ropes and springs is disclosed. That is, high drawability wire rods and a manufacturing method therefor are disclosed, in which the wire drawing is possible without carrying out patenting (an intermediate heat treatment). The high drawability wire rods for making high strength steel wire includes a steel containing, in wt %, 0.4-0.65% of C, 0.1-1.0% of Si, 0.1-1.0% of Mn, 0.3% or less of Cr, 100 ppm or less of B, Fe and other unavoidable impurities. The steel further contains 0.02% or less of one or more elements selected from a group consisting of Ti, Nb and V. The steel has a degenerated pearlite structure with pro-eutectoid ferrite of 10% or less, the remaining part being a discontinuously formed cementite. A billet having the above composition is hot-rolled, and is cooled at a cooling rate of 10-30° C./sec.

Abstract: In a process for producing molten pig iron or steel preproducts from fine-particulate iron containing material in a meltdown gasifying zone of a melter gasifier, under the supply of carbon-containing material and oxygen-containing gas at the simultaneous formation of a reducing gas in a bed formed of solid carbon carriers, the iron-containing material is melted when passing the bed.

Abstract: In a method of charging metal carriers which contain a portion of fines and are at least partially reduced to a melter gasifier in which a melt-down gasifying zone formed by a bed is maintained, the metal carriers and carbon carriers are fed into the melter gasifier above the level of the melt-down gasifying zone. The metal carriers descend to the melt-down gasifying zone and travel through the same forming a metal melt and producing a reducing gas by coal gasification.

Abstract: A method for manufacturing a hot rolled galvanized steel sheet at a high speed, with the pickling skipped, is disclosed, in which an intermediate rapid cooling is carried out at a predetermined temperature so as to make the wüstite component of the scales become 20% or more after a hot rolling, then a reducing heat-treatment is carried out, and then the steel sheet is dipped into a zinc bath containing a predetermined amount of Al, thereby realizing a superior coating adherence and a superior productivity. The hot rolled steel sheet is cooled at a usual cooling rate, and is coiled. Then an intermediate rapid cooling is carried out on the hot rolled steel sheet (thus coiled) to an intermediate rapid cooling temperature of 300-500° C. so as to make a wüstite component of scales become 20% or more. Then a reducing heat treatment is carried out at a temperature of 550-700° C. for 30-300 seconds under a 20% (or more) hydrogen atmosphere.

Abstract: In the process for the production of liquid pig iron 943) or liquid steel pre-products from charging substances comprising iron ore (5) and fluxes and at least partially containing a portion of fines, the iron ore is directly reduced to sponge iron in at least two reduction stages (1, 2) by the fluidized bed method, the sponge iron is melted in a melt-down gasifying zone (39) under the supply of carbon carriers and an oxygen-containing gas, and a CO- and H2-containing reducing gas is produced which is injected into reduction zones of the reduction stages (1, 2), is reacted there, is withdrawn as a top gas and optionally is supplied to a consumer.

Abstract: In a method for treating particulate material in the fluidized bed method, the particulate material is maintained in a fluidized bed by a treating gas flowing from bottom to top and thereby is treated. To minimize the consumption of treating gas and to reduce entrainment of fine particles by the treating gas, a particulate material having a wide grain distribution and a relatively high portion of fines is used for treatment and the treating gas in the fluidized bed is maintained at a superficial velocity less than the velocity required for fluidizing the largest particles of said particulate material.

Abstract: A two step twin-single fluidized bed type reduction apparatus for fine iron ore, and a method therefor, are disclosed. The fluidizing of the fine iron ore is stabilized so as to improve the reduction degree and the gas utilization rate, and so as to minimize the elutriation loss of the iron ore. The apparatus includes a first fluidized bed furnace for carrying out a first pre-reduction on only coarse/intermediate iron ore particles among fine iron ores of a wide particle size distribution by a bubbling/turbulent fluidization after their charge from a charging hopper, while making fine iron ore particles fly away. A second fluidized bed furnace carries out a first pre-reduction on the fine iron ore particles flown from the first fluidized bed furnace by a bubbling fluidization, and a third fluidized bed furnace carries out a second pre-reduction on the iron ores discharged from the first and second fluidized bed furnaces after their first pre-reduction.

Abstract: A device is disclosed for directly charging raw material into a melter-gasifier in a molten iron manufacturing facility using coal and fine iron ore. The elutriation of fine dusts is inhibited while directly charging coal and reduced fines into the melter-gasifier. The direct charging device is applied to a fluidized bed type final reducing furnace and has a plurality of discharging outlets for discharging the fines. The melter-gasifier receives lump coal to form a coal packed bed within it and receives the reduced fine iron ore from the final reducing furnace. The direct charging device includes a plurality of charging inlets formed on the side wall of the melter-gasifier connected by conduits to the discharging outlets of the final reducing furnace whereby reduced fine iron ore is continuously charged from the final reducing furnace to the coal packed bed of the melter-gasifier.