Abstract: Manufacturing a grain-oriented electrical steel sheet, a secondary recrystallization step and a forsterite coating forming step are separated into first batch annealing for developing secondary recrystallization and second batch annealing for forming a forsterite coating, with continuous annealing performed between these two steps of batch annealing, to produce a grain-oriented electrical steel sheet that is superior in both magnetic characteristics and coating characteristics.

Abstract: A high-strength and high-toughness steel product having at least about 0.001% and less than about 0.030% by weight C, not more than about 0.60% by weight Si, from about 0.8 to 3.0% by weight Mn, from about 0.005 to 0.20% by weight Nb, from about 0.0003 to 0.0050% by weight B, and not more than about 0.005% by weight Al, wherein at least 90% of the product has a bainite structure. A method of making this steel product is subject to less stringent production controls because of the nature of the composition.

Abstract: A ferritic stainless steel sheet which has not only superior high-temperature fatigue characteristics, but also superior workability at room temperatures. The steel sheet contains, by weight percent, C: not more than 0.02%, Si: 0.2 to 1.0%, Mn: not more than 1.5%, Cr: 11.0 to 20.0%, Ni: 0.05 to 2.0%, Mo: 1.0 to 2.0%, Al: not more than 1.0%, Nb: 0.2 to 0.8%, and N: not more than 0.02%, balance essentially Fe, and an aspect ratio (dRD/dTD) of grain size in planes at ¼ and ¾ sheet thickness, seen a direction normal to a sheet surface, in the range of 1.03 to 1.35. The steel sheet has a thickness greater than 0.3 mm but not greater than 2.5 mm, and a yield strength Y.S.≦360 MPa and an r-value≧1.3 at 30° C., and wherein after maintaining the steel sheet at 900° C. for one hour, the Y.S.≧18.0 MPa.

Abstract: A method of rapidly reducing chromium oxide-containing slag and the like in large quantities, in a simplified manner and without requiring high temperatures. Chromium oxides are reduced with at least one of elementary sulfur and compounds of sulfur having a valence less than 6. For an aqueous solution of the sulfur component, desirably, its sulfur content is more than 0.03% by weight. As the sulfur source, preferred is blast furnace slag (e.g., non-aged, gradually-cooled blast furnace slag) that is discharged in large quantities in the iron industry. Cr6+ in chromium oxides is reduced in one of the following ways: (a) Chromium oxide-containing substances are sprayed with or immersed in blast furnace slag-released water that has been used in cooling blast furnace slag. (b) Chromium oxide-containing substances are mixed with blast furnace slag, and then kept in an air atmosphere. Optionally, the mixture is sprayed with blast furnace slag-released water.

Abstract: A steel pipe is provided which is excellent in resistance to outer surface stress corrosion cracking (SCC) when used for a pipeline without impairing the fundamental requirement for the steel as a pipeline. The steel pipe has a surface adjusted to have a mean line roughness Ra of up to 7 &mgr;m and a maximum height Rmax of up to 50 &mgr;m. The surface is adjusted by sand blasting to have this roughness.

Abstract: Non-oriented magnetic steel sheets, which are mainly used as materials for iron cores for use in electric apparatuses, have a low iron loss and a high magnetic flux density at the same time. The non-oriented magnetic steel sheet comprises from about 1.5 to about 8.0 weight % Si, from about 0.005 to about 2.50 weight % Mn, and not more than about 50 ppm each of C, S, N, O, and B, in which a crystal orientation parameter <&Ggr;> is 0.200 or less. In addition, the average crystal grain diameter is preferably from about 50 to about 500 &mgr;m, and an areal ratio of crystal grains on a surface of the steel sheet is preferably 20% and less, in which crystal plane orientations of the crystal grains are within 15° from the <111> axis. In addition, the non-oriented magnetic steel sheet preferably contains small amounts of elements such as Al, Sb, Ni, Sn, Cu, P, and Cr. The manufacturing method for the non-oriented magnetic steel is also described.

Abstract: An sintered iron-based powder metal body with outstandingly lower re-compacting load and having a high density and a method of manufacturing an iron-based sintered component with fewer pores of a sharp shape and having high strength and high density, the method comprising mixing, an iron-based metal powder containing at most about 0.05% of carbon, at most about 0.3% of oxygen, at most about 0.010% of nitrogen, with at least about 0.03% and at most about 0.5% of graphite powder and a lubricant, preliminarily compacting the mixture into a preform, the density of which is about 7.3 Mg/m3 or more, and preliminarily sintering the preform in a non-oxidizing atmosphere in which a partial pressure of nitrogen is about 30 kPa or less at a temperature of about 1000° C. or higher and about 1300° C. or lower, thereby forming a sintered iron-based powder metal body with outstandingly lower re-compacting load and having high deformability, the density of which is about 7.

Abstract: A composition for metal surface treatment which comprises an aluminum ion, a magnesium ion, a manganese ion, a water-soluble organic resin, an acid and water; and a surface treated metal material which has been treated with the composition. The resultant surface treated metal material is free from the danger of water contamination owing to chromium, since the composition is free of chromium, and also is excellent in both electrical conductivity and corrosion resistance. Accordingly, the metal material can be used in a wide variety of applications in place of a conventional chromate-treated steel sheet and the like.

Abstract: Method and apparatus for short-term relining or construction of a blast furnace uses a grounding apparatus for grounding of ring-shaped blast furnace segments having shells and a casting floor present as a blast furnace floor for transferring the ring-shaped blocks or shells onto a foundation of the blast furnace, and capable of safely and precisely mounting the ring-like blocks on the casting floor, wherein the grounding apparatus is integrated with a jack system utilizing rod type lift jacks and a sliding apparatus installed with intermittently movable hydraulic cylinders for safe and precision mounting of the ring-shaped blocks or shells on the casting floor.

Abstract: This invention provides a rolling mill and a rolling-mill train which are compact. Reducers to be coupled with them can be made compact. The inner surfaces of pipes to be rolled with the rolling mill and the rolling-mill train can be prevented from becoming squarish. The rolling mill comprises a plurality of rolls disposed symmetrically around the pathline of the rolling mill, an annular driving bevel gear of a large diameter for driving and rotating the rolls, an input-shaft mechanism for rotating the driving bevel gear, a plurality of transmission mechanisms disposed at regular intervals along the driving bevel gear, and a housing for holding them. The input-shaft mechanism (i) has an input shaft inserted in the housing from its outside and an input bevel gear of a small diameter mounted on the input shaft and engaging with the driving bevel gear and (ii) is disposed between two adjacent transmission mechanisms.

Abstract: A process for producing an iron-based powder composition for powder metallurgy having excellent flowability at room temperature and a warm compaction temperature, having improved compactibility enabling lowering ejection force in compaction, and to provide a process for producing a compact of a high density from the iron-based powder composition, wherein the iron-based powder composition comprises an iron-based powder, a lubricant, and an alloying powder, and at least one of the iron-based powder, the lubricant, and the alloying powder is coated with at least one surface treatment agent selected from the group of surface treatment agents of organoalkoxysilanes, organosilazanes, titanate coupling agents, fluorine-containing silicon silane coupling agents, and wherein the iron-based powder composition is compacted at a temperature not lower than the lowest melting point of the employed lubricants, but not higher than the highest melting point of the employed lubricants.

Abstract: In a preliminary molding step 1, a metallic powder mixture 7 obtained by blending an iron-based metal powder 7a with graphite 7b such that the graphite is present in an amount of preferably not less than 0.1% by weight, more preferably not less than 0.3% by weight, is compacted into a preform 8 having a density of not less than 7.3 g/cm3. In a provisional sintering step 2, the preform 8 is provisionally sintered at a predetermined temperature to form a metallic powder-molded body 9 having a structure in which the graphite remains along a grain boundary of the metal powder. In a re-compaction step 3, the metallic powder-molded body 9 is re-compacted into a re-compacted body 10. In a re-sintering step 4, the re-compacted body 10 is re-sintered to obtain a sintered body 11. In a heat treatment step 5, the sintered body 11 is heat-treated to obtain a heat-treated sintered body 11.

Abstract: Producing a ferritic Cr-containing steel sheet having excellent ductility, formability, and anti-ridging properties, and exhibiting excellent surface quality after forming, wherein a ferritic Cr-containing steel sheet contains, by mass %, about 0.001 to 0.12% of C, about 0.001 to 0.12% of N, and about 9 to 32% of Cr, and has a crystal grain structure in which in a section of a hot-rolled annealed steel sheet in the thickness direction parallel to the rolling direction, an elongation index of crystal grains is 5 or less at any position, and in a section of a cold-rolled annealed steel sheet in the thickness direction parallel to the rolling direction, any colony of coarse grains oriented in the rolling direction has an aspect ratio of 5 or less. The production method includes hot rolling, pre-rolling by cold or warm rolling with a rolling reduction of about 2 to 15%, hot-rolled sheet annealing, cold rolling, and finish annealing; preferably the FDT of hot rolling is 850° C., and 0.0002 to 0.

Abstract: The tin-plated steel sheet includes a base steel sheet; a tin plating layer coating approximately more than 97.0% of the base steel sheet; and a chemical conversion coating having approximately 0.5 to 100 mg/m2 phosphorus and approximately 0.1 to 250 mg/m2 silicon formed on the tin plating layer and an unplated region corresponding to approximately less than 3.0%. The tin-plated steel sheet does not contain chromium which is harmful to the environment but has superior overcoat adhesion property, discoloration resistance, and rust resistance.

Abstract: A metallic hollow polygonal column having a smooth outer surface is immersed into a molten slag and immediately pulled up. The contact plane of the slag adhered on the outer surface of the hollow polygonal column is used as the analytical plane. The method of the hollow column has a thickness of 3 mm or greater.

Abstract: A welded steel pipe is formed by heating or soaking an untreated welded steel pipe having a steel composition containing, on the basis of mass percent: about 0.05 % to about 0.2% C; about 0.2% or less of Si; about 1.5% or less of Mn; about 0.1% or less of P; about 0.01% or less of S; about 0.1% or less of Al; and about 0.01 % or less of N; and by reduction-rolling the treated steel pipe at a cumulative reduction rate of at least about 35% and a final rolling temperature of about 500° C. to about 900° C. The welded steel pipe exhibits excellent hydroformability, i.e., has a tensile strength of at least about 400 MPa and an n×r product of at least about 0.22. The treated steel pipe is preferably reduction-rolled at a cumulative reduction rate of at least about 20% below the Ar3 transformation point. The welded steel pipe is suitable for forming structural components.

Abstract: A method of designing a logic circuit including pass transistors is disclosed. A logic group having a complementary variable in a given logical expression to be realized into the logic circuit is mapped using a multiplexer composed of a combination of the pass transistors. The number of transistors used in the logic circuit and the number of stages can be reduced by taking advantage of the multiplexer. When a logic circuit including both pass transistors and a multiple-input logic gate is designed, a logic group having a common variable in the given logical expression is mapped using the multiple-input logic gate. The number of transistors used in the logic circuit and the number of stages can be further reduced by taking advantage of the multiple-input logic gate. In order to ease the above mapping procedure, a complementary variable is identified and the given logical expression is optimized by grouping product terms of the logical expression by the complementary variable.

Abstract: An etching method for use in production of semiconductor devices is disclosed. In the etching method, CBrx or its derivative formed in the plasma is deposited on portions of the surface of a substrate to be etched. A sidewall and/or underlying layer protection effect is obtained concurrently with an improved resist selectivity through the function of the high boiling point of the deposit.

Abstract: An apparatus installed in a molten metal plating line includes a blade pressed against a roll dipped in a molten metal plating bath, in which a metal strip travels. The apparatus removes substances deposited on a surface of the roll. The apparatus also includes an arm for supporting the blade, and a screw member disposed above the plating bath so as to traverse it and moving along an axis of the roll in the bath for removing substances deposited on the roll in the molten metal plating bath. Floats and/or weights are mounted on the arm so as to adjust a press force of the blade applied to the roll in the molten metal plating bath. A method for preventing the occurrence of dents on a molten-metal-plated steel strip using the apparatus is also disclosed.

Abstract: A solidified residual iron within a blast furnace is suspended up by employing a shell suspending device fixed to a tuyere arranged in a lower end portion of an upper portion of a furnace body suspended by a lift jack and a solidified residual iron suspending band, thereafter is descended by employing the lift jack and is mounted on a horizontally moving table. Subsequently, the horizontally moving table mounting the solidified residual iron thereon is moved onto a furnace outer truck rail from a furnace inner truck rail so as to be taken out of the furnace by operating a center hole jack arranged near the furnace outer truck rail, whereby an operation of taking out the solidified residual iron within the blast furnace out of the furnace is economically performed for a short time.