Abstract: In order to improve machinability of a sintered compact, a phosphate compound of an alkali earth metal (calcium phosphate compound or the like) is mixed with an iron-based powder, or an alkali earth metal fluoride (calcium fluoride, or the like) is further mixed with the iron-based powder. Alternatively, the alkali earth metal fluoride, together with a graphite powder, is preferably fixed to recesses of the iron-based powder.

Abstract: A highly compressible iron powder for powder metallurgy has an optimized particle size distribution. The Vickers microhardness of the particles that do not pass through the sieve having the nominal opening of 150 &mgr;m is controlled to be at most about 110. The iron powder is suitable for production of magnetic parts having high magnetism and mechanical parts having high mechanical strength.

Abstract: A steel strip is degreased with low power consumption by subjecting the steel strip to electrolytic washing in a degreasing apparatus including an electrolytic washing apparatus in which electrodes confront each other across the steel strip located therebetween, and charge density and current density are maintained within a predetermined range. There is also provided a simple steel strip degreasing apparatus which is especially suitable for the method.

Abstract: The coating composition includes a methacrylic resin prepared by copolymerization of styrene or a substituted styrene (A), a methacrylic ester obtained from an alcohol having at least two carbon atoms and methacrylic acid (B), and an olefinic compound having at least one carboxylic group (C), in which the molar ratio thereof is 1:(0.05 to 44.5):(0.12 to 13). A metal sheet lubricated with the coating composition has superior characteristics of dissolution of the film in an alkaline solution, chemical processing, paint dryness, blocking resistance, corrosion resistance, stability of coating composition, and press formability (powdering resistance and galling resistance).

Abstract: A method of producing a high-strength high-toughness martensitic stainless steel seamless pipe which includes heating a martensitic stainless steel raw material to an austenitic range and subjecting the raw material to piercing and elongating to form an original pipe. The original pipe is cooled to form a structure substantially composed of martensite in the original pipe. The original pipe is reheated to a temperature in the dual-phase range between the Ac1 transformation point and the Ac3 transformation point, and is subjected to finishing rolling at an initial rolling temperature T (° C.) between the Ac1 transformation point and the Ac3 transformation point. The original pipe is then cooled to form a processed pipe. The processed pipe is tempered at a temperature below the Ac1 transformation point. The reduction in area R in the finishing rolling step may be in the range of 10% to 90%, and the initial rolling temperature T and the reduction in area R may satisfy the relationship 800≦T−0.

Abstract: A fuel cell separator including (a) about 100 parts by weight of graphitized meso-carbon microbeads, (b) about 10 to 35 parts by weight of one of a thermosetting resin and a thermoplastic resin, and (c) about 1 to 40 parts by weight of at least one carbonaceous material selected from the group consisting of graphite powder, carbon black, and fine carbon fibers. The fuel cell separator exhibits low electrical resistivity, low volume resistivity, superior gas impermeability, and superior dimensional accuracy without a graphitizing treatment after molding. A fuel cell using the fuel cell separators can be produced while saving energy using a simplified facility and has superior generation efficiency.

Abstract: A steel material excellent in weathering resistance by defining the chemical ingredients in the steel each to a predetermined range and setting an ingredient parameter formula in accordance with the working circumstance thereby reducing the flow rust and, particularly, forming stable rust with good protective property even in a salty circumstance such as in coast districts is provided.

Abstract: Repairing a chamber coke oven by heat-insulating a repair space in the oven, dividing a brick wall in a portion to be repaired into a plurality of layers stacked one above another, dismantling and removing the brick wall in the repaired portion, and carrying refractory assemblies into the oven one by one, each of the refractory assemblies being manufactured outside the oven by combining a plurality of bricks together correspond in shape to each of the stacked layers in one-to-one relation, thereby building the brick wall in the repaired portion with the refractory assemblies. A damaged combustion chamber brick wall of the coke oven near an oven opening can be repaired with high efficiency.

Abstract: A ladle after teeming for a continuous casting and a subsequent slag discharge is mounted on a ladle truck and then moved by the ladle truck to a tapping station. The ladle on the ladle truck is then stationed over a predetermined stand-by time and is then immediately moved to a tapping position to receive a molten steel from a converter. The ladle is quickly heated during the stand-by time, by a regenerative-type burner system carried by a ladle lid which is attached to the ladle to cover the top opening of the ladle. This allows the tapping temperature of the molten steel to be set to a low level, offering advantages such as a remarkable reduction in the consumption of carbonaceous materials as the temperature controller, as well as extended life of ladle refractories through suppression of thermal attack. At the same time, consumption of fuel gas for heating the ladle by the burner system is reduced to contribute to saving of energy.

Abstract: A high-strength, high-toughness seamless steel pipe used for a line pipe contains 0.03 to 0.06% of C, 0.05 to 0.15% of Si, 1.6 to 2.0% of Mn, 0.010 to 0.10% of Al, 0.3 to 0.7% of Ni, 0.10 to 0.40% of Mo, 0.01 to 0.06% of V, 0.003 to 0.03% of Nb, 0.003 to 0.020% of Ti, and 0.0010 to 0.0100% of N, the relationships Mo+5V≧0.4% and 2Nb−V≦0% being satisfied, and the balance being Fe and incidental impurities. Consequently, it is possible to provide the high-strength, high-toughness seamless steel pipe used for a line pipe in which grade X80 strength and toughness are stably ensured, and the target strength can be easily attained regardless of the size.

Abstract: A Mo source powder is added to and mixed with an iron-based powder containing 1.0% by mass or less of prealloyed Mn to yield a powder mixture containing 0.2 to 10.0% by mass of Mo, the resulting powder mixture is subjected to heat treatment in a reducing atmosphere to thereby yield an alloyed steel powder containing Mo as a powder partially diffused and bonded to a surface of the iron-based powder particles. The prepared alloyed steel powder for powder metallurgy has satisfactory compactability. The use of this alloyed steel powder can produce a sintered powder metal body (an intermediate material after compaction and preliminary sintering in re-compaction of sintered powder materials process) for highly strong sintered member.

Abstract: A steel has a tensile strength of 850 to 1700 MPa, a yield ratio of at most 80%, and a penetration border energy ratio of at least 2.0 relative to the penetration border energy of a reference steel JIS SS400 (corresponding to ASTM A36) of the same thickness. The steel can be produced by first effecting a heat treatment 1 on an unstable austenitic steel; then effecting, at least once, one or more or any combination of the heat treatment 1 and a heat treatment 2 on the steel; and then finally effecting the heat treatment 2 on the steel. Heat treatment 1 heats the unstable austenitic steel to at least the Ac3 transformation temperature and then water-cools the steel to a temperature below 350° C. Heat treatment 2 heats the steel to a temperature between Ac3 and Ac1 transformation temperatures and then water-cools the steel to a temperature below 350° C.

Abstract: Free fluorine is measured in a hydrofluoric acid-containing solution with a coexistent metallic ion based on a total fluorine concentration, a total acid concentration, a metallic ion concentration, the equilibrium constant of hydrofluoric acid, and equilibrium constants of metal fluoride complexes. It is possible to accurately analyze free fluorine in a hydrofluoric acid-containing solution without being affected by a coexistent metal and by the passage of time. This technique may be used to accurately control the concentration of free fluorine in a hydrofluoric acid-containing mixed acid pickling solution at the production site of a stainless steel so that improvement in descaling capability as well as reduction in the amount of chemical materials can be achieved.

Abstract: A hot-dip galvanized high-strength steel sheet having superior workability and galvanizability containing: 0.01% to 0.20% by weight of C; 1.0% by weight or less of Si; more than 1.5% to 3.0% by weight of Mn; 0.10% by weight or less of P; 0.05% by weight or less of S; 0.10% by weight or less of Al; 0.010% by weight or less of N; 0.010% to 1.0% by weight in total of at least one element selected from the group consisting of Ti, Nb, and V; and the balance being Fe and incidental impurities; in which the steel sheet has the metal structure in which the areal rate of the ferrite phase is 50% or more, the ferrite phase has an average grain diameter of 10 &mgr;m or less, and the thickness of a band-like structure composed of the second phase satisfies the relationship Tb/T≦0.005, where Tb is the average thickness in the sheet thickness direction of the band-like structure and T is the thickness of the steel sheet, and a method for producing the same.

Abstract: The coated steel sheet is a zinc-based plated steel sheet which has a zinc phosphate-based coating containing magnesium thereon and a silicone resin coating containing a functional group which reacts with an organic substance on the surface of the zinc phosphate-based coating. The coated steel sheet has superior perforative corrosion resistance, paint adhesion, electrodesposition paintability, press formability, and weldability without using chromium and therefore is useful as an anti-corrosive steel sheet for automobile bodies.

Abstract: An iron-based mixed powder for use in powder metallurgy and excellent in die filling property and compressibility and without segregation, includes an iron-based powder in which alloying powder(s) is adhered to the surface by a binder and, further, a free lubricant. The iron-based powder includes a mixed iron powder of atomized iron powder and reduced iron powder.

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: A welded steel pipe is formed by heating or soaking an untreated welded steel pipe having a steel composition comprising, on the basis of mass percent: about 0.05% to about 0.3% C; about 2.0% or less of Si; more than about 1.5% to about 5.0% Mn; about 0.1% or less of P; about 0.01% or less of S; about 0.1% or less of Cr; about 0.1% or less of Al; about 0.1% or less of Nb; about 0.3% or less of Ti; and about 0.01% or less of N; and by diameter-reduction-rolling the treated steel pipe at a accumulated diameter reduction rate of at least about 35% and a finish rolling temperature of about 500° C. to about 900° C. The welded steel pipe exhibits excellent hydroformability, i.e., has a tensile strength of about 780 MPa or more and a n×r product of at least about 0.15. The treated steel pipe is preferably diameter-reduction-rolled at a accumulated diameter reduction rate of at least about 20% below the Ar3 transformation point.

Abstract: A delayed fracture is effectively prevented by appropriately setting a shape and working stress, and working environment of a high strength member having more than 1,000 MPa of tensile strength. For this end, the relationship between a maximum value of diffusible hydrogen contents of unfailed specimens (Hc) and Weibull stress are found and the content of diffusible hydrogen entered into steel from the environment due to corrosion during the use of the steel member (He) is also found. Then, Weibull stress in the Hc that is equal to the He is found, thus determining the shape and working stress of the steel member so as to provide stress below the Weibull stress.

Abstract: A basic cell is disclosed, which is small in area and has sufficient connection flexibility. for achieving a semiconductor integrated circuit with a higher density and a reduced manufacturing cost. In a basic cell, a terminal wire, which is connected to a transistor terminal with a contact, is placed in a first metal wiring layer, and a plurality of terminal wire connection points, which can be connected to a second metal wire through a first via, are provided on the terminal wire. Further, in a semiconductor integrated circuit, a circuit wire in a second metal wiring layer is placed along grid points with a fixed pitch, and is connected to a terminal connection point of a transistor terminal, which is displaced from the grid points, through a terminal wire provided in the first metal wiring layer.