Abstract: This invention provides a quantitative determination method capable of quickly determining a mean composition of oxide type inclusions and oxygen concentration of a metallic material such as a steel by using an optical emission spectrometer alone. This method comprises the steps of (1) conducting a plurality of times a discharge operation between the metallic material and an opposing electrode in an inert gas atmosphere to obtain an emission spectrochemical spectrum, (2) selecting a discharge in which at least either the oxygen A spectrum or the oxide-forming element spectrum exceed a predetermined intensity for each discharge operation, and (3) subtracting a background from the intensity of the oxygen spectrum and/or the intensity of the oxide-forming elements in the selected discharge, accumulating the balances to obtain a cumulative spectral intensity, and executing quantitative determination by a calibration curve method.

Abstract: Grain-oriented silicon steel sheet with Bi as an auxiliary inhibitor and a forsterite coating film having a Cr spinel oxide subscale of FeCr2O4 or FexMn1-xCr2O4 (0.6≦x≦1), made from a steel slab containing 0.005-0.20 wt % of Bi and 0.1-1.0 wt % of Cr.

Abstract: A method and apparatus for ultrasonic flaw detection of line focus type suitable for detection of flaws in nonmetallic materials included in an object. Ultrasonic transmitter and receiver elements of line focus type are opposed at a distance (L) with an object under test placed between them, and a maximum ultrasonic echo is obtained at a distance Lp expressed by: Lp=0.75(FT+FR)−{(CS/CW)−1}t where FT (mm) is the focal length in the medium of the ultrasonic transmitter element of line focus type, FR (mm) is the focal length in the medium of the ultrasonic receiver element line focus type, CS (m/sec) is the speed of ultrasound in an object under test, CW (m/sec) is the speed of ultrasound in the medium, and t (mm) is the thickness of the object under test.

Abstract: A stainless steel separator having gas channels including grooves and projections for fuel cells. The separator has a composition including about 0.03 mass percent or less of carbon; about 0.03 mass percent or less of nitrogen, the total content of carbon and nitrogen being about 0.03 mass percent or less; about 16 mass percent to about 45 mass percent chromium; about 0.5 mass percent to about 3.0 mass percent molybdenum; and the balance being iron and incidental impurities. The separator has a contact resistance of about 100 m&OHgr;·cm2 or less. Preferably, the projections have an arithmetic average surface roughness Ra in the range of about 0.01 to about 1.0 &mgr;m and a maximum height Ry in the range of about 0.01 to about 20 &mgr;m. The stainless steel separator preferably further includes about 0.001 to about 0.1 mass percent silver. A fuel cell including this separator exhibits a stable output voltage for a long period of time.

Abstract: It is an object to provide an insulating film which enables not only to obtain a good film quality but to achieve an excellent filling property, thick film formation and planarization simultaneously, and to provide an insulating film forming coating solution for forming the insulating film, and to provide a method of manufacturing the insulating film.

Abstract: A corrosion-resistant chromium steel for architectural and civil engineering structural elements, includes 0.0015 to 0.02 mass percent C, 0.0015 to 0.02 mass percent N, 0.1 to 1.0 mass percent Si, 0.1 to 3.0 mass percent Mn, more than 5 mass percent to less than 10 mass percent Cr, 0.01 to 3.0 mass percent Ni, 0.1 mass percent or less of Al, 0.05 mass percent or less of P, 0.03 mass percent or less of S, 0.01 to 1.0 mass percent Co, and the balance being Fe and incidental impurities. The steel has high long-term corrosion resistance and high weld-zone toughness. Preferably, the steel further includes 0.01 to 0.5 mass percent V and 0.001 to 0.05 mass percent W, the Cr content is in the range of more than 5 mass percent to less than 8 mass percent, and the Cr, V, and W contents are within a specified ratio.

Abstract: In a pipe forming process using bending rolls, load applied to an upper roll is reduced to suppress the deflection of the upper roll, thereby suppressing creation of large end gap at the longitudinal center of the pipe, thus enabling production of high-strength, thick-walled elongated pipes. This is achieved either by (1) setting the roll spacing L between lower rolls to a value greater than the sum of the diameter Dwu of the upper roll 34 and the diameter Dwl of each of the lower rolls 32, and setting the amount S of tightening of the upper roll 34 with respect to the lower rolls 32 to a value greater than the radius Rwl of each of the plural rolls; or by (2) effecting pipe forming work on the sheet material such that the spacing L of the lower rolls 32 satisfies the following condition: (Dp+Dwl)>L≧0.

Abstract: A high-Cr steel pipe for line pipes having further improved HAZ toughness and hot workability is provided by limiting the composition to: C: 0.02% or less, Si: 0.5% or less, Mn: 0.2 to 3.0%, Cr: 10.0 to 14.0%, Ni: more than 2.0 to 3.0%, N: 0.02% or less, preferably Nb: 0.3% or less, and the balance being Fe and incidental impurities.

Abstract: An iron-based mixed powder for use in powder metallurgy has an apparent density of at least about 3.1 Mg/m3, is excellent in die filling property and compressibility and without segregation, and includes an iron-based powder to which alloying powder is adhered at the surface by binder and free lubricant. The iron-based powder includes an atomized iron powder, or a mixed powder of an atomized iron powder and a reduced iron powder.

Abstract: The present invention relates to a method for detecting chattering of a cold rolling mill rapidly and accurately, which occurs during cold rolling of a steel strips. The occurrence of the chattering is detected by a plurality of acoustic parameters derived from a sound measured in the vicinity of the cold rolling mill during the rolling. The acoustic parameters are the frequency range characteristic of the occurrence of the chattering, the acoustic intensities in the frequency bands which are n-th harmonics, the peak frequency of the acoustic frequency component distribution, the resonance factor, the peak intensity, and the like. A plurality of parameters may be provided by measuring and calculating the same parameter with different timing.

Abstract: A ferritic stainless steel plate of excellent ridging resistance and formability, as well as a manufacturing method thereof are proposed. Specifically, the rolling is conducted at a rolling reduction of 30% or more in at least 1 pass and at a temperature difference between the center of the plate thickness and the surface of 200° C. or lower in a pass for the maximum rolling reduction to cause the area ratio of a {111} orientation colony to be present by 30% or more in the regions of ⅛ to ⅜ and ⅝ to ⅞ of the plate thickness. The {111} orientation colony is an assembly of adjacent crystals in which the angle of <111> orientation vector for each of the crystals relative to the direction vector vertical to the rolling surface is within 15°.

Abstract: A compact device for measuring crystal orientation and crystal distortion in polycrystalline materials is disclosed. The device includes a focused electron beam generator unit, a sample holder, an electron beam detector, a Kossel X-rays detector, an image processor, and a display. The device employs the Kossel X-rays reflection method to measure crystal distortion and to measure crystal orientation in the inner portion of polycrystalline materials, slightly deeper than the shallow surface, while employing the electron beam diffraction method to measure crystal orientation at the shallow surface.

Abstract: The present invention provides a ferritic stainless steel sheet having excellent formability and excellent surface quality after forming. In specific means, the steel sheet contains, by mass %, 0.02 to 0.06% of C, 1.0% or less of Si, 1.0% or less of Mn, 0.05% or less of P, 0.01% or less of S, 0.005% or less of Al, 0.005% or less of Ti, 11 to 30% of Cr, 0.7% or less of Ni, the balance composed of Fe, and inevitable impurities, wherein N is contained to satisfy the relation to the C content represented by 0.06≦(C+N)≦0.12, and 1≦N/C, and V is contained to satisfy the relation to the N content represented by 1.5×10−3≦(V×N)≦1.5×10−2 (wherein C, N and V: the contents (mass %) of the elements).

Abstract: An oil-country-tubular threaded joint can withstand tensile forces, and in addition, other forces such as compression and bending forces, thus producing highly improved characteristics in regard to the prevention of fluid leakage. The oil-country-tubular threaded joint is formed of male screw threads and female screw threads which have a load face whose load flank angles are in a range of −3° to −25°, in which the load flank angles are varied at a position at which the load face is divided in the height direction of the male screw thread into an upper side and a lower side so that an upper load flank angle is smaller than a lower load flank angle by 0.5° to 2.0°. Also, a thread-machining apparatus for the oil-country-tubular threaded joint uses chasers having cutting edges which are shaped so as to correspond to thread shapes for machining screw threads whose flank angles are partly of negative values for the oil-country-tubular threaded joint.

Abstract: Provided is a non heat-treated steel that requires no particular controls over cooling rates and no aging treatments after hot working, that can sufficiently increase tensile strength, yield strength and toughness even at lightly deformed parts, and furthermore, that has excellent material anisotropy and machinability as an alloy steel for machine structures. In other words, it is a non heat-treated steel that contains: C: more than 0.05 mass % to less than 0.10 mass %; Si: 1.0 mass % or less; Mn: more than 2.2 mass % to 5.0 mass %; S: less than 0.020 mass %; Cu: more than 1.0 mass % to 3.0 mass %; Ni: 3.0 mass % or less; Cr: 0.01 to 2.0 mass %; Al: 0.1 mass % or less; Ti: 0.01 to 0.10 mass %; B: 0.0003 to 0.03 mass %; N: 0.0010 to 0.0200 mass %; O: 0.0060 mass % or less; and the balance Fe and inevitable impurities, and that the steel structure is bainitic having block structures at 10% or more in area ratios.

Abstract: An iron-based powder composition is provided that is greatly flowable and compactible and less dependent on temperature with respect to flowability and compactibility at room temperature or during warming. The iron-based powder composition includes an iron-based powder, a lubricant melted and fixed to the iron-based powder, an alloying powder bonded to the iron-based powder with the aid of the lubricant, and a free lubricant. One or more constituent members are coated with an organosiloxane layer in a coating ratio of greater than about 80%. The organosiloxane has phenyl groups as a functional group. The lubricant melted and fixed to the iron-based powder is a composite melt composed of a calcium soap and a lithium soap, or a composite melt composed of a calcium soap and an amide lubricant. The free lubricant is a mixed powder composed of an amide lubricant and a methyl polymethacrylate powder, or a lithium soap powder. A process for producing the iron-based powder composition is also provided.

Abstract: The present invention eliminates the need to stop the operation of a line even when trouble arises before, during, or after an operation of joining metal blocks in hot rolling. According to a specific solving means of the present invention, when a succeeding metal block is to be subjected to hot finish rolling in succession to a preceding metal block after the leading end of the succeeding metal block is joined to a tail end 10B of the preceding metal block on the inlet side of a finish rolling mill 26, it is determined before and after joining whether or not endless rolling is impossible. When it is impossible, joining is aborted, and the succeeding metal block 12 is temporarily stopped, is fed again after the tail end 10B of the preceding metal block moves out of the finish rolling mill 26, and is finish-rolled under the conditions set for batch rolling.

Abstract: The present invention relates to an H-shaped steel used as a building structure such as a column material or the like for highrise and super highrise building structures. In the bainite structure of extra-low-carbon steel, diffusive &agr;q is finely dispersed in &agr;B to ensure tensile strength at the 590-MPa level and significantly improve toughness in the direction of the flange thickness. Fine dispersion of &agr;q is achieved by controlling Mn and Cu in proper ranges. In other word, the present invention provides 590MPa class heavy gauge H-shaped steel with excellent as-rolled toughness in the direction of the flange thickness, containing 0.001 to 0.025 wt % of C, 0.6 wt % or less of Si, 0.4 to 1.6 wt % of Mn, 0.025 wt % or less of P, 0.010 wt % or less of S, 0.1 wt % or less of Al, 0.6 to 2.0 wt % of Cu, 0.25 to 2.0 wt % of Ni, 0.001 to 0.050 wt % of Ti, and 0.0002 to 0.0030 wt % of B, wherein Mn/Cu≦2.0 and 250≦117 Mn (wt %)+163 Cu (wt %)≦350 are satisfied.

Abstract: A shielding apparatus for intercepting heat from a heating source disposed in a vertical continuous annealing furnace includes a double-walled tube having an outside atmosphere suction port projected horizontally or downward to be exposed to an outside atmosphere, and an exhaust port projected upward to be exposed to the outside atmosphere.

Abstract: An ultrasonic testing method uses surface waves to prevent false detection of primary cracks, to lower the level of structural noises from grain boundaries, and to improve the detectability in the ultrasonic testing by surface wave testing of hot rolling rolls. A surface wave probe 10 capable of transmitting and receiving a surface wave is provided with a piezoelectric element 10A, a resin wedge 10C disposed on the front surface of the piezoelectric element 10A and a damping block 10B disposed on the back surface. The surface wave probe 10 is driven to produce a short pulse having a pulse length being at most 2.5 times the wavelength of the surface wave to be produced. A coupling liquid medium is supplied to the probe 10 in accordance with the peripheral speed of the roll to be tested. Depending on the height of the reflected waves measured, the grinding allowance of the roll is determined, and the roll is ground according to the thus-determined grinding allowance.