Abstract: A cooling apparatus of a steel sheet, which is excellent in discharging water without hindering the movement of a steel sheet, is disposed on a lower process side of a final stand in a row of hot finish rolling mills. The apparatus includes a plurality of cooling nozzles arranged to cool a steel sheet transported on transporting rolls, wherein the cooling nozzles are arranged on upper and lower surface sides of an area in which the steel sheet passes. A lower surface guide is arranged on the lower surface side with the lower surface guide comprising inlet holes through which cooling water sprayed from the cooling nozzles on the lower surface side passes and outlet holes through which the cooling water passes, dropping downwardly to be discharged. The inlet holes and the outlet holes are arranged alternately in a moving direction of the steel sheet.

Abstract: A reducing mill includes a plurality of stands disposed along a rolling direction line. The stands each include n rolls (n?3) disposed around the rolling direction line, the n rolls are shifted by 180°/n around the rolling direction line from n rolls included in a preceding stand. The n rolls included in each of the stands excluding the last stand each have a groove having an arch shape. The bottom of the groove has a circular arc shape around the rolling direction line having a first radius in cross section. The distance between the surface of a roll flange portion between the bottom and the edge of the groove and the rolling direction line is longer than the first radius. The distance between the edge of the groove and the rolling direction line is longer than the first radius in the groove of a roll included in the preceding stand.

Abstract: Disclosed is a low alloy steel for oil well pipes which has excellent sulfide stress cracking resistance and is suitable for casing and tubing for oil wells or gas wells. Specifically disclosed is a low alloy steel for oil well pipes containing, in mass %, 0.2-0.35% of C, 0.05-0.5% of Si, 0.05-1.0% of Mn, not more than 0.025% of P, not more than 0.01% of S, 0.005-0.10% of Al, 0.1-1.0% of Cr, 0.5-1.0% of Mo, 0.002-0.05% of Ti, 0.05-0.3% of V, 0.0001-0.005% of B, not more than 0.01% of N, not more than 0.01% of O (oxygen), 0-0.1% of Nb, 0-0.01% of Ca, 0-0.01% of Mg and 0-0.1% of Zr, and having a half-value breadth (H) and a hydrogen diffusion coefficient (D) (10?6 cm2/s) satisfying the following formula (1): 30H+D?19.5??(1).

Abstract: The method for manufacturing a martensitic stainless pipe includes heating the steel pipe until the external surface temperature thereof reaches a predetermined temperature not lower than A3 transformation point+20° C. and not higher than 980° C. The heated steel pipe is first water cooled until the external surface temperature thereof reaches a predetermined temperature not lower than 350° C. The water cooled steel pipe is air cooled until the external surface temperature thereof reaches a predetermined temperature not higher than 250° C. The air cooled steel pipe is either water or air cooled until the external surface temperature thereof reaches normal temperature. The cooling rate of the steel pipe in the first cooling step is determined according to the wall thickness of the steel pipe so that the amount of heat recuperation for the external surface temperature of the steel pipe in the second cooling step is not higher than 50° C.

Abstract: A martensitic stainless steel for welded structures including by mass %, C: 0.001 to 0.05%, Si: 0.05 to 1%, Mn: 0.05 to 2%, P: 0.03% or less, REM: 0.0005 to 0.1%, Cr: 8 to 16%, Ni: 0.1 to 9% and sol. Al: 0.001 to 0.1%; and further including one or more elements selected from among Ti: 0.005 to 0.5%, Zr: 0.005 to 0.5%, Hf: 0.005 to 0.5%, V: 0.005 to 0.5% and Nb: 0.005 to 0.5%; and O: 0.005% or less, N: 0.1% or less, with the balance being Fe and impurities; and the P and REM content satisfies: P?0.6×REM. This steel possesses excellent SCC (stress corrosion cracking) resistance in welded sections in Sweet environments.

Abstract: A rotary eddy current flaw detection probe device has a plurality of ?-shaped eddy current flaw detection probes attached in a rotating disc for detecting flaws in all directions regardless of the flaw direction. Four ?-shaped eddy current testing probes P11 to P22 are arranged around the rotation center Ds1 of a rotating disc 111, and are embedded in the disc 111. The coil planes of detector coils Ds11 to Ds22 of the testing probes P11 to P22 are parallel with each other, and are perpendicular to the rotation plane of the rotating disc 111. The coil planes of the detector coils incline at an angle ? relative to a line Y passing through the centers Ps11 and Ps12 of the probes P11 and P12. The detector coils Dc11 and Dc12 are cumulatively connected to each other, and the detector coils Dc21 and Dc22 are differentially connected to each other.

Abstract: A martensitic stainless steel comprising C: 0.01-0.10%, Si: 0.05-1.0%, Mn: 0.05-1.5%, P: not more than 0.03%, S: not more than 0.01%, Cr: 9-15%, Ni: 0.1-4.5%, Al: not more than 0.05% and N: not more than 0.1% in mass %, and further comprising at least one of Cu: 0.05-5% and Mo: 0.05-5%, the residual being Fe and impurities, is provided, wherein the contents of Cu and Mo satisfy the following formula (a) or (b), 0.2%?Mo+Cu/4?5%??(a) 0.55%?Mo+Cu/4?5%??(b) and wherein the hardness is 30-45 in HRC and the carbide amount in grain boundaries of the prior austenite is not more than 0.5 volume %. The marensitic stainless steel has excellent properties regarding the sulfide stress cracking resistance, the resistance to corrosive wear and the localized corrosion.

Abstract: A welding material, to be used for welding a base metal made of an austenitic alloy comprising C?2.0%, Si?4.0%, Mn: 0.01 to 3.0%, P: more than 0.03% to not more 0.3%, S?0.03%, Cr: 12 to 35%, Ni: 6 to 80%, sol. Al: 0.001 to 1% and N?0.3%, with the balance being Fe and impurities to a base metal made of another austenitic alloy, which comprises C: more than 0.3% to 3.0%, Si?4.0%, Mn?3.0%, P?0.03%, S?0.03%, Cr: more than 22% to 55%, Ni: more than 30% to not more than 70%, sol. Al: 0.001 to 1% and N?0.3%, with the balance being Fe and impurities can suppress the weld solidification cracking which occurs in an austenitic alloy having a high P content and showing fully austenitic solidification. Therefore, the said welding material can be widely used in such fields where a welding fabrication is required. The said welding material may contain a specific amount or amounts of one or more elements selected from Cu, Mo, W, V, Nb, Ti, Ta, Zr, Hf, Co, B, Ca, Mg and REM.

Abstract: A main object thereof is to provide a non-oriented electrical steel sheet being excellent in surface characteristics and having both excellent mechanical characteristics and magnetic characteristics necessary for a rotor of rotating machines such as motors and generators which rotate at a high speed, and a method for producing the same. To achieve the object, the present invention provides a non-oriented electrical steel sheet comprising in % by mass: 0.06% or less of C; 3.5% or less of Si; from 0.05% or more to 3.0% or less of Mn; 2.5% or less of Al; 0.30% or less of P; 0.04% or less of S; 0.02% or less of N; at least one element selected from the group consisting of Nb, Ti, Zr and V in the predetermined range; and a balance consisting of Fe and impurities; and having a recrystallized fraction being less than 90%.

Abstract: A bending apparatus which manufactures a bent metal member with high productivity and excellent dimensional has a first support mechanism, which supports a steel tube while feeding it, a heating mechanism, which heats all or a portion of the steel tube, a cooling mechanism, which forms a high temperature portion in part of the steel tube by cooling a portion of the heater steel tube, a second support mechanism, which imparts a bending moment to the high temperature portion and bends the steel tube to a desired shape by moving two-dimensionally or three-dimensionally while supporting at least a portion of the steel tube, and a deformation preventing mechanism, which prevents deformation of the steel tube. At least one of the second support mechanism and the deformation preventing mechanism has a chuck which has a tubular member with a circular, polygonal, or special transverse cross section for gripping the steel tube.

Abstract: A carburized component with improved fatigue strength has a base steel containing, by mass %, C: 0.15-0.25%, Si: 0.03-0.50%, Mn: more than 0.60% and not more than 1.5%, P?0.015%, S: 0.006-0.030%, Cr: 0.05-2.0%, Al?0.10%, N?0.03%, and O?0.0020%, and optionally at least one element selected from Mo, Cu, Ni, B, Ti, Nb and V, the balance being Fe and impurities. A surface hardened layer portion satisfies: (a) average carbon concentration in the region from the outermost surface to a point of 0.2 mm depth of 0.35-0.60 mass %, (b) surface roughness Rz?15 ?m, and (c) ?r(0)?-800 MPa, ?r(100)?-800 MPa, and residual stress intensity index Ir?80000, wherein Ir is calculated by [Ir=?|?r(y)|dy], where y ?m is the depth from the outermost surface and ?r(y) is the residual stress for the points from the outermost surface to a depth of 100 ?m with the range of y from 0 to 100 (?m).

Abstract: A non-heat treated connecting rod which comprises, by mass %, C: 0.25-0.35%, Si: 0.50-0.70%, Mn: 0.60-0.90%, P: 0.040-0.070%, S: 0.040-0.130%, Cr: 0.10-0.20%, V: 0.15-0.20%, Ti: 0.15-0.20% and N: 0.002-0.020%, and the balance Fe and impurities, with chemical compositions being less than 0.80 in the value of C+(Si/10)+(Mn/5)+(5Cr/22)+1.65 V?(5S/7) using the symbol of the element as its content, the microstructure of the Big end of the said connecting rod being ferrite-pearlite, all-region hardness of the said big end being 255 to 320 in Vickers hardness, the ferrite-region hardness in the said ferrite-pearlite of the Big end being 250 or more in Vickers hardness and the ratio of the said ferrite-region hardness to the said all-region hardness of the said Big end being 0.80 or more, is excellent in machinability, fracture splitting ability, and fatigue resistance, although no Pb at all is added.

Abstract: An elongation rolling control method is provided which can manufacture a hollow shell of high dimensional accuracy and can suppress rolling problems.

Abstract: A bending apparatus for manufacturing a bent member from a steel pipe with high dimensional accuracy and high productivity can be installed in a small space with good maintainability. The apparatus has a feed mechanism for feeding a steel pipe in its lengthwise direction, a first support mechanism for supporting the steel pipe while feeding it, a heating mechanism for heating a part or all of the steel pipe being fed, a cooling mechanism for cooling the portion of the heated steel pipe being fed, a second support mechanism for imparting a bending moment to the heated portion of the steel pipe to bend the steel pipe into a desired shape by moving two-dimensionally or three-dimensionally while supporting the fed steel pipe in at least one location, and a deformation preventing mechanism for preventing deformation of the steel pipe. The feed mechanism is a vertically articulated robot having seven axes.

Abstract: A manufacturing apparatus comprises a final stand, with standing side members, and a cooling apparatus. The cooling apparatus comprises rows of upper surface cooling nozzles, rows of lower surface cooling nozzles, and an upper surface guide on the upper surface side of the steel sheet. An end portion of the cooling apparatus on a side of the final stand is arranged between the standing side members of the housing. When defining a width of a uniformly cooled region, an average gap distance (WSW) between the end portion of the width of the uniformly cooled region and the standing side member of the housing; a gravity acceleration rate, an average water volume density of the width of the uniformly cooled region, and a value determined by WSW and an average distance h between the upper surface guide and the upper surface of the steel sheet, a specific relation is satisfied.

Abstract: To provide a steel pipe as a fuel injection pipe with high material strength, high internal pressure limit free from fatigue failure, prolonged fatigue life, and high reliability. A steel pipe as a fuel injection pipe of 500 N/mm2 or higher tensile strength comprising, by mass, C: 0.12 to 0.27%, Si: 0.05 to 0.40%, and Mn: 0.8 to 2.0%, and the balance being Fe and impurities, the contents of Ca, P, and S in the impurities being Ca: 0.001% or less, P: 0.02% or less, and S: 0.01% or less, respectively, characterized in that the maximum diameter of nonmetallic inclusions present in at least in a region extending from the inner surface of the steel pipe to a depth of 20 ?m is 20 ?m or less. Further, this steel pipe may contain, in place of a portion of Fe, at least one selected from among Cr: 1% or less, Mo: 1% or less, Ti: 0.04% or less, Nb: 0.04% or less, and V: 0.1% or less.

Abstract: A pipe string component that connects an offshore platform with a sea bed is provided. The pipe string component includes a threaded tubular connection. The threaded tubular connection includes a male tubular element including a tapered male threading, and a female tubular element including a tapered female threading that cooperates with the male threading by makeup to produce a rigid mutual connection of the tubular elements with radial interference between radial load transfer zones of the threadings. The male and female threadings each have a load flank extending substantially perpendicularly to an axis of the male and female threadings. The radial load transfer zones are at a radial distance from envelopes of thread roots of the male and female threadings. The radial load transfer zones of the threadings comprise at least one surface substantially parallel to an axis of the connection.

Abstract: An exemplary embodiment of the invention provides a method for producing an ultra thin wall metallic tube by cold working method with significant wall thickness reduction. In a method for producing the metallic tube with a cold pilger mill according to the invention, cold rolling is performed while tube diameters are being expanded using rolls having tapered groove dies whose calibers increase from an engaging entry side toward a finishing exit side. In a method for producing the metallic tube with a drawing machine according to the invention, cold drawing is performed while the tube diameters are being expanded using a solid die whose calibers increase from an engaging entry side toward a finishing exit side and a plug of a tapered mandrel bar whose diameters increase from an entry side of the die toward an exit side. In the metallic tube producing method, a maximum diameter of the plug or tapered mandrel bar may be larger than an outside diameter of the mother tube.

Abstract: An ultrasonic testing apparatus for a pipe end portion, which enables accurate ultrasonic testing, comprises an ultrasonic probe disposed under the pipe end portion. The probe 1 transmits ultrasonic waves to the pipe end portion and receives the ultrasonic waves therefrom. A probe holder houses the probe which is disposed under the pipe end portion to face the pipe end portion and follows the pipe rotation. The probe holder comprises a coupling medium reserver part that surrounds a space between the probe and the pipe end portion to contain a coupling medium therein and comprises a coupling medium reserver part body into which the coupling medium is supplied. An annular bellows part, which communicates with the reserver part body, can expand and contract vertically and an annular spacer, which is attached to the upper side of the bellows part and an upper surface thereof has a flat horizontal surface.

Abstract: The present invention provides a cooling apparatus of a hot-rolled steel sheet capable of manufacturing a hot-rolled steel sheet having ultra fine crystal grains. In the cooling apparatus, when defining as L1, a length in a transporting direction of a steel sheet, of a zone from a rolling reduction point in a final stand to an exit side of a housing post; defining as L2, a length in the transporting direction of the steel sheet, of an area where high-pressure water is continuously sprayed over the steel sheet, within the zone; and defining a ratio of L2/L1 as X, an average value Ps [kPa], in the transporting direction of the steel sheet, of an impact pressure of the high-pressure water on a surface of the steel sheet in the area of the length L2 satisfies Ps?2.5X(?1/0.6) on the above upper surface and lower surface of the steel sheet.