Abstract: The invention provides a high-carbon steel pipe having superior cold workability and induction hardenability, and a method of producing the steel pipe. The method comprises the steps of heating or soaking a base steel pipe having a composition containing C: 0.3 to 0.8%, Si: not more than 2%, and Mn: not more than 3%, and then carrying out reducing rolling on the base steel pipe at least in the temperature range of (Ac1, transformation point −50° C.) to Ac1, transformation point with an accumulated reduction in diameter of not less than 30%. A structure in which the grain size of cementite is not greater than 1.0 &mgr;m is obtained, thus resulting in improved cold workability and induction hardenability.

Abstract: An apparatus (10) includes a low-carbon steel tube (24). The low-carbon steel tube (24) yields plastically more than about 5% before fracturing at temperatures down to about −40° C. when stress is applied to the low-carbon steel tube sufficient to cause the low carbon steel tube to so yield.

Abstract: A cobalt-free martensitic steel exhibiting good response to hardening and resistance to softening at high temperatures, the steel containing sub-micron and nano-structural precipitates and intermetallic compounds of silicon, nickel, aluminum, copper and manganese.

Abstract: A castable martensitic mold alloy and process for preparing same are disclosed. The composition is characterized by a ductile fine grain tempered martensite having an HRC of about 40 to about 50. The process includes forming a molten fixture of the components and then slow cooling same without requiring an additional tempering heat treatment step as is required in conventional techniques. The components comprise: a) from about 5.0-15% Cr; b) from about 0.5-15% Ni; c) from about 0.1-10% Mo; d) not more than about 2% Si; e) from about 0.1-2% Mn; f) from about 0.1-2% C; g) not more than about 1% S; h) not more than about 1% P; i) not more than about 5% B; j) and the balance being substantially Fe.

Abstract: A ferritic heat-resisting steel that shows a slight decrease in creep strength at the heat affected zone of the welded joint. The steel is characterized by consisting of, by mass %, C: less than 0.05%, Si: not more than 1.0%, Mn: not more than 2.0%, P: not more than 0.030%, S: not more than 0.015%, Cr: 7-14%, V: 0.05-0.40%, Nb: 0.01-0.10%, N: not less than 0.001% but less than 0.050%, sol. Al: not more than 0.010%, and O (oxygen): not more than 0.010%, with the balance being Fe and impurities, and further characterized in that the density of carbide and carbonitride precipitates contained with a grain diameter of not less than 0.3 &mgr;m is not more than 1×106/mm2. This steel may further contain one or more of the following elements: a total of 0.1-5.0% of Mo and W; a total of 0.02-5.00% of Cu, Ni and Co; a total of 0.01-0.20 of Ta, Hf, Nd and Ti; a total of 0.0005-0.0100% of Ca and Mg; and 0.0005-0.0100% of B.

Abstract: A method for identifying additive components for polycrystalline metals and materials that enhance grain boundary cohesion and compositions of such materials comprises calculation of an empirical value &Dgr;BAwhich is dependent upon a summation of various energy values associated with the matrix and additives and identifying the additives having a negative value. Formulations of alloys having improved physical properties and their processing steps are also disclosed.

Abstract: The present invention provides a steel sheet having a chemical composition comprising 0.15% or less C, 2.0% or less Si, 3.0% or less Mn, P, S, Al and N in adjusted amounts, from 0.5 to 3.0% Cu, or one or more of Cr, Mo and W in a total amount of 2.0% or less, and having a composite structure comprising ferrite and martensite having an area ratio of 2% or more. The steel sheet is in the form of a high-strength hot-rolled steel sheet, a high-strength cold-rolled steel sheet, or a hot-dip galvanized steel sheet. There is thus available a steel sheet excellent in press-formability and in strain age hardening property as represented by a &Dgr;TS of 80 MPa or more.

Abstract: Disclosed is a corrosion resistant steel having good machinability with sufficient corrosion resistance in the ordinary indoor circumstances and suitable for manufacturing shafts of various small motors and OA-machines. The steel comprises, by weight %, C: 0.005-0.200%, P: up to 0.05%, Cu: up to 2.0%, Ni: up to 2.0%, Cr: 2.0-9.0%, one or both of Ti and Zr: in such an amount as [Ti %]+0.52[Zr %]: 0.03-1.20%, one or both of S: 0.01-0.50% and Se: 0.01-0.40%, N: up to 0.050% and O: up to 0.030%, the balance being Fe and inevitable impurities. The steel is characterized by the inclusion therein, which are Ti-based, Zr-based or Ti-Zr-based compound or compounds containing C and one or both of S and Se.

Abstract: Disclosed is a steel alloy that includes as alloying ingredients carbon, silicon, manganese, aluminum, and oxygen. In accordance with this embodiment of the disclosed invention, carbon is present in an amount ranging from 0.40 to 0.77 wt. %; silicon is present in an amount ranging from 0.40 to 1.20 wt. %; manganese is present in an amount ranging from 0.40 to 1.20 wt. %, aluminum is present in an amount ranging from 0.003 to 0.060 wt. %; and oxygen is present in an amount ranging up to 0.0030 wt. %. Also disclosed is a railway wheel that comprises a hub, a rim, and a connecting plate. In accordance with this embodiment of the disclosed invention, at least the rim, and preferably the entire railway wheel, is composed of the disclosed steel composition.

Abstract: Steel alloys susceptible to case and core hardening comprising 0.05 to 0.24 weight percent carbon; 15 to 28 weight percent cobalt and 1.5 to 9.5 weight percent in nickel, small percentages of one or more additives: chromium, molybdenum, and vanadium; and the balance iron.

Abstract: The present invention provides a steel pipe excellent in formability during hydraulic forming and the like and a method to produce the same, and more specifically: a steel pipe excellent in formability having an r-value of 1.4 or larger in the axial direction of the steel pipe, and the property that the average of the ratios of the X-ray intensity in the orientation component group of {110}<110> to {332}<110> on the plane at the center of the steel pipe wall thickness to the random X-ray intensity is 3.5 or larger, and/or the ratio of the X-ray intensity in the orientation component of {110}<110> on the plane at the center of the steel pipe wall thickness to the random X-ray intensity is 5.

Abstract: A pre-hardened and pre-tempered tool steel is used for producing molds for plastic parts, in particular matrices of large dimensions. In order to make possible high core hardness without qualitative disadvantages even at large diameters, a tool steel is proposed, which has a composition in weight-% of C=0.25 to 0.30, SI=0.04 to 0.20, Mn=1.2 to 2.0, Cr=1.0 to 2.0, Ni=0.9 to 1.5, Mo=0.3 to 0.8, V≦0.2 and Al=0.01 to 0.03, wherein the remainder consists of iron and the unavoidable impurities. The addition of boron for increasing hardness was intentionally omitted since it has been shown that with larger diameters boron results in non-reproducible hardness, in particular in the core area.

Abstract: A compound structure steel sheet excellent in burring workability made of a steel containing, by mass, 0.01 to 0.3% of C, 0.01 to 2% of Si, 0.05 to 3% of Mn, 0.1% or less of P, 0.01% or less of S, and 0.005 to 1% or Al, and having the microstructure being a compound structure having ferrite as the main phase and martensite or retained austenite mainly as the second phase, the quotient of the volume percentage of the second phase divided by the average grain size of the second phase being 3 or more and 12 or less, and the quotient of the average hardness of the second phase divided by the average hardness of the ferrite being 1.5 or more and 7 or less; or a compound structure steel sheet excellent in burring workability made of a steel containing, by mass, 0.01 to 0.3% of C, 0.01 to 2% of Si, 0.05 to 3% of Mn, 0.1% or less of P, 0.01% or less of S, and 0.

Abstract: A maraging steel for use as a mold steel is disclosed. In general, the use of maraging steels in molds is limited by the fact that the martensitic microstructure is not stable at temperatures above 480° C. The precipitate hardening maraging type steel according to the invention contains titanium, molybdenum, cobalt, chromium and nickel and has, in addition to high strength, good ductility, small thermal expansion coefficient and good thermal conductivity, a significantly better thermal stability than other maraging steels, which makes it suitable for use as a mold material particularly in pressure casting.

Abstract: To provide a high-strength steel having a desired strength (800 N/mm2 or higher) for screws and bolts of a large diameter (M8 or larger) that also have a tapping ability, and a high-strength screw made from such a steel. The steel comprises (by % mass) C: 0.05 to 0.20, Si: 0.20 or less (not including 0), Mn: 0.5 to 2.0, P: 0.015 or less, S: 0.015 or less, sol. Al: 0.020 to 0.080, N: 0.0060 or less, Cr: more than 0.80 to 2.0 and the balance being iron and unavoidable impurities.

Abstract: The present invention provides a hot rolled steel wire rod or bar for machine structural use having, in the as-hot-rolled condition, cold workability equal to that of the conventional wire rods or bars softened through annealing after hot rolling, and a method to produce the same: and relates to a hot rolled steel wire rod or bar for machine structural use, characterized in that; the wire rod or bar is made from a steel consisting of, in weight, 0.1 to 0.5% of C, 0.01 to 0.5% of Si, 0.3 to 1.5% of Mn, and the balance comprising Fe and unavoidable impurities and containing strengthening elements as required; its microstructure consists of ferrite and pearlite; its ferrite crystal grain size number defined under Japanese Industrial Standard (JIS) G 0552 is 11 or higher; and a granular carbide 2 &mgr;m or less in circle-equivalent diameter and having an aspect ratio of 3 or less accounts for a percentage area of 3 to 15%.

Abstract: The present invention provides a steel wire rod for cold forging which can be spheroidizing-annealed in an as hot-rolled state without requiring preliminary drawing and can have high ductility after the spheroidizing annealing, and a method to produce the same: and is characterized in that; the steel contains, by weight, 0.1 to 0.5% of C, 0.01 to 0.5% of Si and 0.3 to 1.5% of Mn, with the balance consisting of Fe and unavoidable impurities, and further contains hardening elements as required; and the steel has a prior austenite grain size number, defined under Japanese Industrial Standard (JIS) G 0551, of 11 or higher, the amount of diffusible hydrogen in the steel measured by the programmed temperature gas chromatography being 0.2 ppm or less, and the hardness being Hv 250 to 700.

Abstract: Rolling structure steel, comprising: 0.90-100% by wt. C; 0.95-1.05% by wt Si; 0.25-0.45% by wt Mn; 0.015% by wt. S max.; 0.025% by wt. P max.; 1.30-1.50% by wt. Cr, and 0.17-0.20% by wt. Mo. Preferably this steel is produced by austenising at 860+20° C., quenched in oil and tempered at 240+20° C. In this way steel is obtained having a high rolling contact fatigue strength and dimensional stability at elevated temperature operating conditions.

Abstract: An outer ring 2 as a stationary ring is fabricated with a steel material having the composition as shown under. The steel material contains, as alloying elements, C 0.80 to 1.10 wt %, Si 0.20 to 0.50 wt %, Mn 0.2 to 1.0 wt %. It also contains any two kinds or more of Cr, Mo and V at rates of Cr: 1.2 to 3.5 wt %, Mo: 0.5 to 1.5 wt % and V: 0.2 to 1.0 wt %. The containing rates of Cr, Mo and V satisfy the under mentioned formula (1). It further contains Ti and/or Cu at rates of Ti: 0.05 to 0.20 wt % and Cu: 0.2 to 2.0 wt % 1.8≦[Cr]×0.6+[Mo]×0.5+[V]≦3.0  (1). Accordingly, it is possible to remarkably lengthen the life of a rolling bearing such as a bearing for alternator to be used under high vibration and high load.

Abstract: A heat resistant steel which comprises, by mass %, C: 0.01-0.25%, Cr: 0.5-8%, V: 0.05-0.5%, Si: not more than 0.7%, Mn: not more than 1%, Mo: not more than 2.5%, W: not more than 5%, Nb: not more than 0.2%, N: not more than 0.1%, Ti: not more than 0.1%, Ta: not more than 0.2%, Cu: not more than 0.5%, Ni: not more than 0.5%, Co: not more than 0.5%, B: not more than 0.1%, Al: not more than 0.05%, Ca: not more than 0.01%, Mg: not more than 0.01%, Nd: not more than 0.01%, with Fe and impurities accounting for the balance, the chemical composition of which satisfies the relations C−0.06×(Mo+0.5 W)≧0.01 and Mn+0.69×log(Mo+0.5 W+0.01)≦0.60 wherein the symbols for elements represent the contents, on the % by mass basis, of the elements in the steel, and in which, among precipitates inside grains, precipitates having an average diameter of not more than 30 nm are present at a density of not less than 1/&mgr;m3.

Abstract: A composition for steel used for tires or solid wheels of rail vehicles, which composition provides improved properties, in terms of wear, crack susceptibility, ability to withstand thermal loads, homogenous microstructural properties and suitability for high dynamic loads, as compared to standard steels used for tires or solid wheels of rail vehicles. The steel is a modification of AISI S2 steel previously only used for antifriction bearings. The elements of the composition and their presence by percentage of total mass of the steel and ratios of the presence of various elements are disclosed.

Abstract: Disclosed is a heat resistant steel casting, comprising C, 0.15-0.3%, Si, 0.1-0.30%, Mn, 0.01-0.1%, Cr, 2.0-2.5%, Mo, 0.3-0.8%, V, 0.23-0.3%, W, 1.6-2.6%, N, 0.005-0.03%, B, 0.001-0.004%, impurity elements including Ni not larger than 0.2%, P not larger than 0.03% and S not larger than 0.01%, B equivalent determined by B+0.5N given below being not larger than 0.02%, Mo equivalent determined by Mo+0.5W given below falling within a range of between 1.4% and 2.0%, and C equivalent determined by C+Mn/6+Si/24+Ni/40+Cr/5+Mo/14+V/14 given below being not smaller than 0.65%, and balance of iron wherein a precipitated phase consisting of a M23C6 carbide, a M7C3 carbide, and MX carbonitride is a texture finely precipitated in a matrix phase, and a ratio of the precipitated phase to the matrix phase falls within a range of between 0.6% and 1.0%.

Abstract: Steel alloys susceptible to case and core hardening comprising 0.05 to 0.24 weight percent carbon; 15 to 28 weight percent cobalt and 1.5 to 9.5 weight percent in nickel, small percentages of one or more additives: chromium, molybdenum, and vanadium; and the balance iron.

Abstract: The present invention is directed to a steel product for machine structural use having excellent machinability and to a structural steel part for machinery manufactured from the steel product. More particularly, the invention is directed to a steel product for machine structural use having excellent machinability, particularly bringing about excellent “drill life” and exhibiting excellent “chip disposability” in the course of drilling, as well as to a structural steel part for machinery manufactured from the steel product. The steel product for machine structural use has a chemical composition comprising, in mass percent, C: 0.05% to 0.55%; Si: 0.50% to 2.5%; Mn: 0.01% to 2.00%; P: not greater than 0.035%; S: 0.005% to 0.2%; N: not greater than 0.0150%; elements to be added as needed: Cu, Ni, Cr, Mo, V, Nb, Ti, B, Al, Bi, Ca, Pb, Te, Nd, and Se; −23C+Si(5−2Si)−4Mn+104S−3Cr−9V+10≧0; 3.2C+0.8Mn+5.2S+0.5Cr−120N+2.

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: 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: The present invention provides a high carbon steel wire remarkably excellent in wire-drawability and fatigue resistance after wire drawing with a low cost due to reduced use of costly alloys. A high carbon steel wire according to the present invention is one excellent in wire-drawability and fatigue resistance after wire drawing, characterized in that; the total oxygen content is 15 to 50 ppm; among non-metallic inclusions included therein, the number of inviscid inclusions is 1.

Abstract: The high-strength race of the present invention comprises using A steel for a high-strength race comprising the following elements in percentage by weight: C: 0.30 to 0.60%, Si: 0.30 to 1.30%, Mn: 0.5 to 1.5%, B: 0.0050% or less, Cr: 0.1 to 0.5%, Mo: 0.1 to 0.5%, Si +Mo: 0.5 to 1.4%, Ni: 0.02 to 1.0%, the balance of Fe and unavoidable impurities, performing induction hardening to make the race have a surface hardness of 58 HRC or more and further a surface hardness of 52 HRC or more even after the surface is tempered at 300° C. The high-strength race is superior in rotating fatigue properties, anti-surface fatigue strength and productivity by a combination of composition control and induction hardening.

Abstract: The present invention provides a ferritic steel sheet, the quasi-static strength of which is enhanced and further the dynamic strength of which is not lowered. There is provided a ferritic steel sheet excellent at strain rate sensitivity characterized in that: Co and/or Cr are contained at pot less than 0.01 mass % and not more than 4.0 mass % in total in the state of solid solution in the ferrite phase.

Abstract: A high strength steel for dies has excellent machinability and including, by weight, 0.005 to 0.1% C, not more than 1.5% Si, not more than 2.0% Mn, from 3.0 to less than 8.0% Cr, not more than 4.0% Ni, 0.1 to 2.0% Al, not more than 3.5% Cu, and balance of Fe and unavoidable impurities including N and O, and which has a metal structure whose primary microstructure is martensite, wherein N and O as impurities are restricted to amount ranges of not more than 0.02% N and not more than 0.003% O. In the invention, an improvement in the machinability in heavy cutting an improvement in the precision electro discharge machining property and high-grade polishing property can be achieved when the above high strength steel has a chemical composition in which the value of (7.7×C (wt %))+(2.2×Si (wt %))+271.2×S (wt %)) is preferably not less than 2.5 and more preferably not more than 6.

Abstract: The present invention provides a spring steel showing a sufficient reduction in area and an impact toughness while the steel has a high strength, in particular a tensile strength as high as at least 1,500 Mpa. A high toughness spring steel according to the present invention comprises, based on mass, 0.45 to 0.85% of C, 0.9 to 2.5% of Si, 0.1 to 1.2% of Mn, 0.1 to 2.0% of Cr, 0.005 to 0.07% of Ti, 0.001 to 0.007% of N, the Ti content being greater than four times the N content in terms of percent by mass, 0.0005 to 0.0060% B, at least one of 0.0005 to 0.01% Mg, 0.0005 to 0.01% La, and 0.0005 to 0.01% Ce, P and S with restrictive contents of less than 0.020% and less than 0.020%, respectively, and the balance of Fe and unavoidable impurities, and selectively contains V, Nb, Ni, Mo and Cu. The percent area of oxides and sulfides is not more than 0.1%.

Abstract: This invention provides a boiler steel pipe that exhibits a high creep rupture strength on a high-temperature high-pressure side and is excellent in electric weldability, and an electric welded boiler steel pipe having fewer defects at an electric welded portion. The boiler steel contains, in terms of wt %, C: 0.01 to 0.20%, Si: 0.01 to 1.0% and Mn: 0.10 to 2.0%, contains further Cr: 0.5 to 3.5%, and limits p≦0.030%, S≦0.010% and 0≦0.20%, wherein a weight ratio of (Si %)/(Mn %) or (Si %)/(Mn %+Cr %) is from 0.005 to 1.5, the balance Fe and unavoidable impurities, and the melting point of the mixed oxide of SiO2 and MnO, or SiO2, MnO and Cr2O3, is not higher than 1,600° C. The oxide that would otherwise result in the defects of the electric welded portion is molten and squeezed out as slag components.

Abstract: The steel of the present invention satisfies the following requirement for non-metallic inclusion area: when the steel is melted by an electron beam under the conditions of an irradiation rate of 200 to 600 J/sec., an irradeation time of 10 to 25 seconds, and an irradeation energy of 5000 J or more, the area of non-metallic inclusions existing in the surface of the sample after solidification falls within 15,000 &mgr;m2 or less. The steel exhibits excellent cold workability and fatigue properties.

Abstract: A bar product prepared from microalloyed bar steel is provided. The bar product is prepared by hot rolling and heat treating a microalloyed bar steel. The hot rolled and heat treated microalloyed bar steel is prepared by steps of hot rolling a preform of the microalloyed bar steel at a temperature of between about 1,400° F. and about 2,200° F. to provide a steel bar having a diameter of between about ¾ inch and about four inches, cooling the steel bar to provide a surface temperature of below about 1,100° F., and heat treating the steel bar in an environment having a temperature of between about 500° F. and about 1,300° F. The bar product is preferably prepared without a step of cold drawing. In particular, the bar product is preferably prepared without a step of drawing to provide a 10% to a 35% reduction.

Abstract: A low carbon high strength steel consists essentially of, by weight, about 0.07% to about 0.12% carbon, about 0.70% to about 1.60% manganese, up to about 0.020% phosphorous, up to about 0.015% sulfur, about 0.06% to about 0.35% silicon, about 0.25% to about 1.20% chromium, up to about 0.65% nickel, about 0.20% to about 0.70% molybdenum, up to about 0.35% copper, about 0.02% to about 0.06% aluminum, up to about 0.05% vanadium, up to about 0.25% residual elements, and the balance iron.

Abstract: Steel for the manufacture of a component for bearings, the chemical composition of which comprises, by weight: 0.6%≦C≦1.5%; 0.4%≦Mn≦1.5%; 0.75%≦Si≦2.5%; 0.2%≦Cr≦2%; 0%≦Ni≦0.5%; 0%≦Mo≦0.2%; 0%<Al≦0.05%; S≦0.04%; the balance being iron and impurities resulting from smelting and the composition furthermore satisfying the relationships: Mn≦0.75+0.55×Si and Mn≦2.5−0.8×Si. Process for the manufacture of a bearing component.

Abstract: A high strength, low alloy, heat resistant steel having excellent weldability has an average crystal grain diameter of at most 110 &mgr;m and consists essentially of, by mass %: C: 0.03-0.15%, Si: at most 1%, Mn: at most 2%, P: at most 0.03%, S: at most 0.03%, Ni: at most 0.5%, Cu: at most 0.5%, Cr: 1.8-2.8%, V: 0.1-0.3%, Nb: 0.01-0.08%, Mo: 0.05-0.35%, W: 1.2-1.8%, Ti: 0.001-0.05%, B: 0-0.02%, Al: at most 0.1%, O: at most 0.1%, N: in an amount satisfying the formula [%N]≦[%Ti]+5[%B]+0.004, and a remainder of unavoidable impurities.

Abstract: Disclosed is a steel alloy that includes as alloying ingredients carbon, silicon, manganese, aluminum, and oxygen. In accordance with this embodiment of the disclosed invention, carbon is present in an amount ranging from 0.40 to 0.77 wt. %; silicon is present in an amount ranging from 0.40 to 1.20 wt. %; manganese is present in an amount ranging from 0.40 to 1.20 wt. %, aluminum is present in an amount ranging from 0.003 to 0.060 wt. %; and oxygen is present in an amount ranging up to 0.0030 wt. %. Also disclosed is a railway wheel that comprises a hub, a rim, and a connecting plate. In accordance with this embodiment of the disclosed invention, at least the rim, and preferably the entire railway wheel, is composed of the disclosed steel composition.

Abstract: The present invention provides a steel wire rod for cold forging which can be spheroidizing-annealed in an as hot-rolled state without requiring preliminary drawing and can have high ductility after the spheroidizing annealing, and a method to produce the same: and is characterized in that; the steel contains, by weight, 0.1 to 0.5% of C, 0.01 to 0.5% of Si and 0.3 to 1.5% of Mn, with the balance consisting of Fe and unavoidable impurities, and further contains hardening elements as required; and the steel has a prior austenite grain size number, defined under Japanese Industrial Standard (JIS) G 0551, of 11 or higher, the amount of diffusible hydrogen in the steel measured by the programmed temperature gas chromatography being 0.2 ppm or less, and the hardness being Hv 250 to 700.

Abstract: A 590 MPa-class rolled steel shape of high strength and excellent toughness for use as a building structural member and a method of producing the high-tensile rolled steel shape are provided. Strength optimization by an alloy that elevates hardenability, texture refinement obtained by fine dispersion of Ti oxides and TiN owing to Ti addition, precipitation strengthening by Cu addition, and formation of a fine bainite texture by temperature-controlled rolling, cooling control and the like enable a high-strength, high-toughness rolled steel shape of high-strength and excellent toughness having mechanical properties of a tensile strength of not less than 590 MPa, a yield strength or 0.2% proof strength of not less than 440 MPa and a Charpy impact absorption energy at 0° C. of not less than 47 J, and method of producing the same.

Abstract: The invention provides a thin high-strength hot-rolled steel sheet with a thickness of not more than 3.5 mm which has excellent stretch flangeability and high uniformity in both shape and mechanical properties of the steel sheet, as well as a method of producing the hot-rolled steel sheet. A slab containing C: 0.05-0.30 wt %, Si: 0.03-1.0 wt %, Mn: 1.5-3.5 wt %, P: not more than 0.02 wt %, S: not more than 0.005 wt %, Al: not more than 0.150 wt %, N: not more than 0.0200 wt %, and one or two of Nb: 0.003-0.20 wt % and Ti: 0.005-0.20 wt % is heated at a temperature of not higher than 1200° C. The slab is hot-rolled at a finish rolling end temperature of not lower than 800° C., preferably at a finish rolling start temperature of 950-1050° C. A hot-rolled sheet is started to be cooled within two seconds after the end of the rolling, and then continuously cooled down to a coiling temperature at a cooling rate of 20-150° C./sec. The hot-rolled sheet is coiled at a temperature of 300-550° C.

Abstract: A high-strength, high damage-resistant rail made of 0.6 to 0.85 wt % C, 0.1 to 1.0 wt % Si, 0.5 to 1.5 wt % Mn, 0.035 wt % or less P, 0.040 wt % or less S, and 0.05 wt % or less Al, with the balance being Fe and inevitable impurities, and having corner and head side portions having a Brinell hardness of 341 to 405, and a head top portion in which a Brinell hardness of a site 20-mm distant from the central portion of the head top portion in a width direction is 341 to 405, and a hardness of the central portion of the head top portion is at least 10 lower in Brinell hardness than that of the site 20-mm distant from the central portion.

Abstract: A heat-resistant steel contains 0.1-3 mass % of Cr and satisfies the following equation: 0.1≦Nb+Mo+V and MX-type complex precipitates formed inside microcrystalline grains contain 30 mass % or more of Mo and 7 mass % or more of Nb. Also provided is a process for producing the alloy steel product involving casting, forging, hot rolling, normalizing, optionally direct quenching, cooling at a predetermined cooling rate, and tempering.

Abstract: A heat treatment process is provided that produces a monoblock, low alloy steel rotor for use in low pressure steam turbines. The process includes austenitizing the rotor at a substantially uniformly applied treatment temperature of about 840° C., quenching the rotor, and then differentially tempering the rotor at different axial locations. The rotor is tempered in a furnace divided into regions by refractory boards enabling different temperatures in each divided region to be maintained. A higher than normal strength condition is achieved in one or more axial locations along the rotor by subjecting the location(s) to a lower tempering temperature. The axial location(s) being tempered at lower temperature approximate those locations less susceptible to stress corrosion cracking whereby increased strength is provided the rotor without increasing net susceptibility to stress corrosion cracking.

Abstract: This invention provides an oil-tempered wire having high strength (tensile strength of not less than 1960 MPa) and excellent workability and specifically provides a steel wire for high-strength springs comprising as steel components, in weight percent, C   0.4-0.7% Si   1.2-2.5% Mn   0.1-0.5% Cr   0.4-2.0% Al 0.0001-0.005%, and being limited to P not more than 0.015% and S not more than 0.015%, the balance being Fe and unavoidable impurities, the steel wire having no nonmetallic inclusions of a size greater than 15 &mgr;m, a tensile strength of not less than 1960 MPa, and a yield ratio (&sgr;0.2/&sgr;B) of not less than 0.8 and not greater than 0.9 or a yield ratio (&sgr;0.2/&sgr;B) of not less than 0.8 and an amount of residual austenite of not greater than 6%. This invention also provides a method of producing the steel wire.

Abstract: A steel for a high bearing pressure-resistant member, having a high machinability. The steel is formed of a machine structural steel comprising carbon in an amount ranging from 0.15 to 0.25% by weight, silicon in an amount of not less than 0.4% by weight, nickel in an amount ranging from 1 to 3% by weight, chromium in an amount ranging from 1.2 to 3.2% by weight, and molybdenum in an amount ranging from 0.25 to 2.0% by weight. The machine structural steel contains carbide precipitated under a heat treatment for spheroidizing. The carbide has an average particle size of not larger than 1 &mgr;m and the maximum particle size of not larger than 3 &mgr;m.

Abstract: Process for manufacturing a pressure vessel intended to work under pressure between −40° C. and 200° C. in the presence of H2S under conditions defined by the NACE MR 0175-97 standard, in which: components of the vessel are manufactured from a steel of chemical composition: 0.03%≦C≦0.15%; 0%≦Si≦0.5%; 0.4%≦Mn≦2.5%; 0.5%≦Ni≦3%; 0%≦Cr≦1%; 0%≦Mo≦0.5%; 0%≦Al≦0.070%; 0%≦Ti≦0.04%; 0%≦B≦0.004%; 0%≦V≦0.02%; 0%≦Nb≦0.05%; Cu≦1%; S≦0.015%; P≦0.03%; the balance being iron and impurities resulting from the smelting operation; CET=C+(Mn+Mo)/10+(Cr+Cu)/20+Ni/40<0.35; 800/500 cct<10 s; the components being quenched and tempered; the structure is martensitic or martensitic-bainitic with less than 10% ferrite; the temper temperature is <680° C. Optionally, a stress-relieving operation is carried out at a temperature ≧595° C.

Abstract: A high-strength spring steel having an Hv of at least 600 and an impact value of at least 40 J/cm2, comprising 0.40 to 0.70 wt. % carbon, 1.00 to 2.50 wt. % silicon, 0.30 to 0.90 wt. % manganese, 0.50 to 1.50 wt. % nickel, 1.00 to 2.00 wt. % chromium, 0.30 to 0.60 wt. % molybdenum, 0.25 to 0.50 wt. % copper, 0.01 to 0.50 wt. % vanadium, 0.010 to 0.050 wt. % niobium, 0.005 to 0.050 wt. % aluminum, 0.0045 to 0.0100 wt. % nitrogen, 0.005 to 0.050 wt. % titanium, and 0.0005 to 0.0060 wt. % boron, with phosphorus limited to 0.010 wt. % or less, sulfur to 0.010 wt. % or less, and OT to 0.0015 wt. % or less, and the remainder being composed of iron and unavoidable impurities. The spring steel has better hardness and toughness than those of existing spring steel.

Abstract: An ultra-low carbon weathering steel has a carbon content of from about 0.015 wt % to about 0.035 wt %; a copper content of from about 0.20 wt % to about 0.40 wt %; a chromium content of from about 0.40 wt % to about 0.70 wt %; a nickel content of from about 0.20 wt % to about 0.50 wt %; a titanium content of from about 0.02 wt % to about 0.05 wt %; a niobium content of from about 0.03 wt % to about 0.06 wt %; a boron content of from about 0.0015 wt % to about 0.003 wt %; a manganese content of from about 2.0 wt % or less; a phosphorous content of from about 0.012 wt % or less; a sulphur content of from about 0.005 wt % or less; a silicon content of from about 0.40 wt % or less; a molybdenum content of from about 0.50 wt % or less; a vanadium content of from about 0.10 wt % or less; an aluminum content of from about 0.03 wt % or less; and a nitrogen content of from about 0.006 wt % or less.

Abstract: The invention concerns a method for manufacturing steel wire comprising the following steps: manufacturing a reinforcing wire of sizeable length by rolling or hot wire drawing from steel containing the following elements: 0.18% to 0.45 % C, 0.4% to 1.8% Mn, 1% to 4% Cr, 0.1% to 0.6% Si, 0% to 1.5% Mo, 0% to 1.5% Ni, at most 0.01% S and 0.02% P, the reinforcing wire having, after being rolled or hot drawn, a temperature at least higher than the AC3 temperature, preferably by 50 to 200° C. and in particular by 100 to 150° C.; winding the wire in reels before air cooling the raw manufacturing wire to obtain a HRC hardness not less than 40 and preferably higher than 45. In a variant, the method consists in quenching and tempering so that the wire has a hardness between 20 HRC and 35 HRC. The invention also concerns a reinforcing wire and a flexible tube for carrying effluents.