Abstract: A method of manufacturing a hot rolled steel sheet for a square column for building structural members includes a hot rolling step, a cooling step, and a coiling step performed on a steel to form a hot rolled steel sheet, wherein the steel has a composition containing, in terms of % by mass, C: 0.07 to 0.18%, Mn: 0.3 to 1.5%, P: 0.03% or less, S: 0.015% or less, Al: 0.01 to 0.06%, N: 0.0006% or less, and the balance being Fe and unavoidable impurities.

Abstract: An object of this invention is to provide a steel for high-cleanliness spring which is useful for the production of a spring excellent in fatigue characteristics in high Si steels. The steel for high-cleanliness spring with excellent fatigue characteristics according to the invention contains: in terms of mass %, C: 1.2% or less (excluding 0%); Si: 1.8% to 4%; Mn: 0.1% to 2.0%; and total Al: 0.01% or less (excluding 0%), with the remainder being iron and inevitable impurities, in which the Si amount and a solute (SIMS) Ca amount in the steel satisfy a relationship of the following expression (1): Si×10?7?solute (SIMS) Ca?Si×5×10?7??(1) (in which each of the solute (SIMS) Ca and Si represents the amount thereof (mass %) in the steel).

Abstract: A hot-rolled steel sheet for high-strength ERW pipes contains about 0.02% to about 0.06% C; about 0.05% to about 0.50% Si; about 0.5% to about 1.5% Mn; about 0.010% or less P; about 0.0010% or less S; about 0.01% to about 0.10% Al; about 0.01% to about 0.10% Nb; about 0.001% to about 0.025% Ti; about 0.001% to about 0.005% Ca; about 0.003% or less 0; and about 0.005% or less N, and at least one element selected from the group consisting of about 0.01% to about 0.10% V; about 0.01% to about 0.50% Cu; about 0.01% to about 0.50% Ni; and about 0.01% to about 0.50% Mo on the basis of mass. The group of C, Si, Mn, Cu, Ni, Mo, and V and the group of Ca, 0, and S satisfy specific relationships, and the microstructure of the steel sheet is composed of about 95% by volume or more bainitic ferrite.

Abstract: A low alloy steel, which has a chemical composition by mass %, of C: 0.1 to 0.55%, Si: 0.05 to 0.5%, Mn: 0.1 to 1%, S: 0.0001 to 0.005%, Al: 0.005 to 0.08%, Ti: 0.005 to 0.05%, Cr: 0.1 to 1.5%, Mo: 0.1 to 1%, O: 0.0004 to 0.005%, Ca: 0.0005 to 0.0045%, Nb: 0 to 0.1%, V: 0 to 0.5%, B: 0 to 0.005%, Zr: 0 to 0.10%, P?0.03%, and N?0.006%, with the balance being Fe and impurities, is manufactured by adjusting the value of ([Ti]/47.9)([N]/14)/([Ca])/40.1) satisfies not less than 0.0008 and not more than 0.0066, at the time of melting the said low alloy steel, wherein [Ti], [N] and [Ca] are the contents in the molten steel by mass % of Ti, N and Ca respectively. The thus-manufactured low steel alloy has a high SSC resistance with a yield stress of not less than 758 MPa.

Abstract: Disclosed is a creep-resistant low-expansion iron-nickel alloy that is provided with increased mechanical resistance and contains 40 to 43 wt. % of Ni, a maximum of 0.1 wt. % of C, 2.0 to 3.5 wt. % of Ti, 0.1 to 1.5 wt. % of Al, 0.1 to 1.0 wt. % of Nb, 0.005 to 0.8 wt. % of Mn, 0.005 to 0.6 wt. % of Si, a maximum of 0.5 wt. % of Co, the remainder being composed of Fe and production-related impurities. Said alloy has a mean coefficient of thermal expansion <5×10<?6>/K in the temperature range of 20 to 200 DEG C.

Abstract: There is provided a high-stiffness high-strength thin steel sheet having a tensile strength of not less than 590 MPa and a Young's modulus of not less than 225 GPa, which comprises C: 0.02-0.15%, Si: not more than 1.5%, Mn: 1.5-4.0%, P: not more than 0.05%, S: not more than 0.01%, Al: not more than 1.5%, N: not more than 0.01% and Nb: 0.02-0.40% as mass %, provided that C, N and Nb contents satisfy 0.01?C+(12/14)×N?(12/92.9)×Nb?0.06 and N?(14/92.9)×(Nb?0.01) and the remainder being substantially iron and inevitable impurities, and has a texture comprising a ferrite phase as a main phase and having a martensite phase at an area ratio of not less than 1%.

Abstract: The present invention is to provide a free-cutting steel capable of suppressing production of coarse inclusions, and having a high fatigue strength and a desirable machinability. The free-cutting steel aimed at solving the foregoing problems consists essentially of, in % by mass, C: 0.1-0.5%, Si: 0.05-2.5%, Mn: 0.1-3.5%, S: 0.0005-0.004%, Al: 0.01-0.06%, Ti: 0.003-0.01%, O: up to 0.0015%, N: 0.003-0.01%, Bi: 0.015-0.025%, and the balance of Fe and inevitable impurities, wherein the formula (1) below is satisfied: ?4.8?log(([N]?0.0015)×[Ti]0.98)??4.3.

Abstract: Disclosed is a free-cutting steel for machine structural use which always exhibits desired machinability, particularly, machinability by cutting with cemented carbide tools. This free-cutting steel is produced by preparing a molten alloy of the composition consisting essentially of, by weight %, C: 0.05-0.8%, Si: 0.01-2.5%, Mn: 0.1-3.5% and O: 0.0005-0.01%, the balance being Fe and inevitable, and adjusting the addition amounts of Al and Ca in such a manner as to satisfy the above ranges, S: 0.01-0.2%, Al: 0.001-0.020% and Ca: 0.0005-0.02%, and the conditions of [S]/[O]: 8-40 [Ca]×[S]: 1×10−5−1×10−3 [Ca]/[S]: 0.01-20 and [Al]: 0.001-0.020% to obtain a steel characterized in that the area in microscopic field occupied by the sulfide inclusions containing Ca of 1.0% or more neighboring to oxide inclusions containing CaO of 8-62% is 2.0×10−4 mm2 or more per 3.5 mm2.

Abstract: A steel article is fabricated by providing an iron-base alloy having less than about 0.5 weight percent aluminum, melting the alloy to form a melt, adding calcium to the melt, thereafter adding aluminum to the melt to increase the aluminum content of the melt to more than about 0.5 weight percent aluminum, and casting the melt to form a casting. Other calcium additions may be made simultaneously with the adding of aluminum, and after the adding of aluminum but before casting the melt. The calcium additions deoxidize the melt to minimize the formation of clustered aluminum-oxygen-based inclusions.

Abstract: The present invention provides a steel for steel sheets excellent in workability and showing significantly decreased formation of surface defects, and a method of deoxidizing molten steel for the steel for steel sheets which prevents nozzle clogging during continuous-casting the molten steel. That is, the steel for steel sheets excellent in workability, comprises, based on weight, 0.0001 to 0.0030% of C, up to 0.03% of Si, 0.05 to 0.30% of Mn, up to 0.015% of P, 0.001 to 0.015% of S, up to 0.008% of Al, 0.02 to 0.08% of Ti, 0.0005 to 0.0020% of Ca, 0.0005 to 0.01% of N, optionally containing at least one of 0.001 to 0.02 wt % of Nb and 0.0001 to 0.0010 wt % of B, and the balance of Fe and unavoidable impurities.

Abstract: Titanium killed steel sheets which are not troubled by nozzle clogging while they are produced in a continuous casting process, have few surface defects caused by cluster-type inclusions, and are highly rust resistant, and are formed from a melt of titanium killed steel that contains any one or two of Ca and metals REM in an amount of not smaller than 0.0005% by weight, and wherein the steel contains major oxide inclusions of any one or two of CaO and REM oxides in an amount of from about 5 to 50% by weight, Ti oxides in an amount of not larger than about 90% by weight, and Al.sub.2 O.sub.3 in an amount of not larger than about 70% by weight.

Abstract: A clean steel consisting essentially of by weight 0.0005%-0.5% of aluminum, 0.0001%-0.5% of silicon, 0.00001%-0.0005% of magnesium, 0.00001%-0.0025% of calcium, 0.00001%-0.003% of oxygen 0.00001%-0.003% of sulfur and 0.0001%-0.015% of nitrogen, less than 2% carbon and the remainder iron, wherein the clean steel is further selected from the group consisting ofcarbon steel consisting of less than 2% of carbon, and common elements of silicon, manganese, phosphorus or sulfur; andalloy steel consisting of general elements and special elements selected from the group consisting of 0.001%-50% of at least nickel, chromium, cobalt or tungsten.

Abstract: A method of producing an alloy containing at least one major ingredient selected from the group consisting of iron (Fe), cobalt (Co), and Nickel (Ni) and having low contents of sulphur, oxygen, and nitrogen, comprises steps of:(a) holding a molten alloy in a container selected from the group consisting of a lime crucible, a lime crucible furnace, a converter and a ladle lined with a basic refractory consisting of 15-85% of calcium oxide (CaO), and 15-75% of magnesium oxide (MgO), wherein said alloy consists essentially of at least one major ingredient selected from the group consisting of iron (Fe), nickel (Ni), and cobalt (Co);(b) adding at least one additive, based on the molten alloy, into said molten alloy in an atmosphere selected from the group consisting of a non-oxidizing atmosphere and a vacuum, wherein said additive is selected from the group consisting of aluminum (Al), aluminum alloys, silicon and silicon alloys;(c) desulphurizing, deoxidizing and denitrifying said molten alloy under an atmosphere

Abstract: A soft steel for machine cutting with high machinability performances having a content of C.ltoreq.0.25%, a content of Mn of 0.8 to 1.5%, a content of P of .ltoreq.0.1%, a content of S of 0.15 to 0.40%, and a content of Si of 0.05 to 0.40%, expressed in percentages by weight. After finishing of the metal, the inclusions of manganese sulfide are surrounded by a plastic oxide layer of an average composition SiO.sub.2 : 35 to 45%; Al.sub.2 O.sub.3 : 10 to 20%; CaO: 15 to 25%; MnO: 10 to 20%. In producing this grade, after the addition of silicon and manganese, the liquid metal is agitated in the presence of a slag of a composition CaO: 20 to 55%; SiO.sub.2 : 35 to 65%; Al.sub.2 O.sub.3 : 15 to 40%; with a CaO %/SiO.sub.2 % ratio of about 1.

Abstract: The disclosed method is a method of manufacturing clean steel comprising refining molten steel by adding additives of from not more than 0.5% to more than 0.001% by weight of molten steel to the molten steel bath, in vacuo or a non-oxidizing atmosphere within a melting furnace or vessel made of or lined with a basic refractory material consisting essentially of 7-90 wt % of CaO and 90-7 wt % of MgO, which total content being 70% to 99.9%, and optionally included a basic refractory material consisting of 30-0.1 wt % of at least one element selected from the group consisting of Al.sub.2 O.sub.3, CrO, ZrO.sub.2.SiO.sub.2, ZrO.sub.2, ZrC and C as selected components, and obtaining clean steel containing less than 30 ppm of oxygen, less than 30 ppm of sulfur, less than 150 ppm of nitrogen, 5 to 0.1 ppm of Mg and 25 to 0.1 ppm of Ca. Said additives comprises Al and at least one optional element selected from Ti, Nb, Ta, B and alkali earth metal. 5% of a solvent can be included to said additives.

Abstract: Composition and method for producing a low-sulphur, free-machining steel, substantially free of lead and including in weight percent about 0.05-0.40 copper, 0.005-0.040 tellurium, 0.002-0.35 bismuth, 0.002-0.05 tin, up to 0.55 carbon, and less than 0.25 sulphur, traces (up to about 0.005 weight percent) of barium, and the balance being iron. The elements bismuth, tellurium and tin are added as a molten alloy to the molten steel and uniformly distributed therethrough. The elements copper and barium can be added separately into the steel stream ahead of the molten addition inflow. The mass is then cooled to provide a solid metal casting substantially free of blemishes and free of surface checking and tearing. The casting is characterized by enhanced machining properties.

Abstract: A method of adding low-melting-point metal to molten steel by injecting molten low-melting-point metal into the vessel containing the molten steel through a portion of the side wall of the vessel that is located below the surface level of the molten steel.

Abstract: A method of producing an alloy containing at least one major ingredient selected from the group consisting of iron (Fe), cobalt (Co), and Nickel (Ni) and having low contents of sulphur, oxygen, and nitrogen, comprises steps of:(a) holding a molten alloy in a container selected from the group consisting of a lime crucible, a lime crucible furnace, a converter and a ladle lined with a basic refractory consisting of 15-85% of calcium oxide (CaO), and 15-75% of magnesium oxide (MgO), wherein said alloy consists essentially of at least one major ingredient selected from the group consisting of iron (Fe), nickel (Ni), and cobalt (Co);(b) adding at least one additive, based on the molten alloy, into said molten alloy in an atmosphere selected from the group consisting of a non-oxidizing atmosphere and a vacuum, wherein said additive is selected from the group consisting of aluminum (Al), aluminum alloys, silicon and silicon alloys;(c) desulphurizing, deoxidizing and denitrifying said molten alloy under an atmosphere

Abstract: Bismuth is added to molten steel in a ladle, and the molten steel is covered with a slag layer sufficiently thick to prevent a decrease in the bismuth content during the time the molten steel is in the ladle.