Abstract: A method for producing hot-rolled strip and plates in a production plant having a continuous casting installation for slabs 100-180 mm thick, descaling sprays, a single- or multiple-stand rolling unit with or without edging, a cooling interval, a heating furnace, and a Steckel mill. Between the continuous casting installation and the heating furnace, only the skin layer of the previously descaled slab is deformed in-line, recrystallized during and after deformation, and then cooled in several stages to a temperature below the Ar3 transformation point and temporarily maintained there until the microstructural transformation of the recrystallized, fine-grained austenite to ferrite/pearlite has been completed.

Abstract: In a surface processing method for removing surface flaws, surface contaminants, and the like from a continuously cast metal product in a hot state, at least a portion of at least one metal product surface is cooled for a defined temperature decrease of a surface to be treated and a surface treatment is then performed. The device therefor has a cooling device for cooling at least a portion of at least one metal product surface for a defined temperature decrease of a surface to be treated and a surface treatment device downstream of the cooling device in the product conveying direction. The production arrangement for this has a continuous slab casting device, a heating arrangement with at least one of a heating device and a temperature equilibration device arranged downstream of the casting device. A hot mill train is arranged downstream of the heating arrangement in the conveying direction.

Abstract: A steel rolling mill including a Steckel mill is provided with an in-line upstream quench station located downstream of the caster and upstream of the reheat furnace, a shear located downstream of the Steckel mill, and a temperature reduction station downstream of the shear. The upstream quench station has spray nozzles that quench a surface layer of the steel to transform same from an austentitic to a non-austentitic microstructure. The shear provides a precise transverse vertical face on the leading end of the steel. The temperature reduction station applies cooling fluid to the rolled steel so as to obtain a preferred microstructure that may be either bainite or martensite. If bainite, the temperature reduction station includes laminar-flow cooling apparatus; if martensite, the station also includes an initial rapid quench, in which latter case the station is followed by a tempering furnace.

Abstract: A steel sheet with a thickness of at least 0.30 mm is made of an ultra-low carbon steel with a chemical composition including C: at most 0.010%, Si: at most 0.5%, Mn: at most 1.5%, P: at most 0.12%, S: at most 0.030%, Ti: at most 0.10%, Al: at most 0.08%, and N: at most 0.0080%. The total number of non- metallic inclusions observed under a microscope in sixty fields in a sample prepared in accordance with JIS G0555 is at most 20. During manufacture of the steel, the amount of FeO+MnO in slag in a ladle at the time of continuous casting is controlled to at most 15%, and the throughput at the time of casting is made at most 5 tons per minute. The steel sheet does not develop pin hole defects or press cracks caused by inclusions when used for applications such as motor housings or oil filter housings requiring severe press forming.

Abstract: The present invention relates to a high carbon steel sheet having chemical composition specified by JIS G 4051 (Carbon steels for machine structural use), JIS G 4401 (Carbon tool steels) or JIS G 4802 (Cold-rolled steel strips for springs), wherein the ratio of number of carbides having a diameter of 0.6 &mgr;m less with respect to all the carbides is 80% or more, more than 50 carbides having a diameter of 1.5 &mgr;m or larger exist in 2500 &mgr;m2 of observation field area of electron microscope, and the &Dgr;r is more than −0.15 to less than 0.15. The high carbon steel sheet of the invention is excellent in hardenability and toughness, and formable with a high dimensional precision.

Abstract: Steel strips and methods for producing steel strips are provided. In an illustrated embodiment, a method includes continuously casting molten low carbon steel into a strip and hot rolling the cast strip within a temperature range such that the strip passes through the Ar3 transformation temperature from austenite to ferrite under strain during rolling, thereby producing a strip having a yield strength above 400 Mpa and an elongation in excess of 30%. The cast steel strip has desired microstructures.

Abstract: Steel strips and methods for producing steel strips are provided. In an illustrated embodiment, a method for producing steel strips includes continuously casting molten steel into a strip, said molten steel comprising a concentration of residuals of 2.0 wt % or less is selected with regard to the microstructure of the finished strip to provide a desired yield strength; and cooling the strip to transform the strip from austenite to ferrite in the temperature range of 850° C. to 400° C. Cast steel with improved yield strength properties is produced by such method.

Abstract: The object of this invention was to create starting copper cathodes which prevent a memory effect during copper electrolysis, achieving a high production output of electrolytic copper and which can also be manufactured from directly shaped copper sheeting material in the form of a coil. A suitable method of producing starting cathodes for processing copper sheet produced by conventional methods. The proposed starting cathodes are made of milled copper sheets with a thickness of 0.3 to 1.2 mm, is soft annealed after milling and has a strength of 210 to 240 N/mm2. The copper sheet is cut to the length and width determined by the dimensions of the electrolysis bath and has a flat, fat-free, burless surface. Ear strips of copper sheet with a thickness of 0.3 to 0.6 mm are mounted on the suspension side.

Abstract: A method and apparatus for the direct production, from molten metal, of scale-free thin metal strip. Hot thin metal strip exiting a continuous caster system is directed to a reducing chamber wherein a reducing gas reduces strip surface oxides while the cast metal strip is at an elevated temperature from retained heat from the molten metal. A cooling unit following the reducing chamber is used to cool the strip to a temperature below about 150° C. prior to exposing the strip to an oxidizing atmosphere. In various embodiments of the invention, strip thickness is reduced with use of hot and cold rolling mills and the scale-free surface of the strip is coated with protective coatings.

Abstract: The method for manufacturing steel sheet comprises the steps of: forming a sheet bar; forming a steel strip; primary-cooling; air-cooling; secondary-cooling; and coiling. The sheet bar is finish-rolled at finish temperatures of (Ar3 transformation point−20° C.) or more. The primary cooling cools the finish-rolled steel strip at cooling speeds of more than 120° C./sec down to the temperatures ranging from 500 to 800° C.

Abstract: An alloy used for the production of a rare-earth magnet alloy, particularly the boundary-phase alloy in the two-alloy method is provided to improve the crushability. The Alloy consists of (a) from 35 to 60% of Nd, Dy and/or Pr, and the balance being Fe, or (b) from 35 to 60% of Nd, Dy and/or Pr, and at least one element selected from the group consisting of 35% by weight or less of Co, 4% by weight or less of Cu, 3% by weight or less of Al and 3% by weight or less of Ga, and the balance being Fe. The volume fraction of R2Fe17 phase (Fe may be replaced with Cu, Co, Al or Ga) is 25% or more in the alloy and the average size of an R2Fe17 phase is 20 &mgr;m or less. The alloy can be produced by a centrifugal casting at an average accumulating rate of melt at 0.1 cm/second or less.

Abstract: The invention provides a method of fabricating “TRIP” steel in the form of thin strip, wherein: a strip from 1.5 to 10 mm thick, preferably from 1 to 5 mm thick, is cast directly from liquid steel having the composition (in weight percent) C % from 0.05 to 0.25, (Mn+Cu+Ni) % from 0.5 to 3, (Si+Al) % from 0.1 to 4, (P+Sn+As+Sb) % not greater than 0.1, (Ti+Nb+V+Zr+rare earths) % less than 0.3, Cr % less than 1, Mo % less than 1, V % less than 1, the remainder being iron and manufacturing impurities; said strip is hot rolled on-line in one or more passes at a temperature higher than the Ar3 temperature of said steel and with a reduction ratio from 25 to 70%; first forced cooling of said strip is carried out at a cooling rate from 5 to 100° C./s; the strip remains at temperatures from 550 to 400° C.

Abstract: The subject for the invention is a process for manufacturing strip. The process includes casting directly from liquid metal a steel strip 1.5 to 10 mm in thickness, subjecting the cast steel strip, in the austenitic phase, to a first hot rolling operation in one or more steps at a temperature of between 950° C. and the Ar3 temperature of said strip with an overall reduction ratio of at least 10%, then subjecting the hot rolled strip, in the ferritic phase, to a second hot rolling operation in one or more steps at a temperature below 850° C., with an overall reduction ratio of at least 50% in the presence of a lubricant, so as to obtain a hot-rolled sheet with a thickness of less than or equal to 2 mm, and recrystallizing the hot rolled sheet at a temperature between 700 and 800° C. The composition of the steel strip comprises (in weight %): carbon less than 0.1%, manganese from 0.03 to 2%, silicon from 0 to 0.5%, phosphorus from 0 to 0.1%, boron from 0 to 0.002%, titanium from 0 to 0.

Abstract: Method for the manufacture of a steel strip, wherein molten steel is cast into a slab, conveyed through a furnace, roughed in a roughing apparatus and finish-rolled in a finishing apparatus. The method comprises an endless or semi-endless process having either step a or step b, wherein a and b respectively comprise (a) manufacturing a ferritically rolled steel strip, wherein the slab is rolled in the roughing apparatus in the austenitic range and then cooled to a ferritic structure, and wherein the strip is rolled in the finishing apparatus at speeds essentially corresponding to the entry speed into the finishing apparatus, and (b) manufacturing an austenitically rolled steel strip, wherein the strip leaving the roughing apparatus is heated to the austenitic range and is rolled in the finishing apparatus and then cooled down to the ferritic range.

Abstract: The present invention provides a method of manufacturing a cold rolled steel sheet and a hot-dip zinc-coated steel sheet having excellent surface properties, an excellent resistance to natural aging and an excellent dent resistance of panel and, thus, adapted to the manufacture of steel sheet for outer panels of vehicles. The method comprises the steps of preparing steel consisting of 0.005 to 0.012% by weight of C, 0.01 to 0.4% by weight of Si, 0.15 to 1.0% by weight of Mn, 0.01 to 0.08% by weight of P, at most 0.02% by weight of S, 0.01 to 0.1% by weight of sol. Al, at most 0.004% by weight of N, and at least one element selected from the group consisting of 0.01 to 0.2% by weight of Nb and 0.04 to 0.1% by weight of Ti, and satisfying the condition 1.2≦(12/93) (Nb%/C%)+(12/48) (Ti*%/C%)≦2.5, applying a hot rolling and a cold rolling to the steel, soaking the cold rolled steel sheet at T(° C.) meeting a formula Ac3≧T(° C.

Abstract: In the production of grain oriented electrical steel sheet, controlling the condition of thin slab continuous casting results in advantageous solidification structures and precipitates. The steel has an initial content of carbon less than 300 ppm and an initial content of acid-soluble aluminum higher than that normally used for said type of steel. During the final processing steps, the annealed sheet is nitrided through a limited amount of nitrogen. This, in turn, renders the process for controlling the grain dimensions much less critical and results in a constant quality product.

Abstract: The present invention aims to produce a cold-rolled metal coated multi-phase steel, characterized by a tensile strength of at least 500 MPa, a yield ratio (Re/Rm) lower than 0.65 in skinned conditions, lower than 0.60 in unskinned conditions, and with good metal coating adhesion behavior. In the case of the aluminised steel according to the invention, the steel also has superior resistance to temperature corrosion up to 900° C. and excellent mechanical properties at this high temperature.

Abstract: A method of manufacturing microalloyed structural steels by rolling in a CSP plant or compact strip production plant, wherein the cast slab strand is supplied divided into rolling lengths through an equalizing furnace to a multiple-stand CSP rolling train and is continuously rolled in the rolling train into hot-rolled wide strip, wherein the strip is cooled in a cooling section and is reeled into coils, and wherein, for achieving optimum mechanical properties, a controlled structure development by thermomechanical rolling is carried out as the thin slab travels through the CSP plant. For manufacturing high-strength microalloyed structural steels with a yield point of ≧480 MPa, the available strengthening mechanisms are utilized in a complex manner in order to achieve an optimum property complex with respect to strength and toughness of the structural steels, by carrying out, in addition to the thermomechanical rolling with the method steps according to U.S. patent application Ser. No. 09/095,338 filed Jun.

Abstract: The present invention provides a cold rolling composite work roll with an outer layer having excellent high abrasion resistance and spalling resistance. The outer layer of the cold rolling composite work roll comprises; 0.9-1.5 wt % C, 0.3-1.0 wt % Si, 0.3-1.0 wt % Mn, 4.0-10.0 wt % Cr, 2.0-8.0 wt % Mo, 0.5-5.0 wt % V, and the remainder Fe and unavoidable impurities. A cold rolling composite work roll with high abrasion resistance has an outer layer with the above-mentioned composition wherein Mo is 3.0-8.0 wt %, formed by a continuous process for cladding around the perimeter of a core material made from ingot steel or forged steel. A cold rolling composite work roll with excellent spalling resistance has the above-mentioned composition wherein the surface portion of the outer layer formed by the continuous pouring process for cladding has a compression residual stress of 60 kgf/mm2 or lower and a Shore hardness of HS 90 or greater.

Abstract: In the manufacture of steel strip or sheet, suitable for use as deep-drawing steel for the manufacture of can bodies by deep-drawing and ironing, a low-carbon steel is provided in the form of a slab, the slab is rolled in the austenitic region to reduce its thickness to a transfer thickness, the rolled slab is cooled having the transfer thickness into the ferritic region, and the rolled slab is rolled in the ferritic region to a finished thickness. To provide a steel having reduced tendency to "earing" in can body manufacture, the transfer thickness is less than 1.8 mm and the total thickness reduction in the ferritic region from the transfer thickness to the finished thickness is less than 90%.

Abstract: A substantially carbon free (e.g. 50-80 ppm carbon max.) iron base melt is strip cast to provide a cast strip having a low strength, high ductility, essentially ferrite matrix substantially free of hardening acicular ferrite, bainite and martensite phases. The strip strength may be enhanced by subjecting the strip to a carburizing or nitriding treatment either directly after casting or after casting followed by cold rolling and annealing.

Abstract: A method and a plant for rolling hot-rolled wide strip from continuously cast thin slabs or slabs of medium thickness of about 40 to 100 mm, wherein the cast slab strand is divided into sections, is subjected to a temperature treatment in a continuous furnace, and is conveyed for rolling into a rolling train. The temperature treatment of a slab section on the continuous furnace is interrupted by a surface treatment and the surface treatment of the slab section is carried out in the production line between the casting plant and the rolling train. The plant for carrying out the method includes a continuous casting plant for thin slabs, a transverse cutting device, a continuous furnace and a rolling train, wherein the continuous furnace, for example, a roller-hearth furnace, is divided into two segments between which is arranged in an in-line position a surface treatment unit for treating deficient slab sections.

Abstract: A method for the manufacture of a strip of formable steel comprises the steps of (i) forming liquid steel by continuous casting into a slab having a thickness of not more than 100 mm, (ii) rolling the slab in the austenitic region into an intermediate slab having a thickness in the range 5 to 20 mm, (iii) cooling the intermediate slab to below the Ar.sub.3 temperature, (iv) holding the intermediate slab in an enclosure for temperature homogenisation, (v) rolling the intermediate slab into strip, with at least one rolling pass applying a thickness reduction of more than 50%, at a temperature below T.sub.t and above 200.degree. C., wherein T.sub.t is the temperature at which 75% of the steel is converted into ferrite, and (vi) coiling said strip at a temperature above 500.degree. C. Advantages of simplicity of the method and the plant required for it are obtained.

Abstract: The carbon content in molten steel is adjusted to be a value not lower than 0.001%, and a thin steel strip is made from this molten steel using a twin drum type continuous casting apparatus by means of direct casting. The thus obtained slab is given a reduction of not lower than 10%. The coagulated steel strip is cooled to a temperature not higher than the temperature determined by a function of the carbon content, cooling speed and ratio of reduction of in-line. After that, the steel strip is reheated and then cooled again to a temperature not higher than the temperature determined by the function of the carbon content. Then the cooled steel strip is coiled. In the above process, a metallic sheet, the surface of which is smooth and the metallic structure of which is fine, can be produced.

Abstract: A method and a plant for rolling hot-rolled wide strip from continuously cast thin slabs of ferritic/pearlitic microalloyed structural steels with a microalloy with vanadium and/or with niobium and/or with titanium in a CSP plant or compact strip production plant, wherein the cast slab strand is supplied divided into rolling lengths through an equalizing furnace to a multiple-stand CSP rolling train and is continuously rolled in the CSP rolling train into hot-rolled wide strip, is then cooled in a cooling stretch and is reeled into coils. For achieving optimum mechanical properties in hot-rolled wide strip by thermomechanical rolling, a controlled structure development is carried out when the thin slabs travel through the CSP plant.

Abstract: Cold rolled steel sheet with excellent deep drawability and excellent anti-aging properties, and manufacturing method. The cold rolled steel sheet comprises about C: above 0.015 to 0.150 wt %, Si: 1.0 wt % or less, Mn: 0.01 to 1.50 wt %, P: 0.10 wt % or less, S: 0.003 to 0.050 wt %, Al: 0.001 to below 0.010 wt %, N: 0.0001 to 0.0050 wt %, Ti: 0.001 wt % or more and Ti(wt %)/[1.5.times.S(wt %)+3.4.times.N(wt %)].ltoreq.about 1.0 and B: about 0.0001 to 0.0050 wt %, during annealing, grain growth is improved; Ti is added to form a nitride and a sulfide to avoid precipitation of fine TiC; B is added to precipitate Boron precipitates (Fe.sub.2 B, Fex(C,B)y) in a cooling the hot rolled steel sheet and in cooling step during annealing after cold rolling; a spherical cementite is precipitated and grown in which the Boron series precipitate is a precipitation site.

Abstract: A method of manufacturing a seamless steel pipe having excellent properties with high productivity in on-line processing, and an apparatus in which includes casting and heat treatment unit on-line. In the method the following steps (1) to (6) are successively performed. (1) A round billet is produced by continuous casting machine 1. (2) The billet is cooled to a temperature not higher than a Ar.sub.1 point, then heated and soaked in a furnace 3. (3) The billet is pierced by a piercer 5 at a strain rate of not higher than 200/sec and made into a hollow shell. (4) The hollow shell is elongated and finish rolled to make into a seamless steel pipe at an average strain rate of not lower than 0.01/sec and with a reduction ratio of not lower than 40%, and finishing the rolling at a temperature from 800.degree. C. to 1050.degree. C. (5) The seamless steel pipe is cooled to a temperature not higher than the Ar.sub.3 point at a cooling rate of not lower than 80.degree. C./min.

Abstract: A method for producing metallic semifinished products such as strip or wire rom metallic work materials which have a high melting point and are difficult to shape, comprising the steps of a) first, alloying at least one element for lowering the melting point with a material that has a high melting point and is difficult to shape; b) then, producing the semifinished product from the alloy with the reduced melting point in the form of strip or wire directly from the melt by quick solidification; and c) finally extracting the elements alloyed with the material in method step a) from the semifinished product by heat treatment in a reactive atmosphere.

Abstract: Adding aluminum and/or silica to molten steel after decarburization containing about 0.005 percent by weight or less of carbon and about 1.0 percent by weight or less of manganese to form a mildly deoxidized molten steel; adding titanium to the mildly deoxidized molten steel to continue deoxidation so that the molten steel contains about 0.005 percent by weight or less of aluminum, about 0.20 percent by weight or less of silicon and about 0.01 to 0.10 percent by weight of titanium, to form inclusions in the molten steel which essentially consist of a complex oxide of titanium and aluminum, a complex oxide of titanium and silicon, and/or a complex oxide of titanium, aluminum and silicon.

Abstract: A powder for covering an ingot mold for the continuous casting of steel, in particular steels with ultra-low carbon content. The powder comprises a base powder and particles of at least one metal nitride, its free carbon content (%C.sub.free) being between 0 and 1% by weight, it being produced by atomization, and having the form of granules of between 20 and 800 .mu.m in diameter. In one application of the invention, the nitride is silicon nitride, and its weight content (%Si.sub.3 N.sub.4) is equal to: %Si.sub.3 N.sub.4 =0.5-0.28.times.%C.sub.free .+-.0.10.

Abstract: The manufacturing method of the present invention comprises steps (1) through (8) which are sequentially arranged, and the steps or equipment from the production of billets to end products are connected in the same single continuous manufacturing line:(1) a step of producing a round billet by continuous casting,(2) a step of cooling the billet to a temperature not higher than an A.sub.r1 transformation temperature,(3) a step of heating the billet to a temperature which allows piercing of the billet,(4) a step of piercing, at a strain rate of not higher than 200/sec, the billet to obtain a hollow shell,(5) a step to form a steel pipe by elongating and finish rolling the hollow shell using a continuous elongating mill and a finish rolling mill which are directly connected to each other, at a predetermined average strain rate, a predetermined reduction ratio, and at a predetermined finishing temperature,(6) a step of recrystallizing the steel pipe at a temperature of not lower than an Ar.sub.

Abstract: Steel having excellent workability and deep drawability is produced by an electric furnace-vacuum degassing process. The steel has a composition which comprises about:C: 0.0050 wt % or lessSi: 1.5 wt % or lessMn: 1.5 wt % or lessP: 0.10 wt % or lessAl: 0.10 wt % or lessS: 0.020 wt % or lessO: 0.01 wt % or lessCu: 0.02-1.5 wt %Ni: 0.02-2.0 wt %Ti and/or Nb: from 0.001 to 0.10 wt %N: from 0.0040 to 0.0090 wt %.

Abstract: An enameling steel having excellent strength after fire includes up to 0.008% C, 0.25-0.35% Mn, 0.03-0.05 Al, 0.010 to 0.014 N and 0.020-0.025 Nb.

Abstract: A method of making an engineering ferrous metal comprising the steps of adding to liquid engineering ferrous metal solid alloy carbide particles and thereafter permitting the ferrous metal to solidify. The alloy carbide particles are coated with iron or an iron alloy to allow wetting to occur between the powder and the liquid ferrous metal and the particles have a density which matches that of the ferrous metal to provide a uniform distribution of the carbide particles in the ferrous metal. A roll may be made having at least a shell made of metal by such a method by centrifugal casting or electroslag remelting.

Abstract: In a method for the production of hot-rolled wide strip in a production plant which includes a continuous casting plant for thin slabs having a thickness of between 40 and 70 mm, an equalizing furnace and a rolling mill, wherein the temperature of the thin slab when exiting the continuous casting plant is above 950.degree. C., the surface temperature of the slab is lowered between the continuous casting machine and the equalizing furnace over a sufficient depth of the slab, so that a conversion of the structure from austenite to ferrite/perlite takes place.

Abstract: The present invention provides a thin cast strip or a thin steel sheet having good cast strip properties and mechanical properties from a molten steel containing a large amount of iron scrap containing Cu and Sn. The thin cast strip or thin steel sheet is characterized by being a thin cast strip or thin steel sheet of a common carbon steel comprising 0.15 to 10% by weight of Cu and 0.03 to 0.5% by weight of Sn, the primary dendrite spacing on a surface layer portion being in the range of from 5 to 100 .mu.m.

Abstract: A high manganese steel having superior hot workability is disclosed, in which small amounts of the alloying elements are added into a high manganese steel of Fe-Mn-Al-C system, so that the rupture strength of the grain boundaries of columnar crystals can be improved, thereby realizing an improved hot workability. Further, a process for manufacturing a high manganese hot rolled steel sheet is disclosed, in which the above mentioned high manganese steel is subjected to be controlled the initial hot rolling conditions during a hot rolling, so that large cracks would not be generated on the edges and on the surface of the hot rolled steel sheet. The process for manufacturing a hot rolled high manganese steel without any cracks includes the following the steps. That is, the process includes the steps of: preparing the ingot or the continuous casting slabs of the conventional Fe-Mn-Al-C steel with one or more elements selected from a group consisting of 0.0005-0.04% of B, 0.0005-0.050% of Ti, 0.0005-0.

Abstract: By rolling a slab with a thickness of 80 mm or less in a plant including a continuous casting machine and a hot strip rolling mill directly combined with each other, low-speed rolling can be achieved while suppressing a drop of the strip temperature and the occurrence of scales. After a slab 2 cast by a continuous casting machine 1 and being 80 mm or less thick is heated and descaled, it is rough-rolled into a bar with a thickness of 20 to 60 mm by a roughing mill 7 constructed as a 4H-twin mill. After being heated and descaled again, the bar is finish-rolled by finishing mills 19 to 21, each of which employs small-diameter work rolls having a diameter not larger than 500 mm, into a thin plate with a thickness in the range of 1.6 mm to 15 mm or a thick plate with a thickness in the range of 3 mm to 40 mm.

Abstract: (Object) IF-based, continuously cast slab essentially freed from defects such as surface defects, difficult production and poor strength, etc. of the product that the IF-based sheet steels have; sheet steels and a process for producing the same are provided.(Structure) A continuously cast slab of extremely low carbon steel comprising not more than 1.5% by mass of Si, not more than 2.0% by mass of Mn, not ore than 0.15% by mass of P, 0.01-0.15% by mass of Al, and not more than 0.0050% by mass of N, where the surface layer further contains 0.01-0.08% by mass of C existing as a cementite and the inner layer further contains not more than 0.0050% by mass of C, and at least one of 0.02-0.10% by mass of Ti, 0.01-0.10% by mass of Nb, 0.02-0.10% by mass of V and 0.03-0.10% by mass of Zr, the carbon existing substantially as carbides of these elements, preferably both the surface layer and the inner layer further contain 0.0001-0.

Abstract: A thin steel sheet having a structure comprising at least one member selected from a transgranular acicular ferrite and a bainite having a packet size of 30 to 300 .mu.m, in a proportion of not less than 95% of the structure, is produced by subjecting a steel comprising, in terms of % by weight, 0.01 to 0.20% of C, 0.005 to 1.5% of Si, 0.05 to 1.5% of Mn and not more than 0.03% of S and optionally 0.0005 to 0.0100% of Ca or 0.005 to 0,050% of REM with the balance consisting of Fe and unavoidable impurities to continuous casting into a thin cast strip having a casting thickness in the range of from 0.5 to 5 mm, cooling the thin cast strip from the temperature range of from the casting temperature to 900.degree. C. to the temperature range of from 650.degree. to 400.degree. C. at an average cooling rate of not less than V (.degree.C./sec) represented by the following formula (1); and coiling the cooled strip at a temperature of not more than 650.degree. C.:log V.gtoreq.0.5-0.8 log Ceq (.degree.C.

Abstract: A thermal refiningless, hot-rolled steel exhibits impact strength in excess of 10kgf.multidot.m/cm.sup.2 and contains, expressed in terms of weight percent, 0.30-0.50% carbon, 0.15-0.60% silicon, 0.80-1.60% manganese, up to 0.02% phosphorus, up to 0.015% sulfur, 0.07-0.20% vanadium, 0.015-0.06% aluminum, 0.005-0.015% nitrogen, up to 0.0015% oxygen, the balance iron and unavoidable impurities. The steel of the above-identified property and composition is produced by casting a steel product of predetermined cross-sectional shape; heating the steel product up to a temperature of 1,100.degree.-1,250.degree. C.; hot-rolling the heated steel product at a final rolling temperature of 850.degree.1,000.degree. C.; normalizing the hot-rolled steel product at a temperature of 880.degree.-950.degree. C.; and cooling the normalized steel product down to 300.degree. C. at a cooling speed of 5.degree.-100.degree. C./min.

Abstract: A fully killed steel has a composition that is tailored to meet a 50 KSI minimum yield strength after hot rolling and accelerated cooling. The steel has a carbon content in the range of from about 0.05 to about 0.10 percent or from about 0.15 to about 0.27 percent, from about 0.005 to about 0.020 percent titanium, from about 0.004 to about 0.015 percent nitrogen, from 0 to about 0.02 percent vanadium, and the remainder iron plus incidental impurities. The steel is continuously cast, hot rolled to plate, and cooled to a temperature of less than about 1100.degree. F. at a cooling rate lying in a cooling rate band extending from about 2.degree. to about 14.degree. F./sec at 2 inches plate thickness, from about 7.degree. to about 26.degree. F./sec at 1 inch plate thickness, and from about 13.degree. to about 45.degree. F./sec at 1/2 inch plate thickness.

Abstract: A fully killed steel has a composition of from about 0.005 to about 0.020 percent titanium and from about 0.004 to about 0.015 percent nitrogen, with the mole ratio of titanium to nitrogen being less than about 3.42. One grad e of this steel exhibiting a 42 KSI minimum yield strength has from about 0.05 to about 0.10 percent or from about 0.15 to about 0.27 percent carbon, and no more than about 0.02 percent vanadium. Another grade exhibiting a 50 KSI minimum yield strength has from about 0.15 to about 0.27 percent carbon and from about 0.02 to about 0.04 percent vanadium. The balance of each steel is iron and other elements. Copper may optionally be provided for strength and corrosion resistance. The steel is prepared by continuous casting and hot rolling, without any quenching and tempering required to achieve the desired properties.

Abstract: A process for hot working a continuous-cast bloom or a steel ingot, the process comprising the steps of: (1) cooling a bloom produced by continuous casting or a steel ingot produced with a mold to bring the surface temperature thereof to 50.degree. to 150.degree. C. higher than the Ar.sub.3 transformation point thereof; (2) quenching the bloom or the steel ingot in such a way that its interior remains red hot while the surface is transformed to have a bainite structure; and (3) heating the bloom or the steel ingot in a furnace followed by hot shaping.

Abstract: The compound roll having a shell portion made of a hard, high-alloy cast steel or iron having excellent wear resistance and resistance to surface roughening and a core portion made of a tough cast iron or cast steel, the cast iron of the shell portion having a composition consisting essentially, by weight ratio, of 1.0-3.0% of C, 2.0% or less of Si, 2.0% or less of Mn, 2.0-15.0% of Cr, 10.0% or less of Mo, 2.0-8.0% of V, the balance being substantially Fe and inevitable impurities, an average diameter of crystal grains constituting a matrix of the metal structure of the shell portion being 100 .mu.m or less in a range from a surface to a depth of 50 mm when determined by an image analysis method on the crystal grains having diameters exceeding 30 .mu.m, and the crystal grains satisfying the formula: m.sub.2 .ltoreq.1.2 m.sub.1, wherein m.sub.1 is an average diameter of the crystal grains at the surface of the shell portion, and m.sub.

Abstract: Disclosed are an amorphous iron based alloy having excellent magnetic characteristics as well as bendability and a method of manufacturing the amorphous iron based alloy. The amorphous iron based alloy has a mean centerline Ra surface roughness of about 0.8 .mu.m or less and the formula Fe.sub.X B.sub.Y Si.sub.Z Mn.sub.a in approximate proportions wherein:75.ltoreq.X.ltoreq.82 at %7.ltoreq.Y.ltoreq.15 at %,7.ltoreq.Z.ltoreq.17 at %, and0.2.ltoreq.a.ltoreq.0.5 at %.The method of manufacturing the amorphous iron based alloy comprises quenching and solidifying a molten alloy having the formula Fe.sub.X B.sub.Y Si.sub.Z Mn.sub.a in approximate proportions wherein:75.ltoreq.X.ltoreq.82 at %7.ltoreq.Y.ltoreq.15 at %,7.ltoreq.Z.ltoreq.17 at %, and0.2.ltoreq.a.ltoreq.0.5 at %, andeffecting the quenching and solidifying steps in a Co.sub.2 atmosphere containing H.sub.2 in an amount of about 1-4% by volume.

Abstract: The invention relates to a process for the production of very hard armour plates from steel slabs, wherein the slabs are hot rolled to a final thickness above 50 mm and then hardened and possibly tempered. The characterizing feature of the invention is that a continuously cast slab is produced from a steel having0.25 to 0.32% C0.05 to 0 75% Si0.10 to 1.50% Mn0.90 to 2.00% Cr0.10 to 0.70% Mo1 20 to 4 50% Ni0.01 to 0.08% Almax 0.015% Pmax 0.005% Smax 0.012% Nresidue Fe, including usual impurities,the slab then being heated to a temperature of 1150.degree. C. or higher and heated through, whereafter following cooling in air and by the spraying of its two wide sides with pressurized water, the slab is hot rolled with a surface temperature in the range of 1050.degree. to 900.degree. C. in shaping passes having an individual deformation of .epsilon..sub.h >0.1 and with a shape factor SF>0.40 to the final thickness.

Abstract: An abrasion-resistant steel having excellent surface property consists essentially of 0.1 to 0.45 wt. % C, 0.1 to 1 wt. % Si, 0.1 to 2 wt. % Mn, 0.04 wt. % or less P, 0.04 wt. % or less S, 0.1 to 1 wt. % Ti, 0.0015 to 0.01 wt. % N, and the balance being Fe and inevitable impurities, the steel including at least 400 TiC precipitates of 0.5 .mu.m or more in particle size per 1 mm.sup.2 and the steel having Ti* of 0.05 wt. % or more and less than 0.4 wt. % the Ti* being defined by the equations of Ti*=Ti(a)-[Ti], Ti(a)=Ti-{(48/14)N+(48/32)S}, log[Ti][C]=(-10580/T)+4.38, [Ti]=4.times.[C]+{Ti(a) -4.times.C}.A method for producing an abrasion-resistant steel having excellent surface property comprising the steps of: preparing a molten steel having the composition specified above; casting continuously the molten steel to produce slab, coarse particles of TiC being precipitated in the slab; hot-working the slab to produce a hot-rolled steel sheet at 1300.degree. C. or less; and quenching the hot-rolled steel sheet.

Abstract: An alloy ingot for permanent magnet consists essentially of rare earth metal and iron and optionally boron. The two-component alloy ingot contains 90 vol % or more of crystals having a crystal grain size along a short axis of 0.1 to 100 .mu.m and that along a long axis of 0.1 to 100 .mu.m. The three-component alloy ingot contains 90 vol % or more of crystals having a crystal grain size along a short axis of 0.1 to 50 .mu.m and that along a long axis of 0.1 to 100 .mu.m. The alloy ingot is produced by solidifying the molten alloy uniformly at a cooling rate of 10.degree. to 1000.degree. C./sec. at a sub-cooling degree of 10.degree. to 500.degree. C. A permanent magnet and anisotropic powders are produced from the alloy ingot.

Abstract: This invention relates to a austenitic stainless steel thin sheet devoid of work-surface roughening, produced by a continuous casting method of a strip comprising a composition which contains not greater than 0.09% of C+N and has an Md.sub.30 of 30.degree. to 60.degree. C., and in which colonies A comprising {112}<111>, etc., and colonies B comprising {110}<111>, etc., exist in a uniform mixture in the steel sheet. As to colony dimensions, d.sub.RD (A) and d.sub.RD (B) are not greater than 300 .mu.m and d.sub.TD (A) and d.sub.TD (B) are not greater than 200 .mu.m. Solidification cooling is carried out at a cooling rate of at least 100.degree. C./sec, and cooling is carried out to 1,200.degree. C. at a rate of 50.degree. C./sec after solidification. Cold rolling is effected by twice cold rolling with interposed intermediate annealing. In this way, there can be obtained a austenitic strip cast stainless steel sheet not causing work-surface roughening.