Abstract: In a method of manufacturing a grain-oriented electrical steel sheet including a nitriding treatment (step S7) and adopting so-called “low-temperature slab heating”, the finish temperature of finish rolling in hot rolling (step S2) is set to 950° C. or below, the cooling is started within 2 seconds after completion of the finish rolling, and a steel strip is coiled at 700° C. or below. The cooling rate over the duration from the end of finish rolling to the start of coiling is set to 10° C./sec or above. In annealing (step S3) of the hot-rolled steel strip, the heating rate in the temperature range from 800° C. to 1000° C. is set to 5° C./sec or above.

Abstract: In a method of manufacturing a grain-oriented electrical steel sheet including a nitriding treatment (step S7) and adopting so-called “low-temperature slab heating”, the finish temperature of finish rolling in hot rolling (step S2) is set to 950° C. or below, the cooling is started within 2 seconds after completion of the finish rolling, and a steel strip is coiled at 700° C. or below. The cooling rate over the duration from the end of finish rolling to the start of coiling is set to 10° C./sec or above. In annealing (step S3) of the hot-rolled steel strip, the heating rate in the temperature range from 800° C. to 1000° C. is set to 5° C./sec or above.

Abstract: Very high magnetic flux density grain-oriented electrical steel slab containing 2.5 to 4.0 weight percent silicon as an essential component and having a very high magnetic flux density B.sub.8 of not less than 1.92 tesla, in which by area not less than 80 percent is accounted for by matrix secondary recrystallization grains having a diameter not larger than 100 mm and not smaller than 10 mm in a direction of cold rolling and not larger than 50 mm and not smaller than 5 mm in a direction perpendicular to the cold rolling direction, and in which, moreover, of the grains in said matrix, not fewer than 50 percent by ratio of number are fine secondary recrystallization grains having an average diameter not larger than 5 mm.

Abstract: The present invention relates to a process for preparing a metal sheet having an excellent rolling property, i.e., a rollable metal sheet, which process comprises the basic steps of: continuously feeding a molten metal on a cooling material having one or two cooling surfaces being transferred and renewed for quench solidification, to thereby prepare a thin cast sheet; impinging a small rigid body particle against the surface of the resultant thin cast sheet, to work the cast sheet; heat-annealing the worked sheet in such a manner that the worked region becomes a fine recrystallized grain layer; and subjecting the cast sheet to a cold or warm rolling, optionally after a removal of oxides present on the surface; and an optional step of heat-treating the rolled sheet for working. The process of the present invention is applicable to the production of various known rollable metal or alloy sheets, such as soft steel, stainless steel, silicon steel, nickel-iron, cobalt-iron, nickel, aluminum, and copper sheets.

Abstract: Disclosed is a process for preparing a thin grain oriented electrical steel sheet having a final thickness of 0.05 to 0.25 mm from a silicon steel cast strip having a thickness of 0.2 to 5 mm and directly obtained from the molten steel by the synchronous continuous casting machine, in which the speed of movement of the strand relative to the inner wall surface of the casting mold is the same, and by which the traditional hot rolling process can be omitted, comprising 0.050 to 0.120% by weight of C, 2.8 to 4.0% by weight of Si and 0.05 to 0.25% by weight of Sn, wherein the starting silicon cast strip further comprises up to 0.035% by weight of S and 0.005 to 0.035% by weight of Se, with the proviso that the total amount of S and Se is in the range of 0.015 to 0.060% by weight, 0.050 to 0.090% by weight of Mn, with the proviso that the Mn content is in the range of {1.5.times.[content (% by weight) of S+content (% by weight) of Se]} to {4.5.times.

Abstract: A method of producing a grain oriented electrical steel sheet having a high magnetic flux density comprises the steps of continuously rapid quench solidifying a molten steel essentially consisting of 0.03 to 0.10% of C, 2.5 to 4.5% of Si, 0.02 to 0.15% of Mn, 0.01 to 0.04% of Al acid soluble by weight and the remainder substantially Fe, to obtain a thin strip, subjecting the thin strip to cold rolling one or two or more stages, with an annealing therebetween, decarburization annealing, and finishing annealing wherein the content of S in the molten steel is 0.01% or less the content of N in the molten steel is 0.003% or less, and sulfide and nitride are contained in the annealing separator for the finishing annealing.

Abstract: The present invention concerns a process for producing a grain-oriented electrical steel sheet by means of a rapid quench-solidification process, for example, a continuous casting by a twin roll strip caster. The feature of the present invention resides in quenching to solidify molten steels into a thin cast sheet of 0.7 to 3.0 mm thickness, at a cooling rate of greater than 50.degree. C./sec. in the central portion along the direction of thickness of the thin cast sheet, cooling the sheet at a cooling rate of greater than 10.degree. C./sec. in a temperature range between 1300.degree. to 900.degree. C. and then applying cold rolling for once or twice or more annealing the thin cast steel for a period between 30 seconds and 30 minutes in a temperature range between 950.degree. and 1,200.degree. C. and subsequently including intermediate annealing under a final cold rolling reduction rate of not less than 80%.