Abstract: According to the present invention, a high-strength electrical steel sheet that is suitable as rotor material for a high speed motor, steadily has high strength, and also has excellent magnetic properties can be obtained by setting the chemical composition thereof to include, by mass %, C: 0.005% or less, Si: more than 3.5% and 4.5% or less, Mn: 0.01% or more and 0.10% or less, Al: 0.005% or less, Ca: 0.0010% or more and 0.0050% or less, S: 0.0030% or less, and N: 0.0030% or less, Ca/S being 0.80 or more, the balance being Fe and incidental impurities, and by setting the sheet thickness to 0.40 mm or less, the non-recrystallized deformed microstructure to 10% or more and 70% or less, tensile strength (TS) to 600 MPa or more, and iron loss W10/400 to 30 W/kg or less.

Abstract: According to the present invention, a high-strength electrical steel sheet that is suitable as rotor material for a high speed motor, steadily has high strength, and also has excellent magnetic properties can be obtained by setting the chemical composition thereof to include, by mass %, C: 0.005% or less, Si: more than 3.5% and 4.5% or less, Mn: 0.01% or more and 0.10% or less, Al: 0.005% or less, Ca: 0.0010% or more and 0.0050% or less, S: 0.0030% or less, and N: 0.0030% or less, Ca/S being 0.80 or more, the balance being Fe and incidental impurities, and by setting the sheet thickness to 0.40 mm or less, the non-recrystallized deformed microstructure to 10% or more and 70% or less, tensile strength (TS) to 600 MPa or more, and iron loss W10/400 to 30 W/kg or less.

Abstract: The present invention provides a non-oriented electrical steel sheet at low cost that has excellent magnetic properties and mechanical properties as well as excellent quality of steel sheet. The non-oriented electrical steel sheet has a chemical composition containing, by mass %, Si: 5.0% or less, Mn: 2.0% or less, Al: 2.0% or less, and P: 0.05% or less, in a range satisfying formula (1), and furthermore, C: 0.008% or more and 0.040% or less; N: 0.003% or less, and Ti: 0.04% or less, in a range satisfying formula (2), with the balance composed of Fe and incidental impurities: 300?85[Si %]+16[Mn %]+40[Al %]+490[P %]?430??(1) 0.008?Ti*<1.2[C %]??(2), where Ti*=Ti?3.4[N %].

Abstract: Disclosed is a method for producing a non-oriented magnetic steel sheet, wherein a steel slab that consists of 0.01-0.1 mass % of C, 4 mass % or less of Si, 0.05-3 mass % of Mn, 3 mass % or less of Al, 0.005 mass % or less of S, 0.005 mass % or less of N and the balance made up of Fe and unavoidable impurities is subjected to hot rolling, cold rolling and final annealing. By carrying out the final annealing, while setting the average heating rate during the heating to 100° C./sec or more and setting the soaking temperature within the temperature range of 750-1100° C., a non-oriented magnetic steel sheet that has extremely increased magnetic flux density in the rolling direction of the steel sheet is advantageously produced.

Abstract: An electrical steel sheet has an insulation coating having excellent corrosion resistance and punchability even without containing chromium and is prepared by applying a coating liquid on the surface of an electrical steel sheet, followed by baking the applied coating liquid, which coating liquid contains 100 parts by weight of polysiloxane polymer prepared by copolymerizing polysiloxane with one or more resins selected from acrylic resin, styrene resin, vinyl acetate resin, polyester resin, urethane resin, polyethylene resin, polypropylene resin, polyamide resin, polycarbonate resin, phenol resin, alkyd resin, and epoxy resin, and 1 to 50 parts by weigh of one or more compounds selected from melamine, isocyanate, silane coupling agent, and oxazoline, as a cross-linking agent.

Abstract: An insulation coating containing a composite resin composed of polysiloxane and a polymer containing carbon is formed on the surface of an electrical steel sheet, thus obtaining an electrical steel sheet having an insulation coating that gives corrosion resistance and punchability equivalent to or higher than those of Cr-containing insulation coating.

Abstract: When a non-oriented electrical steel sheet is manufactured, simultaneously having superior magnetic properties and high strengths, a composition containing 0.02% or less of C, 4.5% or less of Si, 5.0% or less (including 0) of Ni, and 0.2% to 4.0% of Cu is used, and a solute Cu is allowed to appropriately remain in finish annealing. In the steel sheet thus obtained, finely shaped Cu is precipitated by aging treatment, and while the magnetic properties are not degraded, the yield stress is increased to not less than CYS (MPa) represented by the following formula: note CYS=180+5,600[% C]+95[% Si]+50[% Mn]+37[% Al]+435[% P]+25[% Ni]+22d?1/2 where d is an average grain diameter (mm) of crystal grains.

Abstract: An Fe—Cr—Si based non-oriented electrical steel sheet contains 2.5% to 10% by mass of Si, 1.5% to 20% by mass of Cr, 0.006% by mass or less of C, 0.002% by mass or less of N, 0.005% by mass or less of S, 0.005% by mass or less of Ti, 0.005% by mass or less of Nb, and as necessary, 0.1% to 2% by mass of Al and at least one of 0.005% to 1% by mass of Sb and 0.005% to 1% by mass of Sn, and the balance being Fe and incidental impurities, wherein the electrical resistivity of the steel is 60 ??cm or more, and the number of nitrides containing chromium per mm2 in the interior of the steel sheet is 2,500 or less. Consequently, the problem that high electrical resistance resulting from the high Si content and high Cr content is not satisfactorily utilized is advantageously solved, and it is possible to provide a non-oriented electrical steel sheet having excellent magnetic properties in the high-frequency range, in particular, in a frequency range of 1 kHz or more.

Abstract: A method for manufacturing a non-oriented electrical steel sheet including hot-rolling a steel slab containing 0-0.010% of C; at least one of Si and Al in a total amount of 0.03% to 0.5%; 0.5% or less of Mn; 0.10% or more to 0.26% or less of P; 0.015% or less of S; and 0.010% or less of N, on a mass percentage basis, the remainder being Fe and unavailable impurities, under conditions of a heating temperature in a single-phase austenite region and a coiling temperature of 650° C. or less; descaling the hot-rolled sheet to cold-roll the descaled sheet once or twice or more with an intermediate annealing sub-step therebetween; and then finish-annealing the cold-rolled sheet at a temperature of 700° C. or more in the single-phase ferrite region.

Abstract: When a non-oriented electrical steel sheet is manufactured, simultaneously having superior magnetic properties and high strengths, a composition containing 0.02% or less of C, 4.5% or less of Si, 5.0% or less (including 0) of Ni, and 0.2% to 4.0% of Cu is used, and a solute Cu is allowed to appropriately remain in finish annealing. In the steel sheet thus obtained, finely shaped Cu is precipitated by aging treatment, and while the magnetic properties are not degraded, the yield stress is increased to not less than CYS (MPa) represented by the following formula: note CYS=180+5,600[% C]+95[% Si]+50[% Mn]+37[% Al]+435[% P]+25[% Ni]+22d?1/2 where d is an average grain diameter (mm) of crystal grains.

Abstract: The present invention provides a non-oriented electrical steel sheet containing:

Abstract: The invention provides hot-rolled steel strips which, after having been acid-pickled, can be directly used. The strips have no Cr-decreasing layer and no shot blasted marks on their surface and have good corrosion resistance. The invention also provides a technique of efficiently producing the hot-rolled steel strips. A steel slab having a Cr content of from 6.0 to 25.0 wt. % is hot-rolled, then coiled at a temperature not higher than 700° C., then optionally quenched in water immediately after the coiling, then annealing in a reducing atmosphere, and thereafter acid-pickled in a solution of nitric acid/hydrochloric acid.

Abstract: Method of making a hot-rolled steel sheet having superior surface appearance, free of surface patterns and uneven glossiness from an austenitic stainless steel slab containing about 0.03 percent by weight or more of Cu, about 0.03 percent by weight or more of V, and about 0.01 percent by weight or more of Mo under any of the following conditions: (A) pickling in a nitric-hydrofluoric acid solution containing about 20 to 100 g/l of nitric acid and about 100 to 300 g/l of hydrofluoric acid; (B) controlling nitric-hydrofluoric acid content in response to the iron ion content in the solution; (C) a preliminary pickling step prior to finishing pickling; (D) grinding about 2 .mu.m or more of the surface after preliminary pickling and prior to finishing pickling; (E) causing counterflow with a relative flow rate of 0.5 to 5.

Abstract: This invention is a plated steel sheet formed by laminating an iron oxide layer and a plated layer on a steel matrix in this order, in which excellent plating adhesion property can uniformly be given to a full surface of the steel sheet by disposing a connection portion made from a metallic iron or an iron alloy connecting the steel matrix to the plated layer in the iron oxide layer. Particularly, it can provide means for easily forming a plated layer having an excellent adhesion property through hot dipping can be given to steel sheets being difficult to conduct the hot dipping such as high-strength steel sheet, stainless steel sheet and the like.

Abstract: A hot-rolled stainless steel strip contains at least 10 wt % Cr and 1.0 wt % or less of Si, and has a controlled scale thickness of not more than 2.5 .mu.m in the surface layer. The average thickness of the Si-containing oxide layer formed in the scale/alloy substitute interface is 0.1 .mu.m or less. The hot-rolled stainless steel strip is produced by hot rolling at an elongation rate of at least 150 or hot rough rolling to form a sheet bar, descaling by spraying superhigh pressure water to the surface of the sheet bar at an impact pressure (p) of 25 kgf/cm.sup.2 or more and a flow rate density of 0.002 l/cm.sup.2 or more, and then finish rolling so that the maximum reduction ratio per pass satisfies certain disclosed criteria.

Abstract: A ferrite-type hot-rolled stainless steel sheet is composed of a selected class of elements in specified amounts. Even when cold rolling and its subsequent process steps are omitted, the hot-rolled steel sheet is sufficiently workable and excellent in surface roughening resistance and high-temperature fatigue properties after working. The steel sheet is easy to produce with a wide range of annealing temperatures.

Abstract: Fe--Cr--Al alloy foil having high oxidation resistance for a substrate catalytic converter. The alloy foil contains about: C: 0.02 wt. % or less, N: 0.02 wt. % or less, Si: 1.0 wt. % or less, Mn: 1.0 wt. % or less, Cr: from 15 to 26 wt. %, Al: from 4.5 to 8.0 wt. %, Sm: from 0.05 to 0.30 wt. %, Zr: from 0.01 to 0.10 wt. %, and Hf: 0.005 wt. % to 0.10 wt. %, the balance consisting of Fe and incidental impurities.