Abstract: Provided is a technique to reduce the variations in magnetic properties in a coil. A hot-rolled steel sheet for a grain-oriented electrical steel sheet having a chemical composition containing, by mass %, C: 0.002% or more and 0.080% or less, Si: 2.00% or more and 8.00% or less, Mn: 0.02% or more and 0.50% or less, acid-soluble Al: 0.003% or more and less than 0.010%, and at least one of S or Se: 0.001% or more and 0.010% or less in total, with N limited to less than 0.006%, and the balance being Fe and inevitable impurities, where regions from an outermost surface layer and a bottommost surface layer to a depth of 1/4 sheet thickness have a recrystallization ratio of 90% or less.

Abstract: A material for stainless steel cold rolling suitable for producing a cold-rolled stainless steel sheet that has sufficient corrosion resistance and ridging resistance as well as excellent formability and surface properties is provided. The material for stainless steel cold rolling according to the present invention contains, in terms of % by mass, C: 0.007% to 0.05%, Si: 0.02% to 0.50%, Mn: 0.05% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 15.5% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06%, and the balance being Fe and unavoidable impurities, wherein the material has a microstructure that includes 10% to 60% of a martensite phase in terms of area fraction, with the remainder being a ferrite phase, and the martensite phase has a hardness of HV500 or less.

Abstract: Provided is a cold-rolled ferritic stainless steel sheet having a chemical composition that contains, by mass %, C: 0.01% or more and 0.05% or less, Si: 0.02% or more and 0.75% or less, Mn: 0.1% or more and 1.0% or less, P: 0.04% or less, S: 0.01% or less, Al: 0.001% or more and 0.10% or less, N: 0.01% or more and 0.06% or less, Cr: 16.0% or more and 18.0% or less, and the balance being Fe and inevitable impurities. The metallographic structure includes a ferrite phase, in which the average grain diameter is 10 ?m or less, in which the proportion of ferrite grains having a grain diameter of 10 ?m or more and less than 40 ?m is 60% or more, and in which the proportion of ferrite grains having a grain diameter of less than 5 ?m is less than 20%.

Abstract: Provided is a material for a cold-rolled stainless steel sheet having a chemical composition containing, by mass %, C: 0.01% to 0.05%, Si: 0.02% to 0.75%, Mn: 0.1% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 16.0% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06% and the balance being Fe and inevitable impurities. The material has a metallographic structure including a martensite phase having an area ratio of 5% to 50% and the balance being a ferrite phase. A ferrite phase in portions extending from surface layers of front and back surfaces of a steel sheet has an average grain diameter of 20 ?m or more and 50 ?m or less, and a ferrite phase in a central portion of the sheet includes an unrecrystallized ferrite phase.

Abstract: Disclosed is a method comprising: preparing a steel slab with a predetermined chemical composition; subjecting the steel slab to hot rolling by heating it to a temperature of 1100-1300° C., hot rolling it with a finisher delivery temperature of 800-1000° C. to form a hot-rolled steel sheet, and coiling the steel sheet at a mean coiling temperature of 200-500° C.; subjecting the steel sheet to pickling treatment; and subjecting the steel sheet to annealing by retaining the steel sheet at a temperature of 740-840° C. for 10-900 s, then cooling the steel sheet at a mean cooling rate of 5-50° C./s to a cooling stop temperature of higher than 350° C. and 550° C. or lower, and retaining the steel sheet in a temperature range of higher than 350° C. to 550° C. for 10 s or more.

Abstract: Disclosed is a method comprising: preparing a steel slab with a predetermined chemical composition; subjecting the steel slab to hot rolling by heating it to a temperature of 1100-1300° C., hot rolling it with a finisher delivery temperature of 800-1000° C. to form a hot-rolled steel sheet, and coiling the steel sheet at a mean coiling temperature of 200-500° C.; subjecting the steel sheet to pickling treatment; subjecting the steel sheet to annealing by retaining the steel sheet at a temperature of 740-840° C. for 10-900 s, and the cooling the steel sheet at a mean cooling rate of 5-30° C./s to a cooling stop temperature of 150-350° C.; and subjecting the steel sheet to reheating treatment by reheating the steel sheet to a reheating temperature of higher than 350° C. and 550° C. or lower, and retaining the steel sheet at the reheating temperature for 10 s or more.

Abstract: A material for stainless steel cold rolling suitable for producing a cold-rolled stainless steel sheet that has sufficient corrosion resistance and ridging resistance as well as excellent formability and surface properties is provided. The material for stainless steel cold rolling according to the present invention contains, in terms of % by mass, C: 0.007% to 0.05%, Si: 0.02% to 0.50%, Mn: 0.05% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 15.5% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06%, and the balance being Fe and unavoidable impurities, wherein the material has a microstructure that includes 10% to 60% of a martensite phase in terms of area fraction, with the remainder being a ferrite phase, and the martensite phase has a hardness of HV500 or less.

Abstract: Provided are a ferritic stainless steel and a method for producing the ferritic stainless steel. A ferritic stainless steel of the present invention contains, in terms of % by mass, C: 0.005% to 0.05%, Si: 0.02% to 0.50%, Mn: 0.05% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 15.5% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06%, V: 0.01% to 0.25%, Ti: 0.001% to 0.020%, Nb: 0.001% to 0.030%, and the balance being Fe and unavoidable impurities, in which V/(Ti+Nb)?2.0 is satisfied.

Abstract: A portal site providing machine 20 obtains web pages provided by websites A–E at regular time intervals, and compares the latest web pages with the old web pages obtained last time. Then, the item-by-item comparison is made between the latest and old web pages to determine the degree of updating of the contents. The portal site providing machine 20 provides a portal page which contains images representing respective sites A–E with corresponding size and arrangement according to the degrees of updating.

Abstract: A hot rolling line and a hot rolling method capable of finer refining crystal grains are provided. Specifically, the hot rolling line for a metal sheet is composed of a finish rolling mill, a leveler, and a cooling apparatus installed from upstream to downstream in this sequence in a metal sheet transporting direction. The hot rolling method is such that, in the above hot rolling line, a metal sheet obtained by finish rolling a metal piece is subjected to repeated bending processing by the leveler and then cooled.

Abstract: A portal site providing machine 20 obtains web pages provided by websites A-E at regular time intervals, and compares the latest web pages with the old web pages obtained last time. Then, the item-by-item comparison is made between the latest and old web pages to determine the degree of updating of the contents. The portal site providing machine 20 provides a portal page which contains images representing respective sites A-E with corresponding size and arrangement according to the degrees of updating.

Abstract: A false-twist spindle friction disc comprises an annular rotor member whose lateral surfaces are machined to form coupling means and which is made of a highly rigid, centrifugal-force-resistant, high melting point material, and a support base made of a thermoplastic synthetic resin surrounding the annular rotor member while leaving the outer peripheral portion of the latter exposed. With the annular rotor member used as a core, the synthetic resin support base is formed by injection molding so as to unit them together. The presence of the coupling means formed in the lateral surfaces of the annular rotor member adds to the firmness with which the annular rotor member and the support base are united together.