Provided is a method for rolling a steel sheet and a method for manufacturing a steel sheet capable of preventing occurrence of defects in appearance of a steel sheet caused by oil spots of a coolant and preventing occurrence of defects in shape of a steel sheet by appropriately controlling thermal deformation of work rolls. The method for rolling a steel sheet according to the present invention is a method for rolling a steel sheet involving feeding of a coolant to rolls that form a rolling mill during the rolling. The method includes keeping a coolant feeding rate at or lower than a predetermined rate lower than an upper constant rate at a start of operation of the rolling mill, and increasing the coolant feeding rate to the upper constant rate in response to an amount of center buckles of the steel sheet reaching or exceeding an upper target value.

Control system for cold rolling mills to improve sheet metal thickness uniformity. Sensors monitor the state of the cold rolling mill by measuring (i) roll eccentricity, (ii) roll slips during mill operation, (iii) mill disturbances from roll speed or roll force manifestations, and (iv) unknown disturbances referred to as process noise. The controller analyzes data from sensors to compensate. Data collected during the mill operation by the sensors are delayed in reaching the controller. This communication delay is accounted for by using a filter. Since an objective of the controller software is dynamic identification of eccentricity of the back up rolls, which is non-linear by nature, an Extended Kalman Filter may be used.

An aluminium-zinc-hot-dipped and colour-coated steel plate having a 600 MPa yield strength grade and a high elongation and a manufacturing method thereof, with the chemical components in mass percentage of a substrate of the steel plate being: 0.07-0.15% of C, 0.02-0.5% of Si, 1.3-1.8% of Mn, N0.004%, S0.01%, Ti0.20%, Nb0.060%, and the balance being Fe and other inevitable impurities, and meanwhile satisfying the conditions of: (C+Mn/6)0.3%; Mn/S150; Nb satisfying 0.01%(Nb-0.22C-1.1N)0.06% where no Ti is contained; Ti satisfying 0.5Ti/C1.5 where no Nb is contained; and 0.04%(Ti+Nb)0.26% where Ti and Nb are added in combination. The steel plate has a yield strength of 600 MPa, a tensile strength of 650 MPa, an elongation after fracture of 12%, a good strength and toughness and an excellent corrosion resistance.

This non-oriented electrical steel sheet contains a base material having a chemical composition including, in mass %, Si: 3.2 to 4.5%, wherein the tensile strength is 550 MPa or more, and a ratio (P.sub.120B/Fe.sub.700B).sub.B between a peak-to-peak height Fe.sub.700B of Fe at 700 eV and a peak-to-peak height P.sub.120B of P at 120 eV when crystal grain boundaries are measured through Auger electron spectroscopy is not more than twice a ratio (P.sub.120i/Fe.sub.700i).sub.i between a peak-to-peak height Fe.sub.700i of Fe at 700 eV and a peak-to-peak height P.sub.120i of P at 120 eV when the inside of crystals is measured through Auger electron spectroscopy.

The present invention relates to a method for manufacturing a component of austenitic TWIP or TRIP/TWIP steel. A flat product (1) is deformed by achieving at least one indentation (16) on at least one surface of the flat product (1) in order to have in the deformed product (5) areas of a high strength steel embedded in a matrix of a ductile material. The invention also relates to the use of the component where areas of a high strength steel embedded in a matrix of a ductile material are required in the same component.

A roll-changing device (1) for changing the working and/or intermediate rolls (2) of a rolling mill stand includes a roll-changing carriage (3), with which rolls (2) to be changed out or in can be transported. In order to further develop such a roll-changing device in such a way that it is possible to ensure simplified and safe loading and unloading of a roll-changing carriage, the roll-changing device (1) includes a cartridge (4) that can be detachably arranged in the roll-changing carriage (3). The cartridge (4) is provided with receiving spaces (5) for the rolls (2).

A steel sheet for heat treatment having a chemical composition including, by mass %: C: 0.05 to 0.50%; Si: 0.50 to 5.0%; Mn; 1.5 to 4.0%; P: 0.05% or less; S: 0.05% or less; N: 0.01% or less; Ti: 0.01 to 0.10%; B: 0.0005 to 0.010%; Cr: 0 to 1.0%; Ni: 0 to 2.0%; Cu: 0 to 1.0%; Mo: 0 to 1.0%; V: 0 to 1.0%; Ca: 0 to 0.01%; Al: 0 to 1.0%; Nb: 0 to 1.0%; REM: 0 to 0.1%; and the balance: Fe and impurities, wherein a maximum height roughness Rz on a surface of the steel sheet is 3.0 to 10.0 ?m, and a number density of carbide being present in the steel sheet and having circle-equivalent diameters of 0.1 ?m or larger is 8.0?10.sup.3/mm.sup.2 or lower.

An aluminum alloy foil for a current collector of an electrode is provided which has not only high electric conductivity but also high strength before and after a drying step, and is low in manufacturing cost. Provided is an aluminum alloy foil for a current collector of an electrode, containing 1.0 to 2.0 mass % (hereafter, simply referred to as %) of Fe, 0.01 to 0.2% of Si, 0.0001 to 0.2% of Cu, and 0.005 to 0.3% of Ti, the remainder being Al and inevitable impurities, wherein an amount of Fe contained as a solid solution is 300 ppm or more, and particles of intermetallic compounds having an equivalent circle diameter of 0.1 to 1.0 ?m exist at 1.0?10.sup.5 particles/mm.sup.2 or more.

A method for producing a FeCr alloy comprises: rolling a slab having a chemical composition containing, by mass %, C: 0.020% or less, Si: 0.01% to 1.5%, Mn: 1.0% or less, P: 0.040% or less, S: 0.010% or less, Cr: 16.0% to 30.0%, Al: 2.0% to 6.5%, N: 0.020% or less, and Ni: 0.50% or less, with the balance being Fe and inevitable impurities to obtain a sheet material; subjecting the sheet material to siliconizing treatment by a thermal CVD method to obtain a FeCr alloy having a Si content of more than 1.5 mass % and 10.0 mass % or less and satisfying:
14.0%?Si+1.15?% Al+0.35?% Cr(1)
where % Si, % Al, and % Cr indicate Si, Al, and Cr contents, by mass %, respectively in the chemical composition of the FeCr alloy.

In a ferritic stainless steel sheet, the arithmetic average roughness Ra is 0.2 m or more and 1.2 m or less. In addition, the dull pattern transfer rate on the steel sheet surface is 15% or more and 70% or less. Furthermore, micropits with a depth of 0.5 m or more and an open area of 10 m.sup.2 or more which are formed on the steel sheet surface have an existing density of 10.0 or less per 0.01 mm.sup.2 and an open area ratio of 1.0% or less. In addition, a film formed on the steel sheet surface is constituted from an oxide containing SiO.sub.2 as a main constituent, which oxide contains at least Si, N, Al, Mn, Cr, Fe, Nb, Ti and O as film-forming elements other than C, wherein the Si content is 10 at % or more, and the N content is 10 at % or less.