Abstract: A cold rolling method, cold rolling equipment, and a cold-rolled steel sheet manufacturing method capable of preventing sheet breakage by sufficiently suppressing occurrence of an edge crack of a material to be rolled during cold rolling. In the cold rolling method, a rolling mill including a plurality of stands to cold-rolls a material to be rolled. An N-th stand (N is a natural number equal to or greater than 2) arranged in an N-th position from an upstream side of the material to be rolled in a transfer direction among the plurality of stands, includes a tapered work roll having a taper formed on an end portion of a roll having a uniform diameter. The N-th stand rolls the material to be rolled with a linear load of 0.8 t/mm or more.

Abstract: Provided is a hot-band annealing method comprising subjecting a Si-containing hot rolled steel sheet, having an oxidized scale formed on a surface of the steel sheet by hot rolling, to hot-band annealing with a hot-band annealing equipment provided with a heating zone, a soaking zone, a cooling zone, and a rapid heating device at an upstream side of the heating zone and/or in an inlet side of the heating zone, wherein the hot rolled steel sheet is heated by not lower than 50° C. at a heating rate of not less than 15° C./s by using the rapid heating device to improve a descaling property. Also, provided is a descaling method characterized by subjecting the Si-containing hot rolled steel sheet, after the hot-band annealing, to descaling only by pickling without requiring mechanical descaling or heating the steel sheet in the pickling process.

Abstract: A rolling oil supply system is configured to supply rolling oil to a rolling stand selected from a plurality of rolling stands included in a tandem rolling mill, a first rolling oil supply system configured to circulate and supply rolling oil after removing wear powder generated by rolling, and a second rolling oil supply system configured to supply rolling oil containing the wear powder generated by rolling are provided. Mixed rolling oil in which the rolling oil supplied from the first rolling oil supply system and the rolling oil supplied from the second rolling oil supply system are mixed is supplied to selected fourth and fifth rolling stands.

Abstract: A method for shape control in a rolling mill includes: a measurement step of measuring a shape of a steel sheet on a delivery side of the rolling mill; and a control step of controlling the rolling mill in a manner that the shape of the steel sheet falls within an allowable range, based on the shape of the steel sheet measured at the measurement step, wherein the control step includes a step of setting a control gain smaller than a control gain for a width of a steel sheet as a target for rolling being equal to or smaller than the predetermined value when the steel sheet as the target for rolling has a width greater than a predetermined value.

Abstract: A rolling oil supply system is configured to supply rolling oil to a rolling stand selected from a plurality of rolling stands included in a tandem rolling mill, a first rolling oil supply system configured to circulate and supply rolling oil after removing wear powder generated by rolling, and a second rolling oil supply system configured to supply rolling oil containing the wear powder generated by rolling are provided. Mixed rolling oil in which the rolling oil supplied from the first rolling oil supply system and the rolling oil supplied from the second rolling oil supply system are mixed is supplied to selected fourth and fifth rolling stands.

Abstract: Provided is a hot-band annealing method comprising subjecting a Si-containing hot rolled steel sheet, having an oxidized scale formed on a surface of the steel sheet by hot rolling, to hot-band annealing with a hot-band annealing equipment provided with a heating zone, a soaking zone, a cooling zone, and a rapid heating device at an upstream side of the heating zone and/or in an inlet side of the heating zone, wherein the hot rolled steel sheet is heated by not lower than 50° C. at a heating rate of not less than 15° C./s by using the rapid heating device to improve a descaling property. Also, provided is a descaling method characterized by subjecting the Si-containing hot rolled steel sheet, after the hot-band annealing, to descaling only by pickling without requiring mechanical descaling or heating the steel sheet in the pickling process.

Abstract: Provided is a hot-band annealing equipment provided with a heating zone, a soaking zone and a cooling zone for subjecting a Si-containing hot rolled steel sheet to hot-band annealing, wherein when the Si-containing hot rolled steel sheet is subjected to hot-band annealing with the hot-band annealing equipment provided with a rapid heating device at an upstream side of the heating zone and/or in an inlet side of the heating zone, the hot rolled steel sheet is heated by not lower than 50° C. at a heating rate of not less than 15° C./s by using the rapid heating device to improve a descaling property, whereby descaling can be performed only by pickling without requiring mechanical descaling or heating the steel sheet in the pickling process. Also provided are a hot-band annealing method and a descaling method using the above equipment.

Abstract: A cold rolling facility includes: a heating device; a tandem mill including a plurality of rolling mills; a meandering-amount measuring unit; a meandering-movement correction device; a shape measuring unit; a shape controller configured to control a shape of a steel sheet after being cold-rolled by the rolling mill located on the uppermost stream side; and a controller configured to control operations of the meandering-movement correction device based on a measurement value of a meandering-movement amount of the steel sheet by the meandering-amount measuring unit to control a meandering movement of the steel sheet before being heated, and configured to control operations of the shape controller based on a measurement value of a shape of the steel sheet by the shape measuring unit to control the meandering movement of the steel sheet that is attributed to cold rolling of the steel sheet by the tandem mill.

Abstract: A cold rolling apparatus includes: a heating device configured to heat a sequentially transferred steel sheet; a cold rolling mill configured to sequentially cold-roll the steel sheet after being heated; a meandering-movement correction device arranged on an upstream side of the heating device in a transfer direction of the steel sheet, and configured to correct a meandering movement of the steel sheet transferred toward the heating device; and a meandering-movement suppression device arranged between the heating device and the cold rolling mill, and configured to suppress a meandering movement of the steel sheet attributed to the cold rolling of the steel sheet by using the cold rolling mill.

Abstract: A cold rolling facility includes: a heating device; a tandem mill including a plurality of rolling mills; a meandering-amount measuring unit; a meandering-movement correction device; a shape measuring unit; a shape controller configured to control a shape of a steel sheet after being cold-rolled by the rolling mill located on the uppermost stream side; and a controller configured to control operations of the meandering-movement correction device based on a measurement value of a meandering-movement amount of the steel sheet by the meandering-amount measuring unit to control a meandering movement of the steel sheet before being heated, and configured to control operations of the shape controller based on a measurement value of a shape of the steel sheet by the shape measuring unit to control the meandering movement of the steel sheet that is attributed to cold rolling of the steel sheet by the tandem mill.

Abstract: A cold rolling apparatus includes: a heating device configured to heat a sequentially transferred steel sheet; a cold rolling mill configured to sequentially cold-roll the steel sheet after being heated; a meandering-movement correction device arranged on an upstream side of the heating device in a transfer direction of the steel sheet, and configured to correct a meandering movement of the steel sheet transferred toward the heating device; and a meandering-movement suppression device arranged between the heating device and the cold rolling mill, and configured to suppress a meandering movement of the steel sheet attributed to the cold rolling of the steel sheet by using the cold rolling mill.