There is provided a meandering control device for a rolling line capable of setting temperature of a material to be rolled so as to suppress meandering of the material to be rolled. The meandering control includes a tail end roll force calculation unit that calculates a predictive value of roll force when entry side tension is not applied, an allowable meandering amount roll force calculation unit that calculates a reference value of the roll force applied to the material to be rolled when a meandering amount of the material to be rolled is an allowable amount, and a temperature rise amount calculation unit that calculates a temperature rise amount of the material to be rolled, based on a difference between the predictive value of the roll force and the reference value of the roll force.

There is provided a meandering control device for a rolling line capable of setting temperature of a material to be rolled so as to suppress meandering of the material to be rolled. The meandering control includes a tail end roll force calculation unit that calculates a predictive value of roll force when entry side tension is not applied, an allowable meandering amount roll force calculation unit that calculates a reference value of the roll force applied to the material to be rolled when a meandering amount of the material to be rolled is an allowable amount, and a temperature rise amount calculation unit that calculates a temperature rise amount of the material to be rolled, based on a difference between the predictive value of the roll force and the reference value of the roll force.

A method for producing a metallic strip or sheet, in which the strip or sheet is rolled in a multi-stand rolling mill and is discharged downstream of the last roll stand of the rolling mill in a conveying direction. The strip or sheet is cooled in the multi-stand rolling mill and/or downstream of the rolling mill as viewed in the conveying direction, wherein a temperature of the strip or sheet is measured upstream of the last roll stand of the rolling mill as viewed in conveying direction. Based on this measured temperature, a temperature for the strip or sheet at the exit of the last roll stand of the rolling mill is then determined by calculation with the aid of a temperature calculation model, with which further temperature processes of the manufacturing method can be controlled or regulated after a comparison with a predetermined reference value.

A method for producing a metallic strip or sheet, in which the strip or sheet is rolled in a multi-stand rolling mill and is discharged downstream of the last roll stand of the rolling mill in a conveying direction. The strip or sheet is cooled in the multi-stand rolling mill and/or downstream of the rolling mill as viewed in the conveying direction, wherein a temperature of the strip or sheet is measured upstream of the last roll stand of the rolling mill as viewed in conveying direction. Based on this measured temperature, a temperature for the strip or sheet at the exit of the last roll stand of the rolling mill is then determined by calculation with the aid of a temperature calculation model, with which further temperature processes of the manufacturing method can be controlled or regulated after a comparison with a predetermined reference value.

A device to cool a steel material having undergone hot rolling mills, the device including: a conveying mechanism which conveys the steel material while accelerating the steel material; a water cooling mechanism which cools the steel material while the conveying mechanism conveys the steel material; and a control unit which controls the conveying mechanism and the water cooling mechanism to cause the cooling of the steel material to satisfy Formula (1) below, wherein a water cooling time decrease rate in Formula (1) below is decided based on a length of a water cooling zone where the water cooling mechanism is provided and a time t.sub.c(0) required to cool a leading end portion of the steel material down to a target temperature,

t.sub.c(x)=t.sub.c(0).Math.xFormula (1),

where x: a conveyance-direction position in the steel material relative to the leading end portion of the steel material serving as a reference point, and t.sub.c(x): a time required to cool a portion at the position x of the steel material down to the target temperature.

In a cooling path, hot rolled material composed of metal is cooled. The cooling path has a pump which extracts coolant from a coolant reservoir and feeds said coolant via a line system to a number of coolant outlets which are controlled by means of valves positioned upstream of the coolant outlets. A control device of the cooling path determines activation states (Ci) for the valves for a respective point in time taking into consideration coolant flows (Wi) which are intended to be discharged via the coolant outlets at the respective point in time, in conjunction with a working pressure (pA) of the coolant prevailing at the inlet side of the valve. By adding the coolant flows (Wi), said control device determines a total coolant flow (WG).

In a cooling path, hot rolled material composed of metal is cooled. The cooling path has a pump which extracts coolant from a coolant reservoir and feeds said coolant via a line system to a number of coolant outlets which are controlled by means of valves positioned upstream of the coolant outlets. A control device of the cooling path determines activation states (Ci) for the valves for a respective point in time taking into consideration coolant flows (Wi) which are intended to be discharged via the coolant outlets at the respective point in time, in conjunction with a working pressure (pA) of the coolant prevailing at the inlet side of the valve. By adding the coolant flows (Wi), said control device determines a total coolant flow (WG).

A cooling device with variable cooling rate for treating metal materials, in particular for cooling steel sheets in plate mills, hot strip mills or thermal treatment lines, by means of a spray nozzle cooling system. The cooling device consists of at least two cooling bars one of each two cooling bars being situated on the lower side and the other on the upper side transversely to the sheet travel direction of the sheet and centrally between two roller table rollers and includes a spray nozzle cooling system with which a plurality of full jet nozzles and a plurality of full cone nozzles are associated, the full jet nozzles being arranged symmetrically to the full cone nozzles. A method for operating the cooling device according to the disclosure

A piercing machine includes a plurality of skewed rolls, a plug, a mandrel bar and an outer surface cooling mechanism. The outer surface cooling mechanism is disposed around the mandrel bar at a position that is rearward of the plug, and with respect to an outer surface of a hollow shell advancing through a cooling zone which has a specific length in an axial direction of the mandrel bar and which is located rearward of the plug, as seen from an advancing direction of the hollow shell, the outer surface cooling mechanism ejects a cooling fluid toward an upper part of the outer surface, a lower part of the outer surface, a left part of the outer surface and a right part of the outer surface of the hollow shell to cool the hollow shell inside the cooling zone.

A temperature calculation method includes: dividing a cross section perpendicular to a longitudinal direction of a steel plate to be hot-rolled into a plurality of rectangular elements; and calculating a temperature of each of the rectangular elements using a finite difference method. A first region 31 that includes an edge part of the cross section is divided such that a plurality of the rectangular elements are lined up in a plate-thickness direction and such that a plurality of the rectangular elements are lined up in a plate-width direction. A second region 32 that includes a center of the cross section and is wider than the first region 31 is divided such that a plurality of the rectangular elements are lined up in the plate-thickness direction but the second region 32 is not divided in the plate-width direction.