A production equipment line for a hot-rolled steel strip comprises a rough rolling mill comprising rough rolling mills for hot rolling a material, which is heated to a predetermined temperature to a finish rolling start sheet thickness and a finish rolling mill comprising finish rolling mills for controlled-rolling the material to a final sheet thickness. At least one of the rough rolling mills is a reversible rolling mill. The production equipment line is provided on an upstream side of the reversible rolling mill with one of a slow cooling apparatus for slowly cooling at a water volume density of less than 1000 L/min.Math.m.sup.2 and a rapid cooling apparatus for rapidly cooling after the slow-cooling at a water volume density of not less than 1000 L/min.Math.m.sup.2 and the other of the slow cooling apparatus and rapid cooling apparatus on a downstream side of the reversible rolling mill.

A production equipment line for a hot-rolled steel strip comprises a rough rolling mill comprising rough rolling mills for hot rolling a material, which is heated to a predetermined temperature to a finish rolling start sheet thickness and a finish rolling mill comprising finish rolling mills for controlled-rolling the material to a final sheet thickness. At least one of the rough rolling mills is a reversible rolling mill. The production equipment line is provided on an upstream side of the reversible rolling mill with one of a slow cooling apparatus for slowly cooling at a water volume density of less than 1000 L/min.Math.m.sup.2 and a rapid cooling apparatus for rapidly cooling after the slow-cooling at a water volume density of not less than 1000 L/min.Math.m.sup.2 and the other of the slow cooling apparatus and rapid cooling apparatus on a downstream side of the reversible rolling mill.

A cooling device for cooling a metallic item and a method for operating the cooling device. Such cooling devices having a plurality of cooling bars arranged in parallel in groups for applying a coolant to the metallic item are known in the prior art. In order to be able to set a desired distribution function of the coolant over the width of the metallic item as precisely as possible, the cooling device provides that similar application regions in at least two cooling bars within a group are each formed differently with respect to their contour and/or with respect to their surface area.

A device and a method for applying a liquid medium to a roll, and/or to a rolled material, a slab or a roughed strip and/or for removing the liquid medium, wherein the device has at least one spray nozzle, at least one row of spray nozzles or at least one cooling bar for spraying on the medium and at least one plate element, which is designed for collecting the medium. The roll is designed for rolling rolled material, wherein the rolled material, the slab or the roughed strip is conveyed in a conveying direction. In order to allow an improved cooling effect of a roll to be cooled or an improved removal of descaling water, the plate element has on one of its surfaces at least one directing element, which is designed for diverting medium into a transverse direction, which lies horizontally and transversely in relation to the conveying direction.

A hot and cold composite formed square and rectangular steel tube and a production method for the same are provided. The radius of an outer corner of the square and rectangular steel tube meets the following conditions: when t is less than or equal to 6 mm, R is greater than 0 and less than 2.0 t; when t is greater than 6 mm and less than or equal to 10 mm, R is greater than 0 and less than 2.5 t; when t is greater than 10 mm, R is greater than 0 and less than 3.0 t, wherein t is the wall thickness of a straight tube part of the square and rectangular steel tube; R is the radius of each of the outer corners of the four corners of the square and rectangular steel tube; and the wall thickness of each corner of the square and rectangular steel tube is between 1.0 t and 1.8 t.

A lamination lubricant dispensing unit for lubricating a working roller of a rolling mill for laminating a sheet of alkali metal or alloy thereof into a film. The lubricant dispensing unit has a dispensing unit body defining a laterally extending wall; first and second side walls extending forwardly from the laterally extending wall; and a ledge connected to lower ends of the walls. The ledge extends forwardly from the laterally extending wall and extending between the side walls. The ledge and the walls define a recess having an opened side. The ledge has a front edge for abutting a lamination surface of the working roller. At least a portion of the ledge is an angled portion extending upward and rearward from the front edge toward the laterally extending wall. The dispensing unit body defines at least one lubricant passage having an outlet defined in the laterally extending wall.

A cooling apparatus for cooling a metallic material has at least one cooling beam with a plurality of coolant application elements for applying the metallic material with a coolant. Each coolant application element has an outlet opening with a cross-sectional area for discharging the coolant. In order to be able to adapt such known cooling apparatuses even more precisely to different temperature distributions across the width of the metallic material to be cooled the density of the cross-sectional areas of the outlet openings of the coolant application elements in the width direction y of the cooling beam be distributed or dimensioned according to the amount of the slope of the distribution of the temperature T(y) of the metallic material across its width before the inlet under the cooling beam.

The present invention relates to a cooling device and a cooling method capable of controlling, by section, the flow of coolant supplied in a widthwise direction, the cooling device comprising: a base frame connected to an external cooling fluid supply line, and disposed to be able to spray coolant onto a material that passes through a rolling mill after having been heated in a heating furnace; and a nozzle assembly disposed on the base frame, and spraying a cooling fluid in an arbitrary pattern onto a plurality of sections divided along the widthwise direction of the material to minimize a deviation in temperature in the widthwise direction of the material. Through this configuration, the flow of coolant supplied in the widthwise direction of a material can be controlled to be varied, thereby being capable of minimizing a deviation in temperature in the widthwise direction of a high temperature material.

A side trimming device according to an embodiment of the present invention may comprise: a cutting unit for mechanically cutting a transferred steel plate; a groove forming unit for forming a groove in a cutting-scheduled area in front of the cutting unit with reference to the steel plate transfer direction; and a washing unit arranged adjacent to the groove forming unit so as to suction molten material accumulating in the groove in the side direction of the steel plate.

A production equipment line for a hot-rolled steel strip comprises a rough rolling mill group comprised of plural rough rolling mills for hot rolling a material which is heated up to a predetermined temperature to a finish rolling start sheet thickness and a finish rolling mill group comprised of plural finish rolling mills for controlled-rolling the material to a final sheet thickness, wherein at least one of the plural rough rolling mills is a reversible rolling mill. The production equipment line for a hot-rolled steel strip is provided with a slow cooling apparatus for slowly cooling the material at a water volume density of less than 1000 L/min.Math.m.sup.2 and a rapid cooling apparatus which is arranged next to the slow cooling apparatus and rapidly cools the material after the slow-cooling at a water volume density of not less than 1000 L/min.Math.m.sup.2.