Described herein are thin metal strips having hot rolled exterior side surfaces characterized as being primarily or substantially free of all prior austenite grain boundaries, or at least primarily or substantially free of all prior austenite grain boundaries, and including elongated surface structure. As a result, because the prior austenite grain boundaries are not primarily or substantially present, all such prior austenite grain boundaries are not susceptible to grain boundary etching due to acid etching or pickling. In particular examples, the thin metal strips undergo hot rolling performed with a coefficient of friction equal to or greater than 0.20 with or without use of lubrication.

A device and a method for cooling metal strips or sheets conveyed on a conveyor line, in particular hot-rolled strips in the outlet of a rolling train. For these purposes, the device includes at least one cooling beam extending across the width of the conveyor line, and the cooling beam features a connection point to which a supply tube for cooling liquid can be connected, and a number of discharge openings arranged along a longitudinal axis of the cooling beam, such that cooling liquid can be discharged through the discharge openings in the direction of the metal strip or sheet that is to be cooled. Associated with each of the individual discharge openings is a respectively adjusted flow area, such that the flow areas of the respective discharge openings decrease in a direction leading away from the connecting point along the longitudinal axis of the cooling beam.

A cooling-water injection control device and a cooling-water injection control method for a rolling mill suppress influence by change in flow rate characteristics of water injection headers. The cooling-water injection control device for a rolling mill includes a water injection amount control unit. When a plurality of water injection headers are controlled to make temperature of a material to be rolled on a delivery side of a rolling mill coincident with a target value, in a case where a flow rate of any one of the plurality of water injection headers is less than a transient flow rate between a minimum flow rate and a maximum flow rate, the water injection amount control unit controls a flow rate of any one of the plurality of water injection headers based on priority.

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.

Method and control device for controlling a cooling device (10) which is set up to control the temperature of a rolling stock, preferably metal strip (B), which the cooling device (10) runs through along a conveying direction (F), the cooling device (10) preferably in front of a rolling train is arranged and the method comprises: determining a total enthalpy of the system formed by the rolling stock; Determining a measure for the formation of scale, which preferably comprises a scale factor that depends on the chemical composition and the surface temperature of the rolling stock; Calculating a temperature distribution and/or average temperature in the rolling stock on the basis of a temperature calculation model, in which the determined total enthalpy and the measure for the formation of scale are included; and setting a cooling capacity of the cooling device (10) taking into account the calculated temperature distribution and/or average temperature in the rolling stock.

A device for cooling a metal rolling stock (1) rolled in a rolling train, having multiple cooling devices (4), to which water (5) is supplied via a respective branch line (7) and by means of which the water (5) is applied to the rolling stock (1). The branch lines (7) are equipped with a respective valve (8), by means of which the water flow flowing through the respective branch line (7) is adjusted. Each of the valves (8) is paired with a drive (9), via which the respective valve (8) is actuated. The cooling devices (4) form multiple groups, each of which is paired with a dedicated pressure vessel (10) in a proprietary manner. Each pressure vessel (10) is connected to a respective feed line (12) at a respective connection point (11), and the water (5) is supplied to the branch lines (7) of the cooling devices (4) of the corresponding group via said feed line. When viewed in the flow direction of the water (5), each connection point (11) is arranged upstream of the valves (8) of the respective group of cooling devices (4).

A method for cold rolling rolled stock (2) in a mill train (1) with multiple roll stands (3 to 7). An upper limit temperature and/or a lower limit temperature is provided for a rolled stock temperature of the rolled stock (2) for at least one rolling pass, and the rolled stock temperature is controlled and/or regulated by at least one control or regulating measure such that during the at least one rolling pass, the rolled stock temperature does not exceed the upper limit temperature specified for the rolling pass and/or the rolled stock temperature does not fall below the lower limit temperature specified for the rolling pass.

In a tandem type cold rolling mill of a circulating oil-feeding system for continuously rolling a steel sheet by feeding a coolant serving as a rolling oil and a cooling water to each stand, an edge heater for heating both edge portions of the steel sheet to not lower than 60° C. as a steel sheet temperature at an entry side of a roll bite is arranged at an upstream side of the first stand in the cold rolling mill and a device for jetting a coolant having a concentration higher than that of the coolant fed to the firsts stand onto surfaces of both edge portions of the steel sheet is arranged between the edge heater and the first stand. The cold rolling mill can be used to roll a hard-to-roll material such as silicon or stainless steel sheet without causing an edge crack or sheet breakage in low-speed rolling.

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 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.