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 rolling mill has a rolling stand (1) in which a flat rolled product (2) composed of metal is rolled. A sensor device (6), which detects at least one measured variable (M) characteristic of a material property of the flat rolled product (2), is arranged upstream and/or downstream of the rolling stand (1). The material property can be, in particular, an electromagnetic property or a mechanical property of the rolled product (2). The sensor device (6) transfers the detected measured variable (M) to a control device (9) for the rolling mill. Taking into account the measured variable (M), the control device (9) determines a control value (A) for the rolling stand (1). The control of the rolling stand (1) influences the material property of the flat rolled product (2). The control value (A) is a ratio of the peripheral speeds (vO, vU) at which the upper and the lower working rolls (3, 4) of the rolling stand (1) rotate.

A rolling mill has a rolling stand (1) in which a flat rolled product (2) composed of metal is rolled. A sensor device (6), which detects at least one measured variable (M) characteristic of a material property of the flat rolled product (2), is arranged upstream and/or downstream of the rolling stand (1). The material property can be, in particular, an electromagnetic property or a mechanical property of the rolled product (2). The sensor device (6) transfers the detected measured variable (M) to a control device (9) for the rolling mill. Taking into account the measured variable (M), the control device (9) determines a control value (A) for the rolling stand (1). The control of the rolling stand (1) influences the material property of the flat rolled product (2). The control value (A) is a ratio of the peripheral speeds (vO, vU) at which the upper and the lower working rolls (3, 4) of the rolling stand (1) rotate.

A rolling control device (10) updates a preset load value P.sub.set based on operation actual results at timings t.sub.a to t.sub.b. The rolling control device (10) derives a plasticity coefficient Q.sub.chk based on operation actual results at timings t.sub.b to t.sub.c. When the determining that it is necessary to re-update the updated preset load value P.sub.set based on the plasticity coefficient Q.sub.chk, the rolling control device (10) updates the preset load value P.sub.set again based on the operation actual results at the timings t.sub.b to t.sub.c.

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 method for producing a semifinished product with locally different material thicknesses may involve preparing a multilayer, metal material composite, which has a plurality of layers with different ductilities, and rolling the material composite in a method for flexible rolling through a rolling gap formed between two rollers. The rolling gap may be configured such that regions with different material thicknesses are formed. In some cases, the multilayer, metal material composite is rolled at room temperature. Further, the plurality of layers of the multilayer, metal material composite may include a first outer layer disposed on a first side of a middle layer and a second outer layer disposed on a second side of the middle layer, with the second side of the middle layer being opposite the first side.

A method for producing a heat radiating plate, the method containing the steps of: finish cold-rolling an annealed material to obtain a strip; causing the strip to wind in the shape of a coil to prepare a coil stock; unwinding the coil stock by means of an uncoiler to obtain a strip; causing the strip to pass through a gap between the rolls of a leveler to correct the shape thereof; progressively feeding the corrected strip to a progressive die via a feeder to progressively press-working the strip to produce a heat radiating plate.

A method for producing a semifinished product with locally different material thicknesses may involve preparing a multilayer, metal material composite, which has a plurality of layers with different ductilities, and rolling the material composite in a method for flexible rolling through a rolling gap formed between two rollers. The rolling gap may be configured such that regions with different material thicknesses are formed. In some cases, the multilayer, metal material composite is rolled at room temperature. Further, the plurality of layers of the multilayer, metal material composite may include a first outer layer disposed on a first side of a middle layer and a second outer layer disposed on a second side of the middle layer, with the second side of the middle layer being opposite the first side.

In a method for producing a heat radiating plate 20, the method containing the steps of: finish cold-rolling an annealed material to obtain a strip; causing the strip to wind in the shape of a coil to prepare a coil stock; unwinding the coil stock by means of an uncoiler 10 to obtain a strip 12; causing the strip 12 to pass through a gap between the rolls of a leveler 14 to correct the shape thereof; progressively feeding the corrected strip 12 to a progressive die 18 via a feeder 16 to progressively press-working the strip 12 to produce a heat radiating plate 20, the finish cold-rolling is carried out so that a ratio of the Vickers hardness HV after the finish cold-rolling to the Vickers hardness HV before the finish cold-rolling is not less than 1.2, and the corrected strip 12 is allowed to bend due to its own weight between the leveler 14 and the feeder 16 so that the minimum value of deflection (L1L0) is 0.5 to 2.0 m assuming that L0 is a distance between a roll at the last sending side of the leveler 14 and a roll at the first entrance side of the feeder 16 and that L1 is the length of the strip 12 between the roll at the last sending side of the leveler 14 and the roll at the first entrance side of the feeder 16.

This hot-rolled steel sheet has a thickness of 3-20 mm and contains specific amounts of C, Si, Mn, P, S, Al and N with the balance made up of iron and unavoidable impurities. The contents of solid-solved N, C and N are within specific ranges, and bainitic ferrite having a specific average crystal grain size and pearlite have specific area occupancies in the structure, with the balance occupied by polygonal ferrite. This hot-rolled steel sheet has a specific hardness distribution in the thickness direction.