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 control device for a section of a hot rolling mill is supplied with respective primary data for a plurality of rolling materials and respective preliminary target values for the target variables of the respective rolling material. The respective primary data describes the respective rolling material before being supplied to the section of the hot rolling mill. The respective preliminary target values of the target variables describe a desired target state of the respective rolling material after passing through the section of the hot rolling mill. At least one of the target variables is a particular target variable, whereby the control device determines a respective final target value in such a way that it changes the respective preliminary target value by a respective offset. The respective offset is determined independently of the primary data and the other particular target variables and the normal target variables for the respective rolling material.

A metal-strip rapid cooling apparatus includes a cooling fluid ejection device including one set of nozzles or a plurality of sets of nozzles arranged in a horizontal direction, and configured to eject a cooling fluid onto the metal strip from both sides of the metal strip; cooling fluid removing rolls configured to remove a remaining fluid from the metal strip onto which the cooling fluid has been ejected; and movable masking plates on both sides of a metal strip pass line along which the metal strip passes, the movable masking plates each disposed between the metal strip pass line and the nozzles, and configured to move in the horizontal direction to adjust a cooling start position and control a distance from the cooling start position to the cooling fluid removing rolls, the cooling start position positioned such that the metal strip starts to be cooled with the cooling fluid.

A high-strength thin-gauge checkered steel plate/strip and a manufacturing method therefor, wherein residual elements such as Sn and Cu in steel scrap are fully utilized as alloy elements in the smelting of molten steel, and the steel has selectively added micro-alloy elements such as B; during the smelting process, the alkalinity of the slag, the types of inclusion in the steel and the melting point thereof, the content of free oxygen and the content of soluble aluminum (Als) in the molten steel are controlled; and twin-roll thin-strip continuous casting is performed to cast a cast strip (11); after exiting crystallization rollers (8a, 8b), the cast strip (11) directly enters a lower sealed chamber (10) containing a non-oxidizing atmosphere, and enters an online rolling machine (13) in a sealed manner so as to undergo hot rolling, then after rolling, the strip steel is cooled by means of air atomization. The resultant steel roll can be used directly as hot-rolled checkered plate/strip, or as a finished checkered plate/strip after being cut and finished, and is widely applicable to the fields of architecture, mechanical production, automobile, bridges, transportation, ship building, etc.

The invention relates to a method for the inductive surface layer hardening of a surface which runs around an annular component and has an initial zone, an end zone and two intermediate zones extending between the initial zone and the end zone. The initial zone is brought to hardening temperature by an inductor and quenched by a spray. Subsequently, an inductor arrangement is moved in each case along the intermediate zone to the end zone. Each inductor arrangement includes a leading inductor for preheating the region covered by it, a trailing inductor for finish-heating the preheated region and a spray for quenching the finish-heated region. After the inductor arrangements are located at a certain distance from the initial zone, the leading inductor of at least one of the inductor arrangements is moved in the direction of the end zone at an increased feed rate compared to the trailing inductor. The leading inductor thus reaches the end zone by a time interval earlier, whose duration is equal to the duration required by the trailing inductor to overcome the distance previously resulted between said trailing inductor and the leading inductor. In the meantime, the end zone is preheated by the leading inductor that reached it. When one of the trailing inductors of the inductor arrangements has arrived in the end zone, it heats the end zone to the finished hardening temperature.

The invention provides a method for the inductive surface layer hardening of a surface running around an annular component of a hardenable steel, which achieves uniform and uninterrupted hardening. For this purpose, a) an initial zone of the surface is surface layer hardened by it being brought to hardening temperature by means of an inductor and being quenched with a spray. b) The surface is then hardened by means of a stationarily arranged inductor arrangement and a movably arranged inductor arrangement, which each comprise a leading inductor for preheating the region of the surface covered by it, a trailing inductor offset in the direction of the initial zone for finish-heating the pre-heated region to the hardening temperature and a spray for quenching the finish-heated region, wherein the movable inductor arrangement is moved along the surface and at the same time the annular component rotates about an axis of rotation in order to move the surface to be hardened along the stationary inductor arrangement. The speed of the movable inductor arrangement along the surface is greater than its circumferential speed. c) An end zone of the surface is then hardened by the leading inductor of one of the inductor arrangements being moved temporarily in the direction of the end zone at an increased feed rate compared to its trailing inductor when the end zone is located at a certain distance from inductor arrangements such that an enlarged distance results between the leading inductor and the inductor trailing it and the leading inductor is located at the end zone by a time interval earlier, whose duration is equal to the duration required by the trailing inductor to cover the distance resulting between the trailing inductor and the leading inductor such that the at least one leading inductor arriving first at the end zone preheats the end zone until the trailing inductor is located at the end zone and finish-heats the end zone to hardening temperature. Finally, the finish-heated end zone is quenched by means of a spray.

The invention provides a method for the inductive surface layer hardening of a surface running around an annular component of a hardenable steel, which achieves uniform and uninterrupted hardening. For this purpose, a) an initial zone of the surface is surface layer hardened by it being brought to hardening temperature by means of an inductor and being quenched with a spray. b) The surface is then hardened by means of a stationarily arranged inductor arrangement and a movably arranged inductor arrangement, which each comprise a leading inductor for preheating the region of the surface covered by it, a trailing inductor offset in the direction of the initial zone for finish-heating the pre-heated region to the hardening temperature and a spray for quenching the finish-heated region, wherein the movable inductor arrangement is moved along the surface and at the same time the annular component rotates about an axis of rotation in order to move the surface to be hardened along the stationary inductor arrangement. The speed of the movable inductor arrangement along the surface is greater than its circumferential speed. c) An end zone of the surface is then hardened by the leading inductor of one of the inductor arrangements being moved temporarily in the direction of the end zone at an increased feed rate compared to its trailing inductor when the end zone is located at a certain distance from inductor arrangements such that an enlarged distance results between the leading inductor and the inductor trailing it and the leading inductor is located at the end zone by a time interval earlier, whose duration is equal to the duration required by the trailing inductor to cover the distance resulting between the trailing inductor and the leading inductor such that the at least one leading inductor arriving first at the end zone preheats the end zone until the trailing inductor is located at the end zone and finish-heats the end zone to hardening temperature. Finally, the finish-heated end zone is quenched by means of a spray.

A device for heating and quenching a tubular member has a central axis. The device includes a first quenching ring, a second quenching ring axially spaced from the first quenching ring, and a heating ring axially positioned between the first quenching ring and the second quenching ring. Each quenching ring and the heating ring is configured to receive the tubular member. The heating ring is fixably coupled to the first quenching ring and the second quenching ring. The heating ring includes an induction coil configured to heat an annular target zone along the tubular member. The first quenching ring is configured to deliver a first quenching fluid to the target zone and a first annular heat affected zone along the tubular member, and the second quenching ring is configured to deliver a second quenching fluid to the target zone and a second annular heat affected zone along the tubular member.

The production method of a seamless steel pipe includes a heating step of heating an Nb-containing steel material to 800 to 1030° C., a pipe-making step of producing a hollow shell by performing piercing-rolling or elongation-rolling on the Nb-containing steel material, by using a piercing mill including a plurality of skewed rolls, a plug disposed between the plurality of skewed rolls, and a mandrel bar, and a cooling step immediately after rolling, of carrying out cooling using a cooling liquid on a hollow shell portion that passes between rear ends of the plurality of skewed rolls, in the hollow shell, so as to reduce an outer surface temperature of the hollow shell portion to 700 to 1000° C. within 15.0 seconds after the hollow shell portion passes between the rear ends of the plurality of skewed rolls.

A cooling jacket includes a coolant supply member that circulates a coolant, and a coolant injection member to which the coolant is supplied from the coolant supply member, the coolant injection member provided with multiple injection holes through which the coolant is injected. The coolant injection surface of the coolant injection member opposing the workpiece has an upper region, a central region, and a lower region arranged along a vertical direction. An area of each injection hole provided in the central region is larger than an area of each injection hole provided in the upper region and an area of each injection hole provided in the lower region. The coolant injection member moves relative to a workpiece in a horizontal direction. A densest direction in which the multiple injection holes are arranged at the shortest intervals is inclined with respect to both the horizontal direction and the vertical direction.