Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
  • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
  • F27B9/04—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity adapted for treating the charge in vacuum or special atmosphere
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
  • C21D9/54—Furnaces for treating strips or wire
  • C21D9/56—Continuous furnaces for strip or wire
  • C21D9/562—Details
  • C21D9/563—Rolls; Drums; Roll arrangements
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/02—Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/34—Methods of heating
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
  • C21D1/76—Adjusting the composition of the atmosphere
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
  • C21D1/767—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material with forced gas circulation; Reheating thereof
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/0062—Heat-treating apparatus with a cooling or quenching zone
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
  • C21D9/54—Furnaces for treating strips or wire
  • C21D9/56—Continuous furnaces for strip or wire
  • C21D9/561—Continuous furnaces for strip or wire with a controlled atmosphere or vacuum
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
  • C21D9/54—Furnaces for treating strips or wire
  • C21D9/56—Continuous furnaces for strip or wire
  • C21D9/573—Continuous furnaces for strip or wire with cooling
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
  • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
  • F27B9/145—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving along a serpentine path
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
  • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
  • F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace
  • F27B9/24—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace being carried by a conveyor
  • F27B9/2407—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace being carried by a conveyor the conveyor being constituted by rollers (roller hearth furnace)
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D3/00—Charging; Discharging; Manipulation of charge
  • F27D3/12—Travelling or movable supports or containers for the charge

Definitions

• the subject of this invention is one
• Strip treatment plant for the continuous heat treatment of a metal strip with an annealing furnace and a subsequent heatable overaging chamber.
• the metal strip is guided in the aging chamber over a plurality of vertically spaced rollers, so that it meanders through the aging chamber.
• Conventional strip treatment plants consist of several chambers in which the metal strip is first heated to the annealing temperature and kept at this temperature for a certain period of time. It is also possible that a defined temperature curve is followed. Such annealing furnaces are well known. The metal strip is then cooled down according to a specified cooling rate, to a defined one
• overaging chambers are used to keep a metal strip at a specific temperature for a precisely defined period of time (overaging temperature). These chambers are often also referred to as “holding chambers” or “soaking chambers” or also as “partitioning chambers”.
• the temperature within the overaging chamber should be as constant as possible and is between 150°C and 500°C, depending on the metal strip alloy.
• a protective gas atmosphere or a reducing atmosphere for example a hydrogen-nitrogen mixture.
• the metal strip can then be cooled to room temperature or, for example, brought to the coating temperature in galvanizing plants, such as galvanizing plants.
• All of these heat treatment steps affect the mechanical properties of the metal strip. It is important that the metal strip is not only heated to a certain temperature, but also kept at a defined temperature for a precisely defined period of time in the overaging chamber. The heating rates and the cooling rates also influence the strip properties. Metal strips of different thicknesses or compositions also require different heat treatment parameters.
• the dwell time of the metal strip in the overaging chamber is determined by the strip speed and strip length in the overaging furnace.
• the length of the strip in conventional aging chambers is determined by the arrangement of the deflection rollers, so that the dwell time can only be regulated via the strip speed.
• the line speed can only be varied to a very limited extent, since every change in speed naturally also affects the production capacity, the heating rate and the cooling rate.
• the object of the present invention is to provide a strip processing line in which the dwell time of the metal strip in the overaging chamber can be adjusted within broader ranges, so that completely different metal strips can be treated with the same strip processing line, whereby always an optimal residence time in the overaging chamber can be set.
• a strip treatment system according to patent claim 1.
• at least one deflection roller can be moved in the vertical direction, so that the length of the metal strip in the aging chamber can be adjusted.
• the dwell time of the metal strip in the overaging chamber can also be adjusted.
• the dwell time can be adjusted independently of the line speed by changing the length of the line in the chamber.
• one and the same strip processing line can meet different production requirements and can also be flexibly adapted to new conditions.
• the strip speed is set with regard to maximum production capacity.
• the required strip length in the aging chamber is set on the basis of this strip speed, so that the optimal dwell time of the metal strip in the aging chamber, or that specified by the heat cycle, is achieved.
• Loopers also have movable rollers and can accommodate different tape lengths. However, they serve to compensate for different belt speeds in the system. For example, if a new to the plant strip that has been introduced has to be welded to the end of the previous strip and the strip has to be stopped for this purpose, the strip accumulator ensures by releasing stored strip that the strip speed in the subsequent treatment systems does not change.
• loopers are
• Ambient temperature operated in ambient air. They only serve to compensate for different belt speeds and do not carry out any heat treatment.
• one or more upper deflection rollers can be moved in the vertical direction.
• one or more movable deflection rollers are supported or fixed in a specific position, into which they were moved to achieve a predetermined belt length.
• the deflection rollers remain in this defined position anyway. By supporting or fixing the lifting mechanism for the deflection rollers can be relieved.
• the overaging chamber is preferably heated electrically, for example with radiant tubes. However, the gas in the aging chamber can also be sucked off, electrically heated and then injected again.
• the overaging chamber according to the invention is arranged, for example, in front of a coating system.
• the invention also relates to a method for the continuous heat treatment of a metal strip according to patent claim 9.
• a dwell time is set for the heat treatment of the metal strip in the overaging chamber and then the strip length and thus also the dwell time is set by moving at least one deflection roller.
• the metal strip is heat-treated in the overaging chamber in a hydrogen-nitrogen atmosphere.
• FIG. 1 is a schematic view of a prior art overaging chamber.
• FIG. 2 shows an exemplary embodiment of an overaging chamber according to the invention with a movable upper deflection roller
• FIG. 3 shows a further exemplary embodiment of an overaging chamber according to the invention with a movable lower deflection roller; 4 shows an exemplary embodiment of an overaging chamber according to the invention with a plurality of movable upper deflection rollers;
• Figure 6 shows three different roll positions in an overaging chamber 11
• Figures 7 and 8 show an embodiment of a roller motion system
• FIG. 1 shows an overaging chamber 1 according to the prior art.
• a metal strip 6 is introduced from the left into the aging chamber 1 and is deflected vertically upwards by a lower, fixed deflection roller 2 .
• the metal strip 6 is then deflected downwards by 180° by an upper, fixed deflection roller 3.
• the metal strip 6 is thus guided in a meandering manner through the aging chamber 1 until it is finally deflected in the horizontal direction by the last lower deflection roller 2 and leaves the aging chamber 1 .
• the interior of the overaging chamber 1 is tempered to a predetermined temperature, which is typically between 150°C to 500°C lies.
• the housing 4 of the aging chamber 1 is provided with insulation 5 to reduce heat losses.
• the aging chamber is heated by electrically heated radiant tubes 7.
• the metal strip 6 should spend a defined period of time (dwell time) in the overaging chamber 1 .
• FIG. 2 now shows an embodiment of the overaging chamber
• the housing 14 is also provided with an insulation 15 here and the metal strip 6 is also guided in a meandering manner through the aging chamber 11 via lower, fixed deflection rollers 12 and upper, fixed deflection rollers 13 .
• an upper deflection roller 13' can be moved (moved) in the vertical direction. In the present example, it was reduced to half the height.
• the aging chamber is heated by electrically heated radiant tubes 17. These radiant tubes 17 are not arranged here in the area of the movable deflection roller 13', since this would impede the freedom of movement of the deflection roller 13'.
• this overaging chamber 11 to be heated by the supply of hot gas, as will be described further below.
• the strip length of the metal strip 6 in the aging chamber 11 can be changed.
• the dwell time of the metal strip 6 in the overaging chamber 11 can thus be adjusted without the strip speed having to be changed for this purpose.
• the optimum dwell time for a specific metal strip 6 is determined in advance.
• the necessary strip length in the aging chamber 11 is then calculated by specifying a specific strip speed and is set by moving the upper deflection roller 13' or the upper deflection rollers 13'.
• the displaceable upper deflection rollers 13' are preferably no longer moved (moved) during the treatment of a specific metal strip 6, but fixed in their position.
• FIG. 3 shows an overaging chamber 11 in which a lower deflection roller 12' can be moved in the vertical direction.
• FIG. 4 shows an embodiment in which several upper deflection rollers 13' can be moved in the vertical direction.
• the upper deflection rollers 13' can be moved independently of one another.
• FIG. 5 shows a possible embodiment for a mechanism by which the deflection rollers 12' and 13' can be moved in the vertical direction.
• the two gear wheels 21 are coupled to one another via a shaft 22 and connected to a drive 18 . By rotating the shaft 22, the upper deflection roller 13' can be moved in the vertical direction. The arrangement would look similar if a lower deflection roller 12' is to be moved with it.
• Roller supports 19, 19' are provided at different heights on the side of the wall. To this
• the deflection roller 13' or 12' can be laid down or fixed in place on roller supports. Thus, during the heat treatment of a specific metal strip 6, the chains 25 and the drive 18 can be relieved.
• the stationary lower deflection roller 12 and the shaft 22 are mounted outside the aging chamber 11 here. Thus, these bearings 46 do not have to withstand high temperatures.
• the lower deflection roller 12 has a drive 45.
• FIG. 1 Three different strip lengths in an overaging chamber 11 are shown in FIG. 1
• both upper deflection rollers 13' are in their uppermost position, the strip length in the aging chamber 11 is thus at a maximum and the dwell time at a given strip speed is the longest.
• one of the two moveable upper deflection rollers 13' has been lowered somewhat, thus shortening the belt length and thus also the dwell time at a given belt speed.
• both upper deflection rollers 13' are in their lowest position.
• the tape length in the overaging chamber 11 is shortest and thus the dwell time at a given belt speed is also minimized.
• the adjustment mechanism for the movable deflection rollers 12' and 13' is shown in somewhat more detail in FIGS. Since the deflection rollers 12 ′ and 13 ′ are located inside the heated overaging chamber 11 , in which temperatures of up to 500° C. can certainly prevail, they are supported by high-temperature bearings 31 .
• An ordinary roller bearing 27 housed in a bearing housing 26 is sufficient for supporting the shaft 22 .
• the bearing housing 26 is connected to the support structure 30 via a bearing support 29 . On this
• Support structure 30 also rests the motor support 28 and the drive 18.
• An expansion bellows 24 is arranged between the housing 14 of the aging chamber 11 and the bearing housing 26 in order to be able to better compensate for any thermal expansions and to protect against dust.
• FIG. 8 shows the function of the roller support 19, 19'.
• the roller support 19, 19 ' is housed in a housing 32 and can
• Overaging chamber 11 are retracted.
• the housing 32 rests on a steel structure 44 via a substructure 33 .
• a plurality of roller supports 19, 19' are generally arranged at different heights over the height of the chamber, so that the deflection roller 12' or 13' can be supported at different heights.
• the Aging Chamber 11 should have a temperature that is as constant as possible inside for the treatment of a specific metal strip 6; this temperature is between 150° C. and 500° C., depending on the material and treatment. Since there is always heat loss, the chamber must be heated in order to be able to keep the temperature level as constant as possible. Of course, there can be smaller temperature differences within the overaging chamber 11, but these are usually only a few degrees Celsius.
• hot gas for example an inert gas or a reducing gas such as a nitrogen-hydrogen mixture, is blown into the overaging chamber 11 via a supply box 34 arranged on the side and sucked off again by a blower 36 via a suction box 35 on the opposite side.
• the gas is then fed either to an electric heater 40 or to a heat exchanger 39 and fed back into the overaging chamber 11 via a recirculation line 37 .
• the hot gas can be fed to either the heat exchanger 39 or the electric heater 40 via valves 38 and 41 .
• the gas temperature is increased again by the electric heater 40 . If the gas is passed over the heat exchanger 39, it can also be cooled. This is necessary, for example, when switching from one type of steel to another. If, for example, the following steel grade requires a lower overaging temperature, the gas is cooled so that the optimal temperature in the overaging chamber 11 is reached as quickly as possible.
• FIG. 10 shows the heating or cooling device from FIG. 9 again. It can be seen here that the heat exchanger 39 is supplied with cooling water 43 . The motor 42 for the blower 36 is also shown. In this illustration, a hydrogen-nitrogen mixture (HNX) is used as the heating medium.
• HNX hydrogen-nitrogen mixture

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Crystallography & Structural Chemistry (AREA)
• Thermal Sciences (AREA)
• Physics & Mathematics (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• General Engineering & Computer Science (AREA)
• Heat Treatment Of Strip Materials And Filament Materials (AREA)
• Heat Treatment Of Sheet Steel (AREA)
• Tunnel Furnaces (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=80219838

Family Applications (1)

Country Status (10)

Family Cites Families (10)

• 2021
  • 2021-05-27 AT ATA50422/2021A patent/AT524062B1/de active
• 2022
  • 2022-03-02 US US18/562,550 patent/US20240229185A1/en active Pending
  • 2022-03-02 KR KR1020237034147A patent/KR20240013719A/ko unknown
  • 2022-03-02 CA CA3217509A patent/CA3217509A1/en active Pending
  • 2022-03-02 WO PCT/EP2022/055269 patent/WO2022248089A1/de active Application Filing
  • 2022-03-02 BR BR112023020447A patent/BR112023020447A2/pt unknown
  • 2022-03-02 JP JP2023571185A patent/JP2024522254A/ja active Pending
  • 2022-03-02 EP EP22711203.4A patent/EP4348143A1/de active Pending
  • 2022-03-02 CN CN202280037599.9A patent/CN117396716A/zh active Pending
  • 2022-03-24 TW TW111111030A patent/TWI810861B/zh active

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