CN114729413A - Conditioned heat treatment of foil - Google Patents
Conditioned heat treatment of foil Download PDFInfo
- Publication number
- CN114729413A CN114729413A CN202080078797.0A CN202080078797A CN114729413A CN 114729413 A CN114729413 A CN 114729413A CN 202080078797 A CN202080078797 A CN 202080078797A CN 114729413 A CN114729413 A CN 114729413A
- Authority
- CN
- China
- Prior art keywords
- content
- heat treatment
- foil
- furnace
- furnace atmosphere
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000011888 foil Substances 0.000 title claims abstract description 105
- 238000010438 heat treatment Methods 0.000 title claims abstract description 97
- 230000001143 conditioned effect Effects 0.000 title description 2
- 238000000034 method Methods 0.000 claims abstract description 186
- 230000008569 process Effects 0.000 claims abstract description 128
- 229910052751 metal Inorganic materials 0.000 claims abstract description 81
- 239000002184 metal Substances 0.000 claims abstract description 81
- 230000003647 oxidation Effects 0.000 claims abstract description 71
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 71
- 239000007789 gas Substances 0.000 claims abstract description 70
- 238000001704 evaporation Methods 0.000 claims abstract description 68
- 230000008020 evaporation Effects 0.000 claims abstract description 67
- 238000005096 rolling process Methods 0.000 claims abstract description 47
- 230000001105 regulatory effect Effects 0.000 claims abstract description 32
- 230000033228 biological regulation Effects 0.000 claims abstract description 17
- 238000004886 process control Methods 0.000 claims abstract description 16
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 39
- 230000001276 controlling effect Effects 0.000 claims description 20
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 19
- 229910052782 aluminium Inorganic materials 0.000 claims description 13
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 13
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 12
- 229910052799 carbon Inorganic materials 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 10
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 7
- 239000001569 carbon dioxide Substances 0.000 claims description 7
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 7
- 150000002894 organic compounds Chemical class 0.000 claims description 7
- 239000004411 aluminium Substances 0.000 claims description 5
- 229910000838 Al alloy Inorganic materials 0.000 claims description 4
- 239000002912 waste gas Substances 0.000 claims description 3
- 238000007669 thermal treatment Methods 0.000 claims description 2
- 238000002360 preparation method Methods 0.000 claims 14
- 230000002829 reductive effect Effects 0.000 abstract description 10
- 239000000047 product Substances 0.000 description 109
- 238000000137 annealing Methods 0.000 description 77
- 239000010731 rolling oil Substances 0.000 description 32
- 239000000463 material Substances 0.000 description 11
- 238000004140 cleaning Methods 0.000 description 10
- 230000007547 defect Effects 0.000 description 9
- 238000012545 processing Methods 0.000 description 8
- 238000005238 degreasing Methods 0.000 description 7
- 238000001953 recrystallisation Methods 0.000 description 7
- 238000004804 winding Methods 0.000 description 7
- 230000003247 decreasing effect Effects 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 239000005068 cooling lubricant Substances 0.000 description 4
- 230000001419 dependent effect Effects 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 230000001590 oxidative effect Effects 0.000 description 4
- 238000004806 packaging method and process Methods 0.000 description 4
- 239000007858 starting material Substances 0.000 description 4
- 235000013305 food Nutrition 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000012369 In process control Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000011049 filling Methods 0.000 description 2
- 238000000265 homogenisation Methods 0.000 description 2
- 238000010965 in-process control Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000314 lubricant Substances 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 230000036961 partial effect Effects 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 230000002441 reversible effect Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000011282 treatment Methods 0.000 description 2
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000005030 aluminium foil Substances 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000002199 base oil Substances 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 235000011389 fruit/vegetable juice Nutrition 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000012625 in-situ measurement Methods 0.000 description 1
- 238000007373 indentation Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 235000013336 milk Nutrition 0.000 description 1
- 239000008267 milk Substances 0.000 description 1
- 210000004080 milk Anatomy 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
- 239000001993 wax Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 230000037373 wrinkle formation Effects 0.000 description 1
Images
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
- 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
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/02—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working in inert or controlled atmosphere or vacuum
-
- 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
- F27B17/00—Furnaces of a kind not covered by any preceding group
- F27B17/0016—Chamber type furnaces
-
- 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
- F27D19/00—Arrangements of controlling devices
-
- 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
- F27D19/00—Arrangements of controlling devices
- F27D2019/0006—Monitoring the characteristics (composition, quantities, temperature, pressure) of at least one of the gases of the kiln atmosphere and using it as a controlling value
- F27D2019/0012—Monitoring the composition of the atmosphere or of one of their components
-
- 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
- F27D19/00—Arrangements of controlling devices
- F27D2019/0006—Monitoring the characteristics (composition, quantities, temperature, pressure) of at least one of the gases of the kiln atmosphere and using it as a controlling value
- F27D2019/0012—Monitoring the composition of the atmosphere or of one of their components
- F27D2019/0015—Monitoring the composition of the exhaust gases or of one of its components
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention relates to a method for heat treating a metal strip or foil in the form of a coil or foil in a heat treatment furnace to remove rolling residues. The object of the invention is to provide a method for removing rolling residues by heat treatment of metal strips or foils in the form of coils or foil coils in a heat treatment furnace, by means of which high-quality metal products can be provided in a process-reliable and economical manner and the reject rate of the metal strips and foils can be reduced, by determining the content of at least one evaporation and/or oxidation product in the furnace atmosphere and/or in the process exhaust gases during the heat treatment and for process control or process regulation of the heat treatment, wherein the dynamics of the removal of rolling residues on the metal strips or foils is controlled or regulated during the heat treatment. The invention also relates to a device for heat treating a metal strip or foil in order to carry out the method according to the invention.
Description
Technical Field
The invention relates to a method for heat treating a metal strip or foil in a heat treatment furnace, in particular for removing rolling residues. The invention also relates to a device for heat treating a metal strip or foil for carrying out the method according to the invention.
Background
Heat treatment plays a particular role in the manufacture of metal strip or foil. The metal product is therefore usually subjected to hot and cold rolling processes and, if appropriate, intermediate annealing in the production process, as a result of which the properties of the metal product can be influenced in a targeted manner by temperature-dependent processes in the material structure.
The different method steps are usually followed by a final anneal, which is one of the most critical processes, especially in the manufacture of foils. The final annealing is used on the one hand for recrystallization or partial recrystallization, i.e. so-called condition annealing (Zustandsglu hen) or recovery annealing (Luckglu hen) of metal strips and foils, in which recrystallization takes place by exceeding the recrystallization temperature of the material. On the other hand, the final annealing serves for the thermal cleaning of the strip surface, in particular the degreasing of so-called rolling residues, such as lubricants used on rolling mills, for example greases, waxes and rolling oils. In order to ensure a lubricant-free surface in the further processing of the metal product, for example to prevent adhesion problems during subsequent forming, the surface of the strip must be thoroughly cleaned. This is done by temporally staggered annealing stages of evaporating the lubricant and the oily residue on the surface of the strip or foil.
The annealing program used, in which the temperature-time curve, the amount of process air exchange between the environment and the furnace chamber, and the amount of air circulating in the furnace chamber, etc., are taken into account, is therefore always a compromise between the recrystallization and degreasing requirements of the annealing process. During the conditional annealing, the process becomes more complex, as the partial recrystallization is more sensitive to the annealing parameter control. However, since, within the scope of the present annealing process, an overall annealing program is generally used and no differentiation criterion is used, it is in particular not possible to individually respond to the parameters of the starting materials. Furthermore, the instrumentation of process technology is often poor, and the actual effective parameters on the metal strip or foil, such as the metal temperature or the air quantity, are unknown and can only be estimated from auxiliary variables, such as the fan speed or the damper position (blennstellung).
Over the years, the industry has established two annealing concepts. One is mass-driven low-temperature long-time annealing, and the other is resource-driven high-temperature short-time annealing. The low-temperature long-time annealing is characterized by its tolerance to deviations of initial and environmental parameters, such as surface roughness, quality and quantity of oil coating, density and humidity of process air, or winding density in the case of metal strip or foil being wound into coils, and therefore represents an idea of quality optimization, improvement. However, one problem with low temperature long term annealing is rolling oil contamination caused by miscellaneous oils that do not burn off at the lower annealing temperatures. Furthermore, the relatively long annealing time temporarily results in insufficient free annealing capacity and is also a not negligible cost factor. Although the demands on product quality are increasing and tight tolerance limits on surface quality have to be observed, a more efficient use of energy is becoming more and more important in the context of cost-and resource-saving manufacturing processes.
Although high temperature short time annealing represents an efficient, yield-optimized concept, there is a high risk of annealing error frequency because it is not very tolerant to the above-mentioned initial and environmental conditions. The combination of the furnace technology of high-temperature short-time annealing, natural process fluctuation in the pretreatment process and poor instrumentation, which cannot be fault-tolerant, inevitably leads to frequent occurrence of non-uniformity in the degreasing process, thereby leading to annealing defects, which lead to poor unwinding quality, particularly to the adhesion problem near the winding core, and the adhesion problem of the product in the subsequent further processing process. Thin metal strips or foils are particularly sensitive to annealing processes and form stress, flow lines and even annealing bubbles. Uncontrolled wrinkle formation and uneven strength properties negatively affect subsequent processing to the final product. In the worst case, the stresses, flow lines and annealing bubbles can lead to cracks, thereby rendering the metal product completely unusable.
From german patent application DE 197466733 a 1a method for determining the gas atmosphere in a heat treatment furnace is known, by means of which the supply of inert gas during the heat treatment can be optimized. A precise method for controlling the atmosphere in the furnace is also known from european patent application EP 2871248 a 1. However, neither of these documents is concerned with avoiding annealing defects when the coil or foil is annealed.
Disclosure of Invention
It is therefore an object of the present invention to provide a method for the heat treatment of metal strips or metal foils in a heat treatment furnace, in particular for removing rolling residues, by means of which a high-quality metal product can be provided in a process-reliable and economical manner and the reject rate of the metal strips and foils can be reduced. Furthermore, the object of the invention is to propose an advantageous device for the heat treatment of metal strips or foils, in particular for carrying out the method according to the invention.
According to a first teaching of the invention, the above object is achieved by a method for heat treating a metal strip or foil in the form of a coil or foil in a heat treatment furnace for removing rolling residues, wherein, during the heat treatment, the content of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or in the process exhaust gases is determined and used for process control or process regulation of the heat treatment, wherein the dynamics of the removal of rolling residues on the metal strip or foil are controlled or regulated during the heat treatment.
The heat treatment is for example a final annealing of the metal strip or the metal foil. A corresponding annealing may simplify further processing, such as subsequent forming steps, which improve the mechanical properties of the metal product and promote dimensional stability. The final anneal is particularly useful for sub-anneal and cleaning purposes. By cleaning, in particular degreasing, the surface of the rolled metal product can be freed from residues of cooling lubricant and be ready for strip coating, for example. By cleaning the surface of the product, problems during further processing, such as poor unwinding quality or adhesion problems during subsequent forming, can be prevented. For this purpose, the metal strip or foil is annealed in the form of a strip coil or foil coil in a heat treatment furnace.
In principle, the heat treatment may also be an intermediate annealing, for example with the aim of simplifying the subsequent rolling step. Even intermediate annealing leads to annealing defects, especially if the metal strip or foil is in the form of a coil and its thickness is very small.
The removal of the rolling residues depends on the evaporation and oxidation of the cooling lubricant remaining as a residue on the surface of the metal product after rolling, wherein the metal temperature, the type and amount of the rolling oil coating and the atmosphere in the furnace chamber, the so-called furnace atmosphere or process air, are decisive for the steam pressure of the rolling oil to be evaporated and its oxidation. The temperature of the metal product depends among others on the predefined temperature-time curve of the annealing program, the weight and size of the product, the material thickness, the furnace filling level, the furnace construction type and the efficiency. The type and amount of the rolling oil blanket depends on the selection and (variable) composition of the rolling oils used for pre-rolling, double rolling (Doppeln) and final rolling, which in turn consist of base oil and additives. In particular the composition of the furnace atmosphere has a significant influence on the cleaning result. The composition of the furnace atmosphere and of the process exhaust gases discharged from the furnace chamber in turn depend on a number of factors. These factors are in particular the products of the annealing phase, the process steps to be carried out, the charge filling level and the starting materials to be treated, etc.
It has been shown that with the method according to the invention, the conditions of the starting materials, such as the distillation properties and the amount of oil coating, and the state of the annealing process, such as the evaporation and oxidation stages, are implicitly determined by measuring the content of at least one evaporation and/or oxidation product in the furnace atmosphere and/or process off-gas. Content information typically quantifies the proportion of individual substances in a mixture. In the present case, this is also understood to mean, for example, the concentration which represents the amount of product relative to a given air volume. Pure measurements without volume knowledge are also conceivable.
By determining the content of at least one evaporation product and/or oxidation product, information about the evaporation and oxidation dynamics of the cooling lubricant can thus be derived. The method according to the invention can thus be used to influence the control or regulation of the heat treatment, in particular the removal of rolling residues. The evaporation and oxidation kinetics of the rolling residues in, for example, a strip coil or a foil coil can thereby be advantageously controlled. Direct measurement in the furnace atmosphere may preferably provide real-time results, thus highly indicating the content of evaporation and/or oxidation products currently present in the atmosphere. Although the measurement of process exhaust gases is particularly easy, the inertia of the process can lead to time delays.
According to the invention, it has been recognized that the heat treatment, in particular the removal of rolling residues, can in turn be advantageously controlled or regulated by determining the content of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or process off-gases. Process control here means that, in the event of a deviation from a desired target value, the actual value of the manipulated variable is influenced by a suitable process in such a way that it approaches the target value and ideally reaches the target value. The feedback is negative feedback because the deviation from the target value is cancelled. For example, process adjustments may be performed by a PID regulator. In contrast, in process control, there is no feedback and therefore no closed process flow. Control is understood as the influence on the behavior of the system, wherein the system is brought into another state by the control. Here, the control or regulation can be carried out by influencing a selected parameter, for example by decreasing or increasing a certain value.
The control or regulation of the method according to the invention is characterized in that it takes place as a function of the content of at least one evaporation and/or oxidation product present in the furnace atmosphere and/or process off-gases, and thus depends on the conditions of the starting materials and the state of the annealing process. This has the advantage that the cooling lubricant residues can be removed from the surface of the rolled metal product accordingly and reliably in response to the dispersion in the process parameters described above. The method according to the invention can thus use a high temperature short time anneal while avoiding typical anneal defects. It therefore represents a practical, cost-effective solution for removing rolling residues and increases the defect tolerance of high-temperature short-time anneals, which, as far as their properties are concerned, depend to a large extent on the starting conditions and process parameters.
The metal strip or foil is preferably annealed in the form of a coil of strip or foil in a batch furnace. Batch furnaces are generally not as expensive to operate and purchase as continuous furnaces. However, one difficulty with batch furnaces is generally ensuring a uniform temperature distribution, for example when charging a metal coil into the furnace. The inhomogeneities in the cleaning process usually occur mainly on the strip or foil web, since the oxidation of the rolling oil and the discharge of waste gases take place via the end faces of the winding roller. During the heat treatment, heating is initially applied from the outside, relatively slowly heating the metal inside the foil coil. This leads to a delayed, but eventually sudden increase in evaporation products and/or oxidation products in the case of additional heating of the metal inside the foil coil. Non-uniformity can lead to annealing defects and poor unwinding quality and adhesion problems during further processing. Thin metal strips and foils are particularly sensitive to annealing processes and form stress and even annealing bubbles, especially inside the foil coil, which in the worst case can lead to cracks in the product.
The method according to the invention can be used to illustrate the speed and uniformity of the evaporation process of the strip web and the foil web. Furthermore, it is advantageously possible to respond to the initial parameters of the cleaning process and to the dispersion of the process parameters, thus influencing in particular the gas pressure in the strip web or foil web, which is coordinated, for example controlled or regulated, by the method. For example, the regulation of the gas pressure can be understood as the homogenization of the gas pressure increase, i.e. the reduction of the vaporization kinetics during the heat treatment. The method according to the invention thus advantageously makes it possible to control or regulate the dynamics of evaporation and oxidation of rolling residues in strip coils and foil coils. The precisely determined furnace atmosphere by means of the method according to the invention thus also ensures the desired result of the heat treatment of the counterband coil or foil coil and enables an increase in the defect tolerance of high-temperature short-time annealing. The strip and foil webs produced with the method according to the invention can be unwound in particular at increased speeds without blocking.
The metal foils having a thickness of from 1 μm to 250 μm, preferably from 1 μm to 60 μm, particularly preferably from 4 μm to 20 μm, are preferably treated using the process according to the invention. The manufacture of metal foils usually starts from so-called foil pre-rolled strips, the process steps of which include pre-rolling, double rolling, final rolling, separating, winding and final annealing. In this case, pre-rolling and finish rolling are used for height reduction, double rolling is used for combining two strip layers together for double finish rolling, separation is used for separation of the finish rolled foil web, winding is used to provide the foil web, and final annealing is used for degreasing of the foil surface and recrystallization of the material.
The method according to the invention is preferably used for controlling or regulating the gas pressure of the evaporation products and/or oxidation products in the strip or foil web during the heat treatment, so that damage in the metal strip or foil due to too rapid evaporation or too rapid generation of oxidation products can be significantly reduced in a targeted manner.
According to a first embodiment of the method according to the invention, in the process control or regulation, the furnace temperature gradient, the process air exchange volume, the circulation volume of the process air and/or the composition of the furnace atmosphere are controlled or regulated as a function of the content of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or process off-gas. It has been recognized that, among other parameters: the temperature, the temperature gradient, the exchange volume and the circulation volume as well as the composition of the furnace atmosphere have an influence on a particularly efficient and uniform heat treatment of the strip coil or foil coil. To ensure uniform removal of the rolling residues on the surface of the product, uniform evaporation of the residues is required, for which a uniform temperature distribution is particularly important. In order to avoid sudden increases in the furnace atmosphere and/or in the process exhaust gases of evaporation products and oxidation products, the temperature gradient can be adjusted accordingly by the method according to the invention. The uniformity of the temperature distribution in the heat treatment furnace can also be influenced indirectly by means of the circulating volume of the process air. Furthermore, a constant distribution of the individual gas components in the furnace chamber can be achieved by controlling or regulating the circulation volume. The furnace atmosphere can also be influenced by controlling or regulating the process air exchange volume, for example in the framework of convection ventilation.
Thus, according to the invention, the dynamics of the evaporation and oxidation of the rolling residues, in particular of the rolling oil, are controlled, for example, by the setting of the suppression or increase of the furnace temperature, the setting of the furnace temperature gradient and the setting of the furnace atmosphere.
The steam pressure of the rolling oil to be evaporated and the speed of the evaporation process are influenced by the measurement and setting of the furnace chamber temperature and the furnace chamber temperature gradient. For example, a target value may be assigned to the parameter to be measured. In the furnace atmosphere, in case the concentration of rolling oil and partially oxidized rolling oil or the concentration of oxidation products of rolling oil exceeds or falls below a predetermined threshold value, the furnace temperature is changed, e.g. maintained or decreased, or the gradient of temperature increase is changed, e.g. decreased.
The vapor pressure of the rolling oil to be evaporated and the speed of the evaporation process are also influenced by the measurement and setting of the evaporated and/or oxidized rolling oil content in the furnace atmosphere. In the furnace atmosphere, the process air exchange is changed, for example increased or decreased, if the contents of rolling oil and partially oxidized rolling oil, or the content of rolling oil oxidation products, for example, is below a predetermined threshold.
The oxidation behavior and the rate of the oxidation process of the rolling oil to be evaporated and/or evaporated is also influenced by measuring the evaporated and/or oxidized rolling oil content in the furnace atmosphere and by setting the oxidation capacity of the furnace atmosphere.
For example, in case the content of rolling oil and partially oxidized rolling oil or the content of rolling oil oxidation products in the furnace atmosphere exceeds a predetermined threshold value, the oxidizing capacity of the furnace atmosphere may be influenced, preferably reduced, by adding a process gas, such as nitrogen or hydrogen, which impairs or reduces the oxidation. In the case of a content of rolling oil and partially oxidized rolling oil or of rolling oil oxidation products in the furnace atmosphere below a predetermined threshold value, the oxidizing power of the furnace atmosphere is influenced, preferably increased, by the addition of an oxidation-increasing process gas, for example oxygen or ozone.
The advantageous embodiment of the method according to the invention thus makes it possible in particular to influence the gas pressure in the metal strip coil or metal foil coil in many ways, so that it is coordinated over time and thus improves the defect tolerance of high-temperature short-time annealing. By continuously controlling and adjusting the influence of the temperature level and the temperature gradient and/or the composition of the furnace atmosphere, the cleaning process of the surface of the metal strip or metal foil in the form of a coil can be optimized.
According to a further advantageous embodiment of the method according to the invention, in the process control or regulation, the furnace temperature gradient is controlled or regulated as a function of the content gradient of the at least one evaporation product and/or oxidation product in the furnace atmosphere and/or the process offgases. Depending on the increase or decrease in the content of evaporation products and/or oxidation products, the steam pressure of the rolling oil to be evaporated and the speed of the evaporation process can also be influenced in a targeted manner. If the gradient of the content of rolling oil and partially oxidized rolling oil and/or the gradient of the content of oxidation products of rolling oil in the furnace atmosphere exceeds, for example, a predetermined threshold value, the gradient of the temperature increase is adjusted, for example, the gradient of the temperature increase is reduced.
In order to control or regulate the heat treatment, according to a further advantageous embodiment of the method according to the invention, the carbon content (C) in the furnace atmosphere and/or process exhaust gas is determinedgesContent), organic compound content (V)orgContent), carbon monoxide content (CO content) and/or carbon dioxide Content (CO)2Content) and for process control or regulation of the heat treatment. The carbon content of the furnace atmosphere and of the process exhaust gases can be reliably determined in a particularly simple manner andand is characteristic for evaporation products and oxidation products. For example, CO content and/or CO2The content represents the content of oxidation products of rolling oil, and VorgThe content reflects the content of the rolling oil and the partially oxidized rolling oil. The sum of all carbonaceous materials, i.e. including VorgCO and CO2By CgesAnd (4) showing.
C in furnace atmosphere or process exhaust gasesgesContent, VorgContent, CO content and CO2The content is a particularly critical parameter. It was thus possible to ascertain that during the conventional annealing step of a metal strip coil or metal foil coil in the furnace atmosphere or in the process exhaust gas, C occurredgesContent, VorgContent, CO content and/or CO2A sudden increase in the content, resulting in a marked CgesPeak, VorgPeak, CO Peak or CO2Peak(s). However, such conventional methods lead to the above-mentioned problems in the manufacture of the strip or foil and thus produce inadequate product results. In contrast, the method according to the invention can advantageously influence the heat treatment in a targeted manner and such carbon peaks can be reduced or avoided, for example, by controlling or regulating the temperature, the circulation volume or the process air exchange, which leads to good annealing results.
Preferably, the maximum carbon content C in the furnace atmosphere and/or process off-gas, for example at a defined furnace atmosphere exchange volume or process off-gas volumeges maxMaximum content of organic compounds Vorg maxMaximum carbon monoxide content COmaxAnd/or maximum carbon dioxide content CO2 maxIs subject to limitations. By limiting the maximum carbon content C at a defined furnace atmosphere exchange volume or process gas volumeges maxMaximum content of organic compounds Vorg maxMaximum carbon monoxide content COmaxAnd/or maximum carbon dioxide content CO2 maxFor example, the method according to the invention allows to control the maximum evaporation rate, whereby good annealing results can advantageously be achieved, in particular annealing bubbles can be reduced or completely avoided.
According to a further embodiment, the carbon gradient C is present in the furnace atmosphere and/or process exhaust gasges GradGradient V of organic compound contentorg GradCarbon monoxide gradient COGradAnd/or carbon dioxide gradient CO2GradAre subject to limitations. It has been shown that too large of C in the furnace atmosphere or process off-gasgesContent gradient, VorgThe content gradient, CO or CO2 content gradient, represents a sudden and strong increase of evaporation products and/or oxidation products, which in turn can lead to adhesion and the formation of annealing bubbles in the metal article. Thus, the control of the gradient achieves a control of the evaporation rate and, therefore, of the C in the furnace atmosphere and/or the process off-gasges、VorgCO and/or CO2Regardless of the total content, annealing defects, such as annealing bubbles, are avoided.
Preferably, VorgThe content is determined by an FID analyzer, preferably an on-line FID analyzer, and the CO content is determined by a CO analyzer, preferably an on-line CO analyzer2In an amount of passing CO2Analyzer, preferably on-line CO2Analyzer determination, and/or CgesContent passing FID analyzer, CO analyzer and selective CO2And (4) determining by an analyzer. FID (flame ionization detector) analyzers are particularly useful for monitoring volatile carbonaceous materials. Since the detector signal of the FID analyzer is linearly proportional to the carbon content over a wide concentration range, the carbon content can be estimated without calibration, and thus the FID analyzer is particularly suitable for quantitative analysis. In addition, the FID analyzer is not only fast and reliable, but also high in sensitivity. The determination of the carbon content can thus be carried out in a reliable and process-safe manner.
For example, CO or CO2The sensor or infrared analyzer can be used for measuring CO or CO2Its advantages are high content and high precision. Especially CO2Infrared analysis is a particularly accurate in situ measurement method. At the same time, however, infrared analysis is relatively expensive and complex because the analyzer requires periodic calibration.
CgesThe content can be measured using a FID analyzer, preferably an on-line FID analyzer; a CO analyzer, preferably an on-line CO analyzer; and CO2Analyzer, preferably on-line CO2An analyzer. However, it is already possible to use FID analyzers and CO analyzersTo a sufficient degree of accuracy to determine CgesAnd (4) content.
According to a further advantageous embodiment of the process according to the invention, the heat treatment is carried out at a temperature of from 80 to 120 ℃ or above 200 ℃, preferably above 220 ℃, particularly preferably above 300 ℃. When the annealing temperature is higher than 200 ℃, rolling residues on the surface of the product can be substantially completely removed. The duration of the heat treatment depends inter alia on the temperature and the quality of the material to be treated. In the case of low-temperature annealing at 80 to 120 ℃, the method according to the invention can be used to remove rolling residues, for example in the case of cooling the foil after rolling, without significant softening.
The metal strip or foil is preferably processed in the form of a coil. Depending on the coil width, the annealing time may be about 20 to 180 hours to achieve substantially complete removal of rolling residues. The coil width is mainly dependent on the application of the metal strip and the metal foil. For example, the narrow web may have a width of 250mm to 1000 mm. To substantially completely clean the product surface, the annealing time of the narrow coil at an annealing temperature of about 220 ℃ is about 80 hours, the annealing time at a temperature of about 350 ℃ is about 35 hours, and the annealing time at a temperature of about 400 ℃ is only about 20 hours. In contrast, a wide web may have a width of 1000mm to 2500mm, preferably 1300mm to 2100 mm. For example, the annealing time at a temperature of about 220 ℃ is about 180 hours, the annealing time at a temperature of about 350 ℃ is about 80 hours, and the annealing time at a temperature of about 400 ℃ is about 60 hours.
Preferably, aluminum or aluminum alloy strips or foils are treated. Aluminum materials are distinguished by their broad technical application possibilities. Aluminum strips and aluminum foils with different properties can be manufactured by adding alloy elements. In combination with different heat treatments, the mechanical properties of the aluminium can be optimally adapted to the respective processing conditions and use conditions.
Aluminum is considered one of the key materials in the packaging industry. Particularly in the food and pharmaceutical industries, aluminum is ubiquitous in many packaged product forms, such as liquid packaging, e.g., milk or juice cartons. The use of aluminum strip and foil is particularly advantageous for weight sensitive applications due to their low density. Without any competing materials the respective combination of formability, printability and excellent barrier properties, such as low permeability to light, oxygen and taste, can be achieved, whereby the aluminium foil is unparalleled in protecting and preserving the complex food supply chain. It is therefore particularly advantageous to use suitably treated aluminium strips and foils for food packaging, especially for liquid packaging.
According to a second teaching of the invention, the above object is achieved by a device for heat-treating a metal strip or foil in the form of a coil or foil to remove rolling residues by a method according to the invention, having at least one means for determining the content of at least one evaporation and/or oxidation product in the furnace atmosphere and/or process off-gas during the heat treatment, and at least one means for controlling or regulating the heat treatment as a function of the content of at least one evaporation and/or oxidation product in the furnace atmosphere and/or process off-gas, which means are designed in such a way that the dynamics of the removal of rolling residues on the metal strip or foil can be controlled or regulated during the heat treatment. The at least one device for controlling or regulating the heat treatment is designed in particular to control or regulate the heat treatment as a function of the content of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or in the process off-gas. The apparatus according to the invention is therefore suitable for carrying out the method according to the invention.
The apparatus for heat treatment is preferably a batch furnace. Batch furnaces are generally less expensive to operate and purchase than continuous furnaces and are capable of heat treating metal strip or foil wound into coils. For this purpose, the batch furnace has a furnace body and a furnace chamber, wherein the furnace chamber is arranged inside the furnace body and is designed to accommodate at least one strip coil or foil coil.
The device according to the invention also has at least one device for determining the content of at least one evaporation product and/or oxidation product, for example V, in the furnace atmosphere and/or process exhaust gasorgCO and/or CO2An analyzer, preferably a FID or infrared analyzer. The furnace atmosphere is the process air inside the furnace chamber. The process air is exchanged between the furnace chamber and the environment, and the invention also provides a method for determining process wasteA device for evaporation products and/or oxidation products in gas. For example, a PID controller can be provided as a device for controlling or regulating the thermal treatment.
With the aid of the device for heat treatment according to the invention, it is possible, for example, to carry out a final annealing of the metal strip or foil for cleaning purposes. In this case, the device according to the invention is able to monitor the content of evaporation products and/or oxidation products in the furnace atmosphere and/or process off-gases and process parameters which influence the heat treatment in a targeted manner, for example to control or regulate the dynamics of the removal of rolling residues on the metal strip or foil in the coil during the heat treatment. In this way, for example, the gas pressure of the evaporation products and/or oxidation products in the strip coil or foil coil can also be controlled or regulated during the heat treatment, thereby ensuring a controlled, effective and reliable cleaning of the surface of the metal strip or foil with rolling residues. Annealing bubbles, problems in subsequent further processing steps or adhesion problems when unwinding the strip or foil web, which may lead to product damage or even to cracks on the product surface, can thus be avoided.
According to a first advantageous embodiment of the device according to the invention, the device has at least one means for controlling or regulating the furnace temperature, the furnace temperature gradient, the process air exchange volume and/or the process air circulation volume as a function of the content of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or the process offgases.
The device preferably has at least one means for controlling or regulating the furnace temperature gradient as a function of the content gradient of the at least one evaporation product and/or oxidation product in the furnace atmosphere and/or the process exhaust gas. For example, a dynamic adjustment, i.e., for example, homogenization, in particular reduction, of the evaporation of the rolling residues in the strip coil or foil coil can thereby be achieved directly.
In order to be able to influence the heat treatment as a function of the content of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or process off-gas, the device preferably has at least one controllable device for influencing the heat treatment. For example, the temperature or the temperature gradient in the oven chamber can be influenced by means of a heater or a flap. The fan is advantageous for air circulation in the furnace chamber, while process gases, such as protective gases or reaction gases, can be supplied via a metering valve to regulate the furnace atmosphere, in particular the oxidizing power of the furnace atmosphere.
There are now a number of possibilities to design and expand the method according to the invention and the device according to the invention. For this purpose reference is made, on the one hand, to the dependent claims dependent on claims 1 and 11 and, on the other hand, to the description of the embodiments in conjunction with the drawings.
Drawings
In the figure
Figures 1a and b show schematic diagrams of a top view and a side view of an annealing bubble formed in a foil coil,
figure 2 shows a schematic view of an embodiment of the device according to the invention,
FIGS. 3a, b show schematic representations of advantageous embodiments of the method according to the invention, an
Fig. 4a, b show in the form of a graph the test results of the furnace parameter measurements in the case of a degreasing anneal carried out conventionally and in the case of a degreasing anneal according to an advantageous embodiment of the method according to the invention.
Detailed Description
A metal foil 1, preferably an aluminium or aluminium alloy foil, has been wound in a double layer form into a coil 2 as shown in fig. 1a and has been subjected to a conventional incomplete annealing in a heat treatment furnace at 220 to 250 ℃. The web 2 has a width of 250mm to 2500mm, in particular about 1000mm or about 1700 mm. The winding height h is for example 18mm, whereby the foil layer is shown very close to the core 3 of the web 2.
Critical annealing bubbles 4 are formed on the foil surface by a conventionally performed final annealing. Scratches can be seen on the inner surface of the annealing bulb 4 transversely to the running direction, wherein the material is pushed up at these locations. The cross section of the annealing bubble 4 in section a-B is shown in detail in fig. 1B. A compression of the material is formed in the region X on the edge of the annealing bubble 4. The compression may be located inside or outside the annealing bubble 4. In the region Y of the annealing bubble 4, the metal foil 1 has flow lines, which indicate shrinkage of the material and may lead to cracking or fracture of the metal foil 1.
The object of the method according to the invention is to avoid the formation of such annealing bubbles and welds of the metal strip or foil, to provide a high-quality metal product in a process-reliable and cost-effective manner, and thus to reduce the rejection rate of the metal strip or foil. Damage to metal surfaces in the form of indentations and scratches also leads to quality damage and rejection. In contrast, foil webs which are good in terms of process flow and have no or a significantly reduced tendency to local adhesion are evaluated as good. Annealing bubbles with acceptable properties do not stick and can be eliminated with increased strip tension without problems. This also applies in particular to foil layers located in the vicinity of the web core 3, for example at winding heights of up to 12mm or up to 18 mm. The problems known from the prior art can be solved by the method according to the invention for the heat treatment of metal strips or foils, in particular for the treatment of aluminium or aluminium alloy strips or foils in the form of strip or foil coils 2 in a heat treatment furnace for the removal of rolling residues, wherein, when the heat treatment is carried out, the content of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or process off-gas is determined and used for process control or regulation of the heat treatment, wherein the dynamics of the removal of rolling residues on the metal strip or foil are controlled or regulated during the heat treatment. The method according to the invention comprises, for example, atmosphere monitoring and control or regulation taking into account the kinetics of the evaporation and oxidation products, so that by means of the method it is possible in particular to ensure the homogeneity of the metal product and accordingly to improve its quality.
Fig. 2 shows an advantageous embodiment of the device according to the invention for the heat treatment of metal strips or foils, in particular for removing rolling residues, with at least one device 8 for determining the content of at least one evaporation and/or oxidation product in the furnace atmosphere 11 and/or process exhaust gases 12 during the heat treatment and at least one device 9 for controlling or regulating the heat treatment, which is designed such that the dynamics of the removal of rolling residues on the metal strip or foil can be controlled or regulated during the heat treatment.
The device is in the present case a heat treatment furnace 5, in particular a batch furnace, which has, in addition to a furnace chamber 6, a furnace body 10, wherein the furnace chamber 6 is arranged inside the furnace body 10 and is designed to accommodate a metal strip or foil wound into a coil 2 on an annealing stand (not shown here). The process air inside the furnace chamber 6 is referred to as the furnace atmosphere 11. Process air is exchanged between the oven chamber 6 and the environment, whereby process exhaust gases 12 are discharged from the oven chamber 6. The heat treatment furnace 5 also has a fan 7 for air circulation in the furnace chamber 6.
The heat treatment furnace 5 has at least one device 8 for determining the content of at least one evaporation product and/or oxidation product in the furnace atmosphere 11 and/or in the process exhaust gas 12 during the heat treatment. The heat treatment furnace 5 has, in particular, a device for determining VorgA content FID analyzer, preferably an online FID analyzer; a CO analyzer, preferably an on-line CO analyzer, for determining the CO content; and/or for determining CO in the furnace atmosphere 112Content of CO2Analyzer, preferably on-line CO2An analyzer. CO or CO2The analyzer may in particular be an infrared analyzer. Alternatively, the heat treatment furnace 5 can have at least one device 8 for determining the content (here indicated by a dashed line) of at least one evaporation product and/or oxidation product in the process exhaust gas 12.
The heat treatment furnace 5 also has at least one device 9 for controlling or regulating the heat treatment. The at least one device 9 for controlling or regulating the heat treatment is designed in particular to control or regulate the heat treatment as a function of the content of at least one evaporation product and/or oxidation product in the furnace atmosphere 11 and/or the process exhaust gas 12. For example, at least one device 9 may be provided for controlling or adjusting the furnace temperature, the furnace temperature gradient, the process air exchange quantity and/or the process air circulation quantity depending on the content of the at least one evaporation product and/or oxidation product in the furnace atmosphere 11 and/or the process offgases 12, and/or at least one device 9 may be provided for controlling or adjusting the furnace temperature gradient depending on the content of the at least one evaporation product and/or oxidation product in the furnace atmosphere 11 and/or the process offgases 12. In particular, a PID controller can be provided as the means 9 for controlling or regulating the heat treatment.
In order to be able to influence the heat treatment as a function of the content of at least one evaporation and/or oxidation product in the furnace atmosphere and/or the process exhaust gas, at least one controllable device 13 is also provided for influencing the heat treatment, in particular a heater, flap, fan and/or metering valve. For example, the temperature or the temperature gradient in the oven chamber can be influenced by means of a heater or a flap. The fan is advantageous for air circulation in the furnace chamber, while process gases, such as protective gases or reaction gases, can be supplied via a metering valve to regulate the furnace atmosphere, in particular the oxidizing power of the furnace atmosphere.
The heat treatment furnace 5 according to the invention is therefore particularly suitable for carrying out the method according to the invention. For example, the gas pressure of the evaporation products and/or oxidation products in the strip coil or foil coil can also be controlled or regulated during the heat treatment using the heat treatment furnace 5 according to the invention.
An advantageous embodiment of the method according to the invention is shown in fig. 3 a. In this case, during the heat treatment, in particular for removing rolling residues, the content G of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or process exhaust gas is determined in step a and used for the process control of the heat treatment in step C. In step A, V may be determined, for example, in the furnace atmosphere and/or process off-gasesorgContent, for example by FID analyzer. Determination of the CO content, e.g. by CO analyser, and/or CO2Determination of the content, e.g. by CO2Analyser, or by FID analyser and CO analyser and optionally CO2Determination of C by AnalyzergesThe content is also conceivable.
In the case of the heat treatment, the actual content G of at least one evaporation and/or oxidation product is used in step BistE.g. CgesActual value of C of contentges istFor process control of the heat treatment. For this purpose, GistValue and target value GsollA comparison is made. This can be done manually, for example. According to GistThe value controls the heat treatment. For example, if GistValue greater than GsollThe value, at least one parameter P, such as the furnace temperature, is then decreased. If G isistValue less than GsollThe value, parameter P is increased. This may also happen in reverse. If G isistValue equal to GsollValue, then the parameter remains unchanged. In addition to the furnace temperature, the furnace temperature gradient, the process air exchange volume, the process air circulation volume and/or the composition of the furnace atmosphere can also be controlled, for example, in a process control as a function of the content G of at least one evaporation and/or oxidation product in the furnace atmosphere and/or process exhaust gas, for example as a function of CgesContent, and/or control of the furnace temperature gradient as a function of the content gradient of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or process off-gas, for example as a function of CgesAnd (4) gradient.
A further advantageous embodiment of the method according to the invention is shown in fig. 3 b. In this case, during the heat treatment, in particular for removing rolling residues, the content G of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or process exhaust gases is determined in step a 'and used for the process control of the heat treatment in step C'. In this case, for example, V can also be determined in the furnace atmosphere and/or process exhaust gasorgContent, e.g. by FID analyser, wherein the CO content is determined, e.g. by CO analyser, and/or CO2Determination of the content, e.g. by CO2Analyser, or by FID analyser and CO analyser and optionally CO2Determination of C by AnalyzergesThe content is also conceivable.
In the heat treatment, the actual content G of at least one evaporation product and/or oxidation product is usedistProcess regulation for heat treatment. As in process control, G is also set in step BistValue and target value GsollA comparison is made. According to GistThe value in step C' adjusts a parameter P, such as the furnace temperature. For example, if GistValue greater than GsollThe value, then the parameter P is decreased. If G isistValue less than GsollThe value, for example, increases the parameter P. This may also happen in reverse. If G isistValue equal to GsollValue, the parameter P remains unchanged. In addition to the furnace temperature, the furnace temperature gradient, the process air exchange volume, the process air circulation volume and/or the composition of the furnace atmosphere may also be determined, for example, in the course of the process control as a function of at least one evaporation product and/or oxidation productThe content of substances in the furnace atmosphere and/or process exhaust gases being controlled, for example, according to CgesContent, and/or adjusting the furnace temperature gradient in dependence on the content gradient of at least one evaporation product and/or oxidation product in the furnace atmosphere and/or process off-gas, for example in dependence on CgesAnd (4) gradient.
In contrast to the control process, the control process has a closed process. GistThe value is constantly in conjunction with GsollThe values are compared and are intended to be close to GsollBy changing the value of the parameter P to GistThe value has an influence. For example, a PID regulator can be used for process regulation.
The output of the FID analyzer during conventional final annealing on a 1616mm wide web of aluminum foil is shown in fig. 4 a. The final anneal was performed at a program temperature of 330 c for a duration of approximately 72 hours. The figure shows the CO content [ ppm [ ]]Furnace temperature and program temperature of DEG C]Air quantity [ m ]3/h]And fan speed [ rpm]As time [ h ]]Is measured as a function of (c). The CO content was measured in the furnace atmosphere. This allows conclusions to be drawn about the content of evaporation products and/or oxidation products in the furnace atmosphere. Alternatively, the CO content in the process exhaust gas can also be determined. Alternatively or additionally, V in the furnace atmosphere and/or process exhaust gas can also be determinedorgAnd/or CO content or CgesAnd (4) content.
The figure shows very clearly that in a conventional final anneal, after a short time, 1000ppm of CO is already present in the furnace atmospheremaxAnd (4) peak. In this case, the CO gradient is about 200 ppm/h. However, extensive testing has shown, for example, CO in excess of 220ppmmaxPeaks and CO gradients exceeding 10ppm/h reflect negative annealing results. It has been shown that tension in the metal foil, formation of welding and annealing bubbles occur under the corresponding furnace atmosphere. In the worst case, these may lead to cracks in the foil when unwinding the web.
In contrast, in the graph of FIG. 4b, COmaxThe content is limited to about 70ppm, COmaxThe gradient was about 5.5 ppm/h. The temperature program was set at 220 ℃ and the air quantity was kept constant at about 280m3The rotational speed was kept constant at about 640 rpm. As can be seen from the figures, it is,in this case the formation of a distinct CO peak during the annealing treatment can be avoided. To achieve this, according to the method of the present invention, the furnace temperature is controlled or adjusted according to the CO content in the furnace atmosphere. Although the furnace temperature and the CO content in the furnace atmosphere increase uniformly over a period of about 10 hours (see dashed line), the furnace temperature decreases at a critical value of about 50ppm CO content. The CO gradient then flattens out, now only about 1.4ppm/h, until the CO content drops again after about 24 hours. Tension in the metal foil and annealing bubble formation can thereby be reduced or prevented, high-quality metal products can be provided in a process-reliable and cost-effective manner, and the reject rate of the metal strip and the metal foil can be reduced.
Claims (14)
1. Method for the heat treatment of a metal strip or foil (1) in the form of a coil or foil (2) in a heat treatment furnace (5) for the removal of rolling residues,
it is characterized in that the preparation method is characterized in that,
during the heat treatment, the content of at least one evaporation product and/or oxidation product in the furnace atmosphere (11) and/or in the process exhaust gas (12) is determined and used for process control or process regulation of the heat treatment, wherein the dynamics of the removal of rolling residues on the metal strip or foil during the heat treatment are controlled or regulated.
2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,
it is characterized in that the preparation method is characterized in that,
the gas pressure of the evaporation products and/or oxidation products in the strip web or foil web is controlled or regulated during the heat treatment.
3. The method according to claim 1 or 2,
it is characterized in that the preparation method is characterized in that,
in the process control or regulation, the furnace temperature gradient, the process air exchange volume, the circulation volume of the process air and/or the composition of the furnace atmosphere are controlled or regulated as a function of the content of at least one evaporation product and/or oxidation product in the furnace atmosphere (11) and/or the process off-gas (12).
4. The method according to any one of claims 1 to 3,
it is characterized in that the preparation method is characterized in that,
in the process control or regulation, the furnace temperature gradient is controlled or regulated as a function of the content gradient of the at least one evaporation product and/or oxidation product in the furnace atmosphere (11) and/or the process exhaust gas (12).
5. The method according to any one of claims 1 to 4,
it is characterized in that the preparation method is characterized in that,
determining the carbon content (C) in the furnace atmosphere (11) and/or the process exhaust gas (12)gesContent), organic compound content (V)orgContent), carbon monoxide content (CO content) and/or carbon dioxide Content (CO)2Content) and for process control or regulation of the heat treatment.
6. The method of claim 5, wherein the first and second light sources are selected from the group consisting of,
it is characterized in that the preparation method is characterized in that,
maximum carbon content C in the furnace atmosphere (11) and/or process exhaust gas (12)ges maxMaximum content of organic compounds Vorg maxMaximum carbon monoxide content COmaxAnd/or maximum carbon dioxide content CO2 maxIs subject to limitations.
7. The method according to claim 5 or 6,
it is characterized in that the preparation method is characterized in that,
a carbon gradient C in the furnace atmosphere (11) and/or the process exhaust gas (12)ges GradGradient V of organic compound contentorg GradCarbon monoxide gradient COGradAnd/or carbon dioxide gradient CO2GradIs subject to limitations.
8. The method according to any one of claims 5 to 7,
it is characterized in that the preparation method is characterized in that,
Vorgthe content is measured by FID analyzer, preferably on-line FID analyzer, and the content of CO is measured byBy means of a CO analyzer, preferably an on-line CO analyzer, CO2In an amount of CO2Analyzer, preferably on-line CO2Analyzer determination, and/or CgesContent passing FID analyzer, CO analyzer and selective CO2And (4) determining by an analyzer.
9. The method according to any one of claims 1 to 8,
it is characterized in that the preparation method is characterized in that,
the heat treatment is carried out at a temperature of from 80 to 120 ℃ or above 200 ℃, preferably above 220 ℃, particularly preferably above 300 ℃.
10. The method according to any one of claims 1 to 9,
it is characterized in that the preparation method is characterized in that,
treating an aluminium or aluminium alloy strip or foil.
11. Apparatus for heat treating a metal strip or foil (1) in the form of a strip or foil coil (2) to carry out the method according to any one of claims 1 to 10,
it is characterized in that the preparation method is characterized in that,
the device comprises at least one device (8) for determining the content of at least one evaporation and/or oxidation product in the furnace atmosphere (11) and/or the process waste gases (12) during the heat treatment, and at least one device (9) for controlling or regulating the heat treatment as a function of the content of at least one evaporation and/or oxidation product in the furnace atmosphere (11) and/or the process waste gases (12), wherein the devices are designed in such a way that the dynamics of the removal of rolling residues from the metal strip or foil during the heat treatment are controlled or regulated by means of the devices.
12. The apparatus as set forth in claim 11, wherein,
it is characterized in that the preparation method is characterized in that,
the device has at least one device (9) for controlling or regulating the furnace temperature, the furnace temperature gradient, the process air exchange volume and/or the process air circulation volume as a function of the content of at least one evaporation product and/or oxidation product in the furnace atmosphere (11) and/or the process exhaust gas (12).
13. The apparatus of claim 11 or 12,
it is characterized in that the preparation method is characterized in that,
the device has at least one device (9) for controlling or regulating the furnace temperature gradient as a function of the content gradient of at least one evaporation product and/or oxidation product in the furnace atmosphere (11) and/or the process exhaust gas (12).
14. The device according to any one of claims 11 to 13,
it is characterized in that the preparation method is characterized in that,
the device has at least one controllable device (13) for influencing the thermal treatment.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP19208640.3 | 2019-11-12 | ||
| EP19208640 | 2019-11-12 | ||
| PCT/EP2020/081870 WO2021094432A1 (en) | 2019-11-12 | 2020-11-12 | Regulated heat treatment of foil |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114729413A true CN114729413A (en) | 2022-07-08 |
Family
ID=68581282
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202080078797.0A Pending CN114729413A (en) | 2019-11-12 | 2020-11-12 | Conditioned heat treatment of foil |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP4058611A1 (en) |
| JP (1) | JP7378615B2 (en) |
| KR (2) | KR20220070517A (en) |
| CN (1) | CN114729413A (en) |
| BR (1) | BR112022007669A2 (en) |
| WO (1) | WO2021094432A1 (en) |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6456825A (en) * | 1987-08-27 | 1989-03-03 | Kobe Steel Ltd | Heat-treating method for pipe stock |
| EP0572780A2 (en) * | 1992-04-06 | 1993-12-08 | Ebg Gesellschaft Für Elektromagnetische Werkstoffe Mbh | Process and device for cleaning of metal strip surfaces by gas-washing in hydrogen-rich athmospheres |
| WO1995011999A1 (en) * | 1993-10-28 | 1995-05-04 | Loi Thermoprocess Gmbh | Process for annealing items and suitable annealing furnace |
| CN101078096A (en) * | 2006-05-25 | 2007-11-28 | 福建方明钢铁有限公司 | Strip steel continuous zinc heat coating process |
| EP2067871A1 (en) * | 2007-11-30 | 2009-06-10 | Hydro Aluminium Deutschland GmbH | Aluminium strip for lithographic pressure plate carriers and its manufacture |
| CZ200975A3 (en) * | 2009-02-10 | 2010-08-04 | Raclavský@Milan | Refining technology of metalline zinc-containing waste in revolving furnace |
| RU2465080C1 (en) * | 2011-07-08 | 2012-10-27 | Открытое акционерное общество "Магнитогорский металлургический комбинат" | Method of making cold-rolled strips at continuous mill 2500 |
| US20150102538A1 (en) * | 2012-07-04 | 2015-04-16 | Kanto Yakin Kogyo Co., Ltd. | Method for heat treatment, heat treatment apparatus, and heat treatment system |
| CN105268740A (en) * | 2014-05-30 | 2016-01-27 | 宝山钢铁股份有限公司 | Production method for hot rolling pickling-free hot-dip product direct reduction |
| CN105753066A (en) * | 2014-12-15 | 2016-07-13 | 武丽霞 | Test method for recycling iron oxide powder and waste oil from steel rolling emulsion oil sludge |
| CN107002157A (en) * | 2014-10-15 | 2017-08-01 | Sms集团有限公司 | For the grain oriented electrical steel strip starting for manufacturing the technique of grain oriented electrical steel strip starting and being obtained according to the technique |
| CN109266983A (en) * | 2018-11-29 | 2019-01-25 | 天津忠旺铝业有限公司 | A method of prevent aluminum alloy coiled materials Annealing oil stain from generating |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57161036A (en) * | 1981-03-28 | 1982-10-04 | Sumitomo Metal Ind Ltd | Production of clean cold rolled steel strip |
| SE507916C2 (en) * | 1996-10-15 | 1998-07-27 | Aga Ab | Method and apparatus for controlling and / or controlling the gas atmosphere in a heat treatment furnace |
-
2020
- 2020-11-12 BR BR112022007669A patent/BR112022007669A2/en unknown
- 2020-11-12 KR KR1020227014467A patent/KR20220070517A/en not_active IP Right Cessation
- 2020-11-12 CN CN202080078797.0A patent/CN114729413A/en active Pending
- 2020-11-12 JP JP2022527691A patent/JP7378615B2/en active Active
- 2020-11-12 WO PCT/EP2020/081870 patent/WO2021094432A1/en active Search and Examination
- 2020-11-12 EP EP20803186.4A patent/EP4058611A1/en active Pending
- 2020-11-12 KR KR1020247005183A patent/KR20240026248A/en not_active Application Discontinuation
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6456825A (en) * | 1987-08-27 | 1989-03-03 | Kobe Steel Ltd | Heat-treating method for pipe stock |
| EP0572780A2 (en) * | 1992-04-06 | 1993-12-08 | Ebg Gesellschaft Für Elektromagnetische Werkstoffe Mbh | Process and device for cleaning of metal strip surfaces by gas-washing in hydrogen-rich athmospheres |
| WO1995011999A1 (en) * | 1993-10-28 | 1995-05-04 | Loi Thermoprocess Gmbh | Process for annealing items and suitable annealing furnace |
| CN101078096A (en) * | 2006-05-25 | 2007-11-28 | 福建方明钢铁有限公司 | Strip steel continuous zinc heat coating process |
| EP2067871A1 (en) * | 2007-11-30 | 2009-06-10 | Hydro Aluminium Deutschland GmbH | Aluminium strip for lithographic pressure plate carriers and its manufacture |
| CZ200975A3 (en) * | 2009-02-10 | 2010-08-04 | Raclavský@Milan | Refining technology of metalline zinc-containing waste in revolving furnace |
| RU2465080C1 (en) * | 2011-07-08 | 2012-10-27 | Открытое акционерное общество "Магнитогорский металлургический комбинат" | Method of making cold-rolled strips at continuous mill 2500 |
| US20150102538A1 (en) * | 2012-07-04 | 2015-04-16 | Kanto Yakin Kogyo Co., Ltd. | Method for heat treatment, heat treatment apparatus, and heat treatment system |
| CN105268740A (en) * | 2014-05-30 | 2016-01-27 | 宝山钢铁股份有限公司 | Production method for hot rolling pickling-free hot-dip product direct reduction |
| CN107002157A (en) * | 2014-10-15 | 2017-08-01 | Sms集团有限公司 | For the grain oriented electrical steel strip starting for manufacturing the technique of grain oriented electrical steel strip starting and being obtained according to the technique |
| CN105753066A (en) * | 2014-12-15 | 2016-07-13 | 武丽霞 | Test method for recycling iron oxide powder and waste oil from steel rolling emulsion oil sludge |
| CN109266983A (en) * | 2018-11-29 | 2019-01-25 | 天津忠旺铝业有限公司 | A method of prevent aluminum alloy coiled materials Annealing oil stain from generating |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2022550211A (en) | 2022-11-30 |
| EP4058611A1 (en) | 2022-09-21 |
| WO2021094432A1 (en) | 2021-05-20 |
| JP7378615B2 (en) | 2023-11-13 |
| KR20220070517A (en) | 2022-05-31 |
| KR20240026248A (en) | 2024-02-27 |
| BR112022007669A2 (en) | 2022-08-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR20090115195A (en) | Method of continuous annealing for steel strip with curie point and continuous annealing apparatus therefor | |
| CN108779508B (en) | Method for rolling and/or heat treating a metal product | |
| KR101834579B1 (en) | Method for cooling sheet metal by means of a cooling section, cooling section and control device for a cooling section | |
| JP2012512748A (en) | Rolling mill temperature control | |
| US6620465B2 (en) | Physical properties of thermal barrier coatings using electron beam-physical vapor deposition | |
| CN115836140A (en) | Dross defect prediction method, dross defect reduction method, method for manufacturing hot-dip galvanized steel sheet, method for manufacturing alloyed hot-dip galvanized steel sheet, dross defect prediction model generation method, dross defect prediction device, and dross defect prediction terminal system | |
| CN114729413A (en) | Conditioned heat treatment of foil | |
| JP2010066132A (en) | Method of controlling temperature in continuous annealing furnace, and continuous annealing furnace | |
| WO2013175158A1 (en) | Rolling mill temperature control | |
| JP2008255422A (en) | Method and facility for continuous annealing of steel strip having curie point | |
| EP2172281B1 (en) | Hot rolling apparatus | |
| JP5310965B1 (en) | Hot-rolled steel sheet cooling method | |
| EP0626467B1 (en) | Method of continuously carburizing steel strip | |
| EP4306665A1 (en) | Continuous annealing equipment, continuous annealing method, cold-rolled steel sheet manufacturing method, and plated steel sheet manufacturing method | |
| JP2021030239A (en) | Cold tandem rolling equipment and cold tandem rolling method | |
| JP5310964B1 (en) | Steel plate manufacturing method | |
| JP3817812B2 (en) | Calibration method for annealing furnace radiation thermometer | |
| EP3757236A1 (en) | Steel sheet heating method in continuous annealing and continuous annealing facility | |
| US6074493A (en) | Method of continuously carburizing metal strip | |
| JP2017057447A (en) | Production facility and production method for high tensile strength steel plate | |
| JP7218224B2 (en) | Manufacturing method of hot-dip galvanized steel sheet | |
| TWI516317B (en) | Steel sheet manufacturing method | |
| JP3238569B2 (en) | Method for controlling winding temperature of hot rolled steel sheet | |
| US20240158885A1 (en) | Continuous annealing equipment, continuous annealing method, method of producing cold-rolled steel sheets and method of producing coated or plated steel sheets | |
| US5472520A (en) | Method of controlling oxygen deposition during decarbutization annealing on steel sheets |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |