EP0405092A1 - Process for annealing thin steel sheet - Google Patents
Process for annealing thin steel sheet Download PDFInfo
- Publication number
- EP0405092A1 EP0405092A1 EP90108170A EP90108170A EP0405092A1 EP 0405092 A1 EP0405092 A1 EP 0405092A1 EP 90108170 A EP90108170 A EP 90108170A EP 90108170 A EP90108170 A EP 90108170A EP 0405092 A1 EP0405092 A1 EP 0405092A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- hydrogen
- annealing
- coil
- steel sheet
- thin steel
- 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.)
- Withdrawn
Links
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
- 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
-
- 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
- C21D9/663—Bell-type furnaces
- C21D9/667—Multi-station furnaces
- C21D9/67—Multi-station furnaces adapted for treating the charge in vacuum or special atmosphere
Definitions
- the invention relates to a method for annealing thin steel sheet wound into a coil in an oven with a protective atmosphere containing hydrogen.
- the rolling of very thin sheet steel which is used particularly in the packaging industry, requires very good lubrication due to an oil or grease film adhering to the sheet. This lubricating film interferes when the sheet is recrystallized in the final phase of rolling.
- the annealing is carried out in a known manner in an oven with a protective gas atmosphere. These ovens are usually designed as hoods that can be slipped over the coil.
- the alkaline and electrolytic cleaning process can only be saved with thicker sheets that have a thickness of more than 0.5 mm. With thick sheets, such good lubrication is not necessary when rolling. An emulsion of water and easily evaporating fat or oil is therefore sufficient. The few fat or oil components adhering to the surface are evaporated when heated, so that the surface of the sheet is sufficiently clean or clean even without a special cleaning process.
- the invention has for its object to describe a process for recrystallizing annealing of very thin steel sheet, in which the unwinding of the coil and the special cleaning of the sheet in the unwound state, in particular in the alkaline and electrolytic bath, is saved, the usual time of Glow should be kept approximately.
- the furnace can be opened using conventional methods heating and cooling speeds are operated. The time is then sufficiently long so that with an increased hydrogen content in the protective gas atmosphere, the hydrogen reacts sufficiently with the few residues.
- the cleaning effect of the process is better than when using conventional alkaline cleaning processes.
- a particular advantage of the new process is that only flammable gases or vapors are produced which can easily be burned in combustion plants, whereas the alkaline cleaning process represents a much larger disposal problem.
- HNX gas is a mixture of 6% hydrogen and over 90% nitrogen.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
Description
Die Erfindung betrifft ein Verfahren zum Glühen von dünnem, zu einem Coil aufgewickelten Stahlblech in einem Ofen mit schützender, Wasserstoff enthaltender Atmosphäre.The invention relates to a method for annealing thin steel sheet wound into a coil in an oven with a protective atmosphere containing hydrogen.
Das Walzen von sehr dünnem Stahlblech, das besonders in der Verpackungsindustrie gebraucht wird, erfordert eine sehr gute Schmierung durch einen am Blech anhaftenden Schmierfilm aus Öl oder Fett. Dieser Schmierfilm stört, wenn in der Endphase des Walzens das Blech rekristallisierend geglüht wird. Das Glühen wird in bekannter Weise in einem Ofen mit Schutzgasatmosphäre vorgenommen. Diese Öfen sind meist als über das Coil überstülpbare Hauben ausgeführt.The rolling of very thin sheet steel, which is used particularly in the packaging industry, requires very good lubrication due to an oil or grease film adhering to the sheet. This lubricating film interferes when the sheet is recrystallized in the final phase of rolling. The annealing is carried out in a known manner in an oven with a protective gas atmosphere. These ovens are usually designed as hoods that can be slipped over the coil.
Es ist bekannt, das hinter der Walzstraße zu einem Coil aufgewickelte Stahlblech wieder abzuwickeln und zwecks Reinigung durch ein alkalisches und ein elektrolytisches Bad zu führen, zu trocknen und danach wieder zum Coil aufzuwickeln und dann das Coil rekristallisierend zu glühen.It is known to unwind the steel sheet wound up into a coil behind the rolling mill and to pass it through an alkaline and an electrolytic bath for cleaning, to dry it and then to wind it up again to the coil and then to anneal the coil in a recrystallizing manner.
Dieser Reinigungsprozeß ist sehr aufwendig, aber unumgänglich, weil ohne die Reinigung beim Erwärmen des Coils Teile des Öles oder Fettes als verkokte Rückstände auf dem Blech festbrennen würden.This cleaning process is very complex, but unavoidable, because without the cleaning when heating the coil, parts of the oil or fat would burn onto the sheet as coked residues.
Diese Rückstände lassen das nach dem Glühen noch erfolgende letzte Nachwalzen nicht zu, außerdem kann das Blech auch nicht z. B. mit Zinn, anderen Metallen oder organischen Stoffen beschichtet werden.These residues do not allow the final re-rolling to take place after annealing. B. coated with tin, other metals or organic substances.
Den alkalischen und elektrolytischen Reinigungsprozeß kann man nur bei dickeren Blechen, die eine Dicke von über 0,5 mm haben, einsparen. Bei dicken Blechen ist beim Walzen keine so gute Schmierung erforderlich. Es reicht deshalb eine Emulsion aus Wasser und leicht abdampfendem Fett oder Öl aus. Die an der Oberfläche haftenden wenigen Fett- oder Ölbestandteile werden beim Erwärmen abgedampft, so daß die Oberfläche des Bleches auch ohne besonderes Reinigungsverfahren ausreichend rein oder sauber ist.The alkaline and electrolytic cleaning process can only be saved with thicker sheets that have a thickness of more than 0.5 mm. With thick sheets, such good lubrication is not necessary when rolling. An emulsion of water and easily evaporating fat or oil is therefore sufficient. The few fat or oil components adhering to the surface are evaporated when heated, so that the surface of the sheet is sufficiently clean or clean even without a special cleaning process.
Es ist bekannt, dem Schutzgas Wasserstoff zuzusetzten, um einen schnelleren Wärmeübergang und damit eine verkürzte Auf- und Abkühlzeit zu erreichen. Bei diesen bekannten Verfahren wird der Ofen von Anfang an bis zur Rekristallisationstemperatur mit gleicher, meist maximaler Heizleistung betrieben.It is known to add hydrogen to the protective gas in order to achieve faster heat transfer and thus a shorter cooling and cooling time. In these known methods, the furnace is operated from the beginning to the recrystallization temperature with the same, usually maximum, heating power.
Der Erfindung liegt die Aufgabe zugrunde, ein Verfahren zum rekristallisierenden Glühen von sehr dünnem Stahlblech zu beschreiben, bei dem das Abwickeln des Coils und das besondere Reinigen des Bleches im abgewickelten Zustand, insbesondere im alkalischen und elektrolytischen Bad, eingespart wird, wobei die übliche Zeitdauer des Glühens annähernd erhalten bleiben soll.The invention has for its object to describe a process for recrystallizing annealing of very thin steel sheet, in which the unwinding of the coil and the special cleaning of the sheet in the unwound state, in particular in the alkaline and electrolytic bath, is saved, the usual time of Glow should be kept approximately.
Diese Aufgabe wird durch das im kennzeichnenden Teil des Anspruches 1 beschriebene Verfahren gelöst, Weiterbildungen sind in den Ansprüchen 2 und 3 beschrieben.This object is achieved by the method described in the characterizing part of claim 1, further developments are described in claims 2 and 3.
Die gesamte Zeit, die zum Glühen benötigt wird, ist um so kürzer, je höher der Gehalt an Wasserstoff im Schutzgas ist. Bei hohem Gehalt sorgt der Wasserstoff nicht nur für einen schnelleren Wärmeübergang, sondern auch für eine höhere Reaktionsgeschwindigkeit bei der Bildung von Methan.The higher the hydrogen content in the protective gas, the shorter the total time required for annealing. With a high content, the hydrogen not only ensures faster heat transfer, but also a higher reaction rate in the formation of methane.
Da oberhalb einer Temperatur von 450 °C nur noch wenige vom Fett oder Öl herrührende Rückstände auf dem Stahlblech vorhanden sind, kann hier der Ofen mit von herkömmlichen Verfahren bekannten Auf heiz-und Abkühlgeschwindigkeiten betrieben werden. Die Zeit ist dann ausreichend lang, so daß bei erhöhtem Wasserstoffgehalt der Schutzgasatmosphäre, der Wasserstoff mit den wenigen Rückständen ausreichend reagiert.Since above a temperature of 450 ° C there are only a few residues from the fat or oil left on the steel sheet, the furnace can be opened using conventional methods heating and cooling speeds are operated. The time is then sufficiently long so that with an increased hydrogen content in the protective gas atmosphere, the hydrogen reacts sufficiently with the few residues.
Der überraschend starke Reinigungseffekt nach dem erfindungsgemäßen Verfahren kann so erklärt werden, daß durch das langsame Erwärmen viele leicht flüchtigen Bestandteile des Öles oder Fettes abdampfen. Die schwerer verdampfbaren Bestandteile reagieren mit dem Wasserstoff und bilden Methan. Größere abzuleitende Mengen an Methan wurden bei Versuchen gemessen.The surprisingly strong cleaning effect by the process according to the invention can be explained in that many slowly volatile constituents of the oil or fat evaporate due to the slow heating. The more difficult to evaporate components react with the hydrogen and form methane. Larger amounts of methane to be derived were measured in experiments.
Es hat sich herausgestellt, daß bei den bekannten Verfahren zum Glühen in einer Wasserstoff enthaltenden Schutzgasatmosphäre die Zeit, in der das Öl oder Fett teilweise abdampfen kann und in der der Wasserstoff auf die schwerer verdampfbaren Reste chemisch einwirkt, zu kurz ist, um einen Schmierfilm aufzulösen.It has been found that in the known methods for annealing in a protective gas atmosphere containing hydrogen, the time in which the oil or fat can partially evaporate and in which the hydrogen chemically acts on the residues which are more difficult to evaporate is too short to dissolve a lubricating film .
Der reinigende Effekt des Verfahrens ist besser als bei Anwendung der herkömmlichen alkalischen Reinigungsverfahren. Ein besonderer Vorteil des neuen Verfahrens besteht auch darin, daß lediglich brennbare Gase oder Dämpfe entstehen, die leicht in Feuerungsanlagen mit verbrannt werden können, dagegen stellt das alkalische Reinigungsverfahren ein weitaus größeres Entsorgungsproblem dar.The cleaning effect of the process is better than when using conventional alkaline cleaning processes. A particular advantage of the new process is that only flammable gases or vapors are produced which can easily be burned in combustion plants, whereas the alkaline cleaning process represents a much larger disposal problem.
Bei in einem alkalischen Bad gereinigtem und in herkömmlicher Weise unter HNX-Gas geglühtem Stahlband werden in der Regel auf einem Quadratmeter Oberfläche als Rückstände 60 bis 120 mg Eisenauflage und rund 170 mg Kohlenstoffauflage gemessen. HNX-Gas ist ein Gemisch aus 6 % Wasserstoff und über 90 % Stickstoff.In the case of steel strip cleaned in an alkaline bath and annealed in a conventional manner under HNX gas, 60 to 120 mg of iron layer and approximately 170 mg of carbon layer are generally measured as residues on a square meter surface. HNX gas is a mixture of 6% hydrogen and over 90% nitrogen.
Bei einem Versuch nach der Erfindung, bei dem unter reiner Wasserstoffatmosphäre geglüht wurde, wurden rund 1 mg Eisenauflage und rund 1 mg Kohlenstoffauflage gemessen. Zur Schmierung wurde Palmfett und Tinoil verwandt.In an experiment according to the invention, in which annealing was carried out under a pure hydrogen atmosphere, around 1 mg of iron deposit and around 1 mg of carbon deposit were measured. Palm grease and tinoil were used for lubrication.
Mit diesem Versuch wurde bewiesen, daß das Verfahren nach der Erfindung nicht nur in der Wirtschaftlichkeit, sondern auch in der Reinigungsqualität den bekannten Verfahren weit überlegen ist.With this experiment it was proven that the method according to the invention is far superior to the known methods not only in terms of economy but also in terms of cleaning quality.
Claims (3)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19893921321 DE3921321A1 (en) | 1989-06-29 | 1989-06-29 | METHOD FOR BURNING THIN STEEL SHEET |
DE3921321 | 1989-06-29 |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0405092A1 true EP0405092A1 (en) | 1991-01-02 |
Family
ID=6383872
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP90108170A Withdrawn EP0405092A1 (en) | 1989-06-29 | 1990-04-28 | Process for annealing thin steel sheet |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0405092A1 (en) |
DE (1) | DE3921321A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1994013843A1 (en) * | 1992-12-11 | 1994-06-23 | Messer Griesheim Gmbh | Method of annealing steel strip in an annealing furnace without the formation of soot |
WO1999025882A1 (en) * | 1997-11-14 | 1999-05-27 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Improved process for the annealing of drawn carbon steel rolls and coils of carbon steel sheet |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4428614C2 (en) * | 1994-08-12 | 1999-07-01 | Loi Thermprocess Gmbh | Process for annealing metal parts |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3233374A1 (en) * | 1982-09-08 | 1984-03-08 | Sumitomo Metal Industries, Ltd., Osaka | Process for producing purified cold-rolled steel strip |
LU87398A1 (en) * | 1987-12-03 | 1989-06-14 | Centre Rech Metallurgique | METHOD FOR CONDUCTING A BASE-ANNUIT TREATMENT OF A STEEL STRIP |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE450186C (en) * | 1925-12-13 | 1927-11-15 | Theodor Stassinet Dipl Ing | Method and device for removing vapors or vapor mixtures from incandescent vessels during bright annealing |
DE617097C (en) * | 1932-02-26 | 1935-08-12 | Siemens Schuckertwerke Akt Ges | Blank glow furnace |
DE1032294B (en) * | 1954-01-26 | 1958-06-19 | Berkenhoff & Co Kommanditgesel | Process for bright annealing of iron, steel, metals and metal alloys |
-
1989
- 1989-06-29 DE DE19893921321 patent/DE3921321A1/en not_active Withdrawn
-
1990
- 1990-04-28 EP EP90108170A patent/EP0405092A1/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3233374A1 (en) * | 1982-09-08 | 1984-03-08 | Sumitomo Metal Industries, Ltd., Osaka | Process for producing purified cold-rolled steel strip |
LU87398A1 (en) * | 1987-12-03 | 1989-06-14 | Centre Rech Metallurgique | METHOD FOR CONDUCTING A BASE-ANNUIT TREATMENT OF A STEEL STRIP |
Non-Patent Citations (3)
Title |
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CAHIERS D'INF. TECHN. DE LA REVUE DE METALL., Band 86, Nr. 2, Februar 1989, Seiten 173-180; B. CHATELAIN et al.: "Evaluation du recuit sous hydrogene des aciers doux. Réactions gaz-métal" * |
IRON AND STEEL ENGINEER, Band 65, Nr. 8, August 1988, Seiten 43-49; D. POWELL: "High performance hydrogen annealing technology" * |
STAHL UND EISEN, Band 109, Nr. 9/10, 16. Mai 1989, Seiten 513-520; F. HÖHNER et al.: "Verfahrens- und steuerungstechnisches Sicherheitskonzept einer Wasserstoff-Hochkonvektions-Haubenglühanlage" * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1994013843A1 (en) * | 1992-12-11 | 1994-06-23 | Messer Griesheim Gmbh | Method of annealing steel strip in an annealing furnace without the formation of soot |
HRP931483A2 (en) * | 1992-12-11 | 1995-02-28 | Messer Griesheim Gmbh | Method of annealing steel strip in an annealing furnace without the formation of soot |
US5645655A (en) * | 1992-12-11 | 1997-07-08 | Messer Greiesheim Gmbh | Process to anneal steel strips in an annealing furnace without generating carbon black |
WO1999025882A1 (en) * | 1997-11-14 | 1999-05-27 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Improved process for the annealing of drawn carbon steel rolls and coils of carbon steel sheet |
US6358337B1 (en) | 1997-11-14 | 2002-03-19 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Process for the annealing of drawn carbon steel rolls and coils of carbon steel sheet |
Also Published As
Publication number | Publication date |
---|---|
DE3921321A1 (en) | 1991-01-10 |
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
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AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): BE DE FR GB IT NL |
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GBC | Gb: translation of claims filed (gb section 78(7)/1977) | ||
ITCL | It: translation for ep claims filed |
Representative=s name: RICCARDI SERGIO & CO. |
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TCNL | Nl: translation of patent claims filed | ||
ET | Fr: translation filed | ||
17P | Request for examination filed |
Effective date: 19910220 |
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17Q | First examination report despatched |
Effective date: 19921207 |
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RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: KRUPP HOESCH STAHL AG |
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STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
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18D | Application deemed to be withdrawn |
Effective date: 19941031 |