WO2000005422A1 - Method and installation for producing dual-phase steel - Google Patents

Method and installation for producing dual-phase steel Download PDF

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Publication number
WO2000005422A1
WO2000005422A1 PCT/EP1999/005113 EP9905113W WO0005422A1 WO 2000005422 A1 WO2000005422 A1 WO 2000005422A1 EP 9905113 W EP9905113 W EP 9905113W WO 0005422 A1 WO0005422 A1 WO 0005422A1
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Prior art keywords
cooling
ferrite
stage
dual
steels
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PCT/EP1999/005113
Other languages
German (de)
French (fr)
Inventor
August Sprock
Original Assignee
Sms Schloemann-Siemag Aktiengesellschaft
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Publication date
Application filed by Sms Schloemann-Siemag Aktiengesellschaft filed Critical Sms Schloemann-Siemag Aktiengesellschaft
Priority to BR9912310-0A priority Critical patent/BR9912310A/en
Priority to EP99938282A priority patent/EP1108072B1/en
Priority to CA2338743A priority patent/CA2338743C/en
Priority to AT99938282T priority patent/ATE224959T1/en
Priority to DE59902877T priority patent/DE59902877D1/en
Priority to JP2000561368A priority patent/JP2002521562A/en
Publication of WO2000005422A1 publication Critical patent/WO2000005422A1/en

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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
    • C21D1/02—Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/001—Austenite
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/002—Bainite
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite

Definitions

  • the invention relates to a method and a plant for the production of dual-phase steels from the hot-rolled state with a two-phase structure made of 70 to 90% ferrite and 30 to 10% martensite through a controlled temperature control and defined cooling strategy during the cooling of the steels, inter alia by means of Water cooling after its finish rolling, the cooling curve running into the ferrite area in a first cooling stage and further cooling to temperatures below the martensite starting temperature in a second cooling stage after reaching the necessary proportion
  • the targeted microstructure conversion by appropriate cooling of the steel is known.
  • DE 44 16 752 AI describes a process for producing hot wide strip, in which the surface temperature of the slab is sufficiently deep (at least before the first forming between the continuous casting machine and a compensating furnace) 2 mm) to the extent that a structural change from austenite to Fernt / Perlite occurs.
  • the cooling time is selected so that at least 70% austenite is converted to Fernt / Perlite.
  • the compensating furnace there is then a renewed conversion to Austenite with reorientation of Austenite Grain boundaries
  • second-choice scrap in particular scrap containing copper, can be used as a raw material without undesired accumulation of copper at the grain boundaries of the P ⁇ maraustenite
  • sufficient ferrite formation is achieved, for example, by cooling with water to a temperature of around 620 - 650 ° C with subsequent air cooling.
  • the duration of the air cooling (approx. 8 seconds) is selected so that at least 70% of the austenite is converted to ferrite before the second cooling stage begins During the first cooling stage and during air cooling, a conversion in the Perht stage should be avoided
  • the task is solved with the characterizing measures of claim 1 in that during the first cooling stage the cooling curve of the steels is set with a cooling rate of 20 K / s to 30 K / s so low that the cooling curve is at such a high temperature enters the ferrite area so that the ferrite formation can take place quickly and at least 70% of the austenite has already been converted into ferrite before the start of the second cooling stage
  • the cooling curve runs into the ferrite area later at a higher temperature than in the known processes, i.e. the conversion of the austenite into ferrite begins somewhat delayed but at a higher temperature than at the known methods, and it also runs faster due to the higher temperature. It has an advantageous effect if the ferrite area is reached as quickly as possible with a high transformation temperature
  • the principle of loosened cooling is used according to the invention. This is water cooling, in which water is applied to the cooling material from water cooling stages arranged one behind the other by influencing the number of water cooling stages, their distance from one another and The effective length of the water cooling stages allows the cooling rate or the amount of water applied to the cooling material (its cooling material mass and / or the surface of the cooling material) to be optimally adjusted.
  • the cooling can also be achieved with an infinitely variable quantity of coolant
  • the loosened cooling can be extended until the desired degree of conversion is reached, without the risk - as in the known methods with fast cooling - that the cooling curve leaves the ferrite area beforehand due to excessive cooling
  • the production of dual-phase steels can take place on part of the cooling section.
  • the part of the cooling section used is much shorter than in the known processes with Air cooling If the required structural components for dual-phase steels can be set without air cooling, this results in significant advantages for the operator. Fewer system components are required for the production of dual-phase steels.
  • the production spectrum can be modified with changed process and strip parameters (e.g. higher strip speed). compared to be expanded so far.
  • a system for carrying out the method of the invention is characterized by a cooling section arranged behind the last finishing mill stand, comprising a plurality of water cooling stages or cooling systems arranged one behind the other with a continuously variable amount of coolant.
  • the number of water cooling stages, their effective length and their distance from one another can be changed according to the invention, so that this cooling section can be adapted in a simple manner to changed geometries of the goods to be cooled and to different belt speeds
  • Fig. 1 is a schematic representation of the rapid cooling and the loosened cooling and their assignment in a rolling mill
  • Fig. 3 shows the degree of Ausemtumumwandung with the fast
  • Fig. 4 shows the degree of Ausemtumumwandung with the loosened
  • FIG. 1 the end of a rolling mill is shown schematically, consisting of the last finish rolling stand (1), the rolling stock or cooling stock (2) and a reel (3) with deflection rollers or driver (4) Above this part of a rolling train are two different cooling sections drawn in With the cooling section (5) according to the prior art, an early, rapid cooling of the cooling material (2) is brought about by a coherent water supply. In the cooling section (6), according to the invention, water cooling stages (7) are arranged one behind the other, thereby cooling "loosened up"
  • the cooling curve (9) shows the cooling process with the strategy commonly used today (early, rapid cooling to a certain holding temperature with subsequent air cooling, then further cooling to low temperatures below the martensite start temperature)
  • the cooling curve (10) with its first cooling stage (14) reaches the ferrite area (F) at point (15) later in the loosened cooling compared to the cooling curve (9). Since the loosened cooling is initially maintained after reaching the ferrite area (F) no time-consuming holding time with air cooling is required and the cooling curve (10) leaves the ferrite area (F) earlier
  • the loosened cooling is maintained within the ferrite area (F) until the desired degree of conversion is reached. Then the further cooling with the second cooling stage (16) takes place immediately.
  • the invention is not limited to the exemplary cooling curves described in the illustrations, but also other cooling curves, such as, for example, in cooling systems with an infinitely variable amount of cooling agent, which in the sense of the invention lead to higher conversion temperatures, are also possible.
  • the invention is not restricted to water cooling , but other cooling systems can be used, which lead to an early reaching of the ferrite area at high temperatures

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Heat Treatment Of Strip Materials And Filament Materials (AREA)
  • Metal Rolling (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Heat Treatment Of Steel (AREA)
  • Heat Treatments In General, Especially Conveying And Cooling (AREA)
  • Heat Treatment Of Articles (AREA)
  • Control Of Heat Treatment Processes (AREA)

Abstract

The invention relates to the production of dual-phase steel (2) which is obtained by targeted cooling after the final deformation step in a rolling stand (1), whereby a dual-phase structure of between 70 and 90 % ferrite and between 30 and 10 % martensite is adjusted. So as to be independent of steel geometry and strip speed the invention provides for cooling to take the form of fluidized-bed cooling carried out in a cooling line (6) comprising water-cooling stages (7) arranged one behind the other.

Description

Verfahren und Anlage zur Herstellung von Dualphasen-StählenProcess and plant for the production of dual-phase steels
Die Erfindung betrifft ein Verfahren und eine Anlage zur Herstellung von Dualphasen-Stahlen aus dem warmgewalzten Zustand mit einem zweiphasigen Gefuge aus 70 bis 90 % Ferrit und 30 bis 10 % Martensit durch eine kontrollierte Temperaturfuhrung und definierte Kuhlstrategie wahrend der Abkühlung der Stahle, unter anderem mittels Wasserkühlung nach ihrer Fertigwalzung, wobei in einer ersten Abkuhlstufe die Kuhlkurve in das Ferritgebiet einlauft und nach Erreichen des notwendigen Femtanteils in einer zweiten Abkuhlstufe auf Temperaturen unterhalb der Martensitstarttemperatur weiter abgekühlt wirdThe invention relates to a method and a plant for the production of dual-phase steels from the hot-rolled state with a two-phase structure made of 70 to 90% ferrite and 30 to 10% martensite through a controlled temperature control and defined cooling strategy during the cooling of the steels, inter alia by means of Water cooling after its finish rolling, the cooling curve running into the ferrite area in a first cooling stage and further cooling to temperatures below the martensite starting temperature in a second cooling stage after reaching the necessary proportion
Die gezielte Gefugeumwandlung durch eine entsprechende Abkühlung der Stahle ist bekannt So wird beispielsweise in der DE 44 16 752 AI ein Verfahren zur Erzeugung von Warmbreitband beschrieben, bei dem vor der ersten Umformung zwischen der Stranggießmaschine und einem Ausgleichsofen die Oberflachentemperatur der Bramme in ausreichender Tiefe (mindestens 2 mm) soweit abgesenkt wird, dass sich eine Gefugeumwandlung von Austenit in Fernt/Perlit einstellt Hierbei ist die Abkuhlzeit so gewählt, dass mindestens 70 % Austenit in Fernt/Perlit umgewandelt werden Im Ausgleichsofen erfolgt daran anschließend eine erneute Umwandlung in Austenit mit Neuorientierung der Austenit- Korngrenzen Auf diese Weise soll erreicht werden, dass auch Schrott zweiter Wahl, insbesondere Schrott mit Anteilen an Kupfer, ohne unerwünschte Ansammlungen von Kupfer an den Korngrenzen des Pπmaraustenits als Rohstoff eingesetzt werden kannThe targeted microstructure conversion by appropriate cooling of the steel is known.For example, DE 44 16 752 AI describes a process for producing hot wide strip, in which the surface temperature of the slab is sufficiently deep (at least before the first forming between the continuous casting machine and a compensating furnace) 2 mm) to the extent that a structural change from austenite to Fernt / Perlite occurs. The cooling time is selected so that at least 70% austenite is converted to Fernt / Perlite. In the compensating furnace there is then a renewed conversion to Austenite with reorientation of Austenite Grain boundaries In this way, it should be achieved that second-choice scrap, in particular scrap containing copper, can be used as a raw material without undesired accumulation of copper at the grain boundaries of the Pπmaraustenite
Bei der Herstellung von Dualphasen-Stahlen macht man sich gleichfalls eine stattfindende Gefugeumwandlung mit Hilfe einer gezielten Abkühlung zu nutze, nun aber zeitlich nach der erfolgten Umformung Die Einstellung eines Dualphasen-Gefuges hangt dabei wesentlich von den anlagentechnisch möglichen Abkuhlgeschwindigkeiten und der Stahlzusammensetzung ab Wichtig bei der Herstellung von Dualphasen- Stahlen ist eine ausreichende Ferπtbildung in der ersten AbkuhlstufeIn the production of dual-phase steels, one also makes use of a structural transformation that takes place with the help of targeted cooling, but now after the forming has been carried out A dual-phase structure depends essentially on the cooling speeds and the steel composition that are possible in terms of system technology. It is important in the production of dual-phase steels that there is sufficient fermentation in the first cooling stage
Anlagentechnisch wird eine ausreichende Ferπtbildung z B durch Abkühlen mit Wasser auf eine Temperatur um etwa 620 - 650 °C mit anschließender Luftkühlung erreicht Die Dauer der Luftkühlung (ca 8 Sekunden) wird so gewählt, dass mindestens 70 % des Austenits in Ferrit umgewandelt sind, bevor die zweite Abkuhlstufe einsetzt Wahrend der ersten Abkuhlstufe sowie wahrend der Luftkühlung sollte eine Umwandlung in der Perhtstufe vermieden werdenIn terms of plant technology, sufficient ferrite formation is achieved, for example, by cooling with water to a temperature of around 620 - 650 ° C with subsequent air cooling. The duration of the air cooling (approx. 8 seconds) is selected so that at least 70% of the austenite is converted to ferrite before the second cooling stage begins During the first cooling stage and during air cooling, a conversion in the Perht stage should be avoided
In der zweiten Abkuhlstufe müssen noch soviel Kuhlkapazitaten vorhanden sein, dass Haspeltemperaturen unterhalb der Martensitstarttemperatur erreicht werden Nur dann ist die Bildung eines Dualphasen-Gefuges mit ferritischen und martensitischen Bestandteilen sichergestellt Diese bekannte Fertigung ist unproblematisch für kleine Bandgeschwindigkeiten, da nach Ende der ersten Kuhlstufe genügend Kuhlkapazitaten für die Martensitumwandlung vorhanden sindIn the second cooling stage, there must still be enough cooling capacities that reel temperatures below the martensite start temperature are reached.Only then will the formation of a dual-phase structure with ferritic and martensitic components be ensured.This well-known production is unproblematic for low belt speeds, since after the first cooling stage enough cooling capacities are achieved are available for the martensite transformation
Bei sehr hohen Bandgeschwindigkeiten kann allerdings der Beginn der zweiten Kuhlstufe so weit in der vorhandenen Kuhlstrecke verschoben sein, dass die anschließende Martensitbildung nur noch unvollständig oder gar nicht erfolgt, da dann die Kuhlkapazitat zur Einstellung der erforderlichen tiefen Temperatur (< 220 °C) nicht mehr ausreicht Es entsteht dann ein Mischgefuge aus Ferrit Bainit und Anteilen an Martensit, das die angestrebten mechanischen Eigenschaften reiner Dualphasen-Gefuge nicht erreichtAt very high belt speeds, however, the start of the second cooling stage can be shifted so far in the existing cooling section that the subsequent formation of martensite takes place only incompletely or not at all, since then the cooling capacity for setting the required low temperature (<220 ° C) no longer occurs sufficient A mixed structure of ferrite bainite and martensite components is then created, which does not achieve the mechanical properties of pure dual-phase structure
Ausgehend von diesem bekannten Stand der Technik ist es Aufgabe der Erfindung, ein Verfahren und eine Anlage zur Herstellung von Dualphasen- Stahlen anzugeben womit eine schnelle und quantitativ ausreichende Gefugeumwaπdlung des Austenits in Ferrit auch bei hohen Bandgeschwindigkeiten möglich istBased on this known prior art, it is an object of the invention to provide a method and a system for producing dual-phase Specify steel with which a rapid and quantitatively sufficient structural transformation of the austenite into ferrite is possible even at high strip speeds
Die gestellte Aufgabe wird verfahrensmaßig mit den kennzeichnenden Maßnahmen des Anspruchs 1 dadurch gelost dass wahrend der ersten Abkuhlstufe die Abkuhlkurve der Stahle mit einer so niedrigen Abkuhlgeschwindigkeit von 20 K/s bis 30 K/s eingestellt wird, dass die Abkuhlkurve mit einer noch so hohen Temperatur in das Ferritgebiet einlauft dass die Ferritbildung schnell erfolgen kann und vor Beginn der zweiten Abkuhlstufe bereits mindestens 70 % des Austenits in Ferrit umgewandelt sindIn terms of the process, the task is solved with the characterizing measures of claim 1 in that during the first cooling stage the cooling curve of the steels is set with a cooling rate of 20 K / s to 30 K / s so low that the cooling curve is at such a high temperature enters the ferrite area so that the ferrite formation can take place quickly and at least 70% of the austenite has already been converted into ferrite before the start of the second cooling stage
Durch die erfindungsgemaß langsamere Abkühlung mit einer niedrigeren Abkuhlgeschwindigkeit als bei bekannten Verfahren lauft die Abkuhlkurve zeitlich spater aber bei einer höheren Temperatur als bei den bekannten Verfahren in das Ferritgebiet ein, d h die Umwandlung des Austenits in Ferrit beginnt etwas verzögert aber bei einer höheren Temperatur als bei den bekannten Verfahren, und sie verlauft aufgrund der höheren Temperatur auch schneller ab Gunstig wirkt es sich aus, wenn möglichst schnell das Ferritgebiet bei gleichzeitig hoher Umwandlungstemperatur erreicht wirdDue to the slower cooling according to the invention with a lower cooling rate than in known processes, the cooling curve runs into the ferrite area later at a higher temperature than in the known processes, i.e. the conversion of the austenite into ferrite begins somewhat delayed but at a higher temperature than at the known methods, and it also runs faster due to the higher temperature. It has an advantageous effect if the ferrite area is reached as quickly as possible with a high transformation temperature
Gegenüber den bekannten Verfahren wird dabei ein Umwandlungsgrad von mindestens 70 % so früh erreicht, dass noch genügend Kuhlkapazitat in einer gegebenen Kuhlstrecke für die anschließende Martensitbildung zur Verfugung steht D h , nach Ende der ersten Kuhlstufe ist eine ausreichend große Menge an Austenit in Ferrit umgewandelt so dass die sonst übliche Luftkühlung entfallen kann und unmittelbar an die erste Kuhlstufe die zweite Kuhlstufe anschließen kann Um die Kühlung mit der gewünschten niedrigen Abkuhlgeschwindigkeit durchzufuhren wird gemäß der Erfindung das Prinzip der aufgelockerten Kühlung angewendet Dies ist eine Wasserkühlung, bei der aus mit Abstand hintereinander angeordneten Wasserkuhlstufen Wasser auf das Kuhlgut aufgebracht wird Durch Einflußnahme auf die Anzahl der Wasserkuhlstufen, ihrem Abstand voneinander sowie der wirksamen Lange der Wasserkuhlstufen laßt sich die Abkuhlgeschwindigkeit bzw die aufgebrachte Wassermenge an das Kuhlgut (seine Kuhlgutmasse und/oder die Kuhlgutoberflache) optimal anpassen Die Kühlung kann auch mit einer stufenlos veränderbaren Kuhlmittelmenge realisiert werdenCompared to the known methods, a degree of conversion of at least 70% is reached so early that sufficient cooling capacity is still available in a given cooling section for the subsequent formation of martensite D h, after the end of the first cooling stage a sufficiently large amount of austenite has been converted to ferrite that the otherwise usual air cooling can be omitted and the second cooling stage can be connected directly to the first cooling stage In order to carry out the cooling with the desired low cooling rate, the principle of loosened cooling is used according to the invention.This is water cooling, in which water is applied to the cooling material from water cooling stages arranged one behind the other by influencing the number of water cooling stages, their distance from one another and The effective length of the water cooling stages allows the cooling rate or the amount of water applied to the cooling material (its cooling material mass and / or the surface of the cooling material) to be optimally adjusted. The cooling can also be achieved with an infinitely variable quantity of coolant
Durch die Anpassung an das Kuhlgut laßt sich die aufgelockerte Kühlung zeitlich solange ausdehnen, bis der gewünschte Umwandlungsgrad erreicht ist, ohne dass die Gefahr besteht - wie bei den bekannten Verfahren mit schneller Kühlung -, dass die Kuhlkurve durch zu intensive Kühlung schon vorher das Ferritgebiet verlaßtBy adapting to the Kuhlgut, the loosened cooling can be extended until the desired degree of conversion is reached, without the risk - as in the known methods with fast cooling - that the cooling curve leaves the ferrite area beforehand due to excessive cooling
Im Vergleich zur Kühlung nach dem Stand der Technik wird bei einer aufgelockerten Kühlung oder einer stufenlos veränderbaren Kuhlmittelmenge weniger Wasser bis zum Erreichen der Umwandlungstemperatur aufgebracht Diese Differenzwassermenge kann nun wahrend der Umwandlung aufgegeben werden, um die Kohlenstoffentmischung aus dem Ferrit in den Restaustenit zu forcieren und so die Ferπtbildung zu beschleunigen Die zurückgebliebenen Austenitbereiche sind mit Kohlenstoff so weit angereichert, dass sie bereits bei Abkuhlgeschwindigkeiten von 20 - 30 K/s matensitisch umwandelnCompared to the cooling according to the prior art, with loosened cooling or a continuously variable amount of coolant, less water is applied until the conversion temperature is reached.This amount of differential water can now be added during the conversion in order to force the carbon segregation from the ferrite into the remaining austenite and so on Accelerate the formation of the ferten The remaining austenite areas are enriched with carbon to such an extent that they convert matensitically at cooling rates of 20 - 30 K / s
Da eine definierte Haltezeit für die Abkühlung an Luft nicht mehr notwendig ist, um eine ausreichende Ferritbildung zu gewährleisten, kann die Herstellung von Dualphasen-Stahlen auf einem Teil der Kuhlstrecke erfolgen Der genutzte Teil der Kuhlstrecke ist dabei sehr viel kurzer als bei den bekannten Verfahren mit Luftkühlung Wenn die erforderlichen Gefugekomponenten für Dualphasen-Stählen ohne Luftkühlung eingestellt werden können, entstehen daraus für den Betreiber wesentliche Vorteile Es sind weniger Anlagenkomponenten für die Herstellung von Dualphasen-Stählen notwendig Gleichzeitig kann das Produktionsspektrum mit veränderten Prozeß- und Bandparametern (z. B höhere Bandgeschwindigkeit) gegenüber bisher erweitert werden.Since a defined holding time for cooling in air is no longer necessary to ensure sufficient ferrite formation, the production of dual-phase steels can take place on part of the cooling section. The part of the cooling section used is much shorter than in the known processes with Air cooling If the required structural components for dual-phase steels can be set without air cooling, this results in significant advantages for the operator. Fewer system components are required for the production of dual-phase steels. At the same time, the production spectrum can be modified with changed process and strip parameters (e.g. higher strip speed). compared to be expanded so far.
Eine Anlage zur Durchführung des Verfahrens der Erfindung ist gekennzeichnet durch eine hinter dem letzten Fertigwalzgerüst angeordnete Kühlstrecke aus mehreren mit Abstand hintereinander angeordneten Wasserkuhlstufen oder Kühlsystemen mit einer stufenlos veränderbaren Kühlmittelmenge. Die Anzahl der Wasserkühlstufen, ihre wirksame Lange und ihr Abstand voneinander sind gemäß der Erfindung veränderbar, so dass diese Kühlstrecke an veränderte Geometrien des Kühlgutes sowie an unterschiedliche Bandgeschwindigkeiten in einfacher Weise angepasst werden kannA system for carrying out the method of the invention is characterized by a cooling section arranged behind the last finishing mill stand, comprising a plurality of water cooling stages or cooling systems arranged one behind the other with a continuously variable amount of coolant. The number of water cooling stages, their effective length and their distance from one another can be changed according to the invention, so that this cooling section can be adapted in a simple manner to changed geometries of the goods to be cooled and to different belt speeds
Weitere Vorzüge, Einzelheiten und Merkmale der Erfindung ergeben sich aus der nachstehenden Erläuterung eines in den Zeichnungen schematisch dargestellten AusführungsbeispielsFurther advantages, details and features of the invention result from the following explanation of an exemplary embodiment shown schematically in the drawings
Es zeigenShow it
Fig. 1 eine schematische Darstellung der schnellen Kühlung und der aufgelockerten Kühlung sowie ihre Zuordnung in einer WalzstraßeFig. 1 is a schematic representation of the rapid cooling and the loosened cooling and their assignment in a rolling mill
Fig. 2 ein Zeit-Temperatur-Umwandlungs-Schaubild,2 is a time-temperature conversion diagram,
Fig. 3 den Grad der Austemtumwandlung bei der schnellenFig. 3 shows the degree of Ausemtumumwandung with the fast
Umwandlung, Fig 4 den Grad der Austemtumwandlung bei der aufgelockertenConversion, Fig. 4 shows the degree of Ausemtumumwandung with the loosened
Kühlungcooling
In der Figur 1 ist schematisch das Ende einer Walzstraße dargestellt, bestehend aus dem letzten Fertigwalzgerust (1 ), dem Walzgut bzw Kuhlgut (2) und einem Haspel (3) mit Umlenkrollen bzw Treiber (4) Oberhalb dieses Teils einer Walzstraße sind zwei unterschiedliche Kuhlstrecken eingezeichnet Mit der Kuhlstrecke (5) nach dem Stand der Technik wird durch eine zusammenhangende Wasserzufuhr eine frühe, schnelle Abkühlung des Kuhlgutes (2) herbeigeführt In der Kuhlstrecke (6) sind gemäß der Erfindung mit Abstand hintereinander Wasserkuhlstufen (7) angeordnet, wodurch die Abkühlung "aufgelockert" wirdIn Figure 1, the end of a rolling mill is shown schematically, consisting of the last finish rolling stand (1), the rolling stock or cooling stock (2) and a reel (3) with deflection rollers or driver (4) Above this part of a rolling train are two different cooling sections drawn in With the cooling section (5) according to the prior art, an early, rapid cooling of the cooling material (2) is brought about by a coherent water supply. In the cooling section (6), according to the invention, water cooling stages (7) are arranged one behind the other, thereby cooling "loosened up"
Die sich durch die unterschiedlichen Kuhlverfahren (5, 6) ergebenden unterschiedlichen Umwandlungsergebnisse sind in den folgenden schematischen Darstellungen beispielhaft wiedergegebenThe different conversion results resulting from the different cooling processes (5, 6) are shown as examples in the following schematic representations
In Figur 2 ist in einem Zeit-Temperatur-Umwandlungs-Schaubild der Verlauf der Abkuhlkurve (9) bei einer Abkühlung nach bekannten Verfahren und die Abkuhlkurve (10) bei einer aufgelockerten Kühlung dargestellt, wobei auf der Abszisse die Zeit (Z) in Sekunden und auf der Ordinate die Temperatur (T) in °Celsιus angegeben sindIn Figure 2, the course of the cooling curve (9) is shown in a time-temperature conversion diagram during a cooling according to known methods and the cooling curve (10) with a loosened cooling, the time (Z) in seconds and on the ordinate the temperature (T) is given in ° Celsius
Die Abkuhlkurve (9) zeigt den Kuhlverlauf bei der heute üblich verwendeten Strategie (frühes, schnelles Abkühlen auf eine bestimmte Haltetemperatur mit anschließender Luftkühlung, danach weitere Abkühlung auf tiefe Temperaturen unterhalb der Martensitstarttemperatur) Die Abkuhlkurve erreicht mit ihrer ersten Abkuhlstufe (11 ) relativ früh im Punkt (8) das Umwandlungsgebiet für die Ferπtbildung (Ferritgebiet) und verbleibt infolge der Haltezeit (12) mit Luftkühlung auch relativ lange in diesem Gebiet (F), bevor durch die zweite Abkuhlstufe (13) ab dem Punkt (17) die weitere Abkühlung auf eine Temperatur unterhalb der Martensitstarttemperatur (M = Martensit, B = Bainit, P = Per t) erfolgtThe cooling curve (9) shows the cooling process with the strategy commonly used today (early, rapid cooling to a certain holding temperature with subsequent air cooling, then further cooling to low temperatures below the martensite start temperature) The cooling curve reaches its early cooling stage (11) relatively early in the Point (8) the conversion area for the Ferπtbildung (ferrite area) and remains due to the holding time (12) with air cooling in this area (F) for a relatively long time before the second cooling stage (13) from point (17) Cooling to a temperature below the martensite start temperature (M = martensite, B = bainite, P = Per t) takes place
Demgegenüber erreicht die Abkuhlkurve (10) mit ihrer ersten Abkuhlstufe (14) bei der aufgelockerten Kühlung gegenüber der Abkuhlkurve (9) das Ferritgebiet (F) im Punkt (15) erst spater Da nach Erreichen des Ferritgebietes (F) die aufgelockerte Kühlung zunächst beibehalten wird wird keine zeitkostende Haltezeit mit Luftkühlung benotigt und die Abkuhlkurve (10) verlaßt zeitlich früher wieder das Ferritgebiet (F)In contrast, the cooling curve (10) with its first cooling stage (14) reaches the ferrite area (F) at point (15) later in the loosened cooling compared to the cooling curve (9). Since the loosened cooling is initially maintained after reaching the ferrite area (F) no time-consuming holding time with air cooling is required and the cooling curve (10) leaves the ferrite area (F) earlier
Die aufgelockerte Kühlung wird innerhalb des Ferritgebietes (F) dabei solange aufrecht erhalten, bis der gewünschte Umwandlungsgrad erreicht ist Danach erfolgt unmittelbar die weitere Abkühlung mit der zweiten Abkuhlstufe (16)The loosened cooling is maintained within the ferrite area (F) until the desired degree of conversion is reached. Then the further cooling with the second cooling stage (16) takes place immediately.
Die mit den aufgezeigten unterschiedlichen Abkuhlstrategien, der bekannten schnellen Abkühlung und der aufgelockerten Abkühlung erreichbaren Austenitumwandlungsraten sind den beiden nächsten Darstellungen in den Figuren 3 und 4 zu entnehmen, dabei ist jeweils auf der Abszisse die Kuhlzeit (Z) in Sekunden und auf der Ordinate der Umwandlungsgrad (U) der Austenitumwandlung in Ferrit dargestelltThe austenite transformation rates that can be achieved with the different cooling strategies shown, the known rapid cooling and the loosened cooling are shown in the next two representations in FIGS. 3 and 4, the cooling time (Z) in seconds in each case and the degree of conversion on the ordinate (U) shows the austenite transformation in ferrite
Bei der schnellen Abkühlung (Fig 3) findet wahrend der ersten Abkuhlstufe (11 ) der Abkuhlkurve (9) zunächst eine starke Ferπtbildung bis ca 53 % statt, die sich dann bei der folgenden Luftkühlung (12) auf etwa 62 % steigert Dies ist aber für die Herstellung von Dualphasen-Stahlen noch nicht ausreichendIn the case of rapid cooling (FIG. 3), during the first cooling stage (11) of the cooling curve (9) there is initially a strong formation of up to about 53%, which then increases to about 62% in the subsequent air cooling (12) the production of dual-phase steels is not yet sufficient
Bei der aufgelockerten Kühlung (Fig 4) gemäß Abkuhlkurve (10) sind dagegen in der gleichen Zeit bereits deutlich höhere Ferritgehalte in der ersten Abkuhlstufe (14) gebildet und bereits ca 82 % Austenit in Ferrit umgewandelt, bevor die zweite Abkuhlstufe (16) einsetzt (die heute produzierten Dualphasen-Stahlen haben im allgemeinen einen Anteil von > 80 % Ferrit )In contrast, with the loosened cooling (FIG. 4) according to the cooling curve (10), significantly higher ferrite contents are formed in the first cooling stage (14) and about 82% austenite is already converted into ferrite before the second cooling stage (16) begins ( the today Dual-phase steels produced generally have a share of> 80% ferrite)
Die Erfindung ist nicht auf die in den Darstellungen beschriebenen beispielhaften Abkuhlkurven beschrankt, sondern auch andere Abkuhlkurven wie zum Beispiel bei Kuhlsystemen mit einer stufenlos veränderbaren Kuhlmittelmenge, die im Sinne der Erfindung zu höheren Umwandlungstemperaturen fuhren, sind möglich Auch ist die Erfindung nicht auf eine Wasserkühlung beschrankt, sondern es können andere Kuhlsysteme verwendet werden, die zu einem frühen Erreichen des Ferritgebietes bei hohen Temperaturen fuhren The invention is not limited to the exemplary cooling curves described in the illustrations, but also other cooling curves, such as, for example, in cooling systems with an infinitely variable amount of cooling agent, which in the sense of the invention lead to higher conversion temperatures, are also possible. The invention is not restricted to water cooling , but other cooling systems can be used, which lead to an early reaching of the ferrite area at high temperatures

Claims

Ansprüche Expectations
1. Verfahren zur Herstellung von Dualphasen-Stählen aus dem warmgewalzten Zustand mit einem zweiphasigen Gefüge aus 70 bis 90 % Ferrit und 30 bis 10 % Martensit durch eine kontrollierte Temperaturführung und definierte Kühlstrategie während der Abkühlung der Stähle, unter anderem mittels Wasserkühlung nach ihrer Fertigwalzung, wobei in einer ersten Abkühlstufe die Kühlkurve in das Ferritgebiet einläuft und nach Erreichen des notwendigen Ferritanteils in einer zweiten Abkühlstufe auf Temperaturen unterhalb der Martensitstarttemperatur weiter abgekühlt wird, dadurch gekennzeichnet, dass während der ersten Abkühlstufe (14) die Abkühlkurve (10) der Stähle mit einer so niedrigen Abkühlgeschwindigkeit von 20 K/s bis 30 K/s eingestellt wird, dass die Abkühlkurve (10) mit einer noch so hohen Temperatur in das Ferritgebiet einläuft, dass die Ferritbildung schnell erfolgen kann und vor Beginn der zweiten Abkühlstufe (16) bereits mindestens 70 % des Austenits in Ferrit umgewandelt sind.1.Procedure for the production of dual-phase steels from the hot-rolled state with a two-phase structure made of 70 to 90% ferrite and 30 to 10% martensite through controlled temperature control and a defined cooling strategy during the cooling of the steels, including by means of water cooling after their finish rolling, wherein in a first cooling stage the cooling curve enters the ferrite area and after reaching the necessary ferrite content is further cooled in a second cooling stage to temperatures below the martensite starting temperature, characterized in that during the first cooling stage (14) the cooling curve (10) of the steels with a such a low cooling rate of 20 K / s to 30 K / s is set that the cooling curve (10) enters the ferrite area at such a high temperature that the ferrite can form quickly and at least before the start of the second cooling step (16) 70% of the austenite converted into ferrite are bundled.
2. Verfahren nach Anspruch 1 , dadurch gekennzeichnet, dass die zweite Abkühlstufe (16) ohne zwischengeschaltete Luftkühlung und Haltezeit unmittelbar an die erste Abkühlstufe (14) anschließt.2. The method according to claim 1, characterized in that the second cooling stage (16) directly connects to the first cooling stage (14) without intermediate air cooling and holding time.
3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Kühlung wahrend der ersten Abkuhlstufe (14) durch eine aufgelockerte Kühlung mit Hilfe von mit Abstand hintereinander angeordneten Wasserkuhlstufen (7) oder bei Kuhlsystemen mit einer stufenlos veränderbaren Kuhlmittelmenge erfolgt3. The method according to claim 1 or 2, characterized in that cooling takes place during the first cooling stage (14) by means of a loosened cooling with the aid of water cooling stages (7) arranged at a distance from one another or, in the case of cooling systems, with an infinitely variable amount of coolant
Verfahren nach Anspruch 3, dadurch gekennzeichnet, dass wahrend der Umwandlung des Austenits in Ferrit bis zum angestrebten Ferπtgehalt von mindestens 70 % die aufgelockerte Kühlung fortgesetzt wirdA method according to claim 3, characterized in that the loosened cooling is continued during the conversion of the austenite into ferrite up to the desired ferπt content of at least 70%
Anlage zur Durchfuhrung des Verfahrens nach einem oder mehreren der vorhergehenden Ansprüche, zur Herstellung von Dualphasen- Stahlen aus dem warmgewalzten Zustand, gekennzeichnet durch eine hinter dem letzten Fertigwalzgerust (1) angeordnete Kuhlstrecke (6) mit mehreren mit Abstand hintereinander angeordneten Wasserkuhlstufen (7) oder mit Kuhlsystemen mit einer stufenlos veränderbaren KuhlmittelmengeInstallation for carrying out the method according to one or more of the preceding claims, for producing dual-phase steels from the hot-rolled state, characterized by a cooling section (6) arranged behind the last finishing mill stand (1) with a plurality of water cooling stages (7) or arranged one behind the other with cooling systems with an infinitely variable amount of coolant
Anlage nach Anspruch 5, dadurch gekennzeichnet, dass die Anzahl der Wasserkuhlstufen (7), ihre wirksame Lange und ihr Abstand voneinander veränderbar oder bei einer Mengenregelung stufenlos verstellbar sind System according to claim 5, characterized in that the number of water cooling stages (7), their effective length and their distance from one another can be changed or are infinitely adjustable in the case of a quantity control
PCT/EP1999/005113 1998-07-24 1999-07-17 Method and installation for producing dual-phase steel WO2000005422A1 (en)

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BR9912310-0A BR9912310A (en) 1998-07-24 1999-07-17 Process and plant for the manufacture of hot rolled biphasic steels
EP99938282A EP1108072B1 (en) 1998-07-24 1999-07-17 Method and installation for producing dual-phase steel
CA2338743A CA2338743C (en) 1998-07-24 1999-07-17 Method and installation for producing dual-phase steel
AT99938282T ATE224959T1 (en) 1998-07-24 1999-07-17 METHOD AND SYSTEM FOR PRODUCING DUAL PHASE STEELS
DE59902877T DE59902877D1 (en) 1998-07-24 1999-07-17 METHOD AND SYSTEM FOR PRODUCING DUAL-PHASE STEELS
JP2000561368A JP2002521562A (en) 1998-07-24 1999-07-17 Manufacturing method and manufacturing equipment for duplex stainless steel

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DE19833321A DE19833321A1 (en) 1998-07-24 1998-07-24 Method and installation to produce dual phase steels out of hot-rolled strip, with cooling rate at first cooling stage set sufficiently low to obtain temperature which is sufficiently high for rapid transformation of austenite into ferrite

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004111279A2 (en) * 2003-06-18 2004-12-23 Sms Demag Aktiengesellschaft Method and installation for the production of hot-rolled strip having a dual-phase structure
CN104001742A (en) * 2014-05-21 2014-08-27 中冶南方工程技术有限公司 Method for achieving controlled cooling on rolled pieces between and after bar finishing mill units

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE1013359A3 (en) 2000-03-22 2001-12-04 Centre Rech Metallurgique Method for manufacturing a multi-band steel hot rolled.
NL1016042C2 (en) * 2000-08-29 2001-07-24 Corus Technology B V Hot rolled dual phase steel band for, e.g., automotive parts contains vanadium in place of chromium
AUPR048000A0 (en) * 2000-09-29 2000-10-26 Bhp Steel (Jla) Pty Limited A method of producing steel
KR100516519B1 (en) * 2001-12-26 2005-09-26 주식회사 포스코 A method for manufacturing the dual phase carbon steel wire by using controlled rolling and rapid cooling
KR100521596B1 (en) * 2002-11-20 2005-10-12 현대자동차주식회사 Processing method of automotive parts by direct resistance heating
CN104384207A (en) * 2014-10-22 2015-03-04 南京钢铁股份有限公司 Cooling control method for hot rolling bearing steel bar and process arrangement of hot rolling bearing steel bar
KR102440768B1 (en) * 2020-12-18 2022-09-08 주식회사 포스코 Method and apparatus for manufacturng thick-sheet iron

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2488285A1 (en) * 1980-08-11 1982-02-12 Kobe Steel Ltd
JPS57104650A (en) * 1980-12-19 1982-06-29 Kobe Steel Ltd High-strength hot-rolled steel plate and its manufacture
EP0068598A2 (en) * 1981-02-20 1983-01-05 Kawasaki Steel Corporation Dual phase-structured hot rolled high-tensile strength steel sheet and a method of producing the same
EP0072867A1 (en) * 1981-02-20 1983-03-02 Kawasaki Steel Corporation Process for manufacturing high-tensile hot-rolled steel strip having a low yield ratio due to its mixed structure
EP0719868A1 (en) * 1994-12-26 1996-07-03 Kawasaki Steel Corporation Steel sheet for automobiles having excellent impact resistance and method of manufacturing the steel sheet
EP0747495A1 (en) * 1995-06-08 1996-12-11 Sollac S.A. Niobium containing hot rolled steel sheet with high strength and good deep-drawing properties, and process for its manufacture

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5818970B2 (en) * 1978-08-31 1983-04-15 川崎製鉄株式会社 Method for manufacturing high-strength thin steel sheets with excellent cold workability
JPS61170518A (en) * 1985-01-25 1986-08-01 Kobe Steel Ltd Production of high-strength hot rolled steel sheet having excellent formability
JPS6293006A (en) * 1985-10-18 1987-04-28 Kobe Steel Ltd Production of high strength hot rolled steel sheet
KR100301994B1 (en) * 1996-12-24 2001-11-22 이구택 Method for uniformly cooling hot rolled wire rod
KR100747495B1 (en) * 2006-11-10 2007-08-08 삼성전자주식회사 Variable capacity rotary compressor

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2488285A1 (en) * 1980-08-11 1982-02-12 Kobe Steel Ltd
JPS57104650A (en) * 1980-12-19 1982-06-29 Kobe Steel Ltd High-strength hot-rolled steel plate and its manufacture
EP0068598A2 (en) * 1981-02-20 1983-01-05 Kawasaki Steel Corporation Dual phase-structured hot rolled high-tensile strength steel sheet and a method of producing the same
EP0072867A1 (en) * 1981-02-20 1983-03-02 Kawasaki Steel Corporation Process for manufacturing high-tensile hot-rolled steel strip having a low yield ratio due to its mixed structure
EP0719868A1 (en) * 1994-12-26 1996-07-03 Kawasaki Steel Corporation Steel sheet for automobiles having excellent impact resistance and method of manufacturing the steel sheet
EP0747495A1 (en) * 1995-06-08 1996-12-11 Sollac S.A. Niobium containing hot rolled steel sheet with high strength and good deep-drawing properties, and process for its manufacture

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 006, no. 191 (C - 127) 30 September 1982 (1982-09-30) *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004111279A2 (en) * 2003-06-18 2004-12-23 Sms Demag Aktiengesellschaft Method and installation for the production of hot-rolled strip having a dual-phase structure
WO2004111279A3 (en) * 2003-06-18 2005-05-06 Sms Demag Ag Method and installation for the production of hot-rolled strip having a dual-phase structure
CN100381588C (en) * 2003-06-18 2008-04-16 Sms迪马格股份公司 Method and installation for the production of hot-rolled strip having a dual-phase structure
CN104001742A (en) * 2014-05-21 2014-08-27 中冶南方工程技术有限公司 Method for achieving controlled cooling on rolled pieces between and after bar finishing mill units

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