EP1111075A1 - Wire heat treating process - Google Patents
Wire heat treating process Download PDFInfo
- Publication number
- EP1111075A1 EP1111075A1 EP00126743A EP00126743A EP1111075A1 EP 1111075 A1 EP1111075 A1 EP 1111075A1 EP 00126743 A EP00126743 A EP 00126743A EP 00126743 A EP00126743 A EP 00126743A EP 1111075 A1 EP1111075 A1 EP 1111075A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- rolling
- cooling
- winding
- rolling stock
- temperature
- 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.)
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Links
- 238000000034 method Methods 0.000 title claims description 41
- 238000001816 cooling Methods 0.000 claims abstract description 29
- 229910000734 martensite Inorganic materials 0.000 claims abstract description 27
- 238000005496 tempering Methods 0.000 claims abstract description 8
- 238000005096 rolling process Methods 0.000 claims description 37
- 238000004804 winding Methods 0.000 claims description 18
- 229910000831 Steel Inorganic materials 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 10
- 239000010959 steel Substances 0.000 claims description 10
- 229910001566 austenite Inorganic materials 0.000 claims description 9
- 238000010438 heat treatment Methods 0.000 claims description 8
- 239000010410 layer Substances 0.000 claims description 5
- 238000005554 pickling Methods 0.000 claims description 5
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 4
- 229910052796 boron Inorganic materials 0.000 claims description 4
- 238000005336 cracking Methods 0.000 claims description 3
- 238000001556 precipitation Methods 0.000 claims description 3
- 238000001953 recrystallisation Methods 0.000 claims description 3
- 230000003068 static effect Effects 0.000 claims description 3
- 229910001149 41xx steel Inorganic materials 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 239000002344 surface layer Substances 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims 1
- 230000000977 initiatory effect Effects 0.000 abstract 1
- 238000010791 quenching Methods 0.000 description 6
- 230000000171 quenching effect Effects 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000007795 chemical reaction product Substances 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000003303 reheating Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 238000010792 warming Methods 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000029142 excretion Effects 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910001562 pearlite Inorganic materials 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
-
- 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
- C21D9/525—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/54—Furnaces for treating strips or wire
- C21D9/56—Continuous furnaces for strip or wire
- C21D9/573—Continuous furnaces for strip or wire with cooling
-
- 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
- C21D1/19—Hardening; Quenching with or without subsequent tempering by interrupted quenching
Definitions
- the invention relates to a method for the heat treatment of wire, wherein the Rolled material rolled into coils or coiled or by means of a winding device in Winding shape is brought.
- the invention relates to a system for Execution of the procedure.
- EP 0 849 369 A2 discloses a method for the heat treatment of wire or bar steel, in which the rolling stock coming from the rolling heat is coiled in a basket or deposited in turns on a conveyor belt by means of a winding layer and at the end of this conveying means via a mandrel to one Bund is collected, whereby in order to avoid fluctuations in cooling in the reel or as a winding and associated inhomogeneous mechanical properties, it is proposed to lead the cooling from the rolling heat to the conversion area, which is caused by the Ar 3 or Ar 1 line is marked. This cooling is controlled in such a way that the surface of the rolling stock is not supercooled and thus reaches the area of martensite formation in order to avoid undesirable hard spots on the rolling stock surface. According to the process known from EP 0 849 369 A2, the rolling stock from the austenite phase is to be converted almost isothermally into the ferrite / pearlite phase.
- the invention has for its object a method for heat treatment of wire and a system for performing the method of the generic type Provide ways to further develop known processes and systems, the wire is tempered before further processing to the end product and overall an uneven structure over the length of the roll and thus uneven mechanical properties can be avoided.
- the invention is based on the idea that to temper the wire already the still long format, i.e. not yet wound, rolling stock directly from the Rolling heat coming cooled to a temperature below the martensite start temperature becomes.
- the martensite start temperature is the temperature at which the martensite transformation starts. It is due to increasing carbon contents and alloy additives noticeably influenced and is therefore from the special alloy composition dependent. Only after the quenching step is discouraged the rolling stock is then coiled, wound or laid in turns. Subsequently the tempering process takes place.
- a remuneration process is known to consist of three sub-steps, austenitizing a material, i.e. the warming up and warming up of the Workpiece and homogenization of the structure, quenching for adjustment a hardness structure as well as tempering to improve the toughness properties.
- austenitizing a material i.e. the warming up and warming up of the Workpiece and homogenization of the structure
- quenching for adjustment a hardness structure as well as tempering to improve the toughness properties.
- austenitizing because the wire is cooled directly from the rolling heat. It has been recognized that it is it is also possible to lay the wire in turns, even when hardened and then start.
- the effect is preferably exploited that that in the cooling in the surface layer of the long-format rolled material formed by the residual heat is already started in the core.
- the remaining austenite changes later in the federal government to martensite.
- the beneficial properties, in particular the reduced risk of cracking, the less stressed hardness structure has already been pointed out.
- the cooling to a temperature below the martensite start temperature - i.e. quenching - after the finish stitch in the roll stand and before static recrystallization of the roll structure begins.
- the resultant during the rolling process and during cooling also quenched secondary scale by cracking at Winding or winding already mechanically before a subsequent one Pickling process is removed.
- the problem of scale formation in the federal government is eliminated as the material is cooled to temperatures ⁇ 400 ° C during the quenching process becomes. No scale forms at these temperatures. This eliminates the Disadvantage described above that when pickling for safe descaling inner turns for pickling the outer turns.
- edge decarburization of the wire material is avoided, which at a reheating to austenitizing temperature and thus the necessary high Oven temperatures occur and have a negative impact on the end product.
- the method proposed according to the invention also has an environmentally friendly method Aspects on. Steels for cold massive forming - alloyed with boron usually isothermally converted to a cold formable in a salt bath To create structures. In addition to occurring fluctuations in strength the wire length is very harmful to the environment in the salt bath.
- proposed method can be dispensed with the salt bath treatment because the steel grades coming from the rolling heat are below the martensite start temperature be cooled and then converted into a bunch.
- a system for implementing the method is proposed with a Roll stand and downstream device for reeling the rolling stock or device for laying turns next to conveyor device for the turns and collecting station to form a bundle by means of a mandrel and a cooling section, which is immediately downstream of the roll stand online for defined cooling of the long-sized rolling stock below the martensite start temperature, and one Tempering furnace, which is arranged downstream of the reel device or winding laying device is.
- This tempering furnace can because of the fine-grained structure and the residual heat in the bundle is considerably shorter than that of the conventional ones Compensation process required.
- the method according to the invention is preferably used for heat treatment the 50 Cr V4 and temperable steels with pre-eutectoid carbide precipitation, like 90 MnCr V8 or X 36 CrMo 17, or boron-containing steels with subsequent Cold forming for springs, screws, molded parts etc.
- pre-eutectoid carbide precipitation like 90 MnCr V8 or X 36 CrMo 17, or boron-containing steels with subsequent Cold forming for springs, screws, molded parts etc.
- Boron-containing steels for cold massive forming can now be obtained from the rolling heat be compensated. They show after cold forming without additional tempering the desired strength.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
- Heat Treatment Of Steel (AREA)
- Winding, Rewinding, Material Storage Devices (AREA)
Abstract
Description
Die Erfindung betrifft ein Verfahren zum Wärmebehandeln von Draht, wobei das Walzgut zu Bunden gehaspelt oder gespult oder mittels eines Windungslegers in Windungsform gebracht wird. Zudem betrifft die Erfindung eine Anlage zur Durchführung des Verfahrens.The invention relates to a method for the heat treatment of wire, wherein the Rolled material rolled into coils or coiled or by means of a winding device in Winding shape is brought. In addition, the invention relates to a system for Execution of the procedure.
Zur Herstellung von Draht in Abmessungsbereichen von 5 bis 60 mm Durchmesser wird üblicherweise das langformatiges Walzprodukt nach dem Walzen zu einem Bund gehaspelt - sogenanntes Garret-Haspeln -, zu Bunden aufgespult oder mit Hilfe eines Windungslegers in Windungsform überführt, die Windungen auf Transportrollen oder -ketten abgelegt und am Ende dieser Transporteinrichtung zu einem Bund gesammelt.For the production of wire in dimensions from 5 to 60 mm in diameter is usually the long format rolled product after rolling into one Bundle coiled - so-called Garret reel -, wound into bundles or with the help of a winding layer in the form of turns, the turns Transport rollers or chains stored and at the end of this transport device collected a bundle.
Aufgrund der im Haspel oder in der Spule stattfindenden Abkühlung des Materials treten wegen der unterschiedlichen Abkühlbedingungen innerhalb des Bundes Festigkeitsunterschiede über die Stablänge auf. Diese Festigkeitsunterschiede werden nach bekannten Verfahren entweder in einer nachfolgenden Wärmebehandlung im Bund kompensiert oder nach der Weiterverarbeitung durch ein Vergüten des Endproduktes beseitigt.Due to the cooling of the material taking place in the reel or in the coil occur due to the different cooling conditions within the federal government Differences in strength over the bar length. These differences in strength are either known in a subsequent heat treatment compensated in the federal government or after processing by remuneration of the end product eliminated.
In der DE 28 30 153 A1 ist ein Verfahren zum Wärmebehandeln von zu Ringen gehaspeltem Draht oder Band beschrieben. Das Walzprodukt wird hierzu gehaspelt und in Haspelform abgekühlt. Vor dem Wärmebehandeln wird der Draht oder das Band dann auf die vorgesehene Temperatur, in der Regel (bei Stahl) die Austenitisierungstemperatur, gebracht. Die austenitisierten Ringe werden schließlich unter Erregung zu Resonanzschwingungen gehärtet und anschließend angelassen.DE 28 30 153 A1 describes a process for the heat treatment of rings described coiled wire or ribbon. For this purpose, the rolled product is coiled and cooled in reel form. Before the heat treatment, the wire or the strip then to the intended temperature, usually (for steel) the Austenitizing temperature. The austenitized rings will eventually hardened under excitation to resonance vibrations and then tempered.
Insgesamt besteht aber bei derartigen Verfahren nach wie vor das Problem, daß die Abkühlung ungleichmäßig erfolgt und der Draht in der Bundmitte erheblich langsamer abkühlt als am Rand. Dadurch bilden sich an den Drahtwindungen im Inneren des Bundes oder der Wicklung dickere Zunderschichten als an den Randwindungen. Bei dem vor einer Weiterverarbeitung der Drahtprodukte notwendig werdenden Beizprozeß müssen auch die inneren Windungen von den Zunderschichten befreit werden, was mit der Gefahr verbunden ist, daß die äußeren, zunderärmeren Drahtwindungen von der Beizsäure zu stark angegriffen und beschädigt werden.Overall, however, there is still the problem with such methods that the cooling takes place unevenly and the wire in the middle of the collar considerably cools more slowly than at the edge. This will form on the wire windings in the Thicker layers of scale on the inside of the bundle or the winding than on the Edge turns. This is necessary before further processing the wire products pickling process must also the inner turns of the Scale layers are freed, which is associated with the risk that the outer, wire millings that are poorer in scaling are too strongly attacked and to be damaged.
Aus der EP 0 849 369 A2 ist ein Verfahren zur Wärmebehandlung von Draht oder Stabstahl bekannt, bei dem das Walzgut aus der Walzhitze kommend in einem Korb gehaspelt oder mittels eines Windungslegers in Windungen auf ein Förderband abgelegt und am Ende dieses Fördermittels über einen Dorn zu einem Bund gesammelt wird, wobei zur Vermeidung von Schwankungen beim Abkühlen im Haspel oder als Windung und damit verbundenen inhomogenen mechanischen Eigenschaften vorgeschlagen wird, bereits vor dem Wickeln oder Windungslegen die Kühlung aus der Walzhitze bis in den Umwandlungsbereich zu führen, der durch die Ar3- bzw. Ar1-Linie gekennzeichnet ist. Diese Kühlung wird so geregelt, daß die Oberfläche des Walzgutes nicht unterkühlt und somit in den Bereich der Martensitbildung gelangt, um unerwünschte Härteflecken auf der Walzgutoberfläche zu vermeiden. Nach dem aus der EP 0 849 369 A2 bekannten Verfahren soll das Walzgut aus der Austenit-Phase nahezu isothermisch in die Ferrit/Perlit-Phase umwandeln. EP 0 849 369 A2 discloses a method for the heat treatment of wire or bar steel, in which the rolling stock coming from the rolling heat is coiled in a basket or deposited in turns on a conveyor belt by means of a winding layer and at the end of this conveying means via a mandrel to one Bund is collected, whereby in order to avoid fluctuations in cooling in the reel or as a winding and associated inhomogeneous mechanical properties, it is proposed to lead the cooling from the rolling heat to the conversion area, which is caused by the Ar 3 or Ar 1 line is marked. This cooling is controlled in such a way that the surface of the rolling stock is not supercooled and thus reaches the area of martensite formation in order to avoid undesirable hard spots on the rolling stock surface. According to the process known from EP 0 849 369 A2, the rolling stock from the austenite phase is to be converted almost isothermally into the ferrite / pearlite phase.
Der Erfindung liegt die Aufgabe zugrunde, ein Verfahren zur Wärmebehandlung von Draht sowie eine Anlage zur Durchführung des Verfahrens der gattungsgemäßen Art bereitzustellen zur Weiterentwicklung bekannter Verfahren und Anlagen, wobei der Draht bereits vor der Weiterverarbeitung zum Endprodukt vergütet wird und insgesamt eine ungleichmäßige Gefügeausbildung über die Walzlänge und damit ungleichmäßige mechanische Eigenschaften vermieden werden.The invention has for its object a method for heat treatment of wire and a system for performing the method of the generic type Provide ways to further develop known processes and systems, the wire is tempered before further processing to the end product and overall an uneven structure over the length of the roll and thus uneven mechanical properties can be avoided.
Zur Lösung dieser Aufgabe wird ein Verfahren mit den Merkmalen des Anspruchs 1 sowie eine Anlage mit den Merkmalen des Anspruchs 10 vorgeschlagen. Vorteilhafte Weiterentwicklungen sind in den Unteransprüchen sowie der nachfolgenden Beschreibung offenbart.To solve this problem, a method with the features of the claim 1 and a system with the features of claim 10 proposed. Beneficial Further developments are in the subclaims and in the following Description disclosed.
Der Erfindung liegt der Gedanke zugrunde, daß zum Vergüten des Drahtes bereits das noch langformatige, d.h. noch nicht gewickelte, Walzgut unmittelbar aus der Walzhitze kommend auf eine Temperatur unterhalb Martensitstarttemperatur abgekühlt wird. Die Martensitstarttemperatur ist die Temperatur, bei der die Martensitumwandlung einsetzt. Sie wird durch steigende Kohlenstoffgehalte und Legierungszusätze merklich beeinflußt und ist somit von der speziellen Legierungszusammensetzung abhängig. Erst nach dem Vergütungsschritt Abschrecken wird das Walzgut dann gehaspelt, gespult oder in Windungen gelegt. Anschließend erfolgt der Anlaßvorgang des Vergütens.The invention is based on the idea that to temper the wire already the still long format, i.e. not yet wound, rolling stock directly from the Rolling heat coming cooled to a temperature below the martensite start temperature becomes. The martensite start temperature is the temperature at which the martensite transformation starts. It is due to increasing carbon contents and alloy additives noticeably influenced and is therefore from the special alloy composition dependent. Only after the quenching step is discouraged the rolling stock is then coiled, wound or laid in turns. Subsequently the tempering process takes place.
Ein Vergütungsprozeß setzt sich bekanntermaßen aus drei Teilschritten zusammen, dem Austenitisieren eines Werkstoffs, d.h. das Auf- und Durchwärmen des Werkstücks und Homogenisierung des Gefüges, dem Abschrecken zur Einstellung eines Härtegefüges sowie dem Anlassen zur Verbesserung der Zähigkeitseigenschaften. Im vorgeschlagenen Verfahren entfällt ein Austenitisieren, da der Draht direkt aus der Walzhitze kommend abgekühlt wird. Es ist erkannt worden, daß es auch möglich ist, den Draht selbst im gehärteten Zustand in Windungen zu legen und dann anzulassen. A remuneration process is known to consist of three sub-steps, austenitizing a material, i.e. the warming up and warming up of the Workpiece and homogenization of the structure, quenching for adjustment a hardness structure as well as tempering to improve the toughness properties. In the proposed method, there is no austenitizing because the wire is cooled directly from the rolling heat. It has been recognized that it is it is also possible to lay the wire in turns, even when hardened and then start.
Dies wird insbesondere durch solche Abkühlbedingungen erreicht, daß das Walzgut auf eine Temperatur unterhalb der Martensitstarttemperatur, aber oberhalb Martensitfinishtemperatur gekühlt wird und daß Gefüge noch Restaustenit aufweist. Dann schließt sich der Wickelvorgang an bei oder mit anschließendem isothermischen Halten, vorzugsweise unter Hauben. In Abhängigkeit von der Haltezeit wird der verbleibende Restaustenit diffusiongesteuert oder bei erneutem beschleunigten Abkühlen in Martensit umwandeln. Durch das Halten kommt es im anfänglich gebildeten Martensit zu Gefügeentspannungen. Wird der Draht nur bis kurz unter die Martensitstarttemperatur gekühlt und dann gewickelt oder in Windungen gelegt, so kann die Umwandlung des Restaustenits in Martensit im Bund erfolgen. Das so gebildete Martensitgefüge ist nicht tetragonal verspannt, wie es bei beschleunigter Abkühlung unter die Martensitfinishtemperatur der Fall wäre. Durch die verzögerte Abkühlung nach dem Erreichen der Martensitstarttemperatur kann der Restkohlenstoff diffundieren und der entstehende Martensit eigenspannungsarm in kubischen Martensit umwandeln. Hierdurch werden Mikroanrisse im Gefüge vermieden, was vor allem die Dauerwechselfestigkeit des Werkstoffs erheblich verbessert, beispielsweise bei dem 50 CrV4.This is achieved in particular by cooling conditions such that the rolling stock to a temperature below the martensite start temperature, but above Martensite finishing temperature is cooled and that the structure still has residual austenite. Then the winding process follows with or with subsequent isothermal Hold, preferably under hoods. Depending on the holding time the remaining austenite is diffusion-controlled or if it is accelerated again Convert cooling to martensite. By holding it comes in initially formed martensite to structural relaxation. The wire will only go up cooled just below the martensite start temperature and then wrapped or twisted the transformation of the remaining austenite into martensite in the bund respectively. The martensite structure thus formed is not tetragonally braced like it is accelerated cooling below the martensite finish temperature would be the case. Due to the delayed cooling after reaching the martensite start temperature the residual carbon can diffuse and the resulting martensite has low residual stress convert to cubic martensite. This will micro-cracks in Structures avoided, which significantly increases the fatigue strength of the material improved, for example with the 50 CrV4.
Zudem ist es von Vorteil, daß bei Stählen mit voreutektoider Karbidausscheidung - beispielsweise dem 90 MnCrV8 oder X36Mo17 - aufgrund der hohen Abkühlgeschwindigkeit diese Karbidausscheidungen an den Korngrenzen unterdrückt werden. Dadurch wird die Zähigkeit des Werkstoffs deutlich gesteigert. Sollte es dennoch aufgrund eines sehr hohen Ausscheidungspotentials zu Ausscheidungen kommen - beispielsweise bei hohem C-Gehalt -, sind diese Ausscheidungen extrem fein und damit im wesentlichen unschädlich. Grund ist das extrem feine Austenitausgangskorn, das gegenüber dem konventionellen Vergütungsverfahren eine etwa 10-fach größere Kornoberfläche aufweist. It is also an advantage that for steels with pre-eutectoid carbide precipitation - for example the 90 MnCrV8 or X36Mo17 - due to the high cooling rate these carbide deposits at the grain boundaries are suppressed. This significantly increases the toughness of the material. Should it still be due to a very high potential for elimination come - for example with a high C content - these excretions are extreme fine and therefore essentially harmless. The reason is the extremely fine Austenite starting grain compared to the conventional tempering process has an approximately 10 times larger grain surface.
Vorzugsweise wird der Effekt ausgenutzt, daß der bei der Abkühlung in der Randschicht des langformatigen Walzgutes gebildete Martensit durch die Restwärme im Kern bereits selbstangelassen wird. Der verbleibende Restaustenit wandelt später im Bund zu Martensit um. Auf die vorteilhaften Eigenschaften, insbesondere die reduzierte Gefahr einer Rißbildung, des geringer verspannten Härtegefüges wurde bereits hingewiesen.The effect is preferably exploited that that in the cooling in the surface layer of the long-format rolled material formed by the residual heat is already started in the core. The remaining austenite changes later in the federal government to martensite. On the beneficial properties, in particular the reduced risk of cracking, the less stressed hardness structure has already been pointed out.
Vorteilhafterweise wird die Abkühlung auf eine Temperatur unterhalb der Martensitstarttemperatur - d.h. das Abschrecken - nach dem Fertigstich im Walzgerüst und vor Beginn der statischen Rekristallisation des Walzgefüges durchgeführt. Hierbei wirkt sich das extrem feine Austenitkom nach dem Fertigstich, wobei die letzten Walzstiche vorzugsweise bei abgesenkten Endwalztemperaturen stattfinden, bereits vorteilhaft auf die Zähigkeitseigenschaften aus.Advantageously, the cooling to a temperature below the martensite start temperature - i.e. quenching - after the finish stitch in the roll stand and before static recrystallization of the roll structure begins. This affects the extremely fine austenite after the finish stitch, whereby the last passes are preferably carried out at reduced final rolling temperatures, already advantageous on the toughness properties.
Zudem wird vorgeschlagen, daß der beim Walzprozeß entstandene und beim Abkühlen ebenfalls abgeschreckte Sekundärzunder durch erfolgtes Anbrechen beim Wickeln oder Windungslegen bereits mechanisch vor einem sich ggfs. anschließenden Beizvorgang entfernt wird. Das Problem der Zunderbildung im Bund entfällt, da bei dem Abschreckvorgang das Material auf Temperaturen < 400°C gekühlt wird. Bei diesen Temperaturen bildet sich kein Zunder. Damit entfällt der oben beschriebene Nachteil, daß es beim Beizen zum sicheren Entzundern der inneren Windungen zum Überbeizen der Außenwindungen kommen kann.In addition, it is proposed that the resultant during the rolling process and during cooling also quenched secondary scale by cracking at Winding or winding already mechanically before a subsequent one Pickling process is removed. The problem of scale formation in the federal government is eliminated as the material is cooled to temperatures <400 ° C during the quenching process becomes. No scale forms at these temperatures. This eliminates the Disadvantage described above that when pickling for safe descaling inner turns for pickling the outer turns.
Da nach dem vorgeschlagenen Verfahren aus der Walzhitze kommend direkt abgeschreckt wird, werden Randentkohlungen des Drahtmaterials vermieden, die bei einem Wiedererwärmen auf Austenitisiertemperatur und damit notwendigen hohen Ofentemperaturen auftreten und sich negativ auf das Endprodukt auswirken.As directly quenched from the rolling heat according to the proposed method edge decarburization of the wire material is avoided, which at a reheating to austenitizing temperature and thus the necessary high Oven temperatures occur and have a negative impact on the end product.
Zudem wird einer mit einem Austenitisieren verbundenen Grobkornbildung entgegengewirkt. Da die Abkühlung bzw. der Abschreckvorgang das Drahtes unmittelbar aus der Walzhitze erfolgt, vorzugsweise vor der statischen Rekristallisation, ist das Austenitkom erheblich kleiner als bei einem Abschrecken nach einem Abkühlen aus der Walzhitze mit Wiedererwärmen auf Austenitisiertemperatur. Die Unterschiede liegen ungefähr zwischen 9-10 ASTM zu 6-7 ASTM jeweiliger Korngröße. Durch das Gefüge mit feinerer Korngröße werden neben den Festigkeitseigenschaften des Werkstoffs auch die Zähigkeitseigenschaften erheblich verbessert.In addition, coarse grain formation associated with austenitizing is counteracted. Since the cooling or quenching process the wire immediately from the rolling heat, preferably before static recrystallization the austenite is considerably smaller than when quenching after cooling from the rolling heat with reheating to the austenitizing temperature. The differences are approximately between 9-10 ASTM to 6-7 ASTM each grain size. Due to the structure with finer grain size, in addition to the strength properties of the material also significantly improved the toughness properties.
Schließlich weist das erfindungsgemäß vorgeschlagene Verfahren auch umweltschonende Aspekte auf. Stähle für Kaltmassivumformung - mit Bor legiert - werden üblicherweise im Salzbad isotherm umgewandelt, um ein kaltumformbares Gefüge zu erzeugen. Neben dabei auftretenden Festigkeitsschwankungen über die Drahtlänge ist das Salzbad sehr umweltschädlich. Bei Anwendung des erfindungsgemäß vorgeschlagenen Verfahrens kann auf die Salzbad-Behandlung verzichtet werden, weil die Stahlsorten aus der Walzhitze kommend unter die Martensitstarttemperatur gekühlt werden und anschließend im Bund umwandeln.Finally, the method proposed according to the invention also has an environmentally friendly method Aspects on. Steels for cold massive forming - alloyed with boron usually isothermally converted to a cold formable in a salt bath To create structures. In addition to occurring fluctuations in strength the wire length is very harmful to the environment in the salt bath. When using the invention proposed method can be dispensed with the salt bath treatment because the steel grades coming from the rolling heat are below the martensite start temperature be cooled and then converted into a bunch.
Zudem wird eine Anlage zur Durchführung des Verfahrens vorgeschlagen mit einem Walzgerüst sowie nachgeordneter Einrichtung zum Haspeln des Walzgutes oder Einrichtung zum Windungslegen neben Fördereinrichtung der Windungen und Sammelstation zu einem Bund mittels eines Dorns, sowie einer Kühlstrecke, die dem Walzgerüst unmittelbar online nachgeordnet ist, zum definierten Abkühlen des langformatigen Walzgutes unterhalb die Martensitstarttemperatur, und einem Anlaßofen, der der Haspeleinrichtung oder Windungslegereinrichtung nachgeordnet ist. Dieser Anlaßofen kann aufgrund des feinkörnigen Gefüges und der noch im Bund vorhandenen Restwärme erheblich kürzer ausfallen als der bei den herkömmlichen Vergütungsverfahren erforderliche.In addition, a system for implementing the method is proposed with a Roll stand and downstream device for reeling the rolling stock or device for laying turns next to conveyor device for the turns and collecting station to form a bundle by means of a mandrel and a cooling section, which is immediately downstream of the roll stand online for defined cooling of the long-sized rolling stock below the martensite start temperature, and one Tempering furnace, which is arranged downstream of the reel device or winding laying device is. This tempering furnace can because of the fine-grained structure and the residual heat in the bundle is considerably shorter than that of the conventional ones Compensation process required.
Das erfindungsgemäße Verfahren findet bevorzugt Anwendung zur Wärmebehandlung des 50 Cr V4 sowie vergütbarer Stähle mit voreutektoider Karbidausscheidung, wie 90 MnCr V8 oder X 36 CrMo 17, oder borhaltiger Stähle mit anschließender Kaltumformung für Federn, Schrauben, Formteilen etc. Gerade die borhaltigen Stähle für die Kaltmassivumformung können nun aus der Walzhitze vergütet werden. Sie weisen nach dem Kaltumformen ohne ein zusätzliches Vergüten die gewünschte Festigkeit auf.The method according to the invention is preferably used for heat treatment the 50 Cr V4 and temperable steels with pre-eutectoid carbide precipitation, like 90 MnCr V8 or X 36 CrMo 17, or boron-containing steels with subsequent Cold forming for springs, screws, molded parts etc. Just that Boron-containing steels for cold massive forming can now be obtained from the rolling heat be compensated. They show after cold forming without additional tempering the desired strength.
Claims (12)
dadurch gekennzeichnet,
daß zum Vergüten des Drahtes bereits das noch langformatige Walzgut unmittelbar aus der Walzhitze kommend auf eine Temperatur unterhalb der Martensitstarttemperatur abgekühlt wird.Process for the heat treatment of wire, the rolled material being coiled or wound into coils or brought into a winding shape by means of a winding layer,
characterized,
that, to temper the wire, the long-format rolling stock coming directly from the rolling heat is cooled to a temperature below the martensite start temperature.
dadurch gekennzeichnet,
daß das Walzgut nach dem Abkühlvorgang gehaspelt, gespult oder in Windungen gelegt wird und nachfolgend angelassen wird.Method according to claim 1,
characterized,
that the rolling stock is coiled, coiled or laid after the cooling process and then tempered.
dadurch gekennzeichnet,
daß das Walzgut auf eine Temperatur kurz unterhalb der Martensitstarttemperatur und oberhalb der Martensitfinish-Temperatur gekühlt wird, so daß das Gefüge noch Restaustenit aufweist, und sich dann der Wickelprozeß anschließt.Method according to claims 1 and 2,
characterized,
that the rolling stock is cooled to a temperature just below the martensite start temperature and above the martensite finish temperature, so that the structure still has residual austenite, and then the winding process follows.
dadurch gekennzeichnet,
daß das Walzgut nach Abkühlen auf eine Temperatur unterhalb der Martensitstarttemperatur unter Hauben geführt wird. Method according to claim 3,
characterized,
that the rolling stock is guided under hoods after cooling to a temperature below the martensite start temperature.
dadurch gekennzeichnet,
daß der bei der Abkühlung in der Randschicht des langformatigen Walzgutes gebildete Martensit durch die Restwärme im Kern bereits selbstangelassen wird.Method according to claim 1,
characterized,
that the martensite formed during cooling in the surface layer of the long-size rolling stock is already tempered by the residual heat in the core.
dadurch gekennzeichnet,
daß die Abkühlung auf eine Temperatur unterhalb der Martensitstarttemperatur nach dem Fertigstich im Walzgerüst und vor Beginn der statischen Rekristallisation des Walzgefüges durchgeführt wird.Method according to claim 1,
characterized,
that the cooling to a temperature below the martensite start temperature is carried out after the finish pass in the roll stand and before the static recrystallization of the roll structure begins.
dadurch gekennzeichnet,
daß die letzten Walzstiche bzw. der Fertigstich im Walzgerüst zur Einstellung eines feinkörnigen Walzgefüges bei im Verhältnis niedrigen Endwalztemperaturen stattfinden.Method according to claim 5,
characterized,
that the last rolling passes or the finishing pass in the roll stand for setting a fine-grained rolling structure take place at relatively low final rolling temperatures.
dadurch gekennzeichnet,
daß die Abkühlung des Walzgutes aus der Walzhitze mittels einer Wasserkühlung vorgenommen wird.Method according to one of claims 1 to 5,
characterized,
that the cooling of the rolling stock from the rolling heat is carried out by means of water cooling.
dadurch gekennzeichnet,
daß der beim Walzprozeß entstandene und beim Abkühlen ebenfalls abgeschreckte Sekundärzunder durch erfolgtes Anbrechen beim Wickeln oder Windungslegen bereits mechanisch vor einem sich ggfs. anschließenden Beizvorgang entfernt wird. Method according to one of the preceding claims,
characterized,
that the secondary scale formed during the rolling process and also quenched during cooling is already mechanically removed by cracking during winding or winding before a subsequent pickling process, if applicable.
dadurch gekennzeichnet,
daß die Anlage weiterhin umfaßt:
characterized,
that the system also includes:
weiterhin umfassend einen sich an die Kühlstrecke anschließenden Haubenofen.System according to claim 10,
furthermore includes a hood furnace adjoining the cooling section.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19962801A DE19962801A1 (en) | 1999-12-23 | 1999-12-23 | Process for heat treating wire |
| DE19962801 | 1999-12-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP1111075A1 true EP1111075A1 (en) | 2001-06-27 |
Family
ID=7934343
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP00126743A Withdrawn EP1111075A1 (en) | 1999-12-23 | 2000-12-06 | Wire heat treating process |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US6682612B2 (en) |
| EP (1) | EP1111075A1 (en) |
| JP (1) | JP2001220624A (en) |
| KR (1) | KR20010062528A (en) |
| CN (1) | CN1300648A (en) |
| CZ (1) | CZ20004844A3 (en) |
| DE (1) | DE19962801A1 (en) |
| MX (1) | MXPA00012712A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7055244B2 (en) * | 2002-03-14 | 2006-06-06 | Anand Waman Bhagwat | Method of manufacturing flat wire coil springs to improve fatigue life and avoid blue brittleness |
| DE102004048443B3 (en) * | 2004-10-02 | 2005-12-01 | C.D. Wälzholz-Brockhaus GmbH | Method for rolling technical deformation of wire and rod-shaped starting material, apparatus for carrying out the method and produced by the method flat profile |
| CN104511477A (en) * | 2013-09-27 | 2015-04-15 | 贝卡尔特公司 | Thermal mechanical process |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1508443A1 (en) * | 1966-05-07 | 1969-10-23 | Schloemann Ag | Device for the production of patented steel wire from the rolling heat |
| DE2345738B1 (en) * | 1973-09-11 | 1974-07-11 | Salzgitter Peine Stahlwerke | Steel wire and process for its manufacture |
| BE840896A (en) * | 1976-04-16 | 1976-10-18 | Centre Rech Metallurgique | PROCESS FOR MANUFACTURING LAMINATED STEEL PRODUCTS |
| DE2612918A1 (en) * | 1975-04-02 | 1976-10-21 | Florin Stahl Walzwerk | Rolled steel prodn. with softened edge - and strong core by two-step cooling heat-treatable steel |
| FR2445858A1 (en) * | 1979-01-05 | 1980-08-01 | Salzgitter Peine Stahlwerke | WELDABLE CONCRETE STEEL AND PROCESS FOR OBTAINING SAME |
| JPS56119728A (en) * | 1980-02-25 | 1981-09-19 | Sumitomo Metal Ind Ltd | Manufacture of high tensile wire rod |
| DE3427557A1 (en) * | 1983-09-09 | 1985-03-28 | VEB Stahl- und Walzwerk "Wilhelm Florin", DDR 1422 Hennigsdorf | Process for producing high-strength standard components for cold-upsetting steel |
| EP0496726A2 (en) * | 1991-01-25 | 1992-07-29 | EVG Entwicklungs- u. Verwertungs- Gesellschaft m.b.H. | Method and installation for continuous manufacture of coiled wire |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4180418A (en) * | 1973-09-11 | 1979-12-25 | Stahlwerke Peine-Salzgitter A.G. | Method of making a steel wire adapted for cold drawing |
| DE2830153C2 (en) | 1978-07-08 | 1984-02-09 | ARBED Saarstahl GmbH, 6620 Völklingen | Method and device for the heat treatment of wire or strip coiled into rings |
| JPS57126913A (en) * | 1981-01-27 | 1982-08-06 | Kobe Steel Ltd | Production of high-toughness high-strength wire or rod steel |
| JPH04311529A (en) * | 1991-04-10 | 1992-11-04 | Sugita Seisen Kojo:Kk | Continuous heat treating method for oil tempered steel wire for spring having high strength and high toughness |
| DE19653062A1 (en) | 1996-12-19 | 1998-06-25 | Schloemann Siemag Ag | Ferritic winding of wire or bar steel |
-
1999
- 1999-12-23 DE DE19962801A patent/DE19962801A1/en not_active Withdrawn
-
2000
- 2000-12-06 EP EP00126743A patent/EP1111075A1/en not_active Withdrawn
- 2000-12-18 MX MXPA00012712A patent/MXPA00012712A/en unknown
- 2000-12-20 KR KR1020000078939A patent/KR20010062528A/en not_active Application Discontinuation
- 2000-12-20 US US09/752,137 patent/US6682612B2/en not_active Expired - Fee Related
- 2000-12-21 JP JP2000389317A patent/JP2001220624A/en not_active Withdrawn
- 2000-12-21 CZ CZ20004844A patent/CZ20004844A3/en unknown
- 2000-12-22 CN CN00136437A patent/CN1300648A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1508443A1 (en) * | 1966-05-07 | 1969-10-23 | Schloemann Ag | Device for the production of patented steel wire from the rolling heat |
| DE2345738B1 (en) * | 1973-09-11 | 1974-07-11 | Salzgitter Peine Stahlwerke | Steel wire and process for its manufacture |
| DE2612918A1 (en) * | 1975-04-02 | 1976-10-21 | Florin Stahl Walzwerk | Rolled steel prodn. with softened edge - and strong core by two-step cooling heat-treatable steel |
| BE840896A (en) * | 1976-04-16 | 1976-10-18 | Centre Rech Metallurgique | PROCESS FOR MANUFACTURING LAMINATED STEEL PRODUCTS |
| FR2445858A1 (en) * | 1979-01-05 | 1980-08-01 | Salzgitter Peine Stahlwerke | WELDABLE CONCRETE STEEL AND PROCESS FOR OBTAINING SAME |
| JPS56119728A (en) * | 1980-02-25 | 1981-09-19 | Sumitomo Metal Ind Ltd | Manufacture of high tensile wire rod |
| DE3427557A1 (en) * | 1983-09-09 | 1985-03-28 | VEB Stahl- und Walzwerk "Wilhelm Florin", DDR 1422 Hennigsdorf | Process for producing high-strength standard components for cold-upsetting steel |
| EP0496726A2 (en) * | 1991-01-25 | 1992-07-29 | EVG Entwicklungs- u. Verwertungs- Gesellschaft m.b.H. | Method and installation for continuous manufacture of coiled wire |
Non-Patent Citations (1)
| Title |
|---|
| PATENT ABSTRACTS OF JAPAN vol. 005, no. 195 (C - 083) 11 December 1981 (1981-12-11) * |
Also Published As
| Publication number | Publication date |
|---|---|
| CZ20004844A3 (en) | 2001-08-15 |
| US20010011566A1 (en) | 2001-08-09 |
| MXPA00012712A (en) | 2003-06-24 |
| US6682612B2 (en) | 2004-01-27 |
| JP2001220624A (en) | 2001-08-14 |
| KR20010062528A (en) | 2001-07-07 |
| DE19962801A1 (en) | 2001-06-28 |
| CN1300648A (en) | 2001-06-27 |
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