EP0234200A1 - Process and device for the heat treatment of longitudinally welded pipes - Google Patents

Process and device for the heat treatment of longitudinally welded pipes Download PDF

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Publication number
EP0234200A1
EP0234200A1 EP87100199A EP87100199A EP0234200A1 EP 0234200 A1 EP0234200 A1 EP 0234200A1 EP 87100199 A EP87100199 A EP 87100199A EP 87100199 A EP87100199 A EP 87100199A EP 0234200 A1 EP0234200 A1 EP 0234200A1
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EP
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Prior art keywords
annealing
weld seam
tubes
heat treatment
annealed
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Granted
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EP87100199A
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German (de)
French (fr)
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EP0234200B1 (en
Inventor
Friedhelm Schmitz
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Siemens AG
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Kraftwerk Union AG
Siemens AG
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Priority claimed from DE19863639403 external-priority patent/DE3639403A1/en
Application filed by Kraftwerk Union AG, Siemens AG filed Critical Kraftwerk Union AG
Priority to AT87100199T priority Critical patent/ATE58919T1/en
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    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/002—Heat treatment of ferrous alloys containing Cr
    • 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
    • C21D9/50—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for welded joints
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/24—Nitriding
    • C23C8/26—Nitriding of ferrous surfaces

Definitions

  • the present invention relates to a method for the heat treatment of longitudinally welded tubes according to the preamble of claim 1 and device for carrying out the method.
  • Stainless steel pipes e.g. B. for steam condensers
  • heat treatment after longitudinal seam welding to reduce stresses and to reduce segregations that occur through the welding process. This results e.g. B. from an article by K. Schleithoff, F. Schmitz: "Condenser tubes made of stainless steels - operating experience and material development" in "VGB Kraftmaschinestechnik 61", Issue 9, p. 730, Sept. 1981.
  • the heat treatment is usually carried out continuously - Annealing furnaces under protective gas at temperatures of 950 ° C to 1100 0 C and a holding time of a few minutes depending on the material. Other annealing processes are also used.
  • the essential idea of the invention is to carry out only a partial solution annealing of the weld seam and the heat affected zone. This annealing can be carried out inside or outside the welding path.
  • molybdenum-containing steels temperatures can even be set above 1200 ° C or even 13 00 C in the weld area and the heat affected zone, which leads to an optimized solution annealing and lead to a better balance of chrome or molybdenum segregation.
  • the remaining tube wall temperature of the other areas is set so low that problem-free processing in the welding, processing and annealing and deformation section is possible, but a reduction in the stresses which have been introduced by the manufacturing process is achieved.
  • the proposed annealing treatment basically offers the possibility of significantly increasing both the temperature and the holding time compared to conventional methods. It is also possible to manufacture testable thin-walled tubes.
  • the desired selective annealing can be achieved by partial heating and / or partial cooling. Depending on the desired holding time, partial heating may be sufficient, but it can be supplemented at any time by cooling the areas of the pipe that are not to be annealed, as long as the remaining pipe would be heated too much by heat conduction or radiation.
  • Various methods can be used for the partial heating, for example using infrared radiators, lasers or correspondingly guided electrical currents which are induced in the tube.
  • An increased proportion of nitrogen, which would impair the weldability of the material, can be according to claim 8 after welding by annealing in an atmosphere suitable partial pressure of nitrogen or a nitrogen compound can be achieved. This considerably improves the corrosion properties of the pipe or the weld seam.
  • FIG. 1 The cross section shown in FIG. 1 through a longitudinally welded tube 1 illustrates the areas of the tube which are essential for the invention.
  • the individual zones are not shown to scale.
  • the weld seam 2 is generally located on the top of the tube 1 during manufacture. It is surrounded by a heat-affected zone 3, in which the welding process has left changes and inhomogeneities.
  • the rest of the tube consists of unchanged base material, but it makes sense to include an area 4 outside of the heat affected zone 3 during a heat treatment for safety reasons, since the exact extent of the heat affected zone 3 is not always known.
  • FIG. 2 shows a device for the partial annealing of a tube 1 welded by welding.
  • the weld seam 2 with the heat-affected zone 3 surrounding it will again generally lie on the top of the tube.
  • the tube 1 to be annealed should preferably be kept under protective gas during the annealing in order to avoid subsequent pickling.
  • the tube 1 to be annealed is located inside a quartz glass tube 5, the space 9 between the two being filled with protective gas.
  • One or more infrared emitters 6 are arranged above the quartz glass tube 5 and provided with focusing reflectors 8 in a housing 7.
  • the focusing reflectors can, for example, have a parabolic cross section, in the focal point or focal line of which there are infrared radiators.
  • the infrared rays are focused in such a way that they irradiate and heat up the desired area 4 of the tube 1 to be partially annealed.
  • the desired partial annealing can be carried out over almost any holding times, although annealing in a continuous process under a corresponding annealing section is preferable.
  • the present invention enables the use of steels with, for example, a lower molybdenum content for longitudinally welded corrosion-resistant pipes and also enables the production of thin-walled pipes with a wall thickness of, for. B. 0.3 to 0.5mm.

Abstract

These pipes (1) of austenitic, ferritic or austenitic-ferritic non- rusting steels are annealed after the longitudinal seam (2) has been welded. In the process according to the invention, the pipes (1) are only partially solution-annealed in the region of the weld seam (2) and of the heat-affected zone (3) or in a region (4) going slightly beyond the former. This allows even annealing temperatures of, for example, above 1200 DEG C and long holding times, whereby optimised solution-annealing and a better equalisation of segregations of the corrosion resistance-determining elements chromium and molybdenum in the region of the weld seam can be achieved. The only partial heating of the weld seam, for example by means of focused infrared emitters, prevents deformation of the pipes under the action of gravity during the annealing, in spite of the high annealing temperature. As a result, the corrosion resistance of the weld seam (3) can approach the value of the base material. Defined alloying with nitrogen from the surrounding atmosphere can further improve the corrosion resistance. Production of high-quality thin-walled pipes which can be tested for damage is also facilitated. <IMAGE>

Description

Die vorliegende Erfindung betrifft ein Verfahren zur Wärmebehandlung von längsnahtgeschweißten Rohren gemäß dem Oberbegriff des Anspruchs 1 sowie Vorrichtung zur Durchführung des Verfahrens. Rohre aus nichtrostenden Stählen, z. B. für Wasserdampf-Kondensatoren, werden nach dem Längsnahtschweißen zur Reduzierung von Spannungen und zur Minderung von Seigerungen, die durch den Schweißprozeß auftreten, einer Wärmebehandlung unterzogen. Dies ergibt sich z. B. aus einem Artikel von K. Schleithoff, F. Schmitz: "Kondensatorrohre aus nichtrostenden Stählen - Betriebserfahrungen und Werkstoffentwicklung" in "VGB Kraftwerkstechnik 61", Heft 9, S. 730, Sept. 1981. Die Wärmebehandlung erfolgt in der Regel in Durchlauf-Glühöfen unter Schutzgas bei Temperaturen je nach Werkstoff von 950°C bis 11000C und einer Haltezeit von einigen Minuten. Auch andere Glühverfahren werden angewendet.The present invention relates to a method for the heat treatment of longitudinally welded tubes according to the preamble of claim 1 and device for carrying out the method. Stainless steel pipes, e.g. B. for steam condensers, are subjected to heat treatment after longitudinal seam welding to reduce stresses and to reduce segregations that occur through the welding process. This results e.g. B. from an article by K. Schleithoff, F. Schmitz: "Condenser tubes made of stainless steels - operating experience and material development" in "VGB Kraftwerkstechnik 61", Issue 9, p. 730, Sept. 1981. The heat treatment is usually carried out continuously - Annealing furnaces under protective gas at temperatures of 950 ° C to 1100 0 C and a holding time of a few minutes depending on the material. Other annealing processes are also used.

Ein prinzipielles Problem tritt jedoch dadurch auf, daß die optimalen Werte von Temperatur und Haltezeit nicht erreicht werden können. Werden nämlich Rohre auf die gewünschte hohe Temperatur gebracht, so sind sie nicht formstabil, so daß sie sich bei größeren Haltezeiten verformen und unter dem Einfluß der Schwerkraft "zusammenfallen". Eine optimale Lösungsglühung und Verminderung von Seigerungen, z. B. der korrosionsbeständigkeit-bestimmenden Elemente Chrom oder Molybdän im Schweißnahtbereich, kann daher mit herkömmlichen Methoden nicht erreicht werden. Somit kann die Schweißnaht trotz der Verbesserung durch Wärmebehandlung etwas schlechtere Korrosionseigenschaften aufweisen als der Grundwerkstoff. Daher wird z. B. der Molybdängehalt des Grundwerkstoffes höher als eigentlich nötig gewählt, um auch in der Schweißnaht noch die jeweils gewünschten Korrosionseigenschaften sicherzustellen. Vom wirtschaftlichen Standpunkt jedoch ist eine Verminderung des Gehaltes an teuerem Molybdän wünschenswert.A fundamental problem arises, however, in that the optimal values of temperature and holding time cannot be achieved. If pipes are brought to the desired high temperature, they are not dimensionally stable, so that they deform during longer holding times and "collapse" under the influence of gravity. Optimal solution annealing and reduction of segregations, e.g. B. the corrosion resistance-determining elements chrome or molybdenum in the weld area, can therefore not be achieved with conventional methods. Thus, the weld seam despite the Improvement through heat treatment have somewhat poorer corrosion properties than the base material. Therefore z. B. the molybdenum content of the base material chosen higher than actually necessary to ensure the desired corrosion properties in the weld. From the economic point of view, however, a reduction in the expensive molybdenum content is desirable.

Ein weiteres Problem entsteht, insbesondere bei dünnwandigen Rohren, durch die Handhabungs- bzw. Transportvorgänge bei hoher Temperatur. Hierbei entstehen Verformungen, insbesondere Beulen, die eine spätere Qualitätsprüfung, z. B. durch Wirbelstrommessungen, erschweren oder verhindern.Another problem arises, particularly in the case of thin-walled pipes, from the handling or transport processes at high temperature. This creates deformations, in particular dents, which a later quality inspection, e.g. B. by eddy current measurements, complicate or prevent.

Aufgabe der vorliegenden Erfindung ist es daher, unter Vermeidung der genannten Nachteile die Schweißnähte von längsnahtgeschweißten Rohren so zu behandeln, daß diese sich den Korrosionseigenschaften des Grundwerkstoffes annähern. Dazu werden ein Verfahren gemäß dem Anspruch 1 sowie Vorrichtungen zur Durchführung des Verfahrens gemäß dem Anspruch 9 vorgeschlagen. Vorteilhafte Ausgestaltungen sind jeweils in den Unteransprüchen beschrieben.It is therefore an object of the present invention, while avoiding the disadvantages mentioned, to treat the weld seams of longitudinally welded tubes in such a way that they approximate the corrosion properties of the base material. For this purpose, a method according to claim 1 and devices for carrying out the method according to claim 9 are proposed. Advantageous embodiments are described in the subclaims.

Wie anhand der Zeichnung noch näher erläutert wird, besteht der wesentliche Gedanke der Erfindung darin, nur eine partielle Lösungs-Glühung von Schweißnaht und Wärmeeinflußzone durchzuführen. Diese Glühung kann innerhalb oder außerhalb der Schweißstrecke vorgenommen werden, Dabei können z. B. bei hochlegierten, molybdänhaltigen Stählen Temperaturen sogar oberhalb von 1200° C oder sogar 1300 C im Schweißnahtbereich und der Wärmeeinflußzone eingestellt werden, die zu einer optimierten Lösungsglühung und einem besseren Ausgleich der Chrom- oder Molybdan-Seigerungen führen. Die restliche Rohrwandtemperatur der übrigen Bereiche wird so niedrig eingestellt, daß eine problemlose Verarbeitung in der Schweiß-, Bearbeitungssowie Glüh- und Verformungsstrecke möglich ist, jedoch ein Abbau der Spannungen, die durch den Herstellungsprozeß eingebracht wurden, erreicht wird. Dadurch, daß der größte Teil des Rohres nicht auf die maximale Glühtemperatur gebracht werden muß, bleibt die Stabilität des Rohres erhalten und unerwünschte Verformungen unter dem Einfluß der Schwerkraft oder der Transportvorrichtungen können nicht auftreten. Die vorgeschlagene Glühbehandlung bietet grundsätzlich die Möglichkeit, sowohl die Temperatur wie auch die Haltezeit gegenüber herkömmlichen Verfahren deutlich zu erhöhen. Eine Herstellung prüfbarer dünnwandiger Rohre wird ebenfalls möglich.As will be explained in more detail with reference to the drawing, the essential idea of the invention is to carry out only a partial solution annealing of the weld seam and the heat affected zone. This annealing can be carried out inside or outside the welding path. B. in high-alloy, molybdenum-containing steels temperatures can even be set above 1200 ° C or even 13 00 C in the weld area and the heat affected zone, which leads to an optimized solution annealing and lead to a better balance of chrome or molybdenum segregation. The remaining tube wall temperature of the other areas is set so low that problem-free processing in the welding, processing and annealing and deformation section is possible, but a reduction in the stresses which have been introduced by the manufacturing process is achieved. Because the majority of the tube does not have to be brought to the maximum annealing temperature, the stability of the tube is maintained and undesired deformations under the influence of gravity or the transport devices cannot occur. The proposed annealing treatment basically offers the possibility of significantly increasing both the temperature and the holding time compared to conventional methods. It is also possible to manufacture testable thin-walled tubes.

Die gewünschte selektive Glühung kann durch partielle Aufheizung und/oder partielle Kühlung erreicht werden. Je nach der gewünschten Haltezeit kann eine partielle Aufheizung ausreichen, jedoch ist die Ergänzung durch eine Kühlung der nicht zu glühenden Rohrbereiche jederzeit möglich, sofern bei längerer Haltezeit durch Wärmeleitung oder Strahlung das restliche Rohr zu sehr aufgeheizt werden würde.The desired selective annealing can be achieved by partial heating and / or partial cooling. Depending on the desired holding time, partial heating may be sufficient, but it can be supplemented at any time by cooling the areas of the pipe that are not to be annealed, as long as the remaining pipe would be heated too much by heat conduction or radiation.

Für die partielle Aufheizung lassen sich verschiedene Verfahren anwenden, beispielsweise unter Verwendung von Infrarotstrahlern, Lasern oder entsprechend geführten elektrischen Strömen, die in dem Rohr induziert werden.Various methods can be used for the partial heating, for example using infrared radiators, lasers or correspondingly guided electrical currents which are induced in the tube.

Ein erhöhter Stickstoffanteil, der die Schweißbarkeit des Werkstoffes beeinträchtigen würde, kann gemäß Anspruch 8 nach der Schweißung durch Glühung in einer Atmosphäre mit geeignetem Partialdruck von Stickstoff oder einer Stickstoffverbindung erzielt werden. Dies verbessert die Korrosionseigenschaften des Rohres bzw. der Schweißnaht erheblich.An increased proportion of nitrogen, which would impair the weldability of the material, can be according to claim 8 after welding by annealing in an atmosphere suitable partial pressure of nitrogen or a nitrogen compound can be achieved. This considerably improves the corrosion properties of the pipe or the weld seam.

Geeignete Vorrichtungen zur Durchführung der genannten Verfahren sind in den Ansprüchen 9, 10, 11, 12, 13 und 14 angegeben.Suitable devices for carrying out the methods mentioned are specified in claims 9, 10, 11, 12, 13 and 14.

Das Prinzip der Erfindung und eine nur als Ausführungsbeispiel angeführte Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens sind in der Zeichnung dargestellt, und zwar zeigen

  • Fig. 1 einen Querschnitt durch ein längsnahtgeschweißtes Rohe zur Veranschaulichung der verschiedenen Zonen und
  • Fig. 2 schematisch einen Querschnitt durch eine erfindungsgemäße Vorrichtung zur partiellen Glühung eines solchen Rohres.
The principle of the invention and a device for carrying out the method according to the invention, which is only given as an exemplary embodiment, are shown in the drawing and show
  • Fig. 1 shows a cross section through a longitudinally welded tube to illustrate the different zones and
  • Fig. 2 shows schematically a cross section through an inventive device for the partial annealing of such a tube.

Der in Fig. 1 dargestellte Querschnitt durch ein längsnahtgeschweißtes Rohr 1 veranschaulicht die für die Erfindung wesentlichen Bereiche des Rohres. Dabei sind die einzelnen Zonen nicht maßstabgerecht dargestellt. Die Schweißnaht 2 liegt im allgemeinen bei der Herstellung an der Oberseite des Rohres 1. Sie ist umgeben von einer Wärmeeinflußzone 3, in welcher der Schweißvorgang Veränderungen und Inhomogenitäten hinterlassen hat. Der Rest des Rohres besteht aus unverändertem Grundwerkstoff, wobei es jedoch sinnvoll erscheint, aus Sicherheitsgründen einen Bereich 4 außerhalb der Wärmeeinflußzone 3 bei einer Wärmebehandlung einzubeziehen, da die genaue Ausdehnung der Wärmeeinflußzone 3 nicht immer bekannt ist. In Fig. 2 ist eine Vorrichtung zur partiellen Glühung eines lä.igsnahtgeschweißten Rohres 1 dargestellt. Die Schweißnaht 2 mit der sie umgebenden Wärmeeinflußzone 3 wird wiederum im allgemeinen an der Oberseite des Rohres liegen. Die maximale Wärmebehandlung soll sich auf die Schweißnaht 2, die Wärmeeinflußzone 3 und einen zusätzlichen Sicherheitsbereich 4 erstrecken, während der Rest des Rohres bei niedriger Temperatur spannungsarm geglüht wird. Wegen der hohen Glühtemperaturen soll das zu glühende Rohr 1 während der Glühung vorzugsweise unter Schutzgas gehalten werden, um anschließendes Beizen zu vermeiden. Im vorliegenden Ausführungsbeispiel befindet sich das zu glühende Rohr 1 im Inneren eines Quarzglasrohres 5, wobei der Zwischenraum 9 zwischen beiden mit Schutzgas gefüllt ist. Ein oder mehrere Infrarotstrahler 6 sind oberhalb des Quarzglasrohres 5 angeordnet und mit fokussierenden Reflektoren 8 in einem Gehäuse 7 versehen. Die fokussierenden Reflektoren können beispielsweise einen parabolischen Querschnitt haben, in deren Brennpunkt bzw. Brennlinie sich Infrarotstrahler befinden. Es sind jedoch auch andere fokussierende Elemente, so z. B. infrarot-durchlässige Linsensysteme u. dgl., anwendbar. Die Infrarotstrahlen werden so fokussiert, daß sie den gewünschten Bereich 4 des partiell zu glühenden Rohres 1 bestrahlen und aufheizen. Durch Apwendung von Blenden oder durch zusätzliche Kühlung der restlichen Wände des Rohres 1 kann die gewünschte partielle Glühung über beinahe beliebige Haltezeiten durchgeführt werden, wobei jedoch eine Glühung im Durchlaufverfahren unter einer entsprechenden Glühstrecke vorzuziehen ist.The cross section shown in FIG. 1 through a longitudinally welded tube 1 illustrates the areas of the tube which are essential for the invention. The individual zones are not shown to scale. The weld seam 2 is generally located on the top of the tube 1 during manufacture. It is surrounded by a heat-affected zone 3, in which the welding process has left changes and inhomogeneities. The rest of the tube consists of unchanged base material, but it makes sense to include an area 4 outside of the heat affected zone 3 during a heat treatment for safety reasons, since the exact extent of the heat affected zone 3 is not always known. FIG. 2 shows a device for the partial annealing of a tube 1 welded by welding. The weld seam 2 with the heat-affected zone 3 surrounding it will again generally lie on the top of the tube. The maximum heat treatment should extend to the weld 2, the heat affected zone 3 and an additional safety area 4, while the rest of the tube is stress relieved at low temperature. Because of the high annealing temperatures, the tube 1 to be annealed should preferably be kept under protective gas during the annealing in order to avoid subsequent pickling. In the present exemplary embodiment, the tube 1 to be annealed is located inside a quartz glass tube 5, the space 9 between the two being filled with protective gas. One or more infrared emitters 6 are arranged above the quartz glass tube 5 and provided with focusing reflectors 8 in a housing 7. The focusing reflectors can, for example, have a parabolic cross section, in the focal point or focal line of which there are infrared radiators. However, there are other focusing elements, such as. B. infrared transparent lens systems u. Like., Applicable. The infrared rays are focused in such a way that they irradiate and heat up the desired area 4 of the tube 1 to be partially annealed. By using screens or by additional cooling of the remaining walls of the tube 1, the desired partial annealing can be carried out over almost any holding times, although annealing in a continuous process under a corresponding annealing section is preferable.

Die vorliegende Erfindung ermöglicht die Verwendung von Stählen mit beispielsweise niedrigerem Molybdängehalt für längsnahtgeschweißte korrosionsbeständige Rohre und ermöglicht auch die Herstellung dünnwandiger Rohre mit einer Wanddicke von z. B. 0,3 bis 0,5mm.The present invention enables the use of steels with, for example, a lower molybdenum content for longitudinally welded corrosion-resistant pipes and also enables the production of thin-walled pipes with a wall thickness of, for. B. 0.3 to 0.5mm.

Claims (14)

1. Verfahren zur Wärmebehandlung von längsnahtgeschweißten Rohren (1) aus austenitischen, ferritischen oder austenitisch-ferritischen nichtrostenden Stählen, wobei die Rohre (1) nach dem Schweißen der Längsnaht (2) geglüht werden, dadurch gekennzeichnet, daß die Rohre (1) nur partiell im Bereich der Schweißnaht (2) und der Wärmeeinflußzone (3) lösungsgeglüht werden, während der übrige Bereich bei niedrigerer Temperatur wärmebehandelt wird.1. A method for the heat treatment of longitudinally welded tubes (1) made of austenitic, ferritic or austenitic-ferritic stainless steels, the tubes (1) being annealed after welding the longitudinal seam (2), characterized in that the tubes (1) are only partially solution annealed in the area of the weld (2) and the heat affected zone (3), while the remaining area is heat treated at a lower temperature. 2. Verfahren nach Anspruch 1, für hochlegierte molybdänhaltige Stähle, dadurch gekennzeichnet, daß bei einer Temperatur größer 11000C, vorzugsweise größer 1250°C, geglüht wird.2. The method according to claim 1, for high-alloy molybdenum-containing steels, characterized in that at a temperature greater than 1100 0 C, preferably greater than 1250 ° C, annealing. 3. Verfahren nach Anspruch 1 für ferritische Stähle, dadurch gekennzeichnet, daß der Schweißnahtbereich (2) bei einer Temperatur größer 950°C geglüht wird.3. The method according to claim 1 for ferritic steels, characterized in that the weld seam region (2) is annealed at a temperature greater than 950 ° C. 4. Verfahren nach Anspruch 1, 2 oder 3, dadurch gekennzeichnet, daß die Glühtemperatur länger als 5 sec, vorzugsweise ca. 25 sec, beibehalten wird.4. The method according to claim 1, 2 or 3, characterized in that the annealing temperature is maintained for longer than 5 sec, preferably about 25 sec. 5. Verfahren nach Anspruch 1, 2, 3 oder 4, dadurch gekennzeichnet, daß das Rohr (1) zur selektiven Glühung partiell aufgeheizt und /oder partiell gekühlt wird.5. The method according to claim 1, 2, 3 or 4, characterized in that the tube (1) for selective annealing is partially heated and / or partially cooled. 6. Verfahren nach Anspruch 1, 2, 3, 4 oder 5, dadurch gekennzeichnet, daß das Rohr (1) partiell durch Infrarotstrahler (6) oder Laser aufgeheizt wird.6. The method according to claim 1, 2, 3, 4 or 5, characterized in that the tube (1) is partially heated by infrared radiators (6) or lasers. 7. Verfahren nach Anspruch 1, 2, 3, 4 oder 5, dadurch gekennzeichnet, daß das Rohr (1) durch entsprechend geführte elektrische Ströme, z. B. mittels sattelförmiger Induktionsspulen, partiell aufgeheizt wird, ggf. unter zusätzlicher Kühlung von Teilbereichen.7. The method according to claim 1, 2, 3, 4 or 5, characterized in that the tube (1) by appropriately guided electrical currents, for. B. is partially heated by means of saddle-shaped induction coils, possibly with additional cooling of sub-areas. 8. Verfahren zur Wärmebehandlung von längsnahtgeschweißten Rohren, insbesondere nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, daß die Wärmebehandlung unter einer Atmosphäre durchgeführt wird, welche Stickstoff oder eine Stickstoff freisetzende Verbindung mit solchem Partialdruck enthält, daß bei der maximalen Glühtemperatur der Gehalt an gelöstem Stickstoff im Bereich der Schweißnaht (2) über 0,2 % ansteigt, vorzugsweise auf 0,3 bis 0,4 %, ohne jedoch die Löslichkeitsgrenze des Werkstoffes zu überschreiten.8. A method for the heat treatment of longitudinally welded pipes, in particular according to one of the preceding claims, characterized in that the heat treatment is carried out under an atmosphere which contains nitrogen or a nitrogen-releasing compound with such partial pressure that the content of dissolved nitrogen at the maximum annealing temperature in the area of the weld seam (2) rises above 0.2%, preferably to 0.3 to 0.4%, but without exceeding the solubility limit of the material. 9. Vorrichtung zur Wärmebehandlung von längsnahtgeschweißten Rohren (1) aus austenitischen, ferritischen oder austenitisch-ferritischen nichtrostenden Stählen gemäß dem Verfahren nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß Mittel (6, 8) vorhanden sind, welche eine nur partielle Lösungs- Glühung der Rohre (1) im Bereich der Schweißnaht (2), und der Wärmeeinflußzone (3) bewirken.9. Device for heat treatment of longitudinally welded tubes (1) made of austenitic, ferritic or austenitic-ferritic stainless steels according to the method according to one of claims 1 to 6, characterized in that means (6, 8) are present which are only a partial solution - Annealing the pipes (1) in the area of the weld (2) and the heat affected zone (3). 10. Vorrichtung nach Anspruch 9, dadurch gekennzeichnet, daß die Vorrichtung einen oder mehrere Infrarotstrahler (6) aufweist, deren Strahlung durch geeignete Fokussiermittel, insb. Spiegelflächen mit parabolischem Querschnitt (8), auf die Schweißnaht (2) und die Wärmeeinflußzone (3) der Rohre (1) konzentrierbar sind.10. The device according to claim 9, characterized in that the device has one or more infrared emitters (6), the radiation of which by suitable focusing means, in particular mirror surfaces with a parabolic cross-section (8), on the weld seam (2) and the heat affected zone (3) the tubes (1) can be concentrated. 11. Vorrichtung nach Anspruch 10, dadurch gekennzeichnet, daß die zu glühenden Rohre (1) in einer Schutzhülle (5) geführt bzw. gehaltert sind, wobei die Schutzhülle im Inneren mit Schutzgas beaufschlagbar und zumindest in Teilbereichen für Infrarotstrahlung gut durchlässig ist.11. The device according to claim 10, characterized in that the tubes to be annealed (1) in a protective sheath (5) are guided or held, the protective sheath can be acted upon with protective gas and is at least partially permeable to infrared radiation. 12. Vorrichtung nach Anspruch 9, dadurch gekennzeichnet, daß die Vorrichtung Induktionsspulen aufweist, welche durch ihre Form und/oder durch geeignet plazierte Abschirmungen hohe Ströme im Bereich der Schweißnaht (2) und der Wärmeeinflußzone (3) erzeugen können.12. The apparatus according to claim 9, characterized in that the device has induction coils, which can generate high currents in the region of the weld seam (2) and the heat affected zone (3) by their shape and / or by suitably placed shields. 13. Vorrichtung nach einem der Ansprüche 9, 10, 11 oder 12, dadurch gekennzeichnet, daß eine Kühlvorrichtung vorhanden ist, welche die Rohre (1) außer im Bereich der Schweißnaht (2) und der Wärmeeinflußzone (3) kühlt.13. Device according to one of claims 9, 10, 11 or 12, characterized in that a cooling device is provided which cools the tubes (1) except in the region of the weld seam (2) and the heat affected zone (3). 14. Vorrichtung nach Anspruch 9, 10, 11, 12 oder 13, dadurch gekennzeichnet, daß die Vorrichtung Mittel zum Einstellen eines definierten Partialdruckes von Stickstoff oder einer Stickstoff freisetzenden Verbindung in der Umgebung des Rohres bei der Wärmebehandlung aufweist.14. The apparatus of claim 9, 10, 11, 12 or 13, characterized in that the device has means for setting a defined partial pressure of nitrogen or a nitrogen-releasing compound in the vicinity of the tube during the heat treatment.
EP87100199A 1986-01-21 1987-01-09 Process and device for the heat treatment of longitudinally welded pipes Expired - Lifetime EP0234200B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87100199T ATE58919T1 (en) 1986-01-21 1987-01-09 METHODS AND DEVICES FOR THE HEAT TREATMENT OF LONG SEAM WELDED PIPES.

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Application Number Priority Date Filing Date Title
DE3601670 1986-01-21
DE3601670 1986-01-21
DE19863639403 DE3639403A1 (en) 1986-11-18 1986-11-18 Process for improving the corrosion resistance of welded workpieces of stainless steel, and correspondingly produced workpiece
DE3639403 1986-11-18

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EP0234200A1 true EP0234200A1 (en) 1987-09-02
EP0234200B1 EP0234200B1 (en) 1990-12-05

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EP (1) EP0234200B1 (en)
JP (1) JP2668870B2 (en)
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DE (1) DE3766507D1 (en)

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EP0322758A1 (en) * 1987-12-24 1989-07-05 Schoeller Werk GmbH &amp; Co KG Process and device for the heat-treatment of the welding joints of longitudinally welded metal tubes
EP0394754A2 (en) * 1989-04-27 1990-10-31 Siemens Aktiengesellschaft Process and device for the selective heat treatment of the weld seam region of a longitudinally welded pipe
US5022936A (en) * 1988-12-07 1991-06-11 Hitachi, Ltd. Method for improving property of weld of austenitic stainless steel
EP2019149A1 (en) 2007-07-19 2009-01-28 United Technologies Corporation Apparatus and method for localized heat treatment of metal components
DE102022105659A1 (en) 2022-03-10 2023-09-14 Vdm Metals International Gmbh Process for producing a welded component from a nickel-chromium-aluminum alloy
DE102022105658A1 (en) 2022-03-10 2023-09-14 Vdm Metals International Gmbh Process for producing a component from the semi-finished product of a nickel-chromium-aluminum alloy

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US7618503B2 (en) * 2001-06-29 2009-11-17 Mccrink Edward J Method for improving the performance of seam-welded joints using post-weld heat treatment
US7540402B2 (en) * 2001-06-29 2009-06-02 Kva, Inc. Method for controlling weld metal microstructure using localized controlled cooling of seam-welded joints
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Cited By (10)

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Publication number Priority date Publication date Assignee Title
EP0322758A1 (en) * 1987-12-24 1989-07-05 Schoeller Werk GmbH &amp; Co KG Process and device for the heat-treatment of the welding joints of longitudinally welded metal tubes
US5022936A (en) * 1988-12-07 1991-06-11 Hitachi, Ltd. Method for improving property of weld of austenitic stainless steel
EP0394754A2 (en) * 1989-04-27 1990-10-31 Siemens Aktiengesellschaft Process and device for the selective heat treatment of the weld seam region of a longitudinally welded pipe
EP0394754A3 (en) * 1989-04-27 1992-10-14 Siemens Aktiengesellschaft Process and device for the selective heat treatment of the weld seam region of a longitudinally welded pipe
EP2019149A1 (en) 2007-07-19 2009-01-28 United Technologies Corporation Apparatus and method for localized heat treatment of metal components
US7977611B2 (en) 2007-07-19 2011-07-12 United Technologies Corporation Systems and methods for providing localized heat treatment of metal components
DE102022105659A1 (en) 2022-03-10 2023-09-14 Vdm Metals International Gmbh Process for producing a welded component from a nickel-chromium-aluminum alloy
DE102022105658A1 (en) 2022-03-10 2023-09-14 Vdm Metals International Gmbh Process for producing a component from the semi-finished product of a nickel-chromium-aluminum alloy
WO2023169628A1 (en) 2022-03-10 2023-09-14 Vdm Metals International Gmbh Method for producing a component from the semi-finished product of an nickel-chromium-aluminium alloy
WO2023169629A1 (en) 2022-03-10 2023-09-14 Vdm Metals International Gmbh Method for producing a component made of a nickel-chromium-aluminium alloy and provided with weld seams

Also Published As

Publication number Publication date
JPS62180016A (en) 1987-08-07
US4975128A (en) 1990-12-04
BR8700234A (en) 1987-12-01
JP2668870B2 (en) 1997-10-27
EP0234200B1 (en) 1990-12-05
DE3766507D1 (en) 1991-01-17

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