DE102020106192A1 - Thermal treatment of a coated component - Google Patents

Abstract

A method for the thermal treatment of a coated component (2), comprising: a) thermal treatment of the component (2) in a first continuous furnace (3), which in the transport direction (r) of the component (2) in a first zone (6) and a is subdivided into this adjoining second zone (7) through which the component (2) passes later, the component (2) in the first zone (6) at a temperature above the AC3 temperature (TAC3) of the component (2) the first temperature (T1) is heated and in the second zone (7) it is cooled to a second temperature (T2) below the AC3 temperature (TAC3) of the component (2), b) transferring the component (2) from the first continuous furnace ( 3) in a temperature control station (4), c) thermal treatment of the component (2) in the temperature control station (4), a first area of the component (2) being exposed to a temperature that is on average above the AC3 temperature (TAC3) of the component (2) lies, and a second area of the component (2) is cooled the thermal treatment that is different in regions gives the coated component 2 a ductility that is different in regions. This is advantageous for a B-pillar for a motor vehicle, for example. By heating to above AC3 and then cooling to below AC3 in the first continuous furnace 3, a particularly well adjustable thickness of the interdiffusion layer of the coating of the component 2 is achieved.

Description

The invention relates to a method and a device for the thermal treatment of a coated component, in particular a steel component for a motor vehicle.

In the automotive industry in particular, it is known to specifically harden steel components by means of thermal treatment. For this purpose, steel components such as B-pillars are thermally treated differently in areas. Correspondingly, there is a different ductility in certain areas, which is advantageous for the crash behavior of such components. For example, occupants can be protected by a hard area of the B-pillar at seat height, while soft areas in the upper and lower areas of the B-pillar absorb energy through deformation.

It is also known to coat steel components in order to prevent scaling during the thermal treatment. It is desirable to achieve a particularly strong connection between the surface of the component to be coated and the coating.

It is the object of the present invention, proceeding from the described prior art, to present a method for the thermal treatment of a coated component with which the coating is connected particularly firmly to the surface to be coated. In addition, a corresponding device will be presented.

These objects are achieved with the method and the device according to the independent claims. Further advantageous refinements are given in the dependent claims. The features shown in the claims and in the description can be combined with one another in any desired, technologically meaningful manner.

1. a) thermisches Behandeln des Bauteils in einem ersten Durchlaufofen, welcher in Transportrichtung des Bauteils in eine erste Zone und eine an diese anschließende und von dem Bauteil später durchlaufene zweite Zone unterteilt ist, wobei sich das Bauteil in der ersten Zone auf eine oberhalb der AC3-Temperatur des Bauteils liegende erste Temperatur erwärmt und in der zweiten Zone auf eine unterhalb der AC3-Temperatur des Bauteils liegende zweite Temperatur abkühlt,
2. b) Transferieren des Bauteils von dem ersten Durchlaufofen in eine Temperierstation,
3. c) thermisches Behandeln des Bauteils in der Temperierstation, wobei ein erster Bereich des Bauteils einer Temperatur ausgesetzt wird, die im Durchschnitt oberhalb der AC3-Temperatur des Bauteils liegt, und ein zweiter Bereich des Bauteils gekühlt wird.

According to the invention, a method for the thermal treatment of a coated component is presented. The procedure includes:

1. a) thermal treatment of the component in a first continuous furnace, which is divided in the direction of transport of the component into a first zone and a second zone adjoining this and later passed through by the component, the component in the first zone being in a zone above the AC3 Temperature of the component is heated and cooled in the second zone to a second temperature below the AC3 temperature of the component,
2. b) Transferring the component from the first continuous furnace to a temperature control station,
3. c) thermal treatment of the component in the temperature control station, wherein a first area of the component is exposed to a temperature which is on average above the AC3 temperature of the component, and a second area of the component is cooled.

A coated component can be thermally treated with the method described. The component is preferably a steel component. The steel is preferably a quenched and tempered steel, in particular 22MnB5. For example, a component for a motor vehicle, in particular a B-pillar, can be thermally treated with the method described. After the thermal treatment, the component is preferably press-hardened in a press and, to that extent, hot-formed. The method preferably includes as a further step that the component is transferred to a press after the thermal treatment and is press-hardened there. In this case, the method described is a method for thermal treatment and press hardening of a component. The component is preferably coated with Al / Si. Such a coating counteracts scaling of the component surface during the thermal treatment particularly well. The layer thickness of the coating is preferably in the range from 10 to 50 μm. A hardenable carbon steel with an Al-Si coating is preferred as the material for the component.

In step a) the component is thermally treated in the first continuous furnace. After passing through the first continuous furnace, the temperature of the component is higher than before. In this respect, the component is heated in the first continuous furnace. This does not rule out that the temperature of the component drops from an initially reached maximum value in the first continuous furnace and that it cools down to that extent.

A furnace is to be understood as a device which is brought to an adjustable temperature inside and into which a component can be introduced. Over time, the component adopts the temperature inside the furnace. The heat is thus transferred to the component from the gas in the furnace, which can in particular be air. A continuous furnace is a furnace through which the component can be moved, with the component being heated as it passes through the furnace. The dwell time in the first continuous furnace is preferably in the range from 200 to 450 s.

The first continuous furnace is preferably a roller hearth furnace. The first continuous furnace is preferably gas-heated and / or electrically heated. This allows the component to have a particularly evenly distributed temperature. In particular, not only one layer on the surface of the component is heated. By doing The entire component is heated in the first continuous furnace. The component is completely picked up by the first continuous furnace. In addition, heating by a particularly large temperature difference can be achieved with a continuous furnace. With a continuous furnace, the component can in particular be heated from room temperature to a temperature above the AC3 temperature of the component.

The heating in a continuous furnace is in particular in contrast to heating by the so-called "direct energization". This would make it difficult to heat the component evenly and by a sufficiently high amount. With direct energization, the speed of the warming is more important. In addition, direct energization requires contact with the component. In step a) of the method described, the heating is preferably carried out without contact. This does not rule out that the component is moved through the first conveyor oven with transport rollers and is in contact with the transport rollers. The heating is contactless if the heat input into the component takes place via a gas and / or via thermal radiation.

The first continuous furnace and also the rest of the device used for the process are described with the aid of a "transport direction of the component". This is the direction in which the component is moved through the device and its elements. The transport direction of the component is therefore in particular the direction in which the component is moved through the first continuous furnace.

When viewed along the transport direction defined in this way, the first continuous furnace has a first zone and a second zone. The fact that the first continuous furnace is “divided” into these two zones in the direction of transport of the component means that the first continuous furnace only has these two zones when viewed along the direction of transport of the component. The zones preferably each extend across the entire first continuous furnace at right angles to the direction of transport of the component.

The component first passes through the first zone and then the second zone. When viewed in the direction of transport, the second zone is subordinate to the first zone. The first zone and the second zone directly adjoin one another. The first zone adjoins an inlet of the first continuous furnace, the second zone adjoins an outlet of the first continuous furnace. The component can be introduced into the first continuous furnace via the inlet. The component can leave the first continuous furnace via the outlet.

In the first zone, the component is heated to a first temperature above the component's AC3 temperature. In any case, a temperature above the AC3 temperature of the component is set in part of the first zone. Heating to the first temperature results in a diffusion exchange between the materials of the coating and the rest of the component. A so-called interdiffusion layer is formed in which the materials of the coating and the rest of the component are mixed with one another at the atomic level. Tests have shown that the temperature control described allows the desired thickness of the interdiffusion layer to be preset particularly precisely.

For the further process steps, in particular for step c), it is advantageous if the component leaves the first continuous furnace at a temperature below the AC3 temperature of the component. Austenite is formed when the AC3 temperature is exceeded. In any case, in areas of the component that are supposed to have a higher ductility, the austenite produced in this way should be broken down again as soon as possible. The temperature of the first continuous furnace in the second zone is therefore set in such a way that the component in this zone cools down to a second temperature that is below the AC3 temperature of the component.

The temperature of the component is influenced by the set temperature profile of the first continuous furnace. In the simplest case, the temperature in the first zone is set to the first temperature and in the second zone to the second temperature. If the component is moved sufficiently slowly through the first continuous furnace, the component temperature reaches the first temperature at the end of the first zone and the second temperature at the end of the second zone. A suitable transport speed for this depends in particular on the material thickness and the material of the component and can easily be determined by experiments or simulations.

It should be noted that short-term and / or locally limited temperature changes within the first continuous furnace have almost no relevance for the heating of the component. This is because the temperature of the component adapts comparatively slowly to the temperature in the first continuous furnace. In order to take this fact into account, it is preferred that the average temperature in the first zone is above the AC3 temperature of the component and / or that the average temperature in the second zone is below the AC3 temperature of the component. The average temperature is to be understood as the average of the temperature to which the component is exposed in the respective zone. This is the temperature in a component level of the first continuous furnace, i.e. the level in which the component is transported through the first continuous furnace. In particular, should In the case of a gas-fired first continuous furnace, locally increased temperatures in the area of the burners are disregarded, provided that these are spaced apart from the component.

It is sufficient that the zones are only separated from one another by the temperature that is set in the component. This temperature can be determined, for example, by a drag measurement. In addition, it is not necessary for the zones to differ or for the boundaries between the zones to be recognizable as such. In addition, it is possible that a first zone and a second zone can be defined in the first continuous furnace in various ways. It is sufficient if there is a possible assignment of a first zone and a possible assignment of a second zone, with all of the conditions set up for the two zones being met. Alternative allocation options are then irrelevant. However, the zones are preferably not assigned arbitrarily. If the temperature profile has clearly recognizable jumps along the direction of transport of the component, the boundary between the zones preferably coincides with such a clearly recognizable jump. It is particularly preferred that the temperature set in the first continuous furnace at the boundary between the first zone and the second zone is at the AC3 temperature of the component. This is particularly the case when the boundary between the two zones is at a jump in the temperature set in the first continuous furnace from a value above the AC3 temperature of the component to a value below the AC3 temperature of the component.

Furthermore, it is preferred that the temperature set in the first continuous furnace is above the AC3 temperature of the component over at least 50% of an expansion of the first zone in the direction of transport of the component. It is likewise preferred that the temperature set in the first continuous furnace is below the AC3 temperature of the component over at least 80% of an expansion of the second zone in the direction of transport of the component. The temperature in the entire first zone is particularly preferably above the AC3 temperature. The temperature in the entire second zone is particularly preferably below the AC3 temperature. These statements also relate to the temperature to which the component is exposed in the first continuous furnace.

The first continuous furnace preferably has a plurality of heating elements, the temperature of which can preferably be set individually. The first zone and the second zone preferably correspond to a respective group of the heating elements. The assignment of the heating elements to a zone can be done by a control device and in this respect does not have to be recognizable from the heating elements themselves. The only decisive factor is the temperature distribution. By changing the temperature setting of a heating element at the boundary between the first zone and the second zone, the assignment of this heating element can be changed from the first zone to the second zone, and vice versa. In general, the expansion of the zones can be changed by changing the assignment of heating elements at the border between the zones. The temperature distribution of the zone can be adjusted by the respective temperature setting of the heating elements. All heating elements in a zone are preferably set to the same temperature.

In step b) of the method, the component is transferred from the first continuous furnace to the temperature control station. There, the component is thermally treated differently in areas in step c) in that a first area of the component is exposed to a temperature that is on average above the AC3 temperature of the component and a second area of the component is cooled.

The first continuous furnace and the temperature control station are different components that are spatially separated from one another. The transfer between the first continuous furnace and the temperature control station facilitates the cooling of the component between the heating in the first continuous furnace and the thermal treatment in the temperature control station. In any case, the component is cooled down as quickly as possible in certain areas in the temperature control station. Rapid cooling can be done more efficiently outside of the hot first continuous furnace. In this way, the cooling can begin during the transfer. In this respect, the spatial separation of the first continuous furnace from the temperature control station accelerates the process. This is in contrast to a solution in which all process steps are carried out in the same device without having to transfer the component. Such solutions typically aim to keep the expense of component transfers low or to avoid them altogether. The spatial separation between the first continuous furnace and the temperature control station also facilitates the construction because the requirements for the first continuous furnace and the temperature control station are different. Integrating both in one facility would therefore be correspondingly complicated.

In the temperature control station, the first area is exposed to a temperature above the AC3 temperature of the component, in particular 170 to 250 K above the AC3 temperature of the component, and is heated to that extent. The first area of the component is preferably exposed to a temperature above the AC3 temperature of the component to the extent that the component with the first area is exposed a chamber that is open on the component side is maintained, the chamber being kept at this temperature by a heating device. The heating device is preferably an electrical heating device. The heating device can, for example, have a heating element such as a heating loop. Alternatively or additionally, the heating device can comprise a radiant tube which is heated with a burner, in particular with a gas burner.

The second area is cooled in the temperature control station. This is preferably done by keeping the second area outside the chamber described above. There, the second area is preferably acted upon with a cooling fluid, in particular with compressed air. The compressed air preferably has a pressure in the range from 2 to 4.5 bar. As a result of this comparatively high pressure, a large amount of the compressed air can be directed to the second area of the component within a very short time, so that a sufficiently high cooling speed can be achieved.

The cooling of the second area in step c) preferably begins with a delay of 0.5 to 15 s after the completion of step b). The cooling does not begin immediately after the component has entered the temperature control station. In this way, the cooling can also be used for cooling through free radiation to the environment, whereby, for example, cooling fluid can be saved. The cooling that starts after the delay is active cooling. This allows the strength properties of the component to be set particularly precisely.

Whether and to what extent the temperature of the component is above or below the AC3 temperature of the component has a decisive influence on the structure composition obtained. As a result of the different thermal treatment of the areas of the component, the two areas can have different structural compositions and, in this respect, different ductilities. The first area will be harder than the second area. For example, in the case of a B-pillar for a motor vehicle, the crash properties can be set in a targeted manner.

The first area and the second area are not necessarily connected areas. In particular, it is possible that a middle part of a B-pillar represents the first area, while an upper and a lower part of the B-pillar together represent the second area. The component preferably, but not necessarily, only has the first area and the second area, that is to say no further areas.

• d) Transferieren des Bauteils von der Temperierstation in einen zweiten Durchlaufofen,
• e) thermisches Behandeln des Bauteils in dem zweiten Durchlaufofen.

In a preferred embodiment, the method further comprises:

• d) Transferring the component from the temperature control station to a second continuous furnace,
• e) thermal treatment of the component in the second continuous furnace.

The temperature control station and the second continuous furnace are different components that are spatially separated from each other. The transfer between the temperature control station and the second continuous furnace facilitates the cooling of the component between the thermal treatment in the temperature control station and in the second continuous furnace. In this way, the second area of the component can also be cooled down during the transfer. This reduces the required size of the temperature control station and speeds up the process. This is in contrast to a solution in which all process steps are carried out, if possible, in the same device without having to transfer the component. Such solutions typically aim to keep the expense of component transfers low or to avoid them altogether.

The second continuous furnace is preferably a roller hearth furnace. The entire component is thermally treated in the second continuous furnace. The component is completely picked up by the second continuous furnace. The thermal treatment in a continuous furnace stands in particular in contrast to a heating by the so-called "direct energization".

It has been found that, in particular in this embodiment, the advantage described is achieved that a particularly easily adjustable interdiffusion layer thickness can be obtained through the zones with different temperatures in the first continuous furnace. This advantage is achieved in a special way with the combination of steps a) to e).

In a further preferred embodiment of the method, the first temperature is in the range from 10 to 30 K above the AC3 temperature of the component and / or the second temperature is in the range from 80 to 150 K below the AC3 temperature of the component.

The combination is preferred that the first temperature is in the range from 10 to 30 K above the AC3 temperature of the component and that the second temperature is in the range from 80 to 150 K below the AC3 temperature of the component.

Tests have shown that the advantages described can be achieved, in particular with the specified temperature values.

In the case of 22MnB5, it is preferred that the first temperature is 856 to 876 ° C and the second temperature is 696 to 766 ° C.

In a further preferred embodiment of the method, the component in step a) is kept and / or at a temperature within 10 K of the first temperature for 30 to 100 s, in particular for 50 to 80 s, before leaving the first zone of the first continuous furnace the component in step a) is held at a temperature within 10 K of the second temperature for 20 to 60 s, in particular for 35 to 45 s, before leaving the first continuous furnace.

The preferred combination is that the component in step a) is held at a temperature within 10 K of the first temperature for 30 to 100 s, in particular for 50 to 80 s, before leaving the first zone of the first continuous furnace, and that the component in step a) is held at a temperature within 10 K of the second temperature for 20 to 60 s, in particular for 35 to 45 s, before leaving the first continuous furnace.

The component in step a) is preferably kept at the first temperature for 30 to 100 s, in particular for 50 to 80 s, before leaving the first zone of the first continuous oven and for 20 to 60 s, in particular for 35 to 60 s, before leaving the first continuous oven 45 s, held at the second temperature. However, since minor temperature fluctuations are not important, it is sufficient to maintain the temperature at a temperature that differs from the first temperature or the second temperature by at most 10 K.

Holding at the first temperature means that there is enough time for the interdiffusion layer to form. By maintaining the second temperature, the previously formed austenite can be sufficiently degraded without the temperature dropping more than is advantageous for the further process steps.

In a further preferred embodiment of the method, the first zone extends in the direction of transport of the component over 30 to 80% of the first continuous furnace.

The first zone is designed to be so long that the component in it can exceed the AC3 temperature and can preferably be kept at this temperature for the holding time specified above. The second zone is designed to be so long that the component in the second zone can cool down to the second temperature and can be kept at this temperature for the holding time specified above. The longer the first zone, the shorter the second zone. It has been found that the interdiffusion layer can be adjusted particularly well in this embodiment.

The first zone particularly preferably extends over 50 to 70% of the first continuous furnace in the direction of transport of the component.

In a further preferred embodiment of the method, an average temperature in one half of the first zone through which the component first passes is at least 20 K higher than in the remaining first zone.

In this embodiment, the temperature set in the first zone is not constant, but on average is higher in the first half of the first zone than in the second half of the first zone. Due to the higher temperature, the component is heated comparatively quickly at the beginning of the first zone. Rapid heating is advantageous in the first zone because the first zone can be made shorter and a correspondingly larger part of the first continuous furnace remains for the second zone. However, the first component in the first zone should only be heated to the first temperature. The temperature of the first continuous furnace is therefore selected to be lower in the second half of the first zone. At the end of the first zone, the temperature is preferably set to the first temperature.

• - einen ersten Durchlaufofen, welcher in Transportrichtung des Bauteils in eine erste Zone und eine dieser nachgeordnete zweite Zone unterteilt ist,
• - eine dem ersten Durchlaufofen in Transportrichtung des Bauteils nachgeordnete Temperierstation,
• - eine Steuereinrichtung, die dazu eingerichtet ist, in dem ersten Durchlaufofen eine derartige Temperaturverteilung einzustellen, dass sich das Bauteil in der ersten Zone auf eine oberhalb der AC3-Temperatur des Bauteils liegende erste Temperatur erwärmt und in der zweiten Zone auf eine unterhalb der AC3-Temperatur des Bauteils liegende zweite Temperatur abkühlt.

As a further aspect of the invention, a device for the thermal treatment of a coated component is presented. The device comprises:

• - A first continuous furnace, which is divided into a first zone and a second zone downstream in the direction of transport of the component,
• - a temperature control station downstream of the first continuous furnace in the transport direction of the component,
• a control device which is set up to set a temperature distribution in the first continuous furnace such that the component in the first zone is heated to a first temperature above the AC3 temperature of the component and to a temperature below the AC3 temperature in the second zone Temperature of the component lying second temperature cools.

The described particular advantages and design features of the method can be used and transferred to the device, and vice versa. The device is preferably intended and set up for operation in accordance with the method. The method is preferably carried out with the device. The device preferably has a second continuous furnace, the Tempering station is arranged downstream in the transport direction of the component.

The fact that the second zone of the first continuous furnace is arranged downstream of the first zone in the transport direction of the component means that the component passes through the second zone later than the first zone. The same applies to the temperature control station and the second continuous furnace, which are arranged downstream of the first continuous furnace or the temperature control station in the transport direction of the component.

• 1: eine erfindungsgemäße Vorrichtung zum thermischen Behandeln eines Bauteils,
• 2: einen Temperaturverlauf, der sich mit der Vorrichtung aus 1 bei Durchführung eines erfindungsgemäßen Verfahrens zum thermischen Behandeln des Bauteils einstellt.

The invention is explained in more detail below with reference to the figures. The figures show a particularly preferred exemplary embodiment to which, however, the invention is not limited. The figures and the proportions shown therein are only schematic. Show it:

• 1 : a device according to the invention for the thermal treatment of a component,
• 2 : a temperature profile that is related to the device 1 adjusts when carrying out a method according to the invention for the thermal treatment of the component.

1 shows an apparatus 1 for thermal treatment of a coated component 2 . The device 1 comprises a first continuous furnace 3 , which in the transport direction r of the component 2 a first zone 6th and one of the first zone 6th downstream second zone 7th having. The second zone 7th is therefore from the component 2 run through later and is therefore in 1 to the right of the first zone 6th . The first continuous furnace 3 is in the direction of transport r in the first zone 6th and the second zone 7th divided, so has no further zones in this direction. The first zone 6th extends in the direction of transport r of the component 2 over 30 to 80% of the first continuous furnace 3 . The first zone 6th and the second zone 7th extend transversely to the direction of transport r - so in 1 up and down as well as perpendicular to the plane of the drawing - over the entire first continuous furnace 3 .

The device 1 furthermore has one of the first continuous furnace 3 in transport direction r of the component 2 downstream temperature control station 4th on. Furthermore, the device 1 a second continuous furnace 5 in the direction of transport r of the component 2 the temperature control station 4th is subordinate. The temperatures in the first zone 6th of the first continuous furnace 3 , in the second zone 7th of the first continuous furnace 3 , in the temperature control station 4th and in the second continuous furnace 5 are via a control device 8th adjustable. This is indicated by dotted lines. The control device 8th is set up in particular in the first continuous furnace 3 adjust such a temperature distribution that the component 2 in the first zone 6th to one above the AC3 temperature T _AC3 of the component 2 lying first temperature T ₁ heated and in the second zone 7th to one below the AC3 temperature T _AC3 of the component 2 lying second temperature T2 cools.

2 shows a temperature profile in the component 2 adjusts when it is through the device 1 the end 1 is moved. The representation of 2 is schematic. A plot of the temperature is shown T over time t in any units. The component 2 is first in the first continuous furnace 3 warmed up. The dwell time of the component 2 in the first continuous furnace 3 is with t _D1 and in the with t _Z1 designated length of stay in the first zone 6th and the with t _Z2 designated length of stay in the second zone 7th divided. In the first zone 6th is the temperature of the first continuous furnace 3 adjusted so that the component 2 in the first zone 6th at the first temperature T ₁ warmed up. The component 2 will be at the end of the first zone 6th for an initial hold time t _H1 on the first temperature T ₁ held. In the second zone 7th is the temperature of the first continuous furnace 3 adjusted so that the component 2 in the second zone 7th to the second temperature T ₂ cools down. The component will be at the end of the second zone 7th for a second hold time t _H2 held at the second temperature T2.

In a further preferred embodiment is T ₂ chosen so deep that the component 2 the temperature T2 has not been reached in the specified time, but has fallen below the temperature required for the disintegration of the austenite long enough. In this case, there is no approximately isothermal hold at T2.

Then the component 2 in the temperature control station 4th transferred. The associated transfer time is with t _T1 designated. The component cools during this transfer 2 away. In the temperature control station 4th the component remains 2 over a dwell time t _TS . During this time the component will 2 in the temperature control station 4th thermally treated by a first area of the component 2 is exposed to a temperature which is constant at a value above the AC3 temperature T _AC3 of the component 2 and a second area of the component 2 is cooled. The temperature of the first area is marked with TA, the temperature of the second area with T _B .

After the thermal treatment of the component 2 in the temperature control station 4th becomes the component 2 in the second continuous furnace 5 transferred. The transfer time for this is with t _T2 designated. The component also cools here 2 from what depends on the material thickness and transfer time t _T2 can be different.

In the second continuous furnace 5 becomes the component 2 further thermally treated by heating it as a whole. For this purpose the component 2 preferably exposed to a temperature above the AC3 temperature T _AC3 of the component 2 lies. The colder second area of the component 2 is heated faster than the warmer first area due to the greater temperature difference. The dwell time of the component 2 in the second continuous furnace 5 is denoted by T _D2.

The coated component receives due to the different thermal treatment in areas 2 a ductility that differs in certain areas. This is advantageous for a B-pillar for a motor vehicle, for example. By heating to above AC3 and then cooling to below AC3 in the first continuous furnace 3 becomes a particularly well adjustable thickness of the interdiffusion layer of the coating of the component 2 achieved.

List of reference symbols

1

contraption

2

Component

3

first continuous furnace

4th

Temperature control station

5

second continuous furnace

6th

first zone

7th

second zone

8th

Control device

T

temperature

TAC3

AC3 temperature of the component

T1

first temperature

T2

second temperature

TA

Temperature of the first area of the component

TB

Temperature of the second area of the component

t

Time

tD1

Dwell time in the first tunnel oven

tZ1

Dwell time in the first zone of the first continuous furnace

tH1

first hold time

tZ2

Dwell time in the second zone of the first continuous furnace

tH2

two hold time

tT1

Transfer time from the first continuous furnace to the temperature control station

tTS

Dwell time in the temperature control station

tT2

Transfer time from the temperature control station to the second continuous furnace

tD2

Dwell time in the second continuous furnace

r

Transport direction of the component

Claims (7)

A method for the thermal treatment of a coated component (2), comprising: a) thermal treatment of the component (2) in a first continuous furnace (3), which in the transport direction (r) of the component (2) in a first zone (6) and a is subdivided into this adjoining second zone (7) through which the component (2) passes later, the component (2) in the first zone (6) being at a temperature above the AC3 temperature (T _AC3 ) of the component (2) lying first temperature (T ₁ ) is heated and in the second zone (7 _{) is cooled to a second temperature (T 2 ) below the AC3 temperature (T AC3} ) of the component (2), b) transferring the component (2) from the first continuous furnace (3) in a temperature control station (4), c) thermal treatment of the component (2) in the temperature control station (4), a first area of the component (2) being exposed to a temperature that is on average above the AC3- Temperature (T _AC3 ) of the component (2) is, and a second area of the component (2) is cooled t will. Procedure according to Claim 1 , further comprising: d) transferring the component (2) from the temperature control station (4) into a second continuous furnace (5), e) thermal treatment of the component (2) in the second continuous furnace (5). Method according to one of the preceding claims, wherein the first temperature (T ₁ ) is in the range from 10 to 30 K above the AC3 temperature (T _AC3 ) of the component (2) and / or wherein the second temperature (T ₂ ) is in the range from 80 to 150 K below the AC3 temperature (T _AC3 ) of the component (2). Method according to one of the preceding claims, wherein the component (2) in step a) before leaving the first zone (6) of the first continuous furnace (3) for 30 to 100 s at a temperature within 10 K around the first temperature (T ₁ ) is held and / or wherein the component (2) in step a) is held for 20 to 60 s at a temperature within 10 K of the second temperature (T ₂ ) before leaving the first continuous furnace (3). Method according to one of the preceding claims, wherein the first zone (6) extends in the transport direction (r) of the component (2) over 30 to 80% of the first continuous furnace (3). Method according to one of the preceding claims, wherein an average temperature in one half of the first zone (6) through which the component (2) passes first is at least 20 K higher than in the remaining first zone (6). Device (1) for the thermal treatment of a coated component (2), comprising: - a first continuous furnace (3) which, in the transport direction (r) of the component (2), enters a first zone (6) and a second zone (7 ) is subdivided, - a temperature control station (4) downstream of the first continuous furnace (3) in the transport direction (r) of the component (2), - a control device (8) which is set up to provide such a temperature distribution in the first continuous furnace (3) adjust that the component (2) in the first zone (6) is heated to a _{first temperature (T 1 ) lying above the AC3 temperature (T AC3} ) of the component (2) and to a below the AC3 temperature (T _AC3 ) of the component (2) lying second temperature (T ₂ ) cools.

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