EP3530760A1 - Method for producing a thermoformed and hardened steel sheet component - Google Patents

Abstract

The invention relates to a method for producing a hot-formed and hardened sheet steel component with a metallic anti-corrosion coating having the following process steps: Providing a plate 2 with an anti-corrosion coating; fully alloyed, • homogeneous setting of a temperature between 500 ° C and AC3, in particular from 550 ° C to less than or equal to AC1, • transferring the pre-tempered board 2 to a temperature control station 4 and heating in areas to a temperature greater than or equal to AC3 temperature, with the other areas are kept at the pre-temperature or heated to a temperature less than AC3, • hot forming and press hardening of the partially tempered blank 2 in a hot forming and press hardening tool 5 to form a sheet steel component with partially different strength properties.

Description

The present invention relates to a method for producing a hot-formed and hardened sheet steel component on a thermoforming line according to the features in claim 1.

From the prior art it is known to hot-form and harden steel components. This is also referred to as hot forming followed by press hardening. A board made of a hardenable steel alloy is heated at least in some areas to a temperature above AC3 temperature (austenitizing temperature). The board is thus at least partially in an austenitized state. In this warm state, the forming degrees of freedom are increased so that hot working can take place in a press forming tool. Subsequently, the hot-formed component is cooled down so fast that a quench hardening or press hardening takes place. Especially in the before Austenitized areas thus a martensitic and thus high or ultra high strength material structure is set.

So that the boards are first brought to the Austenitisierungstemperatur, thus to about 900 ° C or more, a warming device is connected upstream of the hot forming and press hardening tool. This is usually a continuous furnace, which, however, requires a relatively large amount of energy and space in a production hall.

In recent years, the space-saving and much faster to be performed contact heating has become known. In this case, a tempering station is used which has tempering plates. The metal sheet to be heated is placed in the tempering station and the tempering station is closed. The heat present in the tempering plates is transferred by heat conduction into the board to be heated. This is also known as contact heating. For example, such a tempering of the DE 10 2012 110 649 B3 known.

Object of the present invention is to provide a thermoforming line with tempering, with which it is possible to precisely heat a board partially different from each other, with low energy consumption and a particularly short heating time.

The aforementioned object is achieved with a method for producing a hot-formed and hardened sheet steel component with the features in claim 1.

Advantageous developments are the subject of the dependent claims.

• Bereitstellen einer Platine mit einer Korrsionsschutzbeschichtung,
• Erwärmen der Platine auf eine Temperatur größer AC3 des Stahlwerkstoffes, so dass die Korrosionsschutzschicht mit dem Grundmaterial der Platine durchlegiert,
• Homogenes Einstellen einer Temperatur in der Platine von 500°C bis AC1, insbesondere von 550°C bis kleiner AC1,
• Überführen der so vortemperierten Platine in eine Temperierstation und bereichsweise Erwärmen auf eine Temperatur größer gleich AC3 Temperatur, wobei die anderen Bereiche auf der Vortemperatur gehalten werden oder auf eine Temperatur kleiner gleich AC1 erwärmt werden,
• Warmumformen und Presshärten der partiell temperierten Platine in einem Warmumform- und Presshärtewerkzeug zu einem Stahlblechbauteil mit bereichsweise voneinander verschiedenen Festig keitseigenschaften.

The process for producing a hot-formed and hardened sheet steel component, in particular a motor vehicle component with a metallic corrosion protection coating, in particular an Al-Si coating, comprises the following method steps:

• Providing a board with an anti-corrosive coating,
• Heating the board to a temperature greater than AC3 of the steel material, so that the corrosion protection layer is alloyed with the base material of the board,
• Homogeneous setting of a temperature in the board from 500 ° C to AC1, in particular from 550 ° C to less AC1,
• Transferring the so-preheated board into a tempering station and heating in some areas to a temperature greater than or equal to AC3 temperature, the other areas being kept at the preliminary temperature or heated to a temperature of less than or equal to AC1,
• Hot forming and press hardening of the partially tempered board in a hot forming and press hardening tool to a sheet steel component with area-wise different Festig keitseigenschaften.

As a board, in particular, a sheet metal blank or steel plate made of a hardenable steel alloy is provided, for example, a 22MnB5 steel. The anticorrosive coating is particularly preferably an aluminum-based coating, for example an aluminum-silicon coating or else a zinc-based coating.

It has proved to be particularly advantageous, firstly for the process reliability of the process carried out, secondly from energetic aspects and the space required in a two-part furnace, in particular a continuous furnace, first to heat the board to a temperature greater than the AC3 temperature. This happens in particular with an excess temperature within a first temperature zone of the furnace, so that the applied coating is alloyed with the surface of the steel plate and an intermetallic phase is formed. At the same time, all areas of the board are austenitized, which in turn has an advantageous effect with respect to later fixed, but also soft or ductile areas within the board.

Following the first austenitizing, a temperature in the board is set which is from 500 ° C to AC1 temperature, in particular from 550 ° C to less AC1 temperature. This two-stage tempering process is also called pre-tempering or preheating.

The pre-tempered board, which has already formed an intermetallic phase with the anti-corrosion coating, is then transferred to a tempering station. The temperature control is designed as Kontakttemperiertstation. This means that the tempering station has at least one contact plate and the contact plate dissipates its heat by means of heat conduction to the board to be heated. In the tempering station itself, the board is then heated in some areas to temperatures greater than AC3, that is again austenitized. Other areas may be maintained at the pre-set temperature or may be heated to a temperature less than AC1. It would also be conceivable within the scope of the invention for the other areas to be cooled accordingly. However, the target temperature is also here in a range between 500 ° C and small AC1 temperature.

The so partially tempered board is then transferred from the tempering station in a hot forming and press hardening tool and here hot-formed and press-hardened. The advantage here is that no costly measures such as additional heating and / or only partial cooling must be provided in the hot forming and press hardening tool. The board is already partially tempered and can thus be hot-formed and press-hardened in a conventional hot forming and press hardening tool without additional temperature measures in the tool itself. In particular, in the press-hardening, a cooling rate of at least 40 K / s is selected.

By means of the above-described method according to the invention for producing a thermoformed and press-hardened sheet steel component, it is thus possible to produce a three-dimensionally shaped sheet steel component, in particular a motor vehicle component, that at least in some areas has a tensile strength greater than 1,000 MPa, in particular greater than 1,200 MPa and preferably greater than 1,400 MPa in hard areas , The softer areas, on the other hand, have a tensile strength of less than 1,000 MPa, preferably from 500 MPa to 900 MPa, in particular from 550 MPa to 800 MPa.

It is also guaranteed with certainty that the corrosion protection coating is alloyed with the metal plate and that the corrosion protection coating is not damaged during later forming. At the same time, the energy costs and the tooling costs for setting up and operating the hot forming line for production methods according to the invention are reduced, in particular with regard to the hot forming and press-hardening tool. The space requirement is also significantly lower compared to other hot forming lines.

For the preheating or preheating, a continuous furnace is particularly preferably used within the scope of the invention which has two temperature zones directly adjacent to one another in the direction of passage. In particular, continuous production takes place in one direction through the continuous furnace. A first temperature zone has a temperature greater than the AC3 temperature, a subsequent second temperature zone has a temperature lower than the AC1 temperature, but at least about 500 ° C.

In the first temperature zone, a temperature of the sheet metal plate itself of a maximum of 930 ° C should be set. In particular, it is provided that for the temperature range from 20 ° C. to 700 ° C., a heating rate of 12 K / s is not exceeded, so that an intermetallic phase is formed between the coating and the base material of the board.

In the second temperature zone, an interior temperature of the furnace can be the target temperature of the board or even up to 50 ° C below, thus 500 ° C to less AC1 temperature or up to 50 ° C below. Thus, lowering the temperature from a temperature in the range of AC3 to 500 ° C to less than AC1 can be achieved. Should the run be stopped by a brief interruption in production, the board temperature, in particular in the second temperature zone, does not drop directly to a subcritical temperature level.

The flow time in the first temperature zone of the continuous furnace should be from 2 to 6 minutes, preferably from 3 to 5 minutes and especially about 4 minutes. Preferably, the respective longer times for boards with a wall thickness greater than 1.5 mm and the said shorter times for boards with a wall thickness of up to 1.5 mm are provided.

The cycle time in the second temperature zone should be between 20 s and 240 s, in particular from 40 s to 180 s. The cycle time in the first temperature zone is adjusted according to the temperatures to be reached and cycle times at the aforementioned heating rate between 20 ° C and 700 ° C. Preferably, a conveyor is provided, which promotes both by first and second temperature zone, thus the transport speed through the entire continuous furnace is the same.

Furthermore, according to the invention, the hot forming line can be operated in a cycle time of 5 to 15 seconds, preferably 7 to 12 seconds, more preferably 8 to 10 seconds. This is realized in particular by the tempering station upstream of the hot forming and press hardening tool, which can be operated in the same cycle as the hot forming and press hardening tool itself. The transfer times between the individual stations or tools are preferably even lower. Thus, a transfer time between the end of preheating and the beginning of the contact heating is preferably less than 10 seconds, in particular less than 5 seconds and most preferably within 2 to 5 seconds. As a result, in turn, it has been found according to the invention that the interaction between pre-tempering and partial reheating in conjunction with the heat input to be introduced into the board is carried out particularly effectively. The cycle time and the transfer time overlap.

In particular, when alloying the corrosion protection layer, a 4-layer structure, starting from the board or the hardenable steel alloy to the outside. This 4-layer construction is formed by an interdiffusion layer which bonds to the hardenable steel alloy, followed by an intermediate layer, again followed by an intermetallic layer and the outer surface layer of the corrosion protection coating.

Further, it is possible to produce the sheet steel component with a edge decarburized layer. In this case, a bending angle greater than 50 ° and a layer thickness on the sheet steel component, on which a Randentkohlung has occurred, between 5 microns and 50 microns. It is thus possible for a carbon content greater than 0.20 wt .-% to set a tensile strength greater than 1350 MPa and set for a carbon content less than 0.35 wt .-%, a tensile strength sometimes greater than 1,800 MPa. The edge decarburization is by decarburization of a strip semi-finished product, before before a corresponding steel strip is separated into blanks, by supplying nitrogen and portions of an oxide-containing gas or fluid, such as. As water vapor or water atmosphere, performed prior to dip coating.

The tempering for Kontakttemperierung the board also has a temperature control plate on a lower tool or on an upper tool. The tempering plate itself is heated homogeneously to a temperature greater than AC3 temperature. The tempering preferably covers the entire sheet metal plate to be heated from. So that now the temperature control can be closed on the opposite side of the temperature control one Profiling trained. The profiling comes in closed tempering station with the sheet metal plate in some areas to the plant, such that areas of the first type of sheet metal blank are austenitized due to system contact with the profiling and areas of the second kind are heated to a temperature below AC1 temperature. Areas of the second type are heated only to a temperature below AC1 temperature, wherein no plant contact with the profiling takes place in these areas.

The tempering plate described above and also described below particularly preferably has a temperature greater than the AC3 temperature itself. In system contact thus takes place due to heat conduction heating of the board on at least partially greater AC3 temperature. The temperature of the temperature control plate is particularly preferably heated to more than 50 ° C., in particular more than 100 ° C., and more preferably more than 150 ° C., very particularly preferably more than 200 ° C., greater than the AC3 temperature. However, the tempering plate should have an own temperature which is not more than 300 ° C above the AC3 temperature. The tempering plate itself particularly preferably covers the board completely with its areal extent. Thus, the temperature control plate in terms of area at least equal, preferably larger than the board itself to be heated.

Instead of the profiling described above, it is also possible that a contact plate is provided on the opposite side of the tempering in the tempering. The contact plate has partially areas that are uncooled and / or insulated. The contact plate has further areas, which are actively cooled, wherein the contact plate preferably also covers the board over its entire surface. Preferably, the contact plate is the same size in terms of area as the temperature control.

A further alternative embodiment variant provides that an alternative profiling is provided on the side opposite the tempering plate. This profiling also has areas that protrudes from a surface of the profiling and partially with the Sheet metal board come to rest with closed temperature control station. These coming to the plant areas are in the board areas of the second kind, which are heated to a temperature below AC1, wherein the profiling is cooled. The areas not coming into contact with the profiling are in turn heated to a temperature above AC3 by plant contact with the temperature control plate itself.

In a further alternative embodiment variant, it is conceivable that the tempering station has a tempering plate on both sides of the board, wherein the tempering plate is tempered in regions and / or segmented, such that areas of the first type of board are heated to above AC3 temperature and areas second Kind to be tempered under AC1. These areas are formed in the tempering itself by Isolierwerkstoff and / or a cooled area. The areas of the first type of board are formed in the tempering itself heated, so that a heat conduction from the tempering to the areas of the first kind in the board.

Furthermore, it is preferably provided that the temperature control plate and / or the profiling and / or the contact plate itself is resiliently mounted and in the unloaded state is designed to protrude over an upper tool or lower tool in the temperature control station. It is thus achieved that in the stroke direction of the tempering the board with the temperature control with the profiling or with the contact plate earlier in time comes into contact on both sides, before the tempering has reached its bottom dead center in the stroke direction. The effective contact time with the board is thus greater or longer than the closing time at the bottom dead center of the temperature control itself. Furthermore, an improved system contact is achieved by the resilient mounting. Furthermore, the resilient mounting can also achieve compensation for thermal expansion and / or achieve a uniform contact with the system, in particular pressing force or press pressure, when the temperature control plate and the circuit board are in contact.

Also, the system time for Kontakttemperierung within the cycle time itself is effectively extended by the resilient mounting when closing and opening the tempering.

The tempering plate itself may for example be designed as an electrical resistance or heated or tempered by heating means. These may be, for example, cartridge heaters, inductors or other known heating means. Furthermore, in the temperature control, if this is partially cooled, also be provided according to active coolant.

The profiling itself is preferably passively miterwärmt by the system contact by means of the metal sheet through the tempering itself. In the case of a cooled profiling corresponding cooling or tempering can be provided here.

• Bevorzugte Ausgestaltungsvarianten werden in den schematischen Figuren dargestellt. Diese dienen dem einfachen Verständnis der Erfindung. Es zeigen:

  Figur 1

  einen schematischen erfindungsgemäßen Verfahrensablauf,

  Figur 2

  eine erfindungsgemäße Temperierstation in Seitenansicht,

  Figur 3

  eine alternative Ausgestaltungsvariante der erfindungsgemäßen Temperierstation gemäß Figur 2,

  Figur 4

  eine alternative Ausgestaltungsvariante zu Figur 3,

  Figur 5

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation in Seitenansicht,

  Figur 6

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation in Seitenansicht,

  Figur 7

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation in Seitenansicht,

  Figur 8

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation in Seitenansicht,

  Figur 9

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation in Seitenansicht,

  Figur 10

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation in Seitenansicht,

  Figur 11

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation in Seitenansicht,

  Figur 12

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation in Seitenansicht,

  Figur 13

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation in Seitenansicht,

  Figur 14

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation in Seitenansicht,

  Figur 15

  eine alternative Ausgestaltungsvariante einer Temperierstation und

  Figur 16

  eine weitere alternative Ausgestaltungsvariante einer Temperierstation.

Further advantages, features, characteristics and aspects of the invention are the subject of the following description:

• Preferred embodiments are shown in the schematic figures. These are for easy understanding of the invention. Show it:

  FIG. 1

  a schematic process sequence according to the invention,

  FIG. 2

  a tempering station according to the invention in side view,

  FIG. 3

  an alternative embodiment variant of the tempering according to the invention according to FIG. 2 .

  FIG. 4

  an alternative embodiment variant FIG. 3 .

  FIG. 5

  a further alternative embodiment variant of a tempering station in side view,

  FIG. 6

  a further alternative embodiment variant of a tempering station in side view,

  FIG. 7

  a further alternative embodiment variant of a tempering station in side view,

  FIG. 8

  a further alternative embodiment variant of a tempering station in side view,

  FIG. 9

  a further alternative embodiment variant of a tempering station in side view,

  FIG. 10

  a further alternative embodiment variant of a tempering station in side view,

  FIG. 11

  a further alternative embodiment variant of a tempering station in side view,

  FIG. 12

  a further alternative embodiment variant of a tempering station in side view,

  FIG. 13

  a further alternative embodiment variant of a tempering station in side view,

  FIG. 14

  a further alternative embodiment variant of a tempering station in side view,

  FIG. 15

  an alternative embodiment variant of a tempering and

  FIG. 16

  a further alternative embodiment variant of a temperature control station.

FIG. 1 shows a hot forming line, in which the tempering 4 is preceded by a continuous furnace 22. The continuous furnace 22 has in the direction of passage DL in the embodiment variant shown here two temperature zones T ₁ and T ₂ . A first temperature zone T ₁ can preferably be heated to a temperature of 900 ° C. or more. An optionally precoated, preferably pre-coated with AlSi board can thus fully austenitized and alloyed with the precoating become. A downstream in the direction of passage DL temperature zone T ₂ may have a lower contrast, for example, 500 ° C to 750 ° C, preferably in the range of about 600 ° C. The thus pre-coated and optionally alloyed board has a homogeneous temperature profile. This can then be transferred to the tempering 4. Here, a locally delimited temperature profile is impressed by means of contact heating, so that sharply bordered transition areas between the individual areas are generated with mutually different temperatures in the board 2. Between the individual stations, industrial robots or manipulators, not shown in more detail, can transfer the respectively tempered board or the manufactured component.

FIG. 2 now shows the tempering 4 in the open state in detail view. On a top tool 7, not shown, a temperature control plate 6 is arranged, which is preferably designed as an electrical resistance. Thus, it has terminals for applying electric power. On the opposite side in the region of a lower tool 8, not shown, a support plate 9 is arranged, on which an optional insulating layer 10 is arranged. Opposite the insulating layer 10 are with a height H body 11 as profiling 12 over. Between the bodies 11 free spaces 13 are respectively formed, which lead to a bottom side 14 of the partially heated board 3 shown here to a Nichtanlagenkontakt.

In the area of the body 11, the board 2 is pressed against the temperature control plate 6 with a pressing force. As a result, areas of the first type 15 are formed on the heated board 3, and areas of the second type 16 are formed. The areas of the first type 15 are completely austenitized. The second type 16 regions are heated to a temperature below AC1 temperature. If the temperature control station 4 is closed, heat conduction takes place from the temperature control plate 6 due to system contact of the temperature control plate via an upper side 17 into the circuit board. In particular, the bodies 11 are also heated passively. These are on the bottom 14 of the board 2. Consequently, there is a heat conduction from the tempering plate 6 via the board into the body 11. Cooling channels 18 can optionally be arranged in the carrier plate 9, so that overheating of the carrier plate 9 during continuous operation of the tempering station 4 is counteracted. The tempering 4 is closed in Pressenhubrichtung 20.

FIG. 3 shows the tempering 4 analogous to FIG. 2 , Here, however, the body 11 by springs 21 in Pressenhubrichtung 20 with respect to the insulating layer 10 protruding. Thus, the body 11 are resiliently mounted.

FIG. 4 shows an alternative embodiment variant in which the entire lower tool 8 is resiliently mounted, for example on a tool plate or on a substrate. This also allows the time of the heat-conducting system of board 2 and body 11 are extended.

FIG. 5 shows an alternative embodiment variant of a tempering according to the invention 4. Here, an upper temperature control plate 6 is completely heated and also comes completely with the board 2 to be heated in plant contact. In contrast, a lower temperature-control plate 6 also has a profiling 12 in this case. However, the lower tempering 6 itself is also heated by means of heating means 24, such as inductors, itself. However, there remain free spaces 13 which leave a free space 13 when the temperature control station 4 is closed and system contact is made with the circuit board 2. In the circuit board 2 thus regions of the second type 16 are formed, which are not heated according to AC1 temperature. The areas of the first type 15 of the board 2, which come in a two-sided system contact, are heated accordingly above AC3 temperature.

The heating means mentioned above and below may be resistance heaters, but also burner heaters, heating cartridges or jacket heaters. As mentioned earlier, however, can Also, the respective temperature control plate 6, 23 may be formed as an electrical resistance itself and thus as a resistance heating. The heating means may also be inductors which temper the temperature control plate 6, 23 by means of induction, and the temperature control plate 6, 23 in turn transfers the heat to the circuit board 2 to be heated by means of heat conduction.

FIG. 6 shows an analogous embodiment FIG. 5 , Here, however, a circumferential insulation 25 is disposed on the lower heating plate 23. Furthermore, the springs 21 are not provided in this embodiment variant.

FIG. 7 shows an analogous embodiment variant FIG. 6 also with a peripheral insulation 25, wherein the lower temperature-control plate 23 is in turn supported by springs 21. Thus, in the press lifting direction 20 of the temperature control station 4, the circuit board 2 already comes before a bottom dead center of the temperature control station in mutual system contact between the upper temperature control plate 6 and the lower temperature control plate 23, so that the effective contact time for the temperature control is extended.

In the design variants according to FIGS. 5 to 7 are each the profiling 12 forming protruding body 11 in one piece and formed the same material with the lower tempering 6.

In the embodiment variant according to FIG. 8 Here are the respective body 11 in two parts with the lower tempering 6 formed in the areas of the second type 16 of the board to be tempered third

In the areas where a free space 13 would actually remain, an additional insulation 25 is arranged.

FIG. 9 shows a further alternative embodiment variant. In this case, the upper temperature-control plate 6 is suspended by means of springs 21 on the upper tool 7. It is still a corresponding insulating layer 10 incorporated, in order to avoid cooling of the upper temperature-6. The upper temperature plate 6 is heated to a temperature greater than AC3, not by shown heating means and / or by electrical resistance heating. By the springs 21, the effective contact time is extended in Pressenhubrichtung 20 with the board 2 to be heated. Furthermore, the lower temperature-control plate 6 is provided, on which body 11 are placed to form a profiling 12. Between the bodies 11 cooling plates 26 are arranged. In the cooling plates 26 in turn cooling channels 18 are formed to set a temperature, which may be, for example, 600 ° C. The body 11 and the lower temperature control plate 23 themselves have a temperature of about AC3 temperature. The body 11 itself may also have a lower temperature than the lower temperature control plate 23. At the board 3 to be heated, regions of the first type 15 and regions of the second type 16 are again formed.

FIG. 10 shows a further alternative embodiment variant of the tempering according to the invention 4. Again, a homogenous heated to above AC3 temperature upper temperature-6 is arranged on an upper tool 7. On a lower tool 8 individual body 11 are mounted on springs 21. It can be provided not shown axial guides, so that a lateral tilting of the body 11 is avoided. Furthermore, cooling plates 26 are provided, which have a temperature of preferably 500 ° C to less AC1 temperature, in particular 600 ° C. These cooling plates 26 may in turn have a cooling channel 18. The cooling channels 18 can be heated by the side heated body 11, wherein the body 11 according to FIG. 10 active or passive can be heated via the sheet metal blank. The cooling plates 26 can also be indirectly heated by a corresponding heat conduction from the upper Temperierplatte 6 through the board 3 in the cooling plates 26. The cooling plates 26 themselves can also be heated themselves, but to a temperature which is less than the AC1 temperature.

FIG. 11 shows an upper temperature control plate 6, which is formed in this case as an electrical resistance itself and a lower temperature control plate 23, wherein on the tempering 6 individual body 11 are placed. The body 11 and the lower temperature control plate 23 each have the same temperature, which in particular is above AC3 temperature. The lower tempering plate 23 with attached bodies 11 according to FIGS. 11 and 12 each may also be formed integrally with the body 11.

FIG. 12 shows a similar embodiment variant FIG. 11 , but here, too, the lower temperature-control plate 6 is formed as an electrical resistance itself. In this case, however, the lower temperature-control plate 23 with the profiling 12, but also the upper temperature-control plate 6, may be formed electrically insulated, so that even with the temperature-control station 4 closed and thus contact with the electrically conductive metal plate, a continuous heating of the Tempering plates 6, 23 is performed.

FIG. 13 shows a further embodiment variant. Here, an additional masking or profiling plate 27 is placed on a lower temperature control plate 6. The lower tempering plate 6 is also formed as an electrical resistance itself and is heated to a temperature of for example 500 ° C. In the bodies 11 of the mask plate 27, a temperature of, for example, 600 ° C., which adjusts itself, then appears due to indirect contact with the installation of the board 2 to be heated with the upper contact plate. In between there are plate pieces 28, in which a contrast lower temperature is formed.

FIG. 14 shows a further alternative embodiment variant. Here, a lower temperature control plate 23 is heated to, for example, a temperature of 500 ° C. On the lower temperature control plate 23, an insulating layer 10 is arranged. On the insulating layer 10 body 11 are again arranged, which form a profiling 12. Free spaces 13 are formed between the bodies 11 in order to heat regions of the first and second types 15, 16 at different temperatures on the board 2 to be heated. The upper Temperature control plate 6 has a temperature greater AC3 temperature. In the bodies 11, a temperature of about 800 ° C is established.

FIG. 15 shows a further alternative embodiment variant of the tempering according to the invention 4. Here, a temperature control plate 6 is arranged on the lower tool 8, which preferably has a temperature homogeneously greater than or equal to AC3 temperature. This temperature control plate 6 is heated by a corresponding heating means 24, for example in the form of inductors. Underneath is an insulating layer to avoid temperature losses. An insulating layer 10 is likewise arranged on the upper tool and a profiling in the form of cooling plates 26 is formed in the insulating layer 10. These cooling plates 26 preferably have cooling channels 18 in order to be actively cooled, for example by passage of a cooling fluid. The areas of the first type 15 are thus on the tempering with closed tempering on the temperature control and are heated to a temperature greater than or equal to AC3.

The areas of the second type 16, where the cooling plates 26 come to rest, are cooled and consequently heat less strongly. In particular, by adjusting the cooling capacity in the cooling plates 26, the temperature in the areas of the second type 16 can be adjusted in a targeted manner. A regulation of the temperature control plate 6 can be omitted.

FIG. 16 shows an alternative embodiment variant. Here, the cooling plates 26 on the upper tool 7 are not in the form of a profiling, but are incorporated into the insulating layer 10 and close with their contact surface flush. This offers the advantage that the insulating layer 10 can also exert a contact pressure on the heated plate 3 lying on the temperature-control plate 6 when the temperature-control station 4 is closed. At the same time, in the areas in which the cooling plate 26 is arranged, a controlled temperature control of the regions of the second type 16 is made possible.

Reference numerals:

1 -

Thermoforming line

2 -

circuit board

3 -

heated board

4 -

heating station

5 -

Hot forming and press hardening tool

6 -

tempering

7 -

upper tool

8th -

lower tool

9 -

support plate

10 -

insulating

11 -

body

12 -

profiling

13 -

free space

14 -

bottom

15 -

Area of the first kind

16 -

Area of the second kind

17 -

top

18 -

cooling channel

19 -

component

20 -

Press stroke direction

21 -

feather

22 -

Continuous furnace

23 -

tempering

24 -

heating

25 -

insulation

26 -

cooling plates

27 -

mask plate

28 -

plate Scrap

H -

height

T ₁ -

temperature zone

T ₂ -

temperature zone

DL -

Throughput direction

Claims (13)

Process for producing a hot-formed and hardened sheet steel component with a metallic corrosion protection coating, comprising the following process steps: Providing a board (2) with an anti-corrosive coating, Heating the board (2) to a temperature greater than AC3 of the steel material, so that the corrosion protection layer is alloyed with the base material of the board (2), Homogeneous setting of a temperature from 500 ° C to AC1, Transferring the previously preheated board (2) into a tempering station (4) and heating in some areas to a temperature greater than or equal to AC3 temperature, the other areas being kept at the preliminary temperature or heated to a temperature of less than or equal to AC1, Hot forming and press hardening of the partially tempered board (2) in a hot forming and press hardening tool (5) to form a sheet steel component with different strength properties from one another. A method according to claim 1, characterized in that for the preheating a continuous furnace (22) is used, which in the direction of passage (DL) has two directly adjacent temperature zones (T ₁ , T ₂ ), wherein a first temperature zone (T ₁ ) is a temperature greater than the AC3 temperature and a second temperature zone (T ₂ ) smaller than the AC3 temperature. A method according to claim 1 or 2, characterized in that the method is operated on a thermoforming line (1) in a cycle time of 5 to 15s, preferably from 7 to 12s and more preferably from 8 to 10s. Method according to the preceding claims, characterized in that the transfer time between the end of the preheating and the beginning of the contact heating is not more than 10 seconds and preferably within 2 to 5 seconds. is carried out. Method according to at least claim 1, characterized in that the tempering station (4) has a tempering plate (6) on a lower tool (8) or upper tool (7), which is homogeneously heated to a temperature greater than AC3 temperature, wherein the tempering plate (6) the sheet metal blank (2) to be heated covers the entire surface and on the opposite side a profiling (12) is formed, the area with closed tempering (4) with the sheet metal blank (2) comes to rest, such that areas of the first type of board (2 ) are austenitized due to system contact with the profiling (12) and areas of the second kind to be heated to a temperature below AC1 temperature, in which no areas contact takes place. A method according to claim 5, characterized in that on the temperature control plate (6) opposite side, a contact plate is provided which has partial areas that are uncooled and / or insulated and other areas that are actively cooled, wherein the contact plate preferably the board (2) covering the entire surface. Method according to the preceding claims, characterized in that on the side opposite the tempering plate (6) a profiling (12) is provided, which has partial areas which with closed temperature control (4) with the sheet metal plate comes to rest in such a way that areas of the first type of sheet metal blank (2) are austenitized but do not come into contact with the profiling (12) and areas of the second kind are heated to a temperature below AC3, preferably below AC1 temperature, and with the profiling (12) come to rest, the profiling (12) is cooled. Method according to the preceding claims, characterized in that the temperature control station (4) has a temperature control plate (6) on both sides of the circuit board (2), wherein the temperature control plate (6) is temperature-controlled in regions, such that regions of the first type of the circuit board (2) be heated to above AC3 temperature and tempered areas of the second kind under AC1. Thermoforming line to the preceding claims, characterized in that below the profiling (12) an insulating layer (10) is arranged and / or that the profiling (12) by body (11) is formed of a metallic material and the body (11) relative to the Lower tool (8) and upper tool (7) are formed projecting. Method according to the preceding claims, characterized in that the tempering (6) and / or the profiling (12) are resiliently mounted, in particular in the stroke direction of the tempering (4), such that in particular the effective contact time with the board (2) longer is, as the closing time of the temperature control (4) in the bottom dead center. Method according to the preceding claims, characterized in that by the resilient mounting of the profiling (12) and / or the tempering (6) when closing and opening the temperature control (4), the system time for contact heating, within the cycle time, is extended. Method according to the preceding claims, characterized in that the temperature control plate (6) is designed as an electrical resistance or that the temperature control plate (6) is heated by a heating means. Method according to the preceding claims, characterized in that the profiling (12) is passively heated by the system contact by means of the sheet metal blank (2) through the temperature control plate (6).

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