Thermal treatment of a component made of a silicon-boron steel

Abstract

The invention relates to a method for thermally treating a component (1) made of a silicon-boron steel, having the steps of: a) heating the component (1) to a temperature above the AC1 temperature of the component (1) in a first furnace (2), b) transferring the component (1) from the first furnace (2) into a first temperature-control device (3), c) thermally treating the component (1) in the first temperature-control device (3) by cooling at least a first region (6) of the component (1) to a temperature ranging from 250 to 680° C, d) transferring the component (1) from the first temperature-control device (3) into a second temperature-control device (4), and e) thermally treating the component (1) in the second temperature-control device (4) in such a way that, at least in the first region (6) of the component (1), the temperature of the component (1) drops by at most 100 K in the second temperature-control device (4).

Description

[0001] Thermal treatment of a component made of silicon-boron steel

[0002] The invention relates to a method and a device for the thermal treatment of a metallic component made of silicon-boron steel. The invention also relates to a use of the device.

[0003] It is known to selectively adjust the microstructure of a metallic component by thermal treatment and subsequent press hardening. Various methods and devices are known for this purpose. In particular, it is known to first heat the component in a first furnace, then to subject it to locally varying thermal treatment in a temperature control station, and finally to thermally treat it in a second furnace.

[0004] Good results can already be achieved with known devices and corresponding processes. However, there is potential for improvement insofar as, according to the state of the art, while high strength can be achieved, this is accompanied by low residual deformability. Particularly for components for vehicle bodies, high strength combined with high ductility and high residual deformability is often desirable. Residual deformability allows the component to deform plastically in an accident and thus absorb energy. The component's ability to absorb as much energy as possible in an accident is, in many cases, its most important property. Therefore, a strength in the range of 1200 to 1500 MPa may suffice, which is below, for example, the 1900 MPa that can be achieved with press hardening processes according to the state of the art.

[0005] There is a particular need to improve the CO2 balance of motor vehicles. The CO2 balance comprises the emissions from the manufacture and operation of the vehicle over its lifetime. One way to reduce the CO2 balance is by using thinner body components, which reduces the vehicle's weight and thus saves fuel over its lifespan. More recently, it has been recognized that reducing material used in body manufacturing can also significantly improve a vehicle's CO2 balance. This is because steel production is particularly CO2-intensive. Therefore, it is also advantageous to achieve the desired material properties with the thinnest possible material.

[0006] The object of the invention is therefore to be able to obtain components with comparatively low thickness, high strength and at the same time high ductility and high residual deformability.

[0007] This problem is solved by the method and the apparatus according to the independent claims.

[0008] According to the invention, a method for the thermal treatment of a component made of silicon-boron steel is presented, which comprises:

[0009] a) Heating the component in a first oven to a temperature above the ACI temperature of the component,

[0010] b) Transferring the component from the first furnace to a first tempering unit,

[0011] c) Thermal treatment of the component in the first temperature control unit, by cooling at least a first area of ​​the component to a temperature in the range of 250 to 680 °C,

[0012] d) Transferring the component from the first temperature control unit to a second temperature control unit,

[0013] e) Thermal treatment of the component in the second temperature control unit such that, at least in the first area of ​​the component, the temperature of the component in the second temperature control unit drops by no more than 200 K.

[0014] This process involves the thermal treatment of a component. Thermal treatment is the umbrella term for heating, cooling, and maintaining a specific temperature.

[0015] The component is made of boron-silicon steel. Silicon-boron steel can be synonymously referred to as a steel with silicon-boron steel grade. The silicon-boron steel is preferably 36SiB6 or 38SiB6. In particular, the silicon-boron steel can be the so-called SIBORA steel. This is a steel that, after press hardening, can exhibit particularly high strength and yet also particularly high residual formability, especially if the microstructure of the steel is a mixture of bainite and metastable retained austenite. The residual formability is primarily due to the metastable retained austenite. In contrast, known press hardening processes typically yield martensite as the microstructure. Components with such a microstructure have low residual formability. For example, if a component made of 22MnB5 steel is press hardened, generally only low ductility and low elongation at break can be obtained.A component made of such a material can absorb very little energy in an accident.

[0016] The silicon in silicon-boron steel can suppress the formation of iron carbides. Furthermore, a high carbon content can increase strength and stabilize austenite formed in the steel. Silicon and carbon are also inexpensive. In addition, silicon-boron steel has proven to be particularly well-suited for press hardening. This is because these steel grades form bainite relatively readily.

[0017] Preferably, the component is coated, particularly preferably with AlSi or zinc. Such a coating is preferably already present at the beginning of the process. Alternatively, it is preferred that the component is uncoated, at least at the beginning of the process. It has been found that a layer of silicon oxides forms on the surface of uncoated boron-silicon steel during its thermal treatment. This can provide a limited degree of scale protection. However, the silicon oxide layer can make welding the component more difficult. Therefore, it is also preferred that the component has a weldable coating. Such a coating is preferably already present at the beginning of the process. However, the basic functionality of the process is unaffected by the material from which the component is made and whether and how it is coated.

[0018] The component thermally treated using the described method is preferably a component for a motor vehicle body, in particular a B-pillar, a door ring, or a double door ring. Especially with such components, favorable properties can be achieved through thermal treatment followed by press hardening. However, the described method can also be used in any other context.

[0019] In step a), the component is heated in a first oven to a temperature above its ACI temperature, preferably above its AC3 temperature. Alternatively, instead of defining the temperature based on the component's AC1 or AC3 temperature, it can be generally stated that the component is heated in the first oven to a temperature of at least 700 °C, preferably at least 740 °C. In step a), the component is preferably heated to a temperature above its ACI temperature or even its AC3 temperature, with a maximum of 1100 °C. The component's temperature in step a) preferably does not exceed 1100 °C. In one embodiment, the component's temperature in step a) does not exceed its AC3 temperature.

[0020] By preferentially heating the component to a temperature above the AC3 temperature in step a), it is austenitized. However, this is not necessary. There are applications where austenitization can be omitted entirely. It is also possible to heat the component, either completely or partially, to a temperature above the AC3 temperature after it has passed through the first furnace.

[0021] In step a), the entire component is preferably heated in the first furnace to a temperature above the ACI temperature, in particular above the AC3 temperature of the component. In step a), the entire component is preferably loaded into the first furnace. Locally differentiated thermal treatment of the component is preferably not carried out in step a).

[0022] The first furnace is preferably a continuous furnace, in particular a roller hearth furnace. Alternatively, the first furnace can also be a batch furnace. A furnace can achieve heating by a particularly large temperature difference. In particular, a component can be heated from room temperature to a temperature close to its AC3 temperature. Such extensive heating is not possible with many other heating methods, or at least not without disproportionate effort. This is especially true in comparison to so-called direct energization.

[0023] The first furnace, as is the definition of a furnace, has a heated furnace chamber. This allows the component to receive a particularly evenly distributed temperature. The furnace chamber is preferably heated by one or more burners, especially gas burners. Alternatively or additionally, the furnace chamber can also be heated electrically.

[0024] In step a), the component remains in the first oven for a first dwell time. This first dwell time is preferably at least 100 seconds, more preferably at least 200 seconds. The first dwell time is preferably at most 1,200 seconds, more preferably at most 900 seconds. In particular, the first dwell time can be in the range of 100 to 1,200 seconds. In step b), the component is transferred from the first oven to a first temperature control unit. This can be done, for example, by means of a first transfer unit.Alternatively, the component can be moved through the first furnace by a transport device in step a), transferred from the first furnace to the first temperature control unit in step b), moved through the first temperature control unit in step c), transferred from the first temperature control unit to the second temperature control unit in step d), and moved through the second temperature control unit in step e). The transport device could, for example, be a roller conveyor extending from an inlet of the first furnace, through both temperature control units, to an outlet of the second temperature control unit.

[0025] The first and second temperature control units can be designed as separate elements or combined into a single temperature control assembly. This makes no difference to the operation of the temperature control units. If the first and second temperature control units are separate elements, then the first furnace, the first temperature control unit, and the second temperature control unit are each separate elements. If the first and second temperature control units are combined into a single temperature control assembly, then the first furnace and the temperature control assembly are separate elements.

[0026] In step c), the component is thermally treated in the first temperature control unit by cooling at least a first area of ​​the component to a temperature in the range of 250 to 680 °C, preferably in the range of 380 to 460 °C. For example, cooling to a temperature of 420 °C can be carried out.

[0027] The cooling process in step c) can be single-stage or multi-stage. Single-stage cooling can be achieved by applying a cooling fluid to the component in a single cooling pulse. Multi-stage cooling can be achieved by applying a cooling fluid to the component in several cooling pulses spaced apart. Between cooling pulses, the component can simply be exposed to the environment. In general, the cooling process described in step c) is understood to mean that the temperature under consideration at the end of step c) is lower than at the beginning of step c) – regardless of the temperature profile during the duration of step c).

[0028] Particularly preferably, in step c), the component is thermally treated in the first temperature control unit by cooling at least a first region of the component to a temperature that lies between the component's martensite start temperature and its bainite start temperature. However, it is particularly possible to cool the component below its martensite start temperature.

[0029] The first area can be a single, continuous section or consist of several separate subsections. Preferably, there is a second area of ​​the component in addition to the first area. The second area can also be a single, continuous section or consist of several separate subsections. How the second area is thermally treated in step c) is irrelevant. In a first embodiment, it is preferred that the component is thermally treated in step c) in the first temperature control unit by cooling the entire component uniformly. In this case, at least in step c), no locally differentiated thermal treatment takes place. Therefore, a division of the component into sections can be omitted. In this embodiment, the expression "at least the first area of ​​the component" can always be replaced by "the entire component".As a second embodiment, it is preferred that the component in step c) is thermally treated in the first temperature control unit by cooling the first area of ​​the component and cooling the second area of ​​the component in a different way, in particular to a temperature in the range of 600 and 800 °C. In this respect, the component in step c) can be thermally treated differently in different locations.

[0030] Preferably, in step c), the component is thermally treated in the first temperature control unit by cooling at least the first region of the component with a first fluid. The first fluid is preferably discharged towards the component through at least one nozzle of the first temperature control unit. It is particularly preferred that the first fluid is discharged towards a bottom side of the component through at least one nozzle of the first temperature control unit and towards a top side of the component through at least one nozzle of the first temperature control unit. In this case, the component is thermally treated on both sides and thus particularly intensively. The first fluid is preferably gaseous under normal conditions. The first fluid can, in particular, be air or nitrogen.

[0031] In the first embodiment, the component can be thermally treated (in steps) in the first temperature control unit by cooling the entire component with the first fluid. What was previously stated regarding the cooling of at least the first area applies accordingly to the entire component in this case.

[0032] In the second embodiment, the component can be thermally treated in the first temperature control unit in step c) by cooling the first region of the component with the first fluid. The above also applies accordingly. The second region can be cooled in various ways. In the simplest case, the second region cools down in the ambient air. This can be described as passive cooling. It is therefore preferred that in step c) the first region is actively cooled and the second region is passively cooled. However, it is also possible that the second region is also actively cooled. In particular, the second region can be cooled with the first fluid or with a different fluid. Cooling that differs from that of the first region can also be achieved when using the first fluid, for example, by selecting the appropriate amount of the first fluid, for instance, by adjusting the pressure and / or cooling duration.

[0033] The cooling process in step c) is preferably carried out as quickly as possible. In step c), the component remains in the first temperature control unit for a second dwell time. The second dwell time is preferably at least 1 second, more preferably at least 10 seconds. The second dwell time is preferably at most 240 seconds, more preferably at most 120 seconds. In particular, the second dwell time can be in the range of 1 to 240 seconds.

[0034] The fact that the component is thermally treated in step c) in the first temperature control unit by cooling at least a first region of the component to a temperature in the range of 250 to 680 °C does not preclude the possibility that the entire component or a part thereof is additionally heated in the first temperature control unit. In particular, it is possible that at least the first region of the component is thermally treated in step c) in the first temperature control unit by first heating at least a first region of the component to a temperature above the AC3 temperature and then cooling it to a temperature in the range of 250 to 680 °C. This is particularly preferred if the component is not heated above the AC3 temperature in step a).

[0035] The fact that the component is thermally treated in step c) in the first temperature control unit by cooling at least a first region of the component to a temperature in the range of 250 to 680 °C does not preclude a second region of the component from being heated in the first temperature control unit. The cooling of the first region and the heating of the second region can occur sequentially, overlapping in time, or simultaneously in any order. A temperature difference between the regions can be established by cooling the first region and heating the second region.

[0036] If at least part of the component is heated in step c), the first temperature control device preferably has a heating chamber into which the component is wholly or partially enclosed. In any case, the part of the component to be heated is then enclosed in the heating chamber in step c). However, it is preferred that no heating of the component or part of the component takes place in step c).

[0037] In step d), the component is transferred from the first temperature control unit to a second temperature control unit. This can be done, for example, using a second transfer unit. Alternatively, the transport unit introduced in step b) can also be used for this purpose.

[0038] In step e), the component is thermally treated in the second temperature control unit such that, at least in the first area of ​​the component, the temperature of the component in the second temperature control unit drops by no more than 200 K, preferably by no more than 100 K, and particularly preferably by no more than 50 K.

[0039] Preferably, the component is thermally treated in the second temperature control unit such that, at least in the first region of the component, a local temperature of the component in step e) remains between a bainite start temperature and a martensite start temperature. This causes a portion of the previously formed austenite to transform into bainite. Step e) can therefore also be described as a bainitization phase.

[0040] Ideally, the component is thermally treated in the second temperature control unit in such a way that at least in the first part of the component, a temperature is maintained within the second unit. However, it is not necessary to maintain the temperature precisely. It is sufficient that the temperature is maintained with a tolerance of + / - 100 K. Therefore, it is generally assumed here that the temperature in question changes by no more than 100 K.

[0041] In the first embodiment introduced in step c), it is further preferred that the component in step e) is thermally treated in the second temperature control unit such that the temperature of the entire component in the second temperature control unit drops by no more than 100 K. In this case, no locally differentiated thermal treatment takes place in step e).

[0042] In the second embodiment introduced in step c), it is still preferred that the component is thermally treated in the second temperature control unit such that the local temperature of the component in the second temperature control unit drops by no more than 100 K in both the first and second regions. Ideally, the temperature differences between the two regions resulting from step c) are maintained in step e).

[0043] In the second embodiment introduced in step c), it is alternatively still preferred that the component is thermally treated in the second temperature control unit such that in the first area of ​​the component its local temperature in the second temperature control unit increases by at least 100 K, while in the second area of ​​the component its local temperature in the second temperature control unit decreases by at most 100 K.

[0044] By maintaining the temperature in step e) - possibly taking into account the described tolerance - the microstructure can adjust.

[0045] Preferably, in step e), the component is thermally treated in the second temperature control unit by thermally treating at least the first region of the component with a second fluid. The second fluid is preferably discharged towards the component through at least one nozzle of the second temperature control unit. It is particularly preferred that the second fluid is discharged towards a bottom side of the component through at least one nozzle of the second temperature control unit and towards a top side of the component through at least one nozzle of the second temperature control unit. In this case, the component is thermally treated on both sides and thus particularly intensively. The second fluid is preferably gaseous under normal conditions. The second fluid can, in particular, be air or nitrogen.

[0046] In the first embodiment, the component can be thermally treated (in steps) in the second temperature control unit by thermally treating the entire component with the second fluid. What was previously stated regarding the thermal treatment of at least the first area applies accordingly to the entire component in this case.

[0047] In the second embodiment, the component can be thermally treated (in steps) in the second temperature control unit by thermally treating the first area of ​​the component with the second fluid. The previously stated principles also apply here. The second area can be thermally treated in various ways. For example, the second area can also be thermally treated with the second fluid or with a different fluid. A thermal treatment differing from that of the first area can also be achieved when using the second fluid, for example, by selecting the appropriate quantity of the second fluid, such as by adjusting the pressure and / or treatment duration. Alternatively, the second area can be thermally treated by placing the component in a heating chamber and only exposing the first area within the heating chamber to the second fluid.Alternatively, the second area can be thermally treated by placing only the second area of ​​the component in a heating chamber and exposing the first area to the second fluid outside the heating chamber. Generally, it is preferred that the second temperature control device includes a heating chamber for the thermal treatment of the second area of ​​the component.

[0048] In step e), the component remains in the second temperature control unit for a third dwell time. This third dwell time is preferably at least 3 seconds, and particularly preferably at least 10 seconds. The third dwell time is preferably at most 300 seconds, and particularly preferably at most 150 seconds. In particular, the third dwell time can be in the range of 5 to 150 seconds. Generally, it can be assumed that after press hardening, the strength of at least the first region of the component will be lower, and the ductility of at least the first region of the component will be higher, the longer the third dwell time.

[0049] It is also possible that the component is cooled completely or partially in step e). The temperature can drop by up to 200 K. Such a configuration is particularly possible with the following process routes:

[0050] In one of these process routes,

[0051] a) the entire component is heated to a temperature above the AC3 temperature of the component,

[0052] c) at least a first area of ​​the component is subsequently cooled to a temperature in the range of 400 to 650 °C, e) at least the first area of ​​the component is subsequently cooled to a temperature in the range of 250 to 450 °C.

[0053] In another of these process routes,

[0054] a) the entire component is heated to a temperature above the AC3 temperature of the component,

[0055] c) at least a first area of ​​the component is subsequently cooled in two stages to a temperature in the range of 250 to 450 °C,

[0056] e) at least the first area of ​​the component is thermally treated in such a way that the temperature of the component increases by at least 100 K in the first area.

[0057] In both of these process routes, it is irrelevant whether the component has further areas besides the first area and, if so, how these are thermally treated after step a).

[0058] In a preferred embodiment, the method further comprises:

[0059] f) Transferring the component from the second temperature control unit to a second oven,

[0060] g) Thermal treatment of the component in the second oven, preferably by at least partially heating the component.

[0061] In step f), the component is transferred from the second temperature control unit to a second furnace. This can be done, for example, using a third transfer unit. Alternatively, the transport unit introduced in step b) can also be used for this purpose. In this case, the component can be transferred from the second temperature control unit to the second furnace using the transport unit in step f) and then moved through the second furnace in step g). The transport unit could then be, for example, a roller conveyor extending from an inlet of the first furnace, across both temperature control units, to an outlet of the second furnace.

[0062] If the first and second temperature control units are separate elements, then the first furnace, the first temperature control unit, the second temperature control unit, and the second furnace are each separate elements. If the first and second temperature control units are combined to form a temperature control arrangement, then the first furnace, the temperature control arrangement, and the second furnace are each separate elements. In step g), the component is thermally treated in the second furnace, preferably by at least partially heating the component. Alternatively, instead of at least partially heating the component, it can be thermally treated in step g) such that the temperature of the component varies by no more than 100 K at all points on the component, preferably by no more than 50 K. In this case, the temperature of the component is kept constant within a tolerance of ±100 K or ±50 K.

[0063] The second furnace is preferably a continuous furnace, in particular a roller hearth furnace. Alternatively, the second furnace can also be a batch furnace. As is the case with a furnace by definition, the second furnace has a heated furnace chamber. The furnace chamber is preferably heated by one or more burners, in particular gas burners. The furnace chamber can alternatively or additionally be heated electrically. This, in particular, distinguishes the second furnace from a configuration in which the component is thermally treated by means of so-called direct energization.

[0064] The second furnace is preferably configured to introduce thermal energy into the component. This heats the component at least partially. If the component is not heated completely, a portion of it can be heated while cooling is slowed in the remaining portion. Preferably, the entire component is heated in step e).

[0065] In the first embodiment introduced in step c), it is further preferred that the component is thermally treated in step g) in the second furnace by heating the entire component.

[0066] In the second embodiment introduced in step c), it is further preferred that the component is thermally treated in step g) in the second furnace by heating the first region of the component and slowing down the cooling of the second region. The temperatures of the first and second regions then approach each other in the second furnace. This can facilitate subsequent press hardening by reducing stresses in the component.

[0067] The desired microstructure can develop particularly during the thermal treatment in the second furnace. Maintaining the temperature established after step e) is generally advisable for this. Surprisingly, however, it has been shown that heating the temperature instead of maintaining it can actually promote the microstructure transformation.

[0068] Furthermore, reheating has the advantage that the component is more easily deformable during subsequent press hardening at higher temperatures. It should be noted that the described process can achieve a bainitic microstructure with comparatively high strength. The strength can already be relatively high before pressing, which can complicate the subsequent pressing process. This applies regardless of whether pressing is part of the claimed process or is carried out in a subsequent, further process.

[0069] The aim of the described method is, in particular, to establish a specific microstructure in the component, especially in the first region. From the perspective of the component's microstructure alone, it would be most advantageous not to reheat the component in the second furnace. However, it has been found that the microstructure established according to the invention, which can be formed in particular by bainite and retained austenite, does not decompose again upon reheating in the second furnace. Reheating in the second furnace is therefore particularly unproblematic in these cases.This includes, in particular, the preferred case that the component is not heated by more than 600 K at any point in the second furnace, or at least not at any point in the first region, preferably by more than 400 K at any point in the second furnace, and especially preferably by more than 200 K at any point in the second furnace. It is particularly preferred that the component, or at least the first region of the component, is not heated to a temperature above the ACI temperature of the component at any point in the second furnace. It is further preferred that the component, or at least the first region of the component, is not heated to a temperature within the ferrite phase at any point in the second furnace.Preferably, the component is thermally treated in the second oven such that the local temperature at all points of the component, or at least of the first region of the component, increases by at least 50 K, preferably by at least 200 K, and particularly preferably by at least 400 K. Preferably, the component is thermally treated in the second oven such that the local temperature at all points of the component, or at least of the first region of the component, increases by 50 to 600 K, preferably by 200 to 400 K.

[0070] At the end of step g), the component preferably has a temperature in the range of 600 to 800 °C, for example 700 °C, at least at one location, particularly in the entire first region. It is especially preferred that the entire component has a temperature in the range of 600 to 800 °C, for example 700 °C, at the end of step g). The component is particularly preferably thermally treated in the second furnace such that, at least in the first region of the component, a local temperature of the component in step g) remains between a bainite start temperature and a martensite start temperature. The bainite formation initiated in the second temperature control unit can thus be continued in the second furnace. Steps e) and g) can therefore be collectively referred to as a bainitization phase. The component remains in the second furnace for a fourth dwell time in step g).The fourth dwell time is preferably at least 3 seconds, particularly preferably at least 10 seconds. The fourth dwell time is preferably at most 600 seconds, particularly preferably at most 300 seconds. In particular, the fourth dwell time can be in the range of 10 to 300 seconds. Generally, it can be assumed that after press hardening, the strength of at least the first region of the component is lower and the ductility of at least the first region of the component is higher the longer the fourth dwell time. Conversely, a shorter fourth dwell time generally leads to higher strength, at least in the first region, and thus to better formability.

[0071] The sum of the third and fourth dwell times is preferably in the range of 15 to 450 seconds. The extent to which the component heats up in the second oven depends on component properties such as its thickness and any coating applied to the component. It also depends on the component temperature at which it enters the second oven and the oven temperature at which it is exposed, and for how long. The oven temperature must be distinguished from the component temperature. The component temperature generally approaches the oven temperature while the component is in the second oven. The component temperature can vary locally. Accordingly, the component can also be heated differently in the second oven, even if it is exposed to a uniform oven temperature.

[0072] For example, the component can be exposed to an oven temperature of 1,100 °C for a fourth dwell time of 8 to 20 seconds in the second oven. Depending on the properties of the component and any coating, this could, for example, result in heating.

[0073] Even if the initial microstructure completely or partially disintegrates upon reheating, good results can still be achieved. The microstructure present after press hardening is of primary importance.

[0074] After thermal treatment, the component is preferably press-hardened in a press and thus hot-formed. If the process includes steps f) and g) described above, the process preferably also includes the following steps:

[0075] h) Transferring the component from the second furnace to a press, i) Press hardening the component in the press.

[0076] If the first and second temperature control units are separate elements, then the first furnace, the first temperature control unit, the second temperature control unit, the second furnace, and the press are each separate elements. If the first and second temperature control units are combined to form a temperature control assembly, then the first furnace, the temperature control assembly, the second furnace, and the press are each separate elements. In this case, the method can be described as a method for thermally treating and press-hardening a component made of silicon-boron steel. However, it is not necessary for the press hardening to be part of the described method. The press hardening can also be carried out in a downstream process. The press preferably comprises a press and a press die. The component can be placed in the press die.Subsequently, a force can be applied to the component via the press tool using the press, thus deforming the component. The component can be quenched during deformation. If the method does not include steps f) and g) described above, the method preferably also includes the following steps:

[0077] f) Transferring the component from the second temperature control unit to a pressing unit,

[0078] g) Press hardening of the component in the press.

[0079] The first furnace, the first tempering unit, the second tempering unit and the pressing unit are separate elements.

[0080] In the present embodiment, the process is preferably designed as a BQP process. BQP stands for Bainitizing, Quenching, and Partitioning. The BQP process is a further development of the QP process. For this purpose, the QP process (C, Quenching & Partitioning process) is supplemented by a bainitic phase. In the described process, the bainiticization takes place as described above in the second temperature control unit and optionally also in the second oven. The quenching takes place in the pressing unit.

[0081] Steel treated using the QP process can be designated as QP steel. Similarly, steel treated using the BQP process can be designated as BQP steel. Following this designation, it is preferred that the component produced using the process is made of BQP steel.

[0082] Following press hardening in the BQP process, a heating phase known as partitioning takes place. This post-press hardening heating is distinct from the previously discussed thermal treatment prior to press hardening. If the process includes the previously described steps h) and i), it preferably also includes the following steps:

[0083] j) Transferring the component from the pressing device to a third temperature control device,

[0084] k) Thermal treatment of the component in the third temperature control unit such that the temperature of the component is maintained between 100 and 250 °C for a period of at least 10 minutes, in particular for a period of 10 to 45 minutes.

[0085] Step k) can be combined with a paint-curing step. A suitable paint-curing device can be considered the third temperature control unit. Step k) leads to an improved redistribution of carbon within the component.

[0086] If the method does not include steps h) and i) described above, the method preferably also includes the following steps:

[0087] h) Transferring the component from the pressing device to a third temperature control device,

[0088] i) Thermal treatment of the component in the third temperature control unit such that the temperature of the component is maintained between 100 and 250 °C for a period of at least 10 minutes, in particular for a period of 10 to 45 minutes.

[0089] Step i) can be combined with a paint curing step. A suitable paint curing device can be considered the third temperature control unit. Step i) leads to an improved redistribution of carbon within the component.

[0090] In a preferred embodiment of the method, at least the first region of the component is cooled to a temperature in the range of 400 to 650 °C in step c). Cooling to this temperature allows bainite to form in the affected region of the component during the subsequent stages of the method. It is sufficient that the first region of the component is cooled to a temperature in the range of 400 to 650 °C in step c). The remaining part of the component can undergo a different thermal treatment to obtain a different microstructure than the first region. However, it is also preferred that the entire component is cooled to a temperature in the range of 400 to 650 °C in step c). In this case, the same microstructure is obtained throughout the entire component.

[0091] In particular, the following process routes are possible in the embodiment described here:

[0092] In one of these process routes,

[0093] a) the entire component is heated to a temperature above the AC3 temperature of the component,

[0094] c) at least a first area of ​​the component is subsequently cooled to a temperature in the range of 400 to 650 °C,

[0095] e) at least the first area of ​​the component is subsequently cooled to a temperature in the range of 250 to 450 °C,

[0096] g) the entire component is then thermally treated in such a way that the temperature of the component increases by at least 100 K, at least in the first area. In another of these process routes,

[0097] a) the entire component is heated to a temperature above the AC3 temperature of the component,

[0098] c) at least a first area of ​​the component is subsequently cooled in two stages to a temperature in the range of 250 to 450 °C,

[0099] e) at least the first area of ​​the component is thermally treated in such a way that the temperature of the component increases by at least 100 K in the first area,

[0100] g) then thermally treat the entire component in such a way that the temperature of the component varies by no more than 100 K at all points of the component.

[0101] In both of these process routes, it is irrelevant whether the component has further areas besides the first area and, if so, how these are thermally treated after step a). In a further preferred embodiment of the method, the component is thermally treated in step e) in the second temperature control unit such that, at least in the first area of ​​the component, the temperature of the component in the second temperature control unit varies by a maximum of 100 K.

[0102] In this embodiment, in step e) the temperature of at least the first region of the component is kept constant, taking into account a tolerance of + / - 100 K. This allows bainite formation to begin.

[0103] It is sufficient that the component in step e) is thermally treated in the second temperature control unit such that the temperature of the component in the first region varies by no more than 100 K. A different thermal treatment can be carried out on the remaining part of the component to obtain a different microstructure than in the first region. However, it is also preferred that the component in step e) is thermally treated in the second temperature control unit such that the temperature of the component in the second temperature control unit varies by no more than 100 K across the entire component.

[0104] In this embodiment, in combination with the previously described embodiment, the three possible process routes described below result in particular. Steps a), c), e), and g) are specified for each.

[0105] In a first process route,

[0106] a) the entire component is heated to a temperature above the AC3 temperature of the component,

[0107] c) the entire component was then cooled to a temperature in the range of 400 to 650 °C,

[0108] e) subsequently thermally treat the entire component in such a way that the temperature of the component does not vary by more than 100 K,

[0109] g) then thermally treat the entire component in such a way that the temperature of the component increases by at least 100 K.

[0110] In this process route, the component is not subjected to locally varying thermal treatment. The component is prepared in such a way that, after press hardening, it exhibits high strength yet also exceptionally high residual formability, particularly because the microstructure is a mixture of bainite and metastable retained austenite.

[0111] In a second process route,

[0112] a) the entire component is heated to a temperature above the AC3 temperature of the component,

[0113] c) the entire component was then cooled to a temperature in the range of 400 to 650 °C,

[0114] e) subsequently, a first area of ​​the component is thermally treated in such a way that the temperature of the first area varies by no more than 100 K, while a second area of ​​the component is heated to a temperature in the range of 600 to 800 °C,

[0115] g) then thermally treat the entire component in such a way that the temperature of the first area increases by at least 100 K.

[0116] In this process route, the component undergoes locally different thermal treatments. After press hardening, the first area has lower ductility than the second area. To achieve this, the first area is treated in the same way as the entire component in the first process route. The second area is heated in step e), resulting in a ferrite / pearlite microstructure forming in the second area during press hardening.

[0117] In a third process route

[0118] a) the entire component is heated to a temperature above the AC3 temperature of the component,

[0119] c) then a first area of ​​the component was cooled to a temperature in the range of 400 to 650 °C and a second area of ​​the component was cooled to a temperature in the range of 600 to 800 °C,

[0120] e) subsequently, a first area of ​​the component is thermally treated in such a way that the temperature of the first area does not vary by more than 100 K, while a second area of ​​the component is thermally treated in such a way that the temperature of the second area does not vary by more than 100 K,

[0121] g) The entire component is then thermally treated in such a way that the temperature of the first area increases by at least 100 K. In this process route as well, the component is thermally treated differently in different locations. However, unlike the second process route, the second area is treated differently from the first area as early as step c).

[0122] In a further preferred embodiment of the method, in step c) at least the first area of ​​the component is cooled to a temperature in the range of 250 to 450 °C.

[0123] It was previously described that bainite can be formed in the affected area of ​​the component by cooling it to a temperature in the range of 400 to 650 °C during the further course of the process. However, it has been found that this is also possible by cooling the component further than necessary. In the present embodiment, cooling is therefore carried out to a temperature in the range of 250 to 450 °C. This can be described as undercooling.

[0124] Surprisingly, it has turned out that undercooling is beneficial. While undercooling may seem inefficient, particularly from an energy perspective, as the component, heated using energy input, is cooled more than necessary, this disadvantage is offset by the unexpected advantage that undercooling can accelerate microstructure formation in subsequent steps. This applies especially, but not exclusively, to bainite. This can be explained by the fact that undercooling induces nucleation. Furthermore, it has been shown that undercooling allows for a sharper demarcation between locally differently thermally treated areas of the component. It is sufficient that in step c) the first area of ​​the component is cooled to a temperature in the range of 250 to 450 °C. A different thermal treatment can be applied to the remaining part of the component to obtain a different microstructure than in the first area.However, it is also preferred that in step c) the entire component is cooled to a temperature in the range of 250 to 450 °C. In this case, the same microstructure is maintained throughout the entire component.

[0125] In a further preferred embodiment of the method, the component is thermally treated in step e) in the second temperature control unit such that at least in the first area of ​​the component, the temperature of the component in the second temperature control unit rises to a value in the range of 400 and 650 °C.

[0126] This embodiment is particularly advantageous in combination with the previously described embodiment. Heating at least the first region of the component counteracts the undercooling performed in step c). This allows the desired microstructure to be obtained overall, especially bainite in the first region. In combination with the previously described embodiment, the three possible process routes described below result.

[0127] In a fourth process route,

[0128] a) the entire component is heated to a temperature above the AC3 temperature of the component,

[0129] c) the entire component was then cooled to a temperature in the range of 250 to 450 °C,

[0130] e) then heat the entire component to a temperature in the range of 400 to 650 °C,

[0131] g) the entire component is then thermally treated in such a way that the temperature of the component increases by at least 100 K.

[0132] In this process route, the component is not subjected to locally varying thermal treatment. The component is prepared in such a way that, after press hardening, it exhibits high strength yet retains exceptionally high formability, particularly because its microstructure is a mixture of bainite and metastable retained austenite.

[0133] The fourth process route corresponds to the first process route with subcooling in step c) and counteracting heating in step e).

[0134] In a fifth process route,

[0135] a) the entire component is heated to a temperature above the AC3 temperature of the component,

[0136] c) the entire component is then cooled to a temperature in the range of 250 to 450 °C, e) a first area of ​​the component is then thermally treated in such a way that a first area of ​​the component is heated to a temperature in the range of 400 to 650 °C, while a second area of ​​the component is heated to a temperature in the range of 600 to 800 °C,

[0137] g) then thermally treat the entire component in such a way that the temperature of the first area increases by at least 100 K.

[0138] In this process route, the component undergoes locally different thermal treatments. After press hardening, the first area has lower ductility than the second area. To achieve this, the first area is treated in the same way as the entire component in the fourth process route. The second area is heated in step e), resulting in a ferrite / pearlite microstructure forming in the second area during press hardening.

[0139] The fifth process route corresponds to the second process route with subcooling in step c) and counteracting heating in step e).

[0140] In a sixth process route,

[0141] a) the entire component is heated to a temperature above the AC3 temperature of the component,

[0142] c) then a first area of ​​the component was cooled to a temperature in the range of 250 to 450 °C and a second area of ​​the component was cooled to a temperature in the range of 600 to 800 °C,

[0143] e) subsequently, a first area of ​​the component is thermally treated in such a way that a first area of ​​the component is heated to a temperature in the range of 400 to 650 °C, while a second area of ​​the component is thermally treated in such a way that the temperature of the second area does not vary by more than 100 K, g) subsequently, the entire component is thermally treated in such a way that the temperature of the first area increases by at least 100 K.

[0144] In this process route, the component is also treated with varying temperatures in different areas. However, unlike the fifth process route, the second area is treated differently from the first area as early as step c).

[0145] The sixth process route corresponds to the third process route with subcooling in step c) and counteracting heating in step e). In the six described process routes, reheating by at least 100 K is provided in step g). However, this is not necessary. A modification of the first to sixth process routes in which step g) is omitted is also preferred. Step e) is thus also omitted.

[0146] A modification of the first and fourth process routes is also preferred, in which step g) differs from the wording given above:

[0147] g) then thermally treat the entire component in such a way that the temperature of the component varies by no more than 100 K.

[0148] A modification of the second, third, fifth and sixth process route is also preferred, in which step g) differs from the wording given above:

[0149] g) then the entire component is thermally treated in such a way that the temperature of the first area varies by no more than 100 K.

[0150] In a further preferred embodiment of the method, the component is thermally treated in step c) by applying a first fluid to the component using a first nozzle array, and / or the component is thermally treated in step e) by applying a second fluid to the component using a second nozzle array. The "and" case is preferred.

[0151] The first nozzle array is part of the first temperature control unit. The first fluid is preferably gaseous under normal conditions. In particular, the first fluid can be air or nitrogen. The component can be cooled using the first nozzle array. This requires that the first fluid has a corresponding temperature. If, in step c), only a part of the component is cooled, it is understood that the first fluid is only applied to that specific part of the component. This part of the component can, in particular, be the first area.

[0152] The first nozzle array preferably comprises a plurality of nozzles. The nozzles are preferably arranged in a grid. The second nozzle array is part of the second temperature control unit. The second fluid is preferably gaseous under normal conditions. The second fluid can, in particular, be air or nitrogen. With the second nozzle array, the component can be thermally treated in such a way that, at least in the first region of the component, the temperature of the component in the second temperature control unit drops by a maximum of 100 K. Thus, at least the first region can be maintained at its temperature or heated, in particular by the second nozzle array. For this purpose, thermal energy can be introduced into the component with the second fluid, so that heat loss, in particular through radiation to the surroundings of the component, is compensated or even overcompensated.If only part of the component is thermally treated in step e), it is understood that the second fluid is applied only to that specific part of the component. This part of the component can, in particular, be the first area.

[0153] The second nozzle array preferably comprises a plurality of nozzles. The nozzles are preferably arranged in a grid.

[0154] In a further preferred embodiment of the method, the first nozzle array comprises a plurality of nozzles, wherein the first nozzle array further comprises means for individually closing the nozzles,

[0155] and / or

[0156] The second nozzle array comprises a plurality of nozzles, and furthermore includes means for individually closing the nozzles. The "and" case is preferred.

[0157] The nozzles of the first nozzle array can be individually closed. This allows the first fluid to be applied precisely to the component. The first nozzle array can therefore be adapted to the component's geometry, enabling particularly economical use of the first fluid. Furthermore, the individually closeable design of the nozzles in the first nozzle array allows for targeted application of the first fluid to specific parts of the component, while the rest of the component remains untreated. This allows for the previously described locally differentiated thermal treatment.

[0158] The same applies to the second nozzle array. The nozzles can be designed to be closed in various ways. For example, each nozzle can be assigned a valve that can be individually controlled manually or automatically by a control system. The valve can be integrated into the nozzle itself or into a supply line leading to the nozzle. The valves and any control system then provide the means for closing the nozzles. Alternatively, the nozzle arrays can have means to individually close the nozzle openings from the outside.

[0159] The two nozzle arrays can be described as multifunctional arrays. The individually closable nozzles allow the arrays to be adapted to the geometry of the component being heat-treated. The nozzles can be activated and deactivated using the means for closing them. Therefore, instead of the term "means for closing the nozzles," the term "means for activating and deactivating the nozzles" can also be used.

[0160] In another preferred embodiment of the method, the component is heated by more than 50 K at at least one point in step g).

[0161] In step g), bainite is formed, at least in the first region of the component. Maintaining the component's temperature is generally advantageous for this process. Surprisingly, however, it has been shown that heating the component instead of maintaining the temperature can actually promote bainite formation.

[0162] As explained in more detail above, reheating also has the advantage that the component is more easily deformable during subsequent press hardening at higher temperatures. Therefore, in the present embodiment, the component is heated by more than 50 K at at least one location in step g). Preferably, the component is heated by more than 200 K or even more than 400 K at at least one location. Preferably, the component is heated by an amount in the range of 50 K to 600 K at at least one location, particularly in the range of 200 K to 400 K.

[0163] It is sufficient for the component to be heated at one point as described. Preferably, this point is located in the first region. Preferably, the component is heated at least in the first region as described in step g). It is also possible to heat the entire component as described in step g).

[0164] As a further aspect of the invention, a device for thermally treating a component is presented, wherein the device is configured to be traversed by the component in a through-direction, and wherein the device comprises:

[0165] - a first oven,

[0166] - a first tempering unit downstream of the first furnace in the direction of flow, which is designed to cool the entire component,

[0167] - a second temperature control unit downstream of the first temperature control unit in the flow direction, which is set up for the thermal treatment of the component.

[0168] The described advantages and features of the method are applicable and transferable to the device, and vice versa. The device is preferably configured for operation according to the method. The method is preferably carried out using the device.

[0169] The device can be used to carry out all embodiments of the process in which the component is completely cooled in step c). Such a device embodiment is particularly useful for the treatment of silicon-boron steel. Known devices designed for the treatment of other steel grades or any steel grade therefore do not have a first temperature control unit configured as described, in combination with a second temperature control unit configured as described. This applies in particular to the preferred case where the second temperature control unit is configured for locally differentiated thermal treatment of the component.

[0170] The device is configured to allow the component to pass through it in a continuous direction. The device preferably includes a transport mechanism for moving the component through it. The transport mechanism can, for example, be a roller conveyor. The basic operating principle of the device is unaffected by how the component is moved through it. It is sufficient that a continuous direction is defined. The arrangement of the device elements is described based on this direction. The device elements are arranged sequentially in the continuous direction. This means that the component passes through the device elements one after the other. The first temperature control unit is preferably configured to cool the entire component convectively. The first temperature control unit preferably includes at least one nozzle for dispensing a first fluid onto the component.The device preferably further comprises a first fluid source which is connected to the at least one nozzle of the first temperature control device and which comprises the first fluid.

[0171] The cooling of the component in the first temperature control device is thus a property of the described device and does not merely result from its use. Preferably, the first fluid in the first fluid source has a temperature of no more than 200 °C. For example, the first fluid in the first fluid source can have a temperature in the range of 20 to 200 °C. The first fluid is preferably gaseous under normal conditions. The first fluid is preferably air or nitrogen.

[0172] The second temperature control unit is preferably configured for the convective thermal treatment of the component. The second temperature control unit can be configured for the thermal treatment of the entire component or a part thereof. In particular, the second temperature control unit can be configured for locally differentiated thermal treatment of the component. The second temperature control unit preferably has at least one nozzle for dispensing a second fluid onto the component. The device further preferably includes a second fluid source, which is connected to the at least one nozzle of the second temperature control unit and which contains the second fluid.

[0173] The thermal treatment of the component in the second temperature control unit is thus a characteristic of the described device and does not merely result from its use. Preferably, the second fluid in the second fluid source has a temperature of no more than 200 °C. For example, the second fluid in the second fluid source can have a temperature in the range of 20 to 200 °C. Alternatively, it is preferred that the second fluid in the second fluid source has a temperature of at least 500 °C. For example, the second fluid in the second fluid source can have a temperature in the range of 500 to 700 °C. The second fluid is preferably gaseous under normal conditions. The second fluid is preferably air or nitrogen.

[0174] The first fluid and the second fluid can have different or the same chemical composition. They can also have different or the same temperature. If the first and second fluids have the same chemical composition and temperature, the distinction between first and second fluid becomes irrelevant, and they can all be referred to simply as "fluid." The device can then also include a fluid source that is connected to both the at least one nozzle of the first temperature control unit and the at least one nozzle of the second temperature control unit, and which contains the fluid.

[0175] The device preferably further comprises:

[0176] - one of the second ovens downstream of the second tempering unit in the flow direction.

[0177] As a further aspect of the invention, we present a use of a device designed as described, wherein the component is made of a silicon-boron steel.

[0178] The described advantages and features of the method and the device are applicable and transferable to the use, and vice versa.

[0179] Preferably, the entire component is cooled in the first temperature control unit. Preferably, the component is further treated with locally varying temperatures in the second temperature control unit.

[0180] The invention is explained in more detail below with reference to the figures. The figures show a particularly preferred embodiment, to which, however, the invention is not limited. The figures and the size relationships shown therein are only schematic. They show:

[0181] Fig. 1: a device for thermally treating a component, with which in particular a method according to the invention for the thermal treatment of a component made of silicon-boron steel can be carried out,

[0182] Fig. 2a and 2b: a nozzle field of one of the temperature control devices shown in Fig. 1 with the component to be treated in two different situations.

[0183] Fig. 1 shows a device 11 for the thermal treatment of a component 1, in particular made of silicon-boron steel. The device 11 is configured to be traversed by the component 1 in a flow direction r. This is indicated by an arrow. A transport plane 13 is also shown. The device 11 comprises a first furnace 2, a first temperature control unit 3 downstream of the first furnace 2 in the flow direction r, a second temperature control unit 4 downstream of the first temperature control unit 3 in the flow direction r, and a second furnace 5 downstream of the second temperature control unit 4 in the flow direction r. The device 11 further comprises a press 12 downstream of the second furnace 5 in the flow direction r.

[0184] The first temperature control unit 3 has a first nozzle array 8. The second temperature control unit 4 has a second nozzle array 9.

[0185] Device 11 can be used to thermally treat component 1 and then press-harden it. This can be done using a process with the following steps:

[0186] a) Heating component 1 in the first oven 2 to a temperature above the ACI temperature of component 1,

[0187] b) Transferring component 2 from the first furnace 2 to the first temperature control unit 3, c) Thermally treating component 1 in the first temperature control unit 3 by cooling at least a first area 6 of component 1 (shown in Fig. 2b) to a temperature in the range of 250 to 680 °C,

[0188] d) Transferring component 1 from the first temperature control unit 3 to the second temperature control unit 4,

[0189] e) Thermal treatment of component 1 in the second temperature control unit 4 such that, at least in the first area 6 of component 1, the temperature of component 1 in the second temperature control unit 4 drops by no more than 100 K, f) Transferring component 1 from the second temperature control unit 4 to the second oven 5,

[0190] g) Thermal treatment of component 1 in the second oven 5 by at least partially heating component 1,

[0191] h) Transferring component 1 from the second furnace 5 into the press 12, i) Press hardening component 1 in the press 12.

[0192] Figures 2a and 2b each show a nozzle array in a top view. This could be either the first nozzle array 8 or the second nozzle array 9 from Figure 1. Below the nozzle array 8, 9, component 1 is shown, which in this example is a B-pillar of a motor vehicle. The nozzle array 8, 9 has a plurality of nozzles 10 arranged in a grid. The nozzle array 8, 9 also has means for individually closing the nozzles 10. This is indicated in Figures 2a and 2b by the fact that closed nozzles 10 are shown as black circles and open nozzles 10 as white circles.

[0193] In step c), component 1 can be thermally treated by applying a first fluid to component 1 using the first nozzle array 8. In step e), component 1 can also be thermally treated by applying a second fluid to component 1 using the second nozzle array 9. The individually closable nozzles 10 can be used to ensure that the fluid does not spill over the sides of component 1 and is directed only onto the area of ​​component 1 that needs to be cooled or heated. Figure 2a illustrates how the entire component 1 can be cooled or heated using the nozzle array 8, 9. For this purpose, all nozzles 10 located above component 1 are open.

[0194] Fig. 2b shows an example of how only the first area 6 of component 1 can be cooled or heated by the nozzle array 8, 9, while the second area 7 is not actively thermally treated. For this purpose, only the nozzles 10 located above the first area 6 of component 1 are open. In this example, the second area 7 can cool down, particularly in the ambient air, and thus change its temperature. (Reference numeral list)

[0195] 1 component

[0196] 2 first oven

[0197] 3 first temperature control unit

[0198] 4 second temperature control unit

[0199] 5 second oven

[0200] 6 first area

[0201] 7 second area

[0202] 8 first nozzle field

[0203] 9 second nozzle field

[0204] 10 nozzle

[0205] 11 Device

[0206] 12 Pressing device

[0207] 13 Transport level

[0208] r Direction of flow

Claims

Claims 1. Method for the thermal treatment of a component (1) made of a silicon-boron steel, comprising: a) Heating the component (1) in a first oven (2) to a temperature above the ACI temperature of the component (1), b) Transferring the component (1) from the first furnace (2) to a first tempering unit (3), c) Thermal treatment of the component (1) in the first temperature control unit (3) by cooling at least a first area (6) of the component (1) to a temperature in the range of 250 to 680 °C, d) Transferring the component (1) from the first temperature control unit (3) to a second temperature control unit (4), e) Thermal treatment of the component (1) in the second temperature control unit (4) such that at least in the first area (6) of the component (1) the temperature of the component (1) in the second temperature control unit (4) drops by no more than 200 K.

2. The method of claim 1, further comprising: f) Transferring the component (1) from the second temperature control unit (4) to a second oven (5), g) Thermal treatment of the component (1) in the second oven (5).

3. Method according to one of the preceding claims, wherein in step c) at least the first area (6) of the component (1) is cooled to a temperature in the range of 400 to 650 °C.

4. Method according to claim 3, wherein the component (1) is thermally treated in the second temperature control unit (4) in such a way that at least in the first region (6) of the component (1) the temperature of the component (1) in the second temperature control unit (4) varies by no more than 100 K.

5. Method according to claim 1 or 2, wherein in step c) at least the first region (6) of the component (1) is cooled to a temperature in the range of 250 to 450 °C.

6. A method according to claim 5, wherein the component (1) is thermally treated in the second temperature control unit (4) in steps such that at least in the first region (6) of the component (1) the temperature of the component (1) in the second temperature control unit (4) rises to a value in the range of 400 to 650 °C.

7. A method according to any one of the preceding claims, wherein the component (1) is thermally treated in step c) by applying a first fluid to the component (1) with a first nozzle array (8) and / or the component (1) is thermally treated in step e) by applying a second fluid to the component (1) with a second nozzle array (9).

8. Method according to claim 7, wherein the first nozzle array (8) comprises a plurality of nozzles (10), and wherein the first nozzle array (8) further comprises means which are arranged for individually closing the nozzles (10), and / or the second nozzle array (9) comprises a plurality of nozzles (10), and wherein the second nozzle array (9) further comprises means which are provided for individually closing the nozzles (10).

9. Device (11) for thermally treating a component (1), wherein the device (11) is configured to be traversed by the component (1) in a through-direction (r), and wherein the device (11) comprises: - a first oven (2), - a first tempering device (3) downstream of the first furnace (2) in the flow direction (r), which is designed to cool the entire component (1), - a second temperature control unit (4) downstream of the first temperature control unit (3) in the flow direction (r), which is configured for the thermal treatment of the component (1).

10. Use of a device (11) according to claim 9, wherein the component (1) is made of a silicon-boron steel.

Images