Methods and production lines for hot forming and press hardening

Abstract

Examples of methods of hot forming structural components are provided. The methods include heating a blank made from a press hardenable boron steel and forming the heated blank in a production line or multi-step apparatus. Examples of the present 5 disclosure provide hot forming and cutting of a blank with a cycle time of 10 seconds or less for each of the tools.

Description

AUTOTECH ENGINEERING S.L. OCTOBER 29, 2025P2421 P5515PC00Methods and production lines for hot forming and press hardening

[0001] The present application claims the benefit of European patent application ne24383187.2 filed on October 30th, 2024 and of European patent application neEP25382402.3 filed on April 17th, 2025.

[0002] The present disclosure relates to methods for manufacturing hot formed structural components and uses of ultra-high strength steels in hot forming processes. More particularly, the present disclosure relates to fast methods for hot forming and cutting structural components. The present disclosure further relates to production lines suitable for hot forming and press hardening.BACKGROUND

[0003] In the field of vehicle construction, the development and implementation of lightweight materials or components is becoming more and more important in order to satisfy criteria for lightweight construction. The demand for weight reduction is especially driven by the goal of reduction of CO2 emissions. The growing concern for occupant safety also leads to the adoption of materials which improve the integrity of the vehicle during a crash while also improving the energy absorption.

[0004] A process known as Hot Forming Die Quenching (HFDQ) (also known as hot stamping or press hardening) uses e.g. boron steel sheets to create stamped components with Ultra High Strength Steel (UHSS) properties, with tensile strengths of e.g. 1.500 MPa or more. The increase in strength as compared to other material allows for a thinner gauge material to be used, which results in weight savings over conventionally cold stamped mild steel components.

[0005] In order to improve corrosion protection before, during or after a hot stamping process, coatings may be applied. For example the use of Al-Si coatings or Zn coatings is known.

[0006] Depending on the composition of the base steel material, blanks may need to be quenched (i.e. be cooled down rapidly) to achieve the high tensile strengths. In a well-known process, a blank that has been heated to e.g. 900eC or more is transferred to a press, in which it is deformed. While the blank is in the press, the blank is rapidlyquenched to e.g. a temperature of around 200eC. The rapid quenching is done to obtain a fully martensitic microstructure which leads to high stiffness and strength.

[0007] In order to achieve adequate cooling, the press may stay “closed” (at its dead bottom centre) for e.g. 5 - 10 seconds.

[0008] Examples of steel materials which can harden by leaving them to cool to room temperature by air cooling with relatively low cooling speed are also known. These steels may be referred to as “air hardenable” steels.

[0009] The hot stamping process may be performed in a manner such that a blank to be hot formed is heated to a predetermined temperature e.g. to or above an austenization temperature by, for example, a furnace system so as to decrease the strength of the blank i.e. to facilitate the hot stamping process. The heated blank may be formed by, for example, a press system having a low temperature compared to the blank (e.g. room temperature) and a temperature control, thus a shaping process and a heat treatment using the temperature difference may be performed.

[0010] A hot stamping process may include a conveyor or a transferring device which transfers the heated blank from the furnace to a press tool which is configured to press the blank. Upstream from the furnace system, a cutting system for cutting blanks directly from a steel coil can be provided.

[0011] The use of multistep press apparatus for manufacturing hot formed elements is known. The multistep press apparatus may comprise a plurality of tools configured to perform different operations on different blanks simultaneously. With such arrangements, a plurality of blanks can undergo different manufacturing steps simultaneously during each stroke of the press apparatus. The efficiency and performance of a multistep apparatus may be higher than systems employing a plurality of different machines or apparatuses for different manufacturing steps, such as, laser trimming or hard cutting.

[0012] When zinc coated steel blanks are used, the blanks may need to be cooled down to a certain temperature before a hot forming process to reduce or minimize problems such as microcracks. Once the blank is cooled down, it is transferred from the external pre-cooling tool to the multistep press apparatus.

[0013] US 2022 / 0258223 discloses press apparatus and methods for manufacturing hot formed structural components. The apparatus comprises a fixed lower body, and a mobile upper body. The apparatus comprises a cooling tool and a press tool which is arranged downstream from the cooling tool, and a blank transfer mechanism to transferthe blank from the cooling tool to the press tool. The cooling tool has an upper gas cooling tool connected to the mobile upper body and / or a lower gas cooling tool connected to the fixed lower body. The press tool comprises an upper pressing die connected to the upper body and a lower pressing die is connected to the lower body.

[0014] EP3437750 A1 discloses examples of methods of hot forming structural components. The methods include heating a blank made of an Ultra High Strength Steel with an aluminum coating and forming the heated blank in a multi-step apparatus.

[0015] EP3067129 A1 discloses press systems for manufacturing hot formed structural components. The system comprises a fixed lower body, a mobile upper body and a mechanism configured to provide upwards and downwards press progression of the mobile upper body with respect to the fixed lower body. The system further comprises a cooling / heating tool configured to cool down and / or heat a previously heated blank having locally different microstructures and mechanical properties which comprises: upper and lower mating dies , and the upper and lower dies comprising two or more die blocks adapted to operate at different temperatures corresponding to zones of the blank having locally different microstructures and mechanical properties, and a press tool configured to draw the blank, wherein the press tool is arranged downstream the cooling / heating tool. This system is particularly aimed at creating “soft zones” in order to improve the ductility and energy absorption in specific areas of a component made from Usibor® 1500 (22MnB5). This use of 22MnB5 boron steel requires a specific temperature control between different die blocks of the cooling / heating tool and downstream post-processing tools to achieve the different microstructures and corresponding different characteristics.

[0016] EP3067128 A1 discloses a multistep press system for manufacturing hot formed structural components. The system comprises a fixed lower body, a mobile upper body and a mechanism configured to provide upwards and downwards press progression of the mobile upper body with respect to the fixed lower body. The system further comprises a cooling tool configured to cool down a previously heated blank which comprises: upper and lower mating dies, the lower die connected to the lower body with one or more lower biasing elements and / or the upper die connected to the upper body with one or more upper biasing elements. The system further comprises a press tool configured to draw the blank, wherein the press tool is arranged downstream from the cooling tool. This system is particularly aimed at the use of zinc coated ultra- high strength steels.

[0017] One disadvantage related to the use of zinc coated steels is that a zinc oxide layer can form on the blanks. In many applications, the zinc oxide layer needs to be removed or reduced after the manufacturing process. For example, shot blasting may be used to remove the zinc oxide layer partially or completely. Also, components with an AlSi coating can generally be welded better than components with a Zn coating.

[0018] The most commonly used steel in press hardening processes is coated 22MnB5 steel or similar. For example, llsibor® 1500 is commercially offered by ArcelorMittal™, MBW-W®1500 is commercially offered by ThyssenKrupp, and other steel manufacturers offer further steels. After heating to above Ac3 temperature (e.g. after heating to about 900eC), a heated blank may be formed and quenched. Quenching may occur above a critical cooling rate of about 27eC / s to obtain a substantially fully martensitic microstructure and an ultimate tensile strength of about 1.500 MPa.

[0019] More recently, hot stamping of even higher grades of steel has been intensively investigated. E.g. 37MnB5 steels or similar have a higher carbon content than 22MnB5 and can achieve ultimate tensile strength after hot stamping of 2.000 MPa or even more, llsibor® 2000 which is commercially available from ArcelorMittal™ and MBW- K® 1900 (a 34MnB4 steel) commercially available from ThyssenKrupp™ are two of such steels.

[0020] Such steels may be called “second generation” press hardening steels. This newer generation of press hardening steels may herein be regarded boron-manganese steel suitable for hot stamping with a higher carbon content than 22MnB5, and which obtain an ultimate tensile strength of more than 1 .500 MPa, specifically at least 1 .700 MPa when fully martensitic after press hardening. The silicon content may typically be lower than for the first generation press hardening steels. Examples include 20MnCr, 28MnB5 steel, 30MnB5, 34 MnB5, 34MnB4, 37 MnB5, or 37 MnB4. Steels of this type are commercially available from different companies e.g. Docol® PHS1800 from SSABMBW® 1900 from Thyssenkrupp), Usibor® 2000 from ArcelorMittal, HPF 2000, Docol® PHS2000 from SSAB, phs ultraform® 2000 from Voestalpine and others.

[0021] The new generation of steels may also be described as PHS (“press hardening steel”) 1.700 or higher, i.e. PHS 1.700, PHS 1.800, PHS 1.900 or PHS 2.000, more specifically PHS 1 .900 or higher.

[0022] Throughout the present disclosure, it will be clear that the designation of steels 22MnB5, 34MnB4, 37MnB5 and others refer to the EN10027 naming standard, in which the first number stands for the approximate amount of carbon content (weightpercentage * 100), the letters refer to the most significant alloy components, and the trailing digit refers to the grade or variant.

[0023] Another characteristic of such steels is however its brittleness and very low ductility after hot stamping. This means that post-processing operations including e.g. joining are more complicated and that energy absorption in case of an impact or crash is limited. This is one of the reasons why, in spite of the high tensile strength and potential to even further reduce the weight of automotive structures, these second generation steels have actually only had few practical applications in automotive structures to this day.

[0024] There is a tendency in the automotive field to optimize the use of materials to the maximum extent possible. I.e. to use tailor welded blanks or other technologies to provide the precisely required mechanical characteristics in each area of the component and to minimize the weight of the component.

[0025] There is furthermore a tendency in the field to provide hot stamping using larger blanks to obtain larger components, which require less joining operations after hot stamping. For example, it is known to manufacture a door ring including a portion of the rocker, the B-pillar, A-pillar, and hinge pillar in a single hot stamping operation. Prior to the hot stamping operation, several blanks (which may be of different thickness and / or different materials) are joined to each other to form a composite blank. The composite blank is subsequently heated and deformed. W02020 / 002335 is a prior art document disclosing such door rings, and methods for manufacturing them.

[0026] A blank that is made up of different “sub-blanks” may be a so-called Tailor Welded Blank, i.e. the sub-blanks are joined in an edge-to-edge laser welding process.

[0027] Alternatively, such as illustrated e.g. in WO 2020 / 002335, blanks are partially overlapped with each other when joined together. The resulting composite blank has areas of increased thickness where the overlap was arranged. The local increase in thickness can be used to provide a local increase in stiffness and strength.

[0028] Finally, there is an ever increasing need to make manufacturing of automotive components as efficient and quick as possible to reduce cost of manufacturing. In particular, it would be desirable to provide an automotive component in a process including both hot stamping and cutting of the component with a cycle time of each of the tools of 10 seconds or less. Particularly, it would be desirable to have such a process and be able to provide an automotive component with intended mechanical characteristics in terms of ultimate tensile strength, yield strength and ductility.

[0029] Furthermore, there is a desire to reduce the amount of post-processing after hot stamping as much as possible. In particular, it is desirable that laser trimming, laser cutting and laser trepanning be reduced as much as possible. For smaller components, e.g. a bumper beam or an A-pillar, it would be desirable for laser cutting after hot stamping to be avoided completely. For larger components, e.g. a door ring, or a floor structure, laser cutting can generally not be avoided, but it is desirable to reduce the number of areas that require laser treatment as much as possible.

[0030] EP 3 363 554 A1 discloses a method for manufacturing vehicle parts having ultra-high strength of 1 .500 Mpa or more by using hot stamping. The method includes: forming a heated blank in a press forming apparatus; and taking out the formed blank from the press forming apparatus and consecutively cutting the blank with a trimming die. A blank temperature at the time of trimming may be 150°C to 330°C.

[0031] The present disclosure seeks to provide improvements in hot stamping process of high grade steels, and specifically in multistep processes and apparatuses.SUMMARY

[0032] In a first aspect, a method for hot forming and press hardening a structural component in a production line comprising: a furnace, a press tool configured to deform blanks, and the press tool having an upper press die and a lower press die, a cutting tool arranged downstream from the press tool and configured to perform a cutting and restriking operation, and having an upper cutting tool die and a lower cutting tool die and a transfer system to transfer blanks from the furnace to the press tool and from the press tool to the cutting tool.

[0033] The method comprises providing a press hardenable boron steel blank, heating the blank to above an austenization temperature in the furnace, the press tool deforming and cooling the blank having a first cycle time, transferring the formed blank from the press tool to the cutting tool and the cutting tool cutting one or more areas of the formed blank and cooling the formed blank and having the first cycle time.

[0034] The press tool remains at a dead bottom centre of the press tool for a first holding time and the cutting tool remains at a dead bottom centre of the cutting tool for a second holding time. The second holding time may be longer than the first holding time.

[0035] In accordance with this aspect, an efficient method for manufacturing structural steel components combining both hot forming and cutting components is provided. Thethroughput of the production line may be increased or maximized. Furthermore, structural components with desirable mechanical properties may be obtained. In both tools, the blanks may be rapidly cooled. By choosing suitable cooling times (by controlling the time during which the press is at its dead bottom centre, i.e. when the press is closed), desirable mechanical properties with high yield strength and high ultimate tensile strength can be obtained, whereas cutting is performed at a temperature that does not lead to excessive wear of the tool.

[0036] In some examples, a temperature of the blank before forming the blank may be 600eC - 850eC, a temperature of the formed blank is cooled down to 400 - 600eC in the press tool and the formed blank may be cooled down to 300eC or less, preferably 275eC or less, in the cutting tool.

[0037] Methods provided herein can avoid deformations of the structural component after cutting. By lowering the temperature below 300eC, preferably below 275eC, and in specific examples lower than 200eC, while the component is in the restriking tool, subsequent deformation of the hot components due to the release of heat can be avoided. At the same time, hydrogen-induced delayed fracture (a known problem in hot stamping processes) can be avoided by maintaining a temperature sufficiently high enough at the moment of cutting.

[0038] Cutting of the component can be carried out effectively at a temperature which is high enough (and thus the material is soft enough) to avoid e.g. cracks or bad cutting quality in the cutting area, and thus reducing the risk of delayed fracture. In some steels, in order to avoid such a risk, cutting is preferably carried out around 400eC, whereas in other examples cutting may be carried out at a lower temperature without affecting cutting quality.

[0039] Throughout the present disclosure, cutting may be regarded as encompassing any process step, in which parts of the blanks are removed. Cutting may herein be regarded encompassing operations such as trimming and piercing.

[0040] Throughout the present disclosure, whenever reference is made to a temperature of a blank or component, the mentioned temperature refers to an average temperature of a “main portion” of the blank or component. I.e. it will be appreciated (and is also addressed herein) that a blank or component may have a varying thickness and that temperature differences can occur within the same blank, particularly dependent on the local thickness. However, a temperature can also vary within a blank of uniform thickness, e.g. because during deformation contact with the die is established sooner or later. When addressing specific temperatures of a blank orcomponent, the temperature refers to the average temperature of a portion of the blank that can be regarded as representative for the blank, e.g. the portion of the blank with the predominant thickness or the relevant portion of the blank for the operation being carried out (deformation or cutting).

[0041] In particular, in preferred examples of the present disclosure, a temperature of the blank when being cut may be above 400eC or may be above Ms, martensite start temperature. This temperature range refers in particular to the areas of the blank that will be submitted to trimming or cutting. Specific areas of the blank that are not subject to the cutting operation may have cooled down further. Since they are not cut, the outcome is not negatively affected if they have obtained a lower temperature already.

[0042] In some examples, a cycle time for each of the tools may be e.g. about 10 seconds or about 8 seconds. A cooling rate in the press tool may be 20 - 35eC / s, particularly from about 20eC / S to about 25eC / s with a cycle time of about 10 seconds, and a cooling rate of about 25eC / s to about 30eC / s in the case of a cycle time of about 8 seconds.

[0043] A cooling rate in the cutting tool may be higher than in the press tool. Particularly, the cooling rate may be 30 - 70eC / s. For a cycle time of about 10 seconds, a cooling rate may be about 20eC / s to about 40eC / s. For a cycle time of about 8 seconds, a cooling rate may be about 50eC / s - about 33eC / s.

[0044] A cycle time for the individual tools may herein be regarded as the time it takes for a complete cycle. I.e. a cycle may start with the upper tool in the uppermost position, the upper tool may then progress downwards, contact the blank (and deform and / or cut the blank), until the “dead bottom centre” of the tool. After e.g. a holding time, the upper tool may progress upwards until it reaches its start position again. A cycle ends and a new cycle starts when the upper tool moves downwards again.

[0045] A cooling rate in each of the tools may herein be regarded as a difference in temperature at the beginning of a cycle, and a temperature at the end of the cycle, divided by the cycle time. I.e. the cooling rate is based on the total cycle time of the tool, and not based on the time of actual contact with the blank.

[0046] In some examples, the first holding time may be 0.1 - 4 seconds, specifically 0.5 - 3 seconds. The second holding time may be 1 - 5 seconds, specifically 2 - 4 seconds. Suitable holding times may be determined based particularly on a thickness of the blank. In the forming tool, a cooling process may start as soon as the deformation starts, since this is when the dies may enter into full contact with the blank. In the cuttingtool, cooling may start almost immediately after cutting is performed, when the tool is closed.

[0047] Holding times may be adjusted such that preferably, the temperature after forming and before cutting is effectively lowered with respect to the furnace but still above a martensite start temperature. In the cutting tool, the temperature is then quickly lowered from above the martensite start temperature to below a martensite finish temperature. A predominantly or fully martensitic microstructure may be obtained. By balancing both cooling times, production cycles may be shortened and throughput may be increased while obtaining desirable mechanical properties.

[0048] The difference in holding times between the two tools may e.g. be about 1.5 - 3 seconds. The difference in holding times means that the press tool may be opened before the cutting tool is opened. The blank in the press tool (before and / or after forming) may then be passively air cooled for e.g. about 1.5 - 3 seconds.

[0049] In specific examples, the blanks may be of a “second generation” press hardening steels as defined hereinbefore. In examples of the present disclosure, desirable mechanical characteristics of an ultimate tensile strength of more than 1 .600 MPa e.g. 1.700 MPa - 1.900 MPa can be obtained, in combination with an A50 elongation of 4% (for lower thickness) or more, specifically an A50 elongation of 5 - 6%. The high ultimate tensile strength provides the potential for reducing thickness of the components and thereby their weight. The increased ductility as compared to conventional press hardening of such steels can improve the behaviour in the case of impact / crash and facilitate further post-processing.

[0050] Yield strength, ultimate tensile strength and A50 elongation may be measured in accordance with standard tensile strength test for metallic specimens as defined e.g. in ISO 6892-1 . The A50 elongation refers to the elongation at break for a test specimen with an initial length of 50 mm (to be distinguished from e.g. A80).

[0051] Throughout the present disclosure, whenever reference is made to ductility, it refers to the ability of a material to sustain significant plastic deformation before fracture. The quantities commonly used to define ductility in a uniaxial tensile stress test are relative elongation (in percent) or reduction of area at fracture. I.e. Ductility (%) = [(Initial Area - Final Area) / Initial Area] x 100 or Ductility (%) = [(Final Length - Original Length) / Original Length] x 100.

[0052] In specific examples, 22MnB5 steel may be used e.g. Usibor® 1500. This steel may also be designated as CR1500T-MB according to VDA standard VDA 239-500.CR herein stands for cold rolled. 1500T stands for a tensile strength of 1.500 MPa (after press hardening). MB herein stands for manganese-boron steel. The same nomenclature applies to e.g. CR1700T and CR1900T mentioned in the present disclosure.

[0053] With methods according to examples of the present disclosure, very high strength (about 1.500 MPa or more) may be obtained even if cooling is spread over two tools. The inventors have surprisingly found that a substantially fully martensitic microstructure could be obtained even when cooling is split over two different tools, which implies a slower cooling period in between the two processes in the tools.

[0054] In any of the herein disclosed examples, the press hardenable boron steel blank may be coated, specifically with an aluminum-silicon (AlSi) coating. Since an Ultra High Strength Steel blank with an aluminum silicon coating can be used, shot blasting to remove the zinc oxide layer partially or completely is not necessary. Other coatings, such as AlSi coatings with magnesium in the coating, or zinc (galvannealed or galvanized) may be used.

[0055] Reference is herein made to press hardenable boron steels, with a carbon content of 0.32 - 0.45 % by weight, specifically 0.32 - 0.4% of carbon by weight, and more specifically 0.32 - 0.38%, a content of manganese of 0.6 - 1 .5%, specifically 0.6 - 1 .4% and a boron content of 0.003 - 0.006% by weight, specifically 0.004 - 0.005% by weight. These may be regarded as second generation press hardening boron steels. In practice, there may be slight variations between different coils of steels, even when made with the same manufacturing process by the same steel supplier. In practice, there may even be slight variations between blanks cut from the same steel coil. Suitable steels include e.g. 37MnB5 steel, 38MnB5 steel, 34MnB5 steel and 34 MnB4 steel.

[0056] All steel compositions mentioned throughout the present disclosure are in weight percentages. Unless specifically mentioned, further elements may be present beyond the mentioned elements. It will be understood that the main element is always iron, and that impurities may be present unless otherwise specified.

[0057] One typical composition of a 34MnB4 steel that has been tested is summarized below in weight percentages (rest is iron (Fe) and impurities):Carbon (C) (%) 0.35Silicon (Si) (%) 0.8Manganese (Mn) (%) 0.96Chromium (Cr) (%) 0.19Molybdenum (Mb) (%) 0.18Phosphor (P) 0.012%Sulphur (S) (%) 0.0002Titanium (Ti) + niobium (Nb) 0.055%Aluminium (Al) 0.03%Boron (B) (%) 0.002%Nitrogen (N) 0.003%Nickel (Ni) 0.01%

[0058] Usibor® 2000 may be generally described as 37MnB5 steel. The composition of Usibor® 2000, is summarized below in weight percentages (rest is iron (Fe) and impurities):Maximum carbon (C) (%): 0.36Maximum silicon (Si) (%): 0.8Maximum manganese (Mn) (%): 0.8Maximum phosphorus (P) (%): 0.03Maximum sulphur (S) (%): 0.01Aluminium (Al) (%): 0.01 - 0.06Maximum titanium (Ti) (%): 0.07Maximum niobium (Nb) (%): 0.07Maximum copper (Cu) (%): 0.20Maximum boron (B) (%): 0.005Maximum chromium (Cr) (%): 0.50Maximum molybdenum (Mb) (%): 0.50

[0059] MBW-K® 1900 may generally be described as a 34MnB4 steel. The composition of MBW-K® 1900 is summarized below in weight percentages (rest is iron (Fe) and impurities):Maximum carbon (C) (%): 0.38Maximum silicon (Si) (%): 0.4Maximum manganese (Mn) (%): 1.4Maximum phosphorus (P) (%): 0.025Maximum sulphur (S) (%): 0.01Minimum Aluminium (Al) (%): 0.015Maximum titanium (Ti) (%): 0.05Maximum niobium (Nb) (%): 0.07Maximum boron (B) (%): 0.005Maximum chromium (Cr) + molybdenum (Mb) (%): 0.50

[0060] MBW® 1900 is another manganese-boron steel from ThyssenKrupp™ which may have an ultimate tensile strength of 1900 MPa. It is commercially available with aluminium-silicon coatings and suitable for hot stamping and the methods disclosed herein. The chemical composition of MBW® 1900 is summarized below in weight in percentages (rest is iron (Fe) and impurities):Maximum carbon (C) (%): 0.38Maximum silicon (Si) (%): 0.40Maximum manganese (Mn) (%): 1.40Maximum phosphor (P) (%): 0.025Maximum sulphur (S) (%): 0.010Minimum aluminium (Al) (%): 0.1Maximum niobium (Nb) (%): 0.05Maximum titanium (Ti) (%): 0.05Maximum chromium and molybdenum (Cr + Mo) (%): 0.50Maximum boron (B) (%): 0.005

[0061] B1800HS is yet another boron steel which may have an ultimate tensile strength of about 1800 MPa and suitable for hot stamping and the methods disclosed herein. The chemical composition of B1800HS is summarized below in weight in percentages (rest is iron (Fe) and impurities):Carbon (C) (%): 0.28 - 0.35Maximum silicon (Si) (%): 0.5Manganese (Mn) (%): 1 .0 - 1 .8Maximum phosphor (P) (%): 0.025Maximum sulphur (S) (%): 0.010Aluminium (Al) (%): 0.01 - 0.06Maximum titanium (Ti) (%): 0.05Maximum boron (B) (%): 0.0050Maximum chromium and molybdenum and niobium (Cr + Mo + Nb) (%): 0.80

[0062] A further suitable steel is CR1900T-MB-DS (according to the VDA standard). An example of this steel is Docol® PHS 2000 from SSAB. The chemical composition is summarized below in weight in percentages (rest is Fe and impurities):Carbon (C) (%): 0.30 - 0.38Maximum silicon (Si) (%): 0.8Manganese (Mn) (%): 2.0Maximum chromium (Cr) : 0.25Maximum phosphor (P) (%): 0.03Maximum Molybdenum (Mo): 0.25Maximum sulphur (S) (%): 0.005Aluminium (Al) (%): 0.01 - 0.08Maximum Titanium (Ti) + Niobium (%): 0.20Boron (B) (%): 0.0010 - 0.0050Maximum nickel (Ni): 0.10Maximum nitrogen (N): 0.01

[0063] Yet another suitable steel which may be used in examples of the present disclosure is Hyundai Steel’s SABC1760.

[0064] In examples, the blank may be heated to above Ac3 temperature, and particularly to 870 - 930eC, more specifically 900 - 930eC. Heating may occur particularly in a furnace arranged upstream from the press tool and cutting tool in the production line.

[0065] In some examples, the obtained component may further be submitted to a bakehardening process. E.g. a structural component may be submitted to a temperature of about 180eC during about 20 minutes. A bake hardening process may further increase the yield strength of the obtained component, whereas ultimate tensile strength remains substantially the same.

[0066] In some examples, the production line comprises a multi-step tool comprising a fixed lower body, a mobile upper body, and a mechanism configured to provide upwards and downwards press progression of the mobile upper body with respect to the lower body, and wherein the upper press die is connected to the mobile upper body and the lower press die is connected to the fixed lower body, and the upper cutting die is connected to the mobile upper body, and the lower cutting die is connected to the fixed lower body.

[0067] In these examples, the press tool and the cutting tool are integrated in the same apparatus and the upper press die and the upper cutting die are connected to the same mobile upper body and therefore move in unison. With the integration of the tools in the same apparatus by connecting the upper dies of the press tool and the cutting tool to the mobile upper bode, the transfer time from the press tool to the cutting tool may be reduced, thus the process may be optimized and the productivity may be improved.

[0068] In some examples, the production line comprises a multi-step apparatus comprising a fixed lower body, a first mobile upper body, a first mechanism configured to provide upwards and downwards press progression of the first mobile upper body with respect to the lower body. The apparatus further comprises a second mobile upper body and a second mechanism configured to provide upwards and downwards press progression of the second mobile upper body with respect to the fixed lower body. The upper press die is connected to the first mobile upper body and the lower press die is connected to the fixed lower body, and the upper cutting die is connected to the second mobile upper body, and the lower cutting die is connected to the fixed lower body.

[0069] With the integration of the tools in the same apparatus by connecting the upper dies of the press tool and the cutting tool to the first and second mobile upper bodies respectively, the transfer time from the press tool to the cutting tool may be reduced, thus the process may be optimized and the productivity may be improved. Also the temperature of the blanks during the different steps of the process can be more accurately be controlled. By splitting the multistep apparatus in two independently controlled mobile upper bodies, the time that each of them remains closed (and during which particularly cooling is carried out) can be independently controlled.

[0070] In some examples, the dies of the press tool and / or of the cutting tool may comprise channels conducting cooling water. The dies of the cutting tool may alternatively or additionally comprise channels conducting air.

[0071] In some examples, a cycle time for each of the tools may be 16 seconds or less, specifically 12 seconds or less, more specifically 10 seconds or less. The overall processing time from the moment of extraction from the furnace to the moment of extraction from the cutting and restriking tool may be e.g. 20 - 37 seconds.

[0072] The cycle time for each of the tools is the same, such that they can be integrated in the same press apparatus or the same production line. Precise cycle times may depend particularly on the thickness and other dimensions of the blanks. For a thickness in the range of 1 .2 - 2 mm and blanks having length and width of 1 meter or less, a cycle time in each of the tools may be about 8 seconds in one specific example. For the same thickness and blanks having a length and width of 1 meter or more, a cycle time in each of the tools may be about 10 seconds in one specific example. With an increase in thickness, the cycle time may generally be increased.

[0073] Different types of blanks may be processed in examples of the present disclosure. In some examples, the blanks may have a uniform thickness. In other examples, the blanks may comprise different materials and / or different thicknesses. For example, Tailor Welded Blanks may be used. In other cases, sub-blanks which are partially overlapped with each other, or patches may be used to form the press hardenable boron steel blank. A patch may herein be understood as a blank that completely overlaps with another, larger blank. The combined blank may thus have a local area of increased thickness, corresponding to the position of the patch.

[0074] In some examples, the press hardenable boron steel blank includes a first portion with a first thickness, and a second portion with a second thickness, wherein the second thickness is higher than the first thickness. In the fast forming process, it is important that the different portions of the blank follow a similar temperature profile (and obtain a similar microstructure at the end of the process), in spite of having different thicknesses. In particular, it is desirable for the whole blank to have a substantially homogeneous temperature before the cutting operation is carried out.

[0075] In some examples, the second portion (of increased thickness) may be more actively cooled than the first portion prior to deforming. Alternatively or additionally, the first portion may be actively heated in the press tool and / or cutting tool.

[0076] In some examples, the press hardenable boron steel blank is made by joining two or more sub-blanks.

[0077] In yet a further aspect, a component obtainable by any of the methods herein disclosed is provided.

[0078] In a further aspect, a production line for hot forming and press hardening a structural component is provided. The production line comprises a furnace configured to heat a press hardenable boron steel blank to above an Ac1 temperature, particularly to above an Ac3 temperature, and a press tool arranged downstream from the furnace and configured to deform the heated blanks, and the press tool having an upper press die and a lower press die. The press tool has a first cycle time and the press tool is configured to remain at a dead bottom centre for a first holding time.

[0079] The production line further comprises a first transfer system to transfer blanks from the furnace to the press tool and a cutting tool arranged downstream from the press tool and configured to perform a cutting and restriking operation, and having an upper cutting tool die and a lower cutting tool die. The cutting tool has the first cycle time, and the cutting tool is configured to remain at a dead bottom centre for a second holding time. The production line further comprises a second transfer system to transfer blanks from the press tool to the cutting tool. The second holding time may be longer than the first holding time.

[0080] Restriking may herein be regarded as the re-application of pressure to the already deformed blank to achieve a higher-quality deformation. The restriking further allows the chance to further cool down the blank, or in general to provide further temperature control. The dies of the cutting tool may be mating, and the upper and / or lower die may include cooling channels to quickly cool down the blank.

[0081] In accordance with this aspect, a production line is provided which is configured specifically for quick forming and cutting processes. Even though the cycle time of each of the tools is the same, their holding times are different, whereby cooling of the blanks can be controlled and a short cycle time can be combined with desirable mechanical properties and effective cutting without excessive wear to the cutting tool.

[0082] In yet a further aspect, a method for hot forming and press hardening a structural component in a production line is provided. The production line comprises a furnace, a press tool configured to deform blanks, and the press tool having an upper press die and a lower press die. The production line further comprises a cutting tool arranged downstream from the press tool and configured to perform a cutting andrestriking operation, and having an upper cutting tool die and a lower cutting tool die. And the production line further comprises a transfer system to transfer blanks from the furnace to the press tool and from the press tool to the cutting tool.

[0083] The method comprises providing a press hardenable boron steel blank, heating the blank to above an austenization temperature in the furnace, actively cooling at least a selected portion of the blank, deforming and cooling the blank in the press tool, transferring the formed blank from the press tool to the cutting tool and cutting one or more areas of the formed blank and cooling the formed blank in the cutting tool.

[0084] Herein, a temperature of the blank before forming the blank may be 600eC - 850eC, a temperature of the formed blank may be cooled down to 400 - 600eC in the press tool, and the formed blank may be cooled down to 275eC or less (preferably 200eC or less) in the cutting tool.

[0085] In accordance with this aspect, an efficient method for manufacturing structural steel components is provided. The throughput of the production line may be increased or maximized. Furthermore, structural components with desirable mechanical properties may be obtained.

[0086] Methods provided herein can avoid deformations of the structural component after cutting. By lowering the temperature below 300eC, preferably below 275eC, and in specific examples lower than 200eC, while the component is in the restriking tool, subsequent deformation of the hot components due to the release of heat can be avoided. At the same time, hydrogen-induced delayed fracture (a known problem in hot stamping processes) can be avoided.BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Non-limiting examples of the present disclosure will be described in the following, with reference to the appended drawings, in which:

[0088] Figure 1 schematically represents a production line according to an example of the present disclosure;

[0089] Figures 2A - 2D schematically illustrate a CCD diagram and temperature ranges of a blank as it undergoes a method of manufacturing according to examples of the present disclosure;

[0090] Figure 2E illustrates a further example of temperature ranges for a 22MnB5 steel in a preferred manufacturing process;

[0091] Figure 3 schematically illustrates a press tool incorporating heating and cooling features according to an example;

[0092] Figure 4 schematically illustrates a distribution of die blocks of a press tool according to an example;

[0093] Figure 5 schematically illustrates a multistep apparatus in accordance with an example of the present disclosure;

[0094] Figure 6 schematically illustrates another example of a multistep apparatus in accordance with an example of the present disclosure; and

[0095] Figures 7A - 7C schematically illustrate further examples of a production line in accordance with the present disclosure.DETAILED DESCRIPTION OF EXAMPLES

[0096] Figure 1 schematically represents a production line according to an example. An example of a method for hot forming a structural component in a production line is schematically illustrated in figure 1.

[0097] A steel coil 10 of a press hardenable boron steel is provided. Well known press hardenable boron steel blanks, such as 22MnB5 steels may be used. In other examples, a second generation press hardenable boron steel having a composition by weight of 0.32 - 0.45% of carbon, a manganese content of 0.6 - 1.5%, and a boron content of 0.003 - 0.006% may be used.

[0098] A blanking apparatus 20 may cut suitably sized blanks from coil 100. The steel may or may not have a protective coating.

[0099] The blanks may have a thickness of 0,6 mm - 4 mm, specifically 1 - 3 mm. In some examples, the steel may be 34MnB4 of 37MnB5 steel.

[0100] In specific examples, the steel may have a content by weight of 0.34 - 0.4% carbon, specifically 0.34 - 0.39%, and more specifically 0.34 - 0.38%. The steel may further have a content of 0.8 - 1 .4% of manganese. The steel may have a content by weight of boron of 0.003 - 0.005%, and specifically 0.004 - 0.005%. In specific examples, the steel may have a content by weight of 0.3 - 0.9%, specifically 0.4 - 0.8% of silicon.

[0101] The blanks may be provided to furnace 30. The blanks may be heated to above an austenization temperature, and in particular to above an Ac3 temperature. Inspecific examples, the blanks may be heated in the furnace for between 5 and 10 minutes and may be heated to about 870 - 930eC, specifically 900 - 930eC.

[0102] Different furnace systems suitable for this purpose are known in the art. For example, a furnace may have a length of 30 - 50 meters. At the end of the furnace, a centering table may be provided.

[0103] After exiting the furnace 30, the heated blanks may be transferred to press tool 50 configured to deform or draw the blanks. A suitable press tool may e.g. have a press force of e.g. 1 .400 or 2.000 T n.

[0104] The press tool 50 comprises an upper press die 52 and a lower press die 54. A blank may be positioned in between the upper press die 52 and lower press die 54. The upper press die 52 may perform an upward-downwards progression with respect to lower press die 54 to deform the previously heated blank. The press tool has a first cycle time, and during the press cycle, the press tool remains at a dead bottom centre of the press tool for a first holding time.

[0105] The production line 100 further comprises a cutting tool 60 arranged downstream from the press tool 50 and configured to perform a cutting and restriking operation on the formed blank (a blank that has undergone a drawing process in the press tool). The cutting tool comprises an upper cutting die 62 and a lower cutting die 64. The cutting tool 60 has a same cycle time as the press tool. The cutting tool remains at a dead bottom centre for a second holding time. The second holding time is longer than the first holding time. Particularly, the overall cycle time of the tools may be the same, but the upwards-downwards movement of the upper first post-press die 62 is not synchronized with the upward-downwards movement of the upper press die 52.

[0106] The production line 100 further comprises a transfer system to transfer formed blanks from the press tool 50 to the first post-press tool 60. In this particular example, a plurality of transfer robots with grippers or suction units is provided. A transfer robot 44 may grip the deformed blank after it has undergone the drawing operation in press tool 50 and place it in the first post-press tool 60.

[0107] A further transfer robot 46 may grip the component after the cutting and restriking operation in tool 60 and place the component in a storage or rack for further processing. The component may be finished or semi-finished. In some examples, a further laser cutting station may be provided. The deformed and cut blanks may be transported to the laser cutting station, where further cutting, trimming and trepanningmay be carried out. In other examples, the component is substantially finished and all cutting and trimming operations have been carried out in the cutting tool 60.

[0108] The capacity and throughput of the furnace and the tools arranged downstream may be adapted to each other. I.e. in one example, a furnace may be designed to convey pairs of blanks. In such a case, pairs of press tools and cutting tools may be arranged downstream from the furnace. In another case, half of the blanks of the pairs of blanks may be temporarily retained in the furnace (e.g. by lifting them) to allow the blanks to exit the furnace one by one.

[0109] In further examples, the furnace may convey multiple blanks (e.g. two or three or more) next to each other at the same time. Or two parallel furnaces may be provided, e.g. each having a length of about 30 - 50 meters. A plurality of blanks may thus be output at the same time. An example hereof is schematically illustrated in figure 7. The plurality of blanks may be picked up by a gripper system, or multiple grippers moving in unison. The multiple grippers for transporting the blanks from respective centering table(s) to the press tool(s) may be independent from each other, or may be coupled to each other to move in unison.

[0110] The plurality of blanks that are delivered from the furnace at the same time may be arranged next to each other in the same press tool in some blanks. All blanks may be deformed to obtain the same shape (i.e. to form the same component), or each of the blanks may be deformed to obtain a different shape (i.e. to form different components). Such a setup may be useful for forming multiple components belonging to the same vehicle at the same time, e.g. multiple components of a vehicle door, or multiple components of a vehicle floor or of a battery support structure.

[0111] After the blanks have been partially cooled and deformed in the press tool, the plurality of blanks may be transported in unison to the cutting tool, particularly if all the blanks are used to form the same component. In the cutting tool, the plurality of blanks are cooled and cut at the same time as well. Then the plurality of formed components may be simultaneously extracted from the cutting tool as well.

[0112] The production line illustrated in figure 1 may be used for the manufacture of a variety of structural components. In particular examples, structural components with a length and width of more than 1 meter may be manufactured in such a production line. In some examples, unitary door rings (door rings made of a single integrally formed body) may be manufactured in such a production line. Unitary door rings may be e.g. a single door rings (extending from A-pillar to B-pillar, or from B-pillar to C-pillar) or double door rings (extending from A-pillar to C-pillar).

[0113] Further large structural components which may be manufactured in a production line 100 according to figure 1 include e.g. unitary roof rings, bumper beam assemblies including a bumper beam and a pedestrian beam, a unitary ring surrounding a battery box, a rear framework structure including rear rails and a transverse beam as a unitary structure and others.

[0114] Such large structural components may be manufactured efficiently in a hot stamping process. Due to the size of such components, the different tools (press tool and cutting tool) are difficult to integrate in a single press apparatus. However, the methods and systems may also be used for other components that may be press formed e.g. B-pi liar, A-pillar, hinge pillar, bumper crossbeams and others.

[0115] In some examples, a blank may be composed of multiple smaller blanks or subblanks. Some of the sub-blanks may be joined to other sub-blanks in a Tailor Welded Blank (TWB) edge-to-edge butt joint. Alternatively, or additionally, the sub-blanks may be partially overlapped with each other to form an overlapping region with an increased thickness compared to other areas. The areas of increased thickness may be selected to locally reinforce the structural component. The increased thickness in these areas may require an increased heating time in a furnace. In the drawing or deforming operation, and in subsequent processes, the overlapping areas may cool down more slowly unless specific measures are taken.

[0116] The method for hot forming a structural component comprises heating the blank to above an austenization temperature, particularly above an Ac3 temperature for the selected steel e.g. 890 - 930eC.

[0117] The method further comprises transferring the heated blank from the furnace to the press tool and deforming the heated blank in the press tool 50 and transferring the blank from the press tool 50 to the cutting tool 60. A temperature of the blank before forming the blank is 600eC - 850eC, and a temperature of the formed blank is cooled down to 400 - 600eC in the press tool. The holding time of the press tool may be generally shorter than the holding time of the cutting tool. The deformed blank may thus have to wait for e.g. 1 - 3 seconds before being transferred to the cutting tool. During this time, the deformed blank may be passively air cooled. Its temperature will only slowly decrease during this time.

[0118] The formed blank may be subsequently cooled down to 300eC or lower, preferably to 275eC or even lower in the cutting tool.

[0119] The method may further be illustrated with reference to a CCT diagram, such as illustrated in figure 2A. A Continuous Cooling Transformation (CCT) diagram is a chart that for a specific steel indicates the transformations that occur as it cools at different rates. CCT diagrams can be used to indicate how different cooling rates affect the microstructure and, ultimately, the mechanical properties of materials after heating.

[0120] Figure 2A indicates a CCT diagram for a typical boron steel. It will be clear that depending on the steel used, the CCT diagrams may look slightly different. Different areas in the CCT diagram indicate different microstructures. Herein, the letter A stands for austenite, M for martensite, B for bainite, P for pearlite, and F for ferrite. Further indicated in the CCT diagram are the martensite start temperature, Ms, and the martensite finish temperature Mf.

[0121] Throughout the present disclosure, martensite start temperature, Ms, refers to the temperature at which the transformation of austenite to martensite begins when steel is cooled down. Further, the martensite finish temperature, Mf, relates to the temperature at which the transformation of austenite to martensite in steel is complete. The Ms and Mf temperatures vary depending on the chemical composition of the steel and influence the microstructure and properties of the final steel.

[0122] In the CCT diagram, a maximum critical cooling rate and a minimum cooling rate are indicated which, for the given material indicate an upper and lower cooling rate to obtain a steel with mostly martensitic microstructure (and thus high ultimate tensile strength, and high yield strength) while avoiding hydrogen induced fracture.

[0123] In order to ensure that the blank is cooled at an appropriate rate, during transfer, deforming and cutting, active temperature control may be required, particularly for blanks combining portions with different thicknesses. In other examples (also illustrated hereinafter), no active cooling is required at the stage prior to the deformation, or in between the deformation and the cutting. In these latter cases, the blanks may simply be held by blank holders in the press tool and / or cutting tool respectively or by a transfer system without receiving active cooling.

[0124] In examples, at least a selected portion of the blank (and potentially the whole blank) is actively cooled prior to deforming of the blank. Active cooling may herein be regarded as the use of specific cooling means to achieve a higher cooling rate than passive air cooling.

[0125] Figure 2B schematically indicates a first stage of cooling (interrupted line in figure 2B) which may be incorporated in examples of the present disclosure. In a firststage, the active cooling of at least the selected portion of the blank comprises active cooling in the furnace. That is, the entire blank or portions of the blank may be cooled with relatively cold air in the furnace. Thermal printing, as commercially offered by Shwartz ™ can create multiple regions of different strength and elongation behaviours in a single component. Similarly, Ebner ™ offers commercial solutions for (partial) cooling in the furnace. In furnace cooling may be used to cool down the blank to e.g. 900 - 650eC, particularly 850 - 700eC.

[0126] Additionally, or alternatively, the active cooling of at least the selected portion of the blank comprises active cooling during a transfer from the furnace to the press tool. The transfer mechanism used for transferring the blank from the furnace to the press tool may incorporate air knives or other active air cooling means to cool down (a part) of the blank, in particular parts of the blank with increased thickness. In examples, cooling during transfer may comprise cooling to 850 - 600eC (the dotted line in figure 2B).

[0127] Additionally, or alternatively, the active cooling of at least the selected portion of the blank comprises active cooling in the press tool prior to the deforming of the blank (indicated with a continuous line in figure 2B). Cooling in the press tool may be used to achieve temperatures of e.g. 800 - 550eC. In some examples (illustrated hereinafter), one or more die blocks of the press tool may include slots, through which pressurized cooling gas (e.g. air) may be ejected and impinge upon the blank.

[0128] During the deforming, the whole blank (or at least selected portions thereof) may be cooled down because of contact with cold die blocks. The upper and / or lower press die may include cooling channels conducting cooling liquid (e.g. water).

[0129] The different methods for active cooling described herein may be used for maintaining a substantially constant temperature in a blank, in spite of thickness variations in the blank. In other examples, the different methods of active cooling may be used to lower the temperature of a specific area within the blank prior to forming and cutting. Such an area may obtain a microstructure that comprises less martensites than other areas of the finished component. Such an area may include more ferrite, and / or perlite and / or bainite. As a result, such an area may have a lower ultimate tensile strength and yield strength, and a higher elongation or ductility.

[0130] As illustrated in figure 2C, the temperature of the blank at the end of the process in the press tool may be 650 - 450eC, specifically 650 - 500eC. The temperature should still be high enough to allow for effective cutting when the blank arrives at the cutting tool. Preferably, the temperature remains higher than Ms.

[0131] In some examples, while the blank overall is cooled in the press tool, thinner portions of the blanks may be heated in the press tool in order not to cool down too much. In preferred examples, the blank will have a substantially homogeneous temperature prior to the cutting operation.

[0132] Finally, as illustrated in figure 2D, the blank may be cut and further cooled down in the cutting tool to well below the martensite finish temperature, Mf, and specifically to below 275eC.

[0133] In preferred examples, the cycle time of each of the tools may be 16 seconds or less, specifically 12 seconds or less, more specifically 10 seconds or less. In specific examples, the cycle time of each tool may be 5 - 12 seconds, specifically 7 - 12 seconds, more specifically 8 - 11 seconds.

[0134] The cycle in each of the tools may comprise 1 - 5 seconds of effective cooling and forming or cutting, and 5 - 9 seconds to the transfer and positioning of the blanks. The transfer from the furnace to the press tool may take about 1 - 3 seconds in an example.

[0135] In preferred examples, the first holding time of the press tool may be about 0.1 - 4 seconds, specifically 0.5 - 3 seconds. The second holding time of the cutting tool may be 1 - 5 seconds, specifically 2 - 4 seconds. The longer holding time in the cutting tool allows for longer cooling. In the press tool, the temperature of the blanks is lowered but not so much.

[0136] As previously mentioned, different blanks of different materials, with different thicknesses and with or without coatings may be used in the herein disclosed examples. Depending on the material, thickness, etc. used, the process can be tailored to achieve satisfactory results.

[0137] Figure 2E illustrates different temperature ranges of blanks during a different process. In this particular case, it has been found that in a very quick process including forming and cutting a substantially completely martensitic microstructure may be obtained. In preferred examples, a temperature of the deformed blank remains about a martensite start temperature of the material used prior to cooling in the cutting tool, and is then quickly lowered to below a martensite finish temperature in the cutting tool.

[0138] In the example of figure 2E, the blanks may be made of 22MnB5 steel (like Usibor ® 1.500 and others) or similar. The blanks may be coated or uncoated. After exiting a furnace, the blanks may passively air cool while waiting on the centering table, and during transfer to the press tool (first circular shape in figure 2E on the left handside). Passive air cooling may occur e.g. for 4 - 8 seconds. If there are thicker portions in the blank, these selected portions may be actively cooled so that their temperature stays closer to the other portions of the blank.

[0139] In a next step (second circular shape from the left in figure 2E), the blanks may be deformed and cooled. The press tool may comprise cooling channels with cold water or other liquid, as is well known in the art. However, the press tool remains closed at its dead bottom centre for only a relatively short period of time, e.g. 0.1 - 4 seconds, specifically 0.5 - 3 seconds. The blanks will cool down but remain well above a martensite start temperature.

[0140] The cutting tool at this stage will be cutting a previous blank. The cutting tool may remain closed for a longer period of time than the press tool. During this time, the blank may be passively air cooled (third circular shape from the left in figure 2E). The temperature prior to the cutting operation may preferably remain above a martensite start temperature.

[0141] Then, in the cutting tool (fourth circular shape, located on the right hand side in figure 2E), rapid cooling will occur from above the martensite start temperature to below a martensite finish temperature e.g. to 300eC or lower. It has been found that, in spite of the interrupted cooling, a substantially fully martensitic microstructure can be obtained. In some examples, the cycle of the press tool and cutting tool may be about 8 seconds (for smaller components such as B-pillars, A-pillars, bumper beams etc.) and may be about 10 seconds for larger components (e.g. door ring). An overall time from exiting the furnace to a formed and cut component exiting the cutting tool may be e.g. 20 - 25 seconds in such examples. In preferred examples, no further laser cutting is necessary and the component is ready for further processing (joining, coating, painting etc.).

[0142] Some suitable steels are mentioned in Table 1. The values provided are average or typical values. That is, variations with respect to the mentioned values are possible.

[0144] It should be noted that in the table, mostly ultra-high strength steels are used, but also other steels suitable for hot stamping but are less stiff and strong (and rather more ductile) can be used as well. E.g. steels with an ultimate tensile strength of 500 MPa or 1 .000 MPa after hot forming die quenching may be used as well, e.g. in parts of the blank. Examples of ductile steels include Ductibor® 500, Ductibor ® 1000 and CRL-340LA.

[0145] Ductibor® is a steel material with much higher ductility than Usibor® materials, and components made of this material can be effective for absorbing energy during an impact. The yield strength of Ductibor® 500 may be 400 MPa or more, and the ultimate tensile strength of 550 MPa or more.

[0146] The composition of Ductibor® 500 is summarized below in weight percentages (rest is iron (Fe) and impurities):Maximum carbon (C) (%): 0.1Maximum silicon (Si) (%): 0.5Maximum manganese (Mn) (%): 1.7Maximum phosphorus (P) (%): 0.03Maximum sulphur (S) (%): 0.025Aluminium (Al) (%): 0.015 - 0.2Maximum titanium (Ti) (%): 0.09Maximum niobium (Nb) (%): 0.10Maximum copper (Cu) (%): 0.20Maximum boron (B) (%): 0.001Maximum chromium (Cr) (%): 0.20

[0147] The yield strength of Ductibor® 1000 may be 800 MPa or more, and the ultimate tensile strength of 1000 MPa or more. The composition of Ductibor® 1000 is summarized below in weight percentages (rest is iron (Fe) and impurities):Maximum carbon (C) (%): 0.10Maximum silicon (Si) (%): 0.6Maximum manganese (Mn) (%): 1.8Maximum phosphorus (P) (%): 0.03Maximum sulphur (S) (%): 0.01Aluminium (Al) (%): 0.01 - 0.1Maximum titanium (Ti) (%): 0.05Maximum niobium (Nb) (%): 0.10Maximum copper (Cu) (%): 0.20Maximum boron (B) (%): 0.005Maximum chromium (Cr) (%): 0.20

[0148] In examples, the press hardenable boron steel blank may have a uniform thickness, e.g. a thickness of 0.8 - 2mm. In other examples, the press hardenable boron steel blank may include a first portion with a first thickness, and a second portion with a second thickness, wherein the second thickness is higher than the first thickness. It should be clear that blanks with more that two different portions of differing thickness may also be used.

[0149] In examples, the second (thicker) portion is more actively cooled than the first portion prior to deforming. I.e. in the furnace, and / or during transfer, and / or when placed in the press tool, the thicker portion may be cooled more than the thinner portions. The objective is that, regardless of the local thickness, the entire blank undergoes a rather similar treatment, so that relatively homogeneous properties and microstructure are obtained.

[0150] In further examples, the first (thinner) portion may be actively heated in the press tool and / or cutting tool. Both the press tool and cutting tool may be generally cooled using cooling channels. In order to avoid the thinner portion cooling down too quickly, or much more quickly than a thick portion of the blank, the thinner portion may be heated in the press tool and / or the cutting tool.

[0151] Figures 3 and 4 illustrate examples of systems that may be used particularly for tailored cooling and / or heating.

[0152] Figure 3 illustrates a cross-section of a press tool, including an upper die 1 10 and a mating lower die 120. Further schematically illustrated is a press hardenable boron steel blank 130, including a first portion 132 with a first thickness 132, a second portion 134, with a second thickness and a third portion 136 with a third thickness. The third thickness is higher than the second thickness, which in turn is higher than the first thickness.

[0153] Although not illustrated in figure 3, the blank 130 may be supported on a blank holder.

[0154] As previously discussed, such a press hardenable boron steel blank with different thicknesses may be made by joining two or more sub-blanks. The press hardenable boron steel blank may be a Tailor Welded Blank combining sub-blanks of different thicknesses and / or different materials. In examples, at least one of the subblanks is made of a material having an ultimate tensile strength of 1.100 MPa or less, specifically 1 .000 MPa or less.

[0155] E.g. if in a component a more ductile portion is desired, a sub-blank of Ductibor® 1000 MPa may be combined with a sub-blank of llsibor® 1500 or llsibor® 2000 to name just an example.

[0156] As previously disclosed, particularly for larger components, the press hardenable boron steel blank may be made by welding two or more sub-blanks which partially overlap with each other. When joining multiple sub-blanks by overlapping, the combined blank will have portions of different thickness as illustrated in figure 3. For example, for a unitary vehicle door ring, a blank of e.g. 1 .6 mm may be overlapped with another blank of e.g. 1 .2 mm in a specific area to form a local thickness of 2.8 mm.

[0157] When blanks composed of sub-blanks made of different materials are used, it should be clear that the mechanical properties obtained can vary throughout the component. When reference is made to obtained mechanical properties (like ultimate tensile strength, or yield strength, ductility or elongation), the mechanical properties may refer to a sub-blank only (in the case of the sub-blanks being made of different materials in particular).

[0158] When reference is made to a martensite start temperature, a martensite finish temperature or a critical cooling rate, it should be clear that these can be different for different sub-blanks as well. When reference is made to a process temperature in comparison with a martensite start or finish temperature for a blank composed of subblanks of different materials, the process temperature is to be understood to be applicable for at least one of the sub-blanks.

[0159] When the blank has been placed in the press tool, selected portions of the blank may be cooled (e.g. thicker portion 136), whereas other selected portions of the blank may be heated to avoid them from cooling down too much (e.g. thin portion 132). To this end, the upper and / or lower die may include slots connected to pressurized air. The air may impinge on the thick portion 136 of the blank to locally cool down the blank.Other portions of the upper and / or lower die may include heaters 140, e.g. inductive or resistance heaters to heat thinner portions of the blank. In further examples, the composition of the die block may be different to retain heat. E.g. a die block may include a specific (ceramic) coating with a particularly low reflectance to retain heat. Such a die block may be heated to e.g. 300 - 550eC and since they dissipate little heat may stay close to such temperature in operation.

[0160] In some examples, biasing elements such as e.g. springs may be integrated in the upper and / or lower press dies such that certain mating die blocks of the press tool (a pair of a die block of the upper press tool and a die block of the lower press tool that face each other) enter into contact with the blank before other die blocks enter into contact. In other words, a selection of the die blocks maybe closed earlier than other die blocks.

[0161] In those die blocks wherein contact is established earlier, cooling down may start earlier, and may be quicker than in other die blocks. If overlapping regions are to be cooled down more quickly, a biased die block may be used for that area. Additionally, or alternatively, one or more die blocks may integrate heating means in order to avoid a too rapid cooling down.

[0162] The inventors carried out several experiments to find suitable cycle times and cooling times. Different steels were used, in particular Usibor ® 1500, Usibor ® 2000 and MBW1900 ASPRO (see e.g. table 1 for details). Experiments were carried out using flat blanks, in which flat blanks were deformed into hat profiles. As cycle times for the tools, 8 seconds was chosen. The press tool remained at its dead bottom centre for 0,5 second, whereas the cutting tool (where further cooling takes place) remained at its dead bottom centre for 2,5 or 3,5 seconds. In another experiment, the press tool remained at its dead bottom centre for 0,1 seconds, and the cutting tool for 3,1 seconds. The thickness of the blanks in these experiments was 1 ,5 mm.

[0163] It was found in the experiments that with the indicated cycle and cooling times, material grades were obtained that are the same as in a “conventional” hot stamping process including only deformation. That is, for Usibor® 1500, ultimate tensile strength values of 1 .400 to more than 1 .500 MPa were found. It is noted that for Usibor® 1500, an ultimate tensile strength in a conventional hot stamping process may be expected to be around 1 .500 MPa, but that inevitably variations are found of e.g. 1 .400 or 1 .450 MPa.

[0164] Similarly, for MBW1900, ultimate tensile strengths of close to 1 .900 MPas were found. For llsibor ® 2000, ultimate tensile strengths of around 1 .900 MPa were found. Also yield strengths and A50 elongation values corresponding to the expected grade in a conventional hot stamping process were found.

[0165] In the experiment with the press tool at the dead bottom centre for 0,5 seconds, and the cutting tool remaining at its dead bottom centre for 3,5 seconds, the following approximate temperatures were recorded: prior to stamping, a temperature of about 650eC. After the deformation, different temperatures may be found throughout the hatshaped blank. In particular, in the side flanges and the sidewall, the temperature may be higher, e.g. 350eC or more than in the top of the hat shape. The upper die contacts the blank at the sidewalls and side flanges later, which explains the difference in temperature. A higher temperature in the flanges allows e.g. trimming to be carried out. After the cutting tool, the temperature for the whole hat shape may be about 200eC or less.

[0166] For PET2000H-AL from Posco™, experiments were caried out using similar cooling times, but without actually deforming the blanks. The results obtained also correspond to the expected grade.

[0167] The times that the tools remain at dead bottom centre can be adjusted according to the thickness of the blanks. But the experiments show that with suitable cooling times, and in particular differentiating cooling times in the press tool and in the cutting tool, material grades can be obtained that would be expected in a conventional hot stamping process, in spite of the process being divided into two stages.

[0168] In a further example, as illustrated in figure 4, an upper and / or lower die of the press tool may comprise multiple die blocks E1 - E8. Each of the individual blocks may include individual cooling or heating means and sensors 200 (such as thermocouples) to control the temperature in different parts of the blank.

[0169] Even though figures 3 and 4 illustrate the heating and cooling with respect to the press tool, it should be clear that similar features may be included in the cutting tool.

[0170] In some examples, the method may comprise cutting at least a portion of the press hardenable boron steel blank in the forming tool. I.e. the press tool may include cutting components to cut portions of the blank. Typically, in this case, a small part of the cutting, trimming and / or piercing operations may be carried out in the press toolwhereas the major part of the cutting, trimming and / or piercing may be carried out in the cutting tool.

[0171] In examples, the method may further comprise later cutting the structural component in a laser cutting station. In some examples, directly downstream from the cutting tool, an active cooling tool may be provided to ensure further cooling and ensure dimensional stability of the components.

[0172] Figure 5 illustrates a further example of a press tool 350 and cutting tool 360 which may be used in examples of the present disclosure. The press tool 350 and the cutting tool 360 are integrated in the same press apparatus 300 in this example. The press apparatus 300 comprises a fixed lower body 320, a first mobile upper body 310, and a second mobile upper body 305. A first mechanism configured to provide upwards and downwards press progression of the first mobile upper body 310 with respect to the fixed lower body 320 is provided, as well as a second (independent) mechanism configured to provide upwards and downwards press progression of the second mobile upper body 305 with respect to the fixed lower body 320.

[0173] The upper press tool die 352 is connected to the first mobile upper body and the upper cutting tool die 362 is connected to the second mobile upper body. The lower press tool die 354 and the lower cutting tool die 364 are both connected to the fixed lower body 320.

[0174] The cutting tool and the press tool move upwards and downwards independently from each other. An aspect of using a single press apparatus incorporating both the press tool 350 and the cutting tool 360 is that transfer time may be reduced. Passive air cooling time is thus reduced and temperature control in general may be improved.

[0175] Schematically illustrated in figure 5 are a first component 374 after forming and cutting, a blank 372 which has been deformed (but not cut yet), and a blank 373 which still has to undergo both operations.

[0176] In some examples, the obtained structural component may further be submitted to a bake hardening process. A temperature of bake hardening may be between 170eC and 200eC, and a bake hardening time may be between 15 and 25 minutes.

[0177] With bake hardening, an increase in yield strength of the structural component may be obtained. Energy absorption and toughness of the material may thereby be increased. These results have been experimentally confirmed for the above-referenced steels.

[0178] The mechanisms of the press may be driven mechanically, hydraulically or servo mechanically. The progression of the mobile upper bodies 310, 305 with respect to the fixed lower body 320 may be determined by the mechanisms. In this particular example, the press may be a servo mechanical press, thus a constant press force during the stroke may be provided. The servo mechanical press may be provided with infinite slide (ram) speed and position control. The servo mechanical press may also be provided with a good range of availability of press forces at any slide position, thus a great flexibility of the press may be achieved. Servo drive presses have capabilities to improve process conditions and productivity in metal forming. The press may have a press force of e.g. 2000 Tn.

[0179] In some examples, the press may be a mechanical press, thus the press force progression towards the fixed lower body 320 may depend on the drive and hinge system. Mechanical presses therefore can reach higher cycles per unit of time. Alternatively, hydraulic presses may also be used.

[0180] In some examples, one or more of the lower dies 354, 364 may be connected to the lower body 320 with a lower biasing element configured to bias the lower die to a position at a predetermined first distance from the lower body 320. In some examples, a single lower biasing element may be provided, or more than two lower biasing elements can be provided. The biasing elements may comprise, for example, a spring e.g. a mechanical spring or a gas spring although some other biasing elements may be possible e.g. hydraulic mechanism. The biasing elements ensure that the upper and / or lower dies are “closed” or enter into contact with the blank before reaching the bottom dead center of the press.

[0181] In some examples, one or more of the upper dies 352, 362 may also be connected to the respective mobile upper bodies 310, 305 with one or more upper biasing elements configured to bias the upper die in a position at a predetermined second distance from the upper body.

[0182] With the insertion of the upper and / or lower biasing elements, the contact time between the upper dies and the lower dies may be regulated and increased during a stroke cycle (up and down movement of the mobile upper body with respect to the lower body.

[0183] The use of such biasing elements allows the cooling tool to have a different cycle time than the other tools integrated in the same apparatus. This is explained in more detail in EP3067128. However, within the scope of the present disclosure, theuse of biasing elements is merely optional. Depending on the steel of the blanks and their coating, biasing elements may not be needed at all. As mentioned herein, such biasing elements may be used for closing of complete tools or “dies”. In examples, biasing elements may be used only for a selection of die blocks.

[0184] In examples, the press tool may be provided with a blank holder configured to hold a blank and to positioning the blank onto the lower die. The blank holder may also be provided with e.g. springs to bias the blank holder to a position at a predetermined distance from the lower die.

[0185] Figure 6 schematically illustrates another apparatus incorporating both the press tool 350 and the cutting tool 360. The description of the apparatus of figure 5 and the mentioned variants generally apply to the apparatus of figure 6 as well. The main difference is that the apparatus 300 of figure 6 comprises a single mobile upper body 310. A single mechanism configured to provide upwards and downwards press progression of the mobile upper body 310 with respect to the fixed lower body 320 is provided. Both the upper press tool die 352 and the upper butting tool die 362 are connected to the mobile upper body.

[0186] The cutting tool and the press tool move upwards and downwards in unison. An aspect of using a single press apparatus incorporating both the press tool 350 and the cutting tool 360 is that transfer time may be reduced. Passive air cooling time is thus reduced and temperature control in general may be improved.

[0187] A difference with the apparatus of figure 5 is that the ability to differentiate cooling times between the cutting tool and the press tool is reduced. With the appropriate use of biasing elements as described in relation with figure 5, it can still be achieved that the contact of the press dies with the blank is established later than the contact of the cutting dies with the blank, thus differentiating the active cooling by the dies in the press tool and the cutting tool.

[0188] Schematically illustrated in figure 6 are a first component 374 after forming and cutting, a blank 372 which has been deformed (but not cut yet), and a blank 373 which still has to undergo both operations.

[0189] An automatic transfer device (not shown) e.g. a plurality of industrial robots or a conveyor, or beams with gripping elements may also be provided to perform the transfer of blanks between the tools. Since the transfer devices may be integrated in the same press system, there is less transfer time, and the temperature control is better.

[0190] Figure 7 schematically illustrates a further example of a production line for the manufacture of vehicle components. In the illustrated example, a door ring is used as an example for the vehicle component. It should be clear however, that other components may be manufactured using similar systems and methods.

[0191] In this particular case, the production line 100 includes two parallel furnaces 30. Each of the furnaces may heat up blanks 70. Although in this case, only four blanks are shown within each furnace, it should be clear that such furnaces may be e.g. 30 - 50 meters long and may include many more blanks at any given moment.

[0192] In the furnaces 30, the blanks 70 are heated up to above an austenization temperature, in particular to above Ac3. Each of the furnaces 30 includes a centering table 30. An industrial robot picks up the heated up blank from the centering table and transports it to the press tool 50. In this particular example, the press tool may include upper and lower dies suitable for pressing and two blanks at the same time. That is, each of the furnaces 30 delivers a heated up blank at substantially the same time. The blanks are then delivered to the same press tool 50 which deforms and cools down the blanks. The press tool comprises a single mobile upper body, configured to perform an upward and downwards press progression movement with respect to a fixed lower body.

[0193] Both deformed blanks may then be picked up by individual transfer robots 44 and conveyed to the cutting tool 60. The cutting tool is also configured to perform the cutting operations on two blanks at the same time. The cutting tool comprises a single mobile upper body including cutting dies for two blanks and is configured to perform an upward and downwards press progression movement with respect to a fixed lower body.

[0194] Further transfer robots 46 may pick up the finished or semi-finished component from the cutting tool and convey them for further processing. In this particular case, the press tool and cutting tool are shown to be formed by separate press apparatus. It should be clear however, that they both could also be integrated in a single press apparatus, e.g. using a configuration such as shown in figure 5. An example hereof is schematically illustrated in figure 7B.

[0195] Even though in this example, the transfer system is shown to be embodiment by multiple industrial robots with grippers to pick up and transport the blanks between the various stages, it should be clear that other transfer systems could also be used.

[0196] Figure 7B illustrates an alternative example. The description of figure 7A is mostly applicable to this example as well. The production line 100 includes two parallel furnaces 30. Each of the furnaces may heat up blanks 70.

[0197] In the furnaces 30, the blanks 70 are heated up to above an austenization temperature, in particular to above Ac3. Each of the furnaces 30 includes a centering table 30 at the exit of the furnace. In this example, the output of the conveyor of the furnace may be timed such that the blanks are delivered sequentially from one furnace, and then the other.

[0198] One of the industrial robots 42 picks up the heated up blank from the corresponding centering table and transports it to the press tool 50. In this particular example, the press tool may include upper and lower dies suitable for pressing a single blank at the same time.

[0199] The deformed blanks may then be picked up by a transfer system 48, which is herein represented by beams with grippers and conveyed to the cutting tool 60. In this particular case, the cutting tool 60 and the press tool 50 are integrated in the same press apparatus, although they may perform the upward-downwards press progression independently. In particular, the cutting tool may remain at its dead bottom center for a longer time than the press tool.

[0200] Further transfer robots 46 may pick up the finished or semi-finished component from the cutting tool and convey them for further processing.

[0201] An advantage of this configuration is that the efficiency of the production line is high while reducing the investment in the press apparatus. The cycle of the press apparatus is short (e.g. 8 seconds or 10 seconds as explained herein). Both furnaces deliver blanks sequentially at a pace that the press and cutting tools can handle.

[0202] Figure 7C illustrates yet a further example of a suitable production line 100. The production line 100 of figure 7C is generally comparable to the production line of figure 7B. The only difference is that the press tool 50 and cutting tool 60 are not integrated in the same press apparatus, and rather are separate presses.

[0203] As illustrated in figure 7C, a suitable robot 44 with grippers may be used to transfer the deformed blank from the press tool to the cutting tool. In examples, for larger blanks / components, such as door rings or double door rings, more than one robot 44 may be arranged for the transfer from the press tool 50 to the cutting tool 60.

[0204] In all examples, temperature sensors and control systems in order to control the temperature may be provided in any tools or in the transfer system. The tools may also be provided with further cooling systems, blanks holders, etc.

[0205] In some examples, a centering element e.g. pins and / or guiding devices may be provided upstream the cooling tool, thus the blank may be properly centered.

[0206] In examples of the present disclosure, reference has been made to temperature control means, such as e.g. heaters or cooling systems in the press tool and / or cutting tool. It should be clear that in examples of the present disclosure, individual heaters or individual cooling systems can be controlled to provide different temperature conditions within the press tool or cutting tool in order to create a zone within the final component with a different microstructure. For example, the press tool dies and / or the cutting tool dies may be composed of die blocks, wherein one or more of the die blocks or all of the die blocks can have an individual temperature control. By controlling the temperature of individual die blocks, local areas with different mechanical properties can be obtained. In particular, whereas a component obtained may have an ultimate tensile strength of 1 .500 MPa or more, or 1 .700 MPa or more, a local area within the component may be more ductile, and have a lower ultimate tensile strength and a lower yield strength.

[0207] In such a case, when reference is made to the mechanical properties and / or microstructure of the obtained component, it is to be understood that reference is made to the predominant properties of the obtained component, acknowledging that locally the component may have different properties, and in particular may be more ductile or “soft”.

[0208] In yet further examples, local areas with lower ultimate tensile strength, and yield strength, but increased elongation and ductility may be obtained using a local heat treatment in the component after stamping and cutting. For example, a laser beam, infrared heater or induction heating may be used to locally heat an area of the component, e.g. to between 500 - 750eC, depending on the desired microstructure. Such a temperature may be maintained for as long as desired, whereas the area is then generally left to cool down with air cooling. Depending on the heat treatment chosen, the local area may have a microstructure comprising bainite, ferrite, perlite, martensite and / or tempered martensite.

[0209] For reasons of completeness, various aspects of the present disclosure are set out in the following numbered clauses:Clause 1 . A method for hot forming and press hardening a structural component in a production line comprising: a furnace; a press tool configured to deform blanks, and the press tool having an upper press die and a lower press die; a cutting tool arranged downstream from the press tool and configured to perform a cutting and restriking operation, and having an upper cutting tool die and a lower cutting tool die; a transfer system to transfer blanks from the furnace to the press tool and from the press tool to the cutting tool, and the method comprising: providing a press hardenable boron steel blank; heating the blank to above an austenization temperature in the furnace; transferring the blank to the press tool; the press tool deforming and cooling the blank in a press cycle having a first cycle time, the press tool remaining at a dead bottom centre of the press tool for a first holding time; transferring the formed blank from the press tool to the cutting tool; the cutting tool cutting one or more areas of the formed blank and cooling the formed blank in a cutting cycle having the first cycle time, and the cutting tool remaining at a dead bottom centre of the cutting tool for a second holding time, wherein the second holding time is equal to or longer than the first holding time, particularly wherein the second holding time is longer than the first holding time.Clause 2. The method according to clause 1 , wherein a temperature of the formed blank at a start of the cutting cycle is above a martensite start temperature.Clause 3. The method according to clause 2, wherein the temperature of the formed and cut blank at an end of the cutting cycle is below a martensite finish temperature.Clause 4. The method according to any of clauses 1 - 3, wherein a temperature of the blank before forming the blank is 600eC - 850eC, wherein a temperature of the formed blank is cooled down to 400 - 600eC in the press tool; and wherein the formed blank is cooled down to 300eC or less, preferably to 275eC or less, and more preferably to 200eC or less in the cutting tool.Clause 5. The method according to any of clauses 1 - 4, wherein a cooling rate of the blank in the press tool is 20-35eC / s, specifically 20 - 30eC / s.Clause 6. The method according to any of clauses 1 - 5, wherein a cooling rate of the blank in the cutting tool is higher than in the press tool.Clause 7. The method according to any of clauses 1 - 6, wherein the cooling rate of the blank in the cutting tool is above 20eC / s, specifically above 25eC / s, more specifically above 30eC / s.Clause 8. The method according to clause 7, wherein the cooling rate of the blank in the cutting tool is 30eC - 60eC / s, specifically 30eC / s - 50eC / s.Clause 9. The method according to any of clauses 1 - 8, wherein a cycle time in the cutting tool and in the press tool is 5 - 12 seconds, specifically 7 - 12 seconds, and more specifically 8 - 11 seconds.Clause 10. The method according to any of clauses 1 - 9, further comprising actively cooling at least a selected portion of the blank after heating the blank to above an austenization temperature and before forming in the press tool.Clause 11. The method according to clause 10, wherein the active cooling of at least the selected portion of the blank comprises active cooling in the furnace.Clause 12. The method of clause 10 or 11 , wherein the active cooling of at least the selected portion of the blank comprises active cooling during a transfer from the furnace to the press tool.Clause 13. The method according to any of clauses -10 - 12, wherein the active cooling of at least the selected portion of the blank comprises active cooling in the press tool prior to the deforming of the blank.Clause 14. The method according to any of clauses 1 - 13, wherein the blank is heated to 890 - 930eC in the furnace.Clause 15. The method according to any of clauses 1 - 14, wherein the whole blankis heated to above an Ac1 temperature in the furnace, and specifically wherein the whole blank is heated to above an Ac3 temperature in the furnace.Clause 16. The method according to any of clauses 1 - 15, further comprises active cooling of the formed and cut component after the cutting tool.Clause 17. The method according to any of clauses 1 - 16, wherein the press hardenable boron steel blank has a carbon content by weight of 0.32 - 0.45%, a manganese content of 0.6 - 1 .5%, and a boron content of 0.003 - 0.006%.Clause 18. The method according to clause 17, wherein the press hardenable boron steel blank has a carbon content by weight of 0.32 - 0.4 %, a manganese content of 0.6 - 1 .4%, specifically 0.8 - 1 .4% and a boron content of 0.004 - 0.005%.Clause 19. The method according to clause 17 or 18, wherein the press hardenable boron steel blank has a content by weight of 0.3 - 0.9%, specifically 0.4 - 0.8% of silicon.Clause 20. The method according to any of clauses 1 - 19, wherein the press hardenable boron steel blank is coated.Clause 21. The method according to clause 20, wherein the press hardenable boron steel blank has an AlSi coating.Clause 22. The method according to clause 21 , wherein the AlSi coating further comprises magnesium.Clause 23. The method according to clause 20, wherein the press hardenable boron steel blank has a zinc or zinc alloy coating.Clause 24. The method according to any of clauses 1 - 23, wherein a time from the moment of extracting a blank from the furnace to extracting the blank from the cutting tool is 20 - 37 seconds, specifically 20 - 25 seconds.Clause 25. The method according to any of clauses 1 - 24, wherein the press hardenable boron steel blank has a uniform thickness.Clause 26. The method according to any of clauses 1 - 24, wherein the press hardenable boron steel blank includes a first portion with a first thickness, and a second portion with a second thickness, wherein the second thickness is higher than the first thickness.Clause 27. The method according to clause 26, wherein the first portion is not actively cooled prior to deforming in the press tool, and the second portion is actively cooled prior to deforming in the press tool.Clause 28. The method according to clause 27, wherein the second portion is actively cooled more than the first portion prior to deforming in the press tool.Clause 29. The method according to any of clauses -26 - 28, wherein the first portion is actively heated in the press tool and / or cutting tool.Clause 30. The method according to any of clauses 1 - 29, wherein the press hardenable boron steel blank is made by joining two or more sub-blanks.Clause 31. The method according to clause 30, wherein the press hardenable boron steel blank is a Tailor Welded Blank.Clause 32. The method according to clause 30 or 31 , wherein the press hardenable boron steel blank is made by welding two or more sub-blanks which partially overlap with each other.Clause 33. The method according to any of clauses -30 - 32, wherein the press hardenable boron steel blank is made by positioning a patch blank completely overlapping with another blank and joining the patch blank to the other blank.Clause 34. The method according to any of clauses 30 - 33, wherein the sub-blanks are made from the same material.Clause 35. The method according to any of clauses 30 - 34, wherein at least one of the sub-blanks is made of a material having a maximum ultimate tensile strength of 1 .100 MPa or less, specifically 1 .000 MPa or less.Clause 36. The method according to any of clauses 1 - 35, further comprising cutting at least a portion of the press hardenable boron steel blank in the forming tool.Clause 37. The method according to any of clauses 1 - 36, wherein an ultimate tensile strength of the structural component is 1 .500 MPa or more.Clause 38. The method according to clause 37, wherein the press hardenable boron steel blank is made of 22MnB5 or CR 1500T-MB.Clause 39. The method according to any of clauses 1 - 36, wherein an ultimate tensile strength of the structural component is 1 .600 MPa or more, specifically 1 .700 - 1.900 MPa.Clause 40. The method according to clause 40, wherein the press hardenable boron steel blank is CR1900T-MB or CR1700T-MB.Clause 41. The method according to clause 39 or 40, wherein the structural component obtained has an A50 elongation of 5% or more.Clause 42. The method according to any of clauses 39 - 41 , wherein the structural component obtained has a yield strength of 1.000 MPa or more, specifically 1.100 - 1.300 MPa.Clause 43. The method according to any of clauses 1 - 36, wherein the press hardenable boron steel blank is made of 34MnB4, 34MnB5 steel, 37MnB5 or 37MnB4 steel.Clause 44. The method according to any of clauses 1 - 36, wherein the press hardenable boron steel blank is made of 22MnB8 steel, or 22MnSiB9-5.Clause 45. The method according to any of clauses 1 - 44, further comprising transporting the component to a laser cutting station, and cutting the structural component in the laser cutting station.Clause 46. The method according to any of clauses 1 - 44, wherein the component does not undergo any further laser cutting.Clause 47. The method according to any of clauses 1 - 46, wherein the press tool and the cutting tool are integrated in the same press apparatus, the press apparatus comprising a fixed lower body, a first mobile upper body, a second mobile upper body, a first mechanism configured to provide upwards and downwards press progression of the first mobile upper body with respect to the fixed lower body, and a second mechanism configured to provide upwards and downwards press progression of the second mobile upper body with respect to the fixed lower body and, wherein the upper press tool die is connected to the first mobile upper body, and the upper cutting tool die is connected to the second mobile upper body, and the lower press tool die and the lower cutting tool die are connected to the fixed lower body.Clause 48. The method according to clause 47, wherein an operational cycle of the press apparatus is less than 16 seconds, preferably less than 12 seconds, specifically about 10 seconds or less.Clause 49. The method according to clause 48, wherein the structural component has a length of 1 meter or more, and a width of 1 meter or more, specifically 2 - 4 meters, and a width of the structural component after forming is at least 1 meter, specifically 1 - 2 meters.Clause 50. The method according to clause 49, wherein the structural component is a unitary door ring, and wherein the unitary door ring is one of a front door ring extending from hinge-pillar and A-pillar to B-pillar, a rear door ring extending from B- pi liar to C-pillar or a double door ring extending from hinge-pillar and A-pillar to C-pi liar.Clause 51 . The method according to clause 49, wherein the structural component is a unitary roof ring, a bumper beam assembly including a bumper beam and a pedestrian beam, or a unitary reinforcement ring surrounding a battery box, or a rear framework structure including rear rails and a transverse beam as a unitary structure.Clause 52. The method according to any of clauses 1 - 48, wherein the structural component has a length and / or a width of less than 1 meter.Clause 53. The method according to clause 52, wherein the structural component is a B-pillar, C-pillar, hinge pillar, bumper beam, seat cross-member or a side impact protection beam.Clause 54. The method according to any of clauses 1 - 53, wherein a waiting time for the blank after exiting the furnace and before transfer is 1 - 5 seconds.Clause 55. The method according to any of clauses 1 - 54, wherein a transfer time between the furnace and the press tool is between 1 and 3 seconds, specifically between 1 ,5 and 2,5 seconds.Clause 56. The method according to any of clauses 1 - 55, wherein the first holding time is 0.1 - 4 seconds, specifically 0.5 - 3 seconds.Clause 57. The method according to any of clauses 1 - 56, wherein the second holding time is 1 - 5 seconds, specifically 2 - 4 seconds.Clause 58. The method according to any of clauses 1 - 57, further comprising bake hardening the structural component obtained, wherein a temperature of bake hardening is between 170eC and 200eC, and wherein a bake hardening time is between 15 and 25 minutes.Clause 59. The method according to any of clauses 1 - 58, wherein the press hardenable boron steel blank has a thickness of 0,6 mm - 4 mm, specifically 0,8 - 3, more specifically 1 - 2 mm, and more specifically 1 - 1.6 mm.Clause 60. A structural component obtainable by any of the methods according to clauses 1 - 59.Clause 61. A production line for hot forming and press hardening a structural component comprising: a furnace configured to heat a press hardenable boron steel blank to above an Ac1 temperature, particularly to above an Ac3 temperature; a press tool arranged downstream from the furnace and configured to deform and cooling the heated blanks, and the press tool having an upper press die and a lower press die, and the press tool having a first cycle time and the press toolconfigured to remain at a dead bottom centre for a first holding time; a first transfer system to transfer blanks from the furnace to the press tool; a cutting tool arranged downstream from the press tool and configured to perform a cutting and restriking operation during which the blank is cooled, and having an upper cutting tool die and a lower cutting tool die, and the cutting tool having the first cycle time, and the cutting tool configured to remain at a dead bottom centre for a second holding time; a second transfer system to transfer blanks from the press tool to the cutting tool, wherein the second holding time is equal to or longer than the first holding time.Clause 62. The production line of clause 61 , wherein the furnace and / or the first transfer system and / or the press tool comprises cooling elements for actively cooling at least a selected portion of the heated blank.Clause 63. The production line of clause 62, wherein the furnace is configured for tailored tempering.Clause 64. The production line of clause 62 or 63, wherein the first transfer system is configured for tailored cooling of the selected portion of the heated blank.Clause 65. The production line of any of clauses 61 - 64, wherein the upper press die and / or the lower press die have cooling channels for conducting cooling liquid.Clause 66. The production line of any of clauses 61 - 65, wherein the press tool comprises a plurality of die blocks.Clause 67. The production line of clause 66, wherein the press tool comprises one or more first die blocks with holes for ejecting cooling air to the selected portion of the heated blank.Clause 68. The production line of clause 66 or 67, wherein the press tool comprises one or more second die blocks configured for heating a portion of the blanks.Clause 69. The production line of clause 68, wherein the second die blocks configured for heating a portion of the blanks comprises an induction heater or aresistance heater.Clause 70. The production line of clause 68 or 69, wherein the second die blocks comprise a coating or cladding configured to retain heat.Clause 71 . The production line of any of clauses 55 - 64, wherein a cycle time from extracting a blank from the furnace to extracting the blank from the cutting tool is 37 seconds or less, specifically 28 seconds or less, more specifically 25 seconds or less.Clause 72. The production line of any of clauses 55 - 65, wherein the press tool comprises one or more cutting element to partially cut the blanks.Clause 73. The production line of any of clauses 55 - 66, further comprising a laser cutting station arranged downstream from the cutting tool.Clause 74. The production line of any of clauses 61 - 73, wherein the first transfer system comprises a multi-axis robot with a gripper.Clause 75. The production line of any of clauses 61 - 74, wherein the press tool and the cutting tool are integrated in the same press apparatus, the press apparatus comprising a fixed lower body, a first mobile upper body, a second mobile upper body and a first mechanism configured to provide upwards and downwards press progression of the first mobile upper body with respect to the fixed lower body, and a second mechanism configured to provide upwards and downwards press progression of the second mobile upper body with respect to the fixed lower body, and wherein the upper press tool die is connected to the first mobile upper body and the upper cutting tool die is connected to the second mobile upper body, and the lower press tool die and the lower cutting tool die are connected to the fixed lower body.Clause 76. The production line of clause 75, wherein the second transfer system to transfer blanks from the press tool to the cutting tool comprises mechanical transfer arms, optionally with gripping fingers.Clause 77. The production line of any of clauses 61 - 74, wherein the press tool andthe cutting tool are separated press apparatus, and the second transfer system comprises a multi-axis robot with a gripper.Clause 78. The production line of any of clauses 61 - 77, further comprising a cooling tool arranged downstream from the cutting tool, and further comprising a third transfer system for transferring the blanks from the cutting tool to the cooling tool.Clause 79. The production line of any of clauses -61 - 78, wherein the press hardenable boron steel blank has a carbon content by weight of 0.32 - 0.45%, a manganese content of 0.6 - 1 .5%, and a boron content of 0.003 - 0.006%.Clause 80. The production line according to clause 79, wherein the press hardenable boron steel blank has a carbon content by weight of 0.32 - 0.4 %, a manganese content of 0.6 - 1 .4%, specifically 0.8 - 1 .4% and a boron content of 0.004 - 0.005%.Clause 81. The production line according to clause 79 or 80, wherein the press hardenable boron steel blank has a content by weight of 0.3 - 0.9%, specifically 0.4 - 0.8% of silicon.Clause 82. The production line according to any of clauses 61 - 78, wherein the press hardenable boron steel blank is made of 34MnB4, 34MnB5, 37MnB5 or 37MnB4 steel.Clause 83. The production line according to any of clauses 61 - 78, wherein the press hardenable boron steel blank is made of 22MnB8 steel, or 22MnSiB9-5.Clause 84. The production line according to any of clauses 61 - 78, wherein the press hardenable boron steel blank is made of 22MnB5 steel.Clause 85. The production line according to any of clauses 61 - 68, wherein the press hardenable boron steel blank is made of CR1500T-MB, CR1700T-MB or CR1900T-MB.Clause 86. The production line according to any of clauses -61 - 85, wherein the press hardenable boron steel blank is coated.Clause 87. The production line according to clause 86, wherein the press hardenable boron steel blank has an AlSi coating.Clause 88. The production line according to clause 87, wherein the AlSi coating further comprises magnesium.Clause 89. The production line according to clause 86, wherein the press hardenable boron steel blank has a zinc or zinc alloy coating.Clause 90. The production line of any of clauses 61 - 89, wherein the press hardenable boron steel blank has a uniform thickness.Clause 91. The production line according to any of clauses -61 - 89, wherein the press hardenable boron steel blank includes a first portion with a first thickness, and a second portion with a second thickness, wherein the second thickness is higher than the first thickness.Clause 92. The production line of clause 91 , wherein the furnace and / or the first transfer system and / or the press tool comprises cooling elements for actively cooling the first portion of the heated blank.Clause 93. The production line of clause 91 , wherein the furnace and / or the first transfer system and / or the press tool comprises cooling elements for actively cooling the first portion of the heated blank and for actively cooling the second portion of the heated blank.Clause 94. The production line according to any of clauses -61 - 93, wherein the press hardenable boron steel blank is made by joining two or more sub-blanks.Clause 95. The production line according to clause 94, wherein the press hardenable boron steel blank is a Tailor Welded Blank.Clause 96. The production line according to clause 94 or 95, wherein the press hardenable boron steel blank is made by welding two or more sub-blanks which partially overlap with each other.Clause 97. The production line according to any of clauses 94 - 96, wherein the press hardenable boron steel blank is made by positioning a patch blank completely overlapping with another blank and joining the patch blank to the other blank.Clause 98. The production line according to any of clauses 94 - 97, wherein the sub-blanks are made from the same material.Clause 99. The production line according to any of clauses 61 - 98, wherein a length of the structural component after forming is at least 1 meter, specifically 2 - 4 meters, and a width of the structural component after forming is at least 1 meter, specifically 1- 2 meters.Clause 100. The production line according to clause 99, wherein the structural component is a unitary door ring, and wherein the unitary door ring is one of a front door ring extending from hinge-pillar and A-pillar to B-pi liar, a rear door ring extending from B-pillar to C-pillar or a double door ring extending from hinge-pillar and A-pillar to C-pillar.Clause 101. The production line according to clause 99, wherein the structural component is a unitary roof rings, a bumper beam assembly including a bumper beam and a pedestrian beam, or a unitary reinforcement ring surrounding a battery box, or a rear framework structure including rear rails and a transverse beam as a unitary structure.Clause 102. The production line according to any of clauses -61 - 101 , wherein the press hardenable boron steel blank has a thickness of 0,6 mm - 4 mm, specifically 0,8- 3mm, more specifically 1 - 2 mm, and more specifically 1 - 1.6 mm.Clause 103. The method according to any of clauses 61 - 102, wherein the first holding time is 0.1 - 4 seconds, specifically 0.5 - 3 seconds.Clause 104. The method according to any of clauses 61 - 103, wherein the second holding time is 1 - 5 seconds, specifically 2 - 4 seconds.Clause 105. A method for hot forming and press hardening a structural component in a production line comprising: a furnace;a press tool configured to deform blanks, and the press tool having an upper press die and a lower press die; a cutting tool arranged downstream from the press tool and configured to perform a cutting and restriking operation, and having an upper cutting tool die and a lower cutting tool die; a transfer system to transfer blanks from the furnace to the press tool and from the press tool to the cutting tool, and the method comprising: providing a press hardenable boron steel blank; heating the blank to above an austenization temperature in the furnace; actively cooling at least a selected portion of the blank; deforming and cooling the blank in the press tool; transferring the formed blank from the press tool to the cutting tool; cutting one or more areas of the formed blank and cooling the formed blank in the cutting tool, wherein a temperature of the blank before forming the blank is 600eC - 850eC, wherein a temperature of the formed blank is cooled down to 400 - 600eC in the press tool; and wherein the formed blank is cooled down to 300eC, preferably to 275eC in the cutting tool.Clause 106. The method according to clause 105, wherein the active cooling of at least the selected portion of the blank comprises active cooling in the furnace.Clause 107. The method of clause 105 or 106, wherein the active cooling of at least the selected portion of the blank comprises active cooling during a transfer from the furnace to the press tool.Clause 108. The method according to any of clauses 105 - 107, wherein the active cooling of at least the selected portion of the blank comprises active cooling in the press tool prior to the deforming of the blank.Clause 109. The method according to any of clauses 105 - 108, wherein the blank is heated to 890 - 930eC in the furnace.Clause 110. The method according to any of clauses 105 - 109, wherein the whole blank is heated to above an Ac1 temperature in the furnace, and specifically whereinthe whole blank is heated to above an Ac3 temperature in the furnace.Clause 111. The method according to any of clauses 105 - 110, further comprises active cooling of the formed and cut blank after the cutting tool.Clause 112. The method according to any of clauses 105 - 111 , wherein the press hardenable boron steel blank has a content by weight of 0.32 - 0.45%, a manganese content of 0.6 - 1 .5%, and a boron content of 0.003 - 0.006%.Clause 113. The method according to clause 112, wherein the press hardenable boron steel blank has a content by weight of 0.32 - 0.4 %, a manganese content of 0.6 - 1 .4%, specifically 0.8 - 1 .4% and a boron content of 0.004 - 0.005%.Clause 114. The method according to clause 112 or 113, wherein the press hardenable boron steel blank has a content by weight of 0.3 - 0.9%, specifically 0.4 - 0.8% of silicon.Clause 115. The method according to any of clauses 105 - 114, wherein the press hardenable boron steel blank is coated.Clause 116. The method according to clause 115, wherein the press hardenable boron steel blank has an AlSi coating, and optionally wherein the AlSi coating further comprises magnesium.Clause 117. The method according to clause 115, wherein the press hardenable boron steel blank has a zinc or zinc alloy coating.Clause 118. The method according to any of clauses 105 - 117, wherein a time from the moment of extracting a blank from the furnace to extracting the blank from the cutting tool is 20 - 25 seconds.Clause 119. The method according to any of clauses 105 - 118, wherein the press hardenable boron steel blank has a uniform thickness.Clause 120. The method according to any of clauses 105 - 118, wherein the press hardenable boron steel blank includes a first portion with a first thickness, and a secondportion with a second thickness, wherein the second thickness is higher than the first thickness.Clause 121. The method according to clause 120, wherein the second portion is actively cooled more than the first portion prior to deforming.Clause 122. The method according to clause 120 or 121 , wherein the first portion is actively heated in the press tool and / or cutting tool.Clause 123. The method according to any of clauses 105 - 122, wherein the press hardenable boron steel blank is made by joining two or more sub-blanks.Clause 124. The method according to clause 123, wherein the press hardenable boron steel blank is a Tailor Welded Blank.Clause 125. The method according to clause 123 or 124, wherein the press hardenable boron steel blank is made by welding two or more sub-blanks which partially overlap with each other.Clause 126. The method according to any of clauses 123 - 125, wherein the press hardenable boron steel blank is made by positioning a patch blank completely overlapping with another blank and joining the patch blank to the other blank.Clause 127. The method according to any of clauses 123 - 126, wherein the subblanks are made from the same material.Clause 128. The method according to any of clauses 123 - 127, wherein at least one of the sub-blanks is made of a material having a maximum ultimate tensile strength of 1 .100 MPa or less, specifically 1 .000 MPa or less.Clause 129. The method according to any of clauses 105 - 128, further comprising cutting at least a portion of the press hardenable boron steel blank in the forming tool.Clause 130. The method according to any of clauses 105 - 129, wherein an ultimate tensile strength of the structural component is 1 .600 MPa or more, specifically 1 .700 - 1.900 MPa.Clause 131 . The method according to clause 130, wherein the structural component obtained has an A50 elongation of 5% or more.Clause 132. The method according to clause 130 or 131 , wherein the structural component obtained has a yield strength of 1.000 MPa or more, specifically 1.100 - 1.300 MPa.Clause 133. The method according to any of clauses 105 - 132, further comprising transporting the component to a laser cutting station, and cutting the structural component in the laser cutting station.Clause 134. The method according to any of clauses 105 - 133, wherein the press tool and the cutting tool are integrated in the same press apparatus, the press apparatus comprising a fixed lower body, a mobile upper body, and a mechanism configured to provide upwards and downwards press progression of the mobile upper body with respect to the fixed lower body, and wherein the upper press tool die and the upper cutting tool die are connected to the moving upper body.Clause 135. The method according to clause 134, wherein an operational cycle of the press apparatus is less than 12 seconds, specifically about 10 seconds or less.Clause 136. The method according to any of clauses 105 - 135, wherein in the press tool and the cutting tool, a cooling time is 1 - 5 seconds, and a transfer time is 5 - 9 seconds.Clause 137. The method according to any of clauses 105 - 136, wherein a transfer time between the furnace and the press tool is between 1 and 3 seconds, specifically between 1 ,5 and 2,5 seconds.Clause 138. The method according to any of clauses 105 - 137, further comprising bake hardening the structural component obtained, wherein a temperature of bake hardening is between 170eC and 200eC, and wherein a bake hardening time is between 15 and 25 minutes.Clause 139. The method according to any of clauses 105 - 138, wherein a length ofthe structural component after forming is at least 1 meter, specifically 2 - 4 meters, and a width of the structural component after forming is at least 1 meter, specifically 1 - 2 meters.Clause 140. The method according to clause 139, wherein the structural component is a unitary door ring, and wherein the unitary door ring is one of a front door ring extending from hinge-pillar and A-pillar to B-pillar, a rear door ring extending from B- pi liar to C-pillar or a double door ring extending from hinge-pillar and A-pillar to C-pi liar.Clause 141 . The method according to clause 139, wherein the structural component is a unitary roof ring, a bumper beam assembly including a bumper beam and a pedestrian beam, or a unitary reinforcement ring surrounding a battery box, or a rear framework structure including rear rails and a transverse beam as a unitary structure.Clause 142. The method according to any of clauses 105 - 141 , wherein the press hardenable boron steel blank has a thickness of 0,6 mm - 4 mm, specifically 0,8 - 3, more specifically 1 - 2 mm, and more specifically 1 - 1.6 mm.Clause 143. The method according to any of clauses 105 - 142, wherein the press hardenable boron steel blank is made of 34MnB4, 34MnB5 steel, 37MnB5 or 37MnB4 steel.Clause 144. The method according to any of clauses 105 - 142, wherein the press hardenable boron steel blank is made of 22MnB8 steel, or 22MnSiB9-5.Although only a number of examples have been disclosed herein, other alternatives, modifications, uses and / or equivalents thereof are possible. Furthermore, all possible combinations of the described examples are also covered. Thus, the scope of the present disclosure should not be limited by particular examples, but should be determined only by a fair reading of the claims that follow.

Claims

55CLAIMS1. A method for hot forming and press hardening a structural component in a production line comprising a furnace, a press tool configured to deform blanks, and the press tool having an upper press die and a lower press die, a cutting tool arranged downstream from the press tool and configured to perform a cutting and restriking operation, and having an upper cutting tool die and a lower cutting tool die and a transfer system to transfer blanks from the furnace to the press tool and from the press tool to the cutting tool, and the method comprising: providing a press hardenable boron steel blank; heating the blank to above an austenization temperature in the furnace; transferring the blank to the press tool; the press tool deforming and cooling the blank in a press cycle having a first cycle time, the press tool remaining at a dead bottom centre of the press tool for a first holding time; transferring the formed blank from the press tool to the cutting tool; the cutting tool cutting one or more areas of the formed blank and cooling the formed blank in a cutting cycle having the first cycle time, and the cutting tool remaining at a dead bottom centre of the cutting tool for a second holding time, wherein the second holding time is longer than the first holding time, and wherein a temperature of the formed blank at a start of the cutting cycle is above a martensite start temperature of the press hardenable boron steel blank, and wherein the temperature of the formed and cut blank at an end of the cutting cycle is below a martensite finish temperature of the press hardenable boron steel blank.

2. The method according to claim 1 , wherein the first holding time is 0.1 - 4 seconds, specifically 0.5 - 3 seconds.

3. The method according to claim 1 or 2, wherein the second holding time is 1 - 5 seconds, specifically 2 - 4 seconds.

4. The method according to any of claims 1 - 3, wherein the cooling rate of the blank in the cutting tool is above 20eC / s, specifically above 25eC / s, more specifically above 30eC / s.

5. The method according to any of claims 1 - 4, wherein the cooling rate of the blank in the cutting tool is 30eC - 60eC / s, specifically 30eC / s - 50eC / s.

566. The method according to any of claims 1 - 5, wherein a cycle time in the cutting tool and in the press tool is 7 - 12 seconds, specifically 8 - 11 seconds.

7. The method according to any of claims 1 - 6, wherein a temperature of the blank before forming the blank is 600eC - 850eC, wherein a temperature of the formed blank is cooled down to 400 - 600eC in the press tool; and wherein the formed blank is cooled down to 275eC or less, preferably 200eC or less, in the cutting tool.

8. The method according to any of clauses 1 - 7, wherein an ultimate tensile strength of the structural component is 1 .500 MPa or more.

9. The method according to -claim 8, wherein the press hardenable boron steel blank is made of 22MnB5 or CR1500T-MB.

10. The method according to any of claims 1 - 9, wherein a microstructure of the structural component is substantially fully martensitic.11 . The method according to any of claims 1 - 10, wherein at least a portion of the heated blank is actively cooled before pressing in the press tool.

12. The method according to any of claims 1 - 11 , wherein a cycle time from the moment of extracting a blank from the furnace to extracting the blank from the cutting tool is 37 seconds or less, specifically 28 seconds or less, more specifically 25 seconds or less.

13. The method according to any of claims 1 - 12, further comprising cutting at least a portion of the press hardenable boron steel blank in the forming tool.

14. A production line for hot forming and press hardening a structural component, particularly for a method according to any of claims 1 - 13, comprising: a furnace configured to heat a press hardenable boron steel blank to above an Ac1 temperature, particularly to above an Ac3 temperature; a press tool arranged downstream from the furnace and configured to deform and cooling the heated blanks, and the press tool having an upper press die and a57 lower press die, and the press tool having a first cycle time and the press tool configured to remain at a dead bottom centre for a first holding time; a first transfer system to transfer blanks from the furnace to the press tool; a cutting tool arranged downstream from the press tool and configured to perform a cutting and restriking operation during which the blank is cooled, and having an upper cutting tool die and a lower cutting tool die, and the cutting tool having the first cycle time, and the cutting tool configured to remain at a dead bottom centre for a second holding time; a second transfer system to transfer blanks from the press tool to the cutting tool, wherein wherein the second holding time is longer than the first holding time.

15. The production line of claim 14, wherein the press tool and the cutting tool are integrated in the same press apparatus, the press apparatus comprising a fixed lower body, a first mobile upper body, a second mobile upper body and a first mechanism configured to provide upwards and downwards press progression of the first mobile upper body with respect to the fixed lower body, and a second mechanism configured to provide upwards and downwards press progression of the second mobile upper body with respect to the fixed lower body, and wherein the upper press tool die is connected to the first mobile upper body and the upper cutting tool die is connected to the second mobile upper body, and the lower press tool die and the lower cutting tool die are connected to the fixed lower body.

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