EP3856947B1 - Method for improving the phosphatability of metal surfaces which are provided with a temporary pre- or post-treatment - Google Patents

Description

The present invention relates to a method for producing a formed component, comprising at least the steps (A) providing a flat steel product, (B) skin rolling the flat steel product from step (A), (C) applying a functional coating to the flat steel product from step (B), (D) forming the flat steel product from step (C) to obtain a formed component, (E) removing the functional coating from the formed component from step (D), (F) applying activation particles to the formed component from step (E), and (G) applying a phosphating to the formed component from step (F), wherein additional activation particles are applied to the flat steel product before and/or during step (B) and/or before and/or during step (C). Furthermore, the present invention relates to a corresponding flat steel product and its use in the automotive sector.

In the prior art, methods for improving phosphated surfaces of anti-corrosive coated flat steel products or for improving the adhesion of such surfaces are already known.

In the EP 2 824 213 A1 A process for improving the adhesion to an anti-corrosive coated steel sheet is described. For this purpose, an aqueous solution containing fluoride ions is applied to the ZnO and Al ₂ O ₃ -containing oxide layer of the protective coating based on Zn-Al-Mg. The fluoride ions ensure that the oxide layer is modified but densely decapitated, so that an adhesive subsequently applied shows better adhesion.

US 2015/0352825 A1 discloses a process in which a flat steel product having an anti-corrosive coating is first treated with an acidic solution so that a subsequently applied adhesive shows better adhesion.

WO 2017/125131 A1 discloses a method for producing a steel product having a zinc-based protective coating and a tribologically active layer applied to the protective coating.

The anti-corrosive coated steel flat products known from the state of the art often have the problem that during their production a temporary pre- or post-treatment, i.e. a functional coating such as an adhesion-promoting layer, a forming aid, a passivation or a combination thereof, is applied and then removed again. This removal is usually carried out by a cleaning step. It can happen that the cleaning step is not completed, i.e. that residues of the functional coating remain on at least some areas of the flat steel product. In a subsequent two-stage phosphating step, which includes the application of activation particles and phosphating, the activation particles cannot fully reach the actual surface of the flat steel product due to the residues of the functional layer, so that the result is a phosphate layer that consists in areas of zinc phosphate crystals of different sizes that appear uneven when viewed macroscopically, which is undesirable.

The object of the present invention is therefore to provide a method for producing a phosphated flat steel product which, compared to the prior art, produces improved phosphated surfaces which, in particular, exhibit better adhesive adhesion. In particular, the invention aims to provide a method which produces good phosphated surfaces, in particular with improved adhesive adhesion, even when functional coatings applied in the meantime have not been completely removed.

1. (A) Bereitstellen eines Stahlflachprodukts,
2. (B) Dressieren des Stahlflachprodukts aus Schritt (A),
3. (C) Aufbringen einer funktionalen Beschichtung auf das Stahlflachprodukt aus Schritt (B),
4. (D) Umformen des Stahlflachprodukts aus Schritt (C), um ein umgeformtes Bauteil zu erhalten,
5. (E) Entfernen der funktionalen Beschichtung von dem umgeformten Bauteil aus Schritt (D),
6. (F) Aufbringen von Aktivierungspartikeln auf das umgeformte Bauteil aus Schritt (E), und
7. (G) Aufbringen einer Phosphatierung auf das umgeformte Bauteil aus Schritt (F),

wobei vor und/oder während Schritt (B) und/oder vor und/oder während Schritt (C) zusätzliche Aktivierungspartikel auf das Stahlflachprodukt aufgebracht werden.These objects are achieved according to the invention by the method for producing a formed component, comprising at least the following steps:

1. (A) Providing a flat steel product,
2. (B) skin passing of the flat steel product from step (A),
3. (C) applying a functional coating to the flat steel product from step (B),
4. (D) forming the flat steel product from step (C) to obtain a formed component,
5. (E) removing the functional coating from the formed component from step (D),
6. (F) applying activation particles to the formed component from step (E), and
7. (G) applying a phosphating to the formed component from step (F),

wherein additional activation particles are applied to the flat steel product before and/or during step (B) and/or before and/or during step (C).

The method according to the invention is described in detail below.

Step (A):

Step (A) of the method according to the invention comprises providing a flat steel product. Preferably, in step (A), a flat steel product provided with a coating that protects against corrosion is provided.

In general, the flat steel product used according to the invention can consist of any steel grade known to the person skilled in the art, for example CR3 or DX51. This steel preferably used according to the invention contains, for example, max. 0.08 wt.% C, max. 0.45 wt.% Mn, max. 0.030 wt.% P, max. 0.030 wt.% S, max. 0.15 wt.% Cr, max. 0.20 wt.% Cu, max. 0.06 wt.% Mo, max. 0.008 wt.% Nb, max. 0.20 wt.% Ni, where the sum of Cu, Ni, Cr and Mo must not exceed 0.50 wt.% and the sum of Cr and Mo must not exceed 0.16 wt.%, the remainder being Fe and unavoidable impurities.

According to the invention, the flat steel product according to the invention is a hot strip or a cold strip. These can be obtained by methods known to those skilled in the art. In addition to steel strips, so-called blanks can also be used in step (A) of the method according to the invention, which are preferably obtained by cutting pieces from a hot or cold strip using suitable methods.

The flat steel product according to the invention is based on a steel sheet, preferably containing a coating that protects against corrosion. The coating that protects against corrosion, which is preferably present according to the invention, is preferably metallic. The steel sheet can be coated in a known manner, for example in a hot-dip process (hot-dip galvanizing) or by electrolytic deposition. According to the invention, the coating is preferably carried out in a hot-dip process. Corresponding processes are known per se to those skilled in the art.

The coating that is preferably present on the flat steel product according to the invention is preferably based on zinc, a zinc alloy, aluminum or an aluminum alloy. According to the invention, a non-coated, in particular non-galvanized, steel surface can also be used in step (A).

Suitable coatings therefore contain, for example, zinc or zinc and magnesium, zinc and aluminium or zinc which has been applied electrolytically.

The flat steel product, in particular the steel strip, is preferably coated by first mechanically and/or chemically cleaning the strip surface in a first stage of the coating process. The strip surface is then roughened, preferably in an acidic pickling solution, before the strip is passed through an electrolytic coating cell and coated, in particular galvanized, there. In the coating cell, the steel strip is dipped in a sulfuric acid zinc electrolyte and simultaneously switched as a cathode. In the case of soluble electrodes, these are also dipped in the electrolyte solution and switched as an anode. The cations migrate from the anode through the electrolyte to the steel strip surface and are cathodically deposited there. In the case of insoluble anodes, on the other hand, the metal, for example zinc, is already dissolved in the electrolyte, whereby the anodes consist of correspondingly more noble materials. The amount of metal deposited on the strip surface depends on the current density and the coating duration. In order to achieve a metal layer thickness of a few micrometers at a belt speed of, for example, 100 m/min, the steel strip must pass through several coating cells connected in series in an electrolytic cell because of the relatively short coating time and thus the correspondingly low deposition rate at such a belt speed. In order to then remove the electrolyte from the strip surface and thus avoid electrolyte being carried over into the next process step, the electrolytically coated steel strip is preferably passed through a multi-stage rinsing device.

According to the invention, the present coating particularly preferably consists of zinc or a zinc alloy, which has more preferably been applied by hot-dip coating. Methods for hot-dip coating are known per se to those skilled in the art.

According to the invention, the coating, in particular made of zinc or a zinc alloy, is preferably present with a coating weight of 1 to 600 g/m ² , ie 0.5 to 300 g/m ² per side, particularly preferably 20 to 300 g/m ² , ie 10 to 150 g/m ² per side.

Step (B):

Step (B) of the process according to the invention comprises the skin passing of the flat steel product from step (A).

Dressing is known to the expert and is described, for example, in Handbook of forming, Günter Spur, ISBN: 978-3-446-43004-4, page 155 .

The present invention preferably relates to the method according to the invention, wherein the skin-passing in step (B) is carried out using a skin-passing agent. In a particularly preferred embodiment of the method according to the invention, at least one skin-passing agent is therefore applied to the flat steel product before and/or during step (B). Usable skin-passing agents are known per se to the person skilled in the art. Preferably, the at least one dressing agent contains organic compounds selected from the group consisting of saturated hydrocarbons, in particular hydrogenated naphtha, alkoxylated alcohols, in particular 2-(2-butoxyethoxy)ethanol, 2-(methoxymethyloxy)propane and/or branched poly(oxy-1,2-ethanediyl)-alpha-tridecyl-omega-alcohol, adducts of organic acids and amines, for example the adduct of 3,5,5-trimethylhexanoic acid and 2-aminoethanol, derivatives of fatty acids, for example oleoylsarcosine, amines, for example dodecylpropylenetriamine, glycols, for example hexylene glycol, and mixtures thereof.

Most preferably, the at least one dressing agent is selected from the group consisting of compositions with the trade names Friocut LF 280, Gardolube L 8256, QWERL 4305 and mixtures thereof.

In a preferred embodiment of the method according to the invention, not only is at least one dressing agent applied before and/or during step, but additional activation particles are applied simultaneously or separately from the at least one dressing agent before and/or during step (B).

The present invention therefore preferably relates to the process according to the invention, wherein at least one skin-pass agent and additional activation particles are applied to the flat steel product before and/or during step (B).

In a preferred embodiment according to the invention, a mixture containing at least one skin-pass agent and additional activation particles is applied to the flat steel product before and/or during step (B).

In a further preferred embodiment according to the invention, at least one skin-pass agent and additional activation particles are applied separately to the flat steel product before and/or during step (B).

The at least one skin-pass agent is generally applied to the flat steel product in an amount such that the subsequent skin-pass step can proceed advantageously. Preferably, the at least one skin-pass agent is applied in an amount of 1 to 50 g/L, particularly preferably 10 to 30 g/L.

The application of the at least one dressing agent and optionally the activation particles can generally be carried out by all methods known to the person skilled in the art, for example spraying, dipping or coating methods.

Appropriate additional activation particles that may be applied before and/or during step (B) are described in detail below.

Step (C):

Step (C) of the process according to the invention comprises applying a functional coating to the flat steel product from step (B).

The steel product obtained after the skin passing in step (B) contains on the surface at least parts of the possibly applied skin passing agent and, if applicable, additional activation particles.

In step (C) of the method according to the invention, at least one functional coating is applied to this flat steel product. Functional coatings are also known to the person skilled in the art under the term "pre- or post-treatments". Functional coatings that can be applied to the flat steel product in the method according to the invention are known to the person skilled in the art and are selected, for example, from the group consisting of adhesion-promoting layer, forming aid, passivation or a combination thereof.

Suitable adhesion-promoting coatings (adhesion promoters) are known to the person skilled in the art and contain, for example, alcohols, for example methanol, silane components, for example Polysiloxanes, silicate components, ammonium or amino compounds, organic polymers and mixtures thereof.

Most preferably, the at least one adhesion promoter is selected from the group consisting of compositions with the trade names GBX 4537, Bonderite 1461 and mixtures thereof.

An adhesion-promoting layer can be applied to the flat steel product by any method known to the person skilled in the art, for example spraying, dipping or coating processes.

An adhesion-promoting coating is generally applied in an amount sufficient to exert the adhesion-promoting effect, for example 1 mg/m ² to 10 mg/m ² , preferably 2 mg/m ² to 6 mg/m ² , in each case per layer of the silicon conductive element.

Suitable coatings that can act as a forming aid are known per se to the person skilled in the art and contain, for example, acids, for example phosphoric acid, bases, for example potassium hydroxide or organic amines, cyclic organic compounds, for example benzotriazole, other organic compounds, for example fatty acids, sulfonates, for example methanesulfonate, or alcohols, for example aminoethanol, inorganic salts, for example sulfates, in particular zinc sulfate or potassium sulfate, or carbonates, for example sodium carbonate, preferably as aqueous solutions.

Most preferably, the at least one forming aid is selected from the group consisting of compositions with the trade names Lubitreat, NIT, L-FM50000, L-FM50100, L-FM50200 and mixtures thereof.

A coating acting as a forming aid can be applied to the flat steel product by any method known to the person skilled in the art, for example spraying, dipping or coating processes.

A coating acting as a forming aid is generally applied in an amount sufficient to produce the corresponding effect, for example 5 mg/m ² to 40 mg/m ² , preferably 10 mg/m ² to 25 mg/m ² , in each case based on the sulfur conductive element.

Suitable passivating coatings (passivating agents) are known per se to the person skilled in the art and contain, for example, chromium salts, for example chromium orthophosphate, chromium nitrate, chromium trifluoride, organic acids, for example citric acid, inorganic acids, for example hydrofluoric acid, and mixtures thereof.

Most preferably, the at least one passivating agent is selected from the group consisting of compositions with the trade names Gardolene D 6804, Gardolene D 6811, Bonderite M-PA 6003 and mixtures thereof.

A passivating coating can be applied to the flat steel product by any method known to the person skilled in the art, for example spraying, dipping or coating processes.

A passivating coating is generally applied in an amount sufficient to exert the passivating effect, for example 5 mg/m ² to 40 mg/m ² , preferably 10 mg/m ² to 25 mg/m ² , in each case based on the conductive element chromium, in the case of chromium-containing passivations.

If a combination of the functional coatings mentioned is desired in step (C) of the process according to the invention, two or more of the coatings mentioned are applied in appropriate amounts. This can be done sequentially or simultaneously.

The present invention preferably relates to the process according to the invention, wherein at least one functional coating agent and additional activation particles are applied before and/or during step (C).

In a preferred embodiment of the invention, a mixture containing at least one functional coating agent and additional activation particles is applied to the flat steel product before and/or during step (C).

In a further preferred embodiment according to the invention, at least one functional coating agent and additional activation particles are applied separately to the flat steel product before and/or during step (C).

Details about the additional activation particles are given below.

Step (D):

Step (D) of the method according to the invention comprises forming the flat steel product from step (C) in order to obtain a formed component. In the embodiment according to the invention in which a hot strip or a cold strip was used as the flat steel product in steps (A), (B) and (C), blanks are preferably first cut from the hot strip or cold strip at the beginning of step (D). This can be done using methods known to those skilled in the art.

According to the invention, the forming of the flat steel product from step (C) can be carried out by all methods known to the person skilled in the art, for example according to DIN 8580 (2010) and in particular DIN 8584 (2010).

The transformation preferably takes place at room temperature.

Step (E):

Step (E) of the method according to the invention comprises removing the functional coating from the formed component from step (D).

Step (E) of the process according to the invention can generally be carried out by any method known to the person skilled in the art, for example described in EP 2 311 928 A2 , EP 2 851 452 A1 and EP 2 937 411 A1 .

Preferably, step (E) of the method according to the invention is carried out in that the formed component from step (D) can be treated with at least one cleaning agent in order to remove the functional coating.

According to the invention, the functional coating is removed in step (E) of the method according to the invention by treating the surface of the formed component with a cleaning agent. According to the invention, the cleaning agent can be acidic, neutral or alkaline. In a preferred embodiment, an alkaline cleaning agent is used.

The cleaning agent is also preferably used as an aqueous solution. The cleaning-active substance, for example a surfactant, is preferably present in an amount that appears suitable to the person skilled in the art.

Further components of the cleaning agent which are preferably present according to the invention are, for example, selected from the group consisting of sodium hydroxide or potassium hydroxide and mixtures thereof.

Step (E) of the method according to the invention can also be carried out using mechanical energy, for example by brushing the surfaces to be cleaned or by applying water and/or cleaning agents to the surface under high pressure. Step (E) of the method according to the invention is preferably carried out at a temperature of 30 to 70 °C.

Preferably, the cleaning in step (E) of the method according to the invention is complete, since the best result is then achieved in the phosphating in step (G). However, it has surprisingly been found that if additional activation particles are applied to the flat steel product before and/or during step (B) and/or before and/or during step (C), the cleaning in step (E) of the method according to the invention does not necessarily have to be complete in order to obtain a particularly advantageous result in the phosphating step. According to the invention, by applying additional activation particles to the flat steel product before and/or during step (B) and/or before and/or during step (C), it is possible to obtain a very good phosphating result, even though the functional coating does not have to have been completely removed. This circumstance greatly simplifies the process and helps to obtain high-quality phosphated and formed components.

The method according to the invention therefore comprises the feature essential to the invention that additional activation particles are applied to the flat steel product before and/or during step (B) and/or before and/or during step (C).

According to the invention, the additional activation particles may differ from the activation particles used in step (F). In a further preferred embodiment of the invention In this embodiment, the additional activation particles and the activation particles used in step (F) of the process according to the invention are the same.

The additional activation particles are preferably selected from the group consisting of powder activations, in particular based on titanium phosphates, or liquid activations, in particular based on zinc phosphates and metal oxides. Preferably, water-dispersible compounds are used, for example oxalates of silver or copper compounds, disodium phosphate in combination with titanium compounds, in particular with water-soluble titanium compounds, for example titanium phosphate or sodium titanyl phosphates, zinc phosphates and mixtures of zinc phosphates and metal oxides, e.g. zinc or iron oxides and mixtures thereof. The additional activation particles are preferably applied in powder form or as an aqueous composition.

The batch concentration of the activating agent (in powder form or as a liquid concentrate) is, for example, 0.1 to 20 g _{activating agent concentrate} /I _{pre- or post-treatment} , particularly preferably 1 to 6 g _{activating agent concentrate} /I _{pre- or post-treatment} .

Step (F):

Step (F) of the method according to the invention comprises the application of activation particles to the formed component from step (E).

According to the invention, activation particles are applied in step (F) and before and/or during step (B) and/or before and/or during step (C) in order to improve the nucleation process of the subsequent phosphating. The additional application of crystallization nuclei increases the number of nucleation sites on the substrate, since the zinc phosphate precipitating from the phosphating solution preferentially crystallizes on the additional nuclei. The number of phosphate crystals per unit area is increased, so that the crystals are increasingly hindered in their growth. This leads to a reduction in crystal size and weight per unit area, while the crystal formation rate increases and the degree of coverage increases. The phosphate layer is formed more evenly and the consumption of chemicals can be reduced. The crystals become mechanically more stable and the adhesion of the crystals to the substrate is improved. Likewise, the formation of smaller, evenly distributed phosphate crystals leads to an improvement in the adhesion of the paint film applied in the subsequent process. The higher The higher the degree of coverage, the lower the porosity, which in turn increases corrosion resistance. The phosphating process can therefore be precisely adjusted and controlled.

According to the invention, the actual activation step is generally preceded by a separate cleaning step in which the surface is first freed of electrolyte, oils, fats, solid particles, oxides and other contaminants using an alkaline or acidic cleaner. The pH range can be between 6 and 13. The surface is then rinsed with fresh water and deionized water to prevent carryover into the subsequent activation bath.

The additional activation particles that are applied in step (F) of the process according to the invention are preferably selected from the group consisting of powder activations, in particular based on titanium phosphates, or liquid activations, in particular based on zinc phosphates and metal oxides. Preferably, water-dispersible compounds are used, for example oxalates of silver or copper compounds, disodium phosphate in combination with titanium compounds, in particular with water-soluble titanium compounds, for example titanium phosphate or sodium titanyl phosphates, zinc phosphates and mixtures of zinc phosphates and metal oxides, e.g. zinc or iron oxides and mixtures thereof. The additional activation particles are preferably applied in powder form.

The present invention therefore preferably relates to the process according to the invention, wherein the additional activation particles which are applied to the flat steel product before and/or during step (B) and/or before and/or during step (C) are selected from the group consisting of powder activations, in particular based on titanium phosphates, or liquid activations, in particular based on zinc phosphates and metal oxides.

The concentration of the activating agent (powder or liquid concentrate) is, for example, 0.1 to 20 g _{activating agent concentrate} /I _{pre- or post-treatment} , particularly preferably 1 to 6 g _{activating agent concentrate} /I _{pre- or post-treatment.}

Overall, activation particles with a concentration (powder or liquid) are thus present on the formed component after step (F) of the process according to the invention. Concentrate) of 0.1 to 20 g _{activating agent concentrate} /I _{pre- or post-treatment} , particularly preferably 1 to 6 g _{activating agent concentrate} /I _{pre- or post-treatment} .

Step (G):

Step (G) of the process according to the invention comprises applying a phosphating to the formed component from step (F).

The phosphating of flat steel products is known to the person skilled in the art and is described, for example, in Rausch, W., The phosphating of metals, Eugen G. Leuze Verlag, Saulgau/Württ, 2nd edition, 1988, ISBN: 3-87480-043-1 .

In step (G) of the process according to the invention, an aqueous solution containing zinc phosphate, phosphoric acid, optionally nickel and/or manganese cations, and an accelerator is preferably used. According to the invention, the accelerator used is, for example, nitrate, for example zinc nitrate, nitrite, for example sodium nitrite, or hydrogen peroxide.

Step (G) of the process according to the invention is preferably carried out by immersing the formed components from step (F) in an aqueous solution containing the above-mentioned components. The contact time is, for example, 100 to 200 s.

According to the invention, the process steps are preferably carried out in the order (A), (B), (C), (D), (E) and (F). In addition to the process steps (A) to (F) mentioned, the process according to the invention can optionally comprise further steps, for example oiling and/or bonding, which then take place between the steps mentioned.

In the process according to the invention, steps (C), (F) and/or (G) are preferably carried out by a spraying, dipping or coating process.

The application of solutions in steps (B), (C), (F), (G) of the process according to the invention, in particular the application of the additional activation particles before and/or during step (B) and/or before and/or during step (C), is preferably carried out in a coating process. Coating processes are known to the person skilled in the art. The ratio is preferably the rotational speed of the application roller to the belt speed 70 to 130%. The temperature of the solution, in particular the aqueous solution, is preferably 15 to 30 °C. A wet film with a thickness of 1 to 4 µm, corresponding to 1 to 4 ml/m ² , is preferably applied. After the wet film has been applied, the coated board is preferably dried. The temperature of the dryer is set so that a suitable temperature is set in relation to the belt speed, for example 60 to 130 °C. During coating, the belt speed is for example 30 to 180 m/min, preferably 80 to 120 m/min, for example 100 m/min.

The present invention also relates to a component manufactured by the method according to the invention. The components manufactured according to the invention are characterized in that they have a particularly homogeneous phosphating layer on the surface. The activation causes the zinc phosphate crystals to become particularly finely crystalline, i.e. this results in lower chemical consumption, the mechanical stability is higher, which means better paint adhesion and corrosion resistance. Furthermore, the process times are shorter because small crystals crystallize out more quickly than large ones.

The present invention also relates to the use of a component according to the invention in the automotive sector.

Commercial applicability

The component according to the invention is suitable for use in the automotive sector due to its advantageous properties.

Figures

• Figure 1 shows a coating obtained according to comparative test V5.
• Figure 2 shows a coating obtained according to inventive experiment 6.

Examples

Corresponding steel plates, which are coated with a ZM (zinc-magnesium) coating on both sides, are dress-rolled. Then an adhesion promoter (HM) containing methanol, a polysiloxane, a silicate component and ammonium or amino compounds, available under the trade name GB X4537, is applied to the top and bottom of the strip in an aqueous solution in a strip coater. The concentration of the adhesion promoter is 2 to 6 (silicon coating as a conductive element) g/L. In experiments 3 to 7, a wetting agent, available under the trade name H7475, is also applied. In experiments 6 and 7 according to the invention, activation particles, available under the trade name ZL 6, are also applied.

The aqueous solutions are applied at a temperature of 15 to 30 °C, the wet film thickness of the applied solution is 1 to 4 µm, corresponding to 1 to 4 ml/m ² . After application of the solution, the coated tape is dried at a temperature of 60 to 130 °C. During the process, the tape speed is 100 m/min ^-1 .

The boards treated in this way are then phosphated after applying activation particles. The phosphated top and bottom surfaces are examined using SEM or EDX analysis. The results are shown in Table 1. Table 1: Comparative and inventive tests No. Q[%] Ingredients of the applied aqueous solution Quality of the applied phosphate layer EDX analysis of the non-closed areas V1 110 HM not closed Main component Zn, additionally P and traces of Si, Mn and Ni V2 80 HM not closed V5 80 HM + NM not closed V4 100 HM + NM not closed V5 110 HM + NM not closed 6 110 HM + NM + AP OS: closed US: not closed 7 80 HM + NM + AP OS: closed US: not closed Q Ratio of the rotational speed of the application roller to the belt running speed HM Adhesion promoter NM Wetting agent AP additional activation particles OS Top US bottom V Comparison test

Claims (11)

1. A method for producing a formed component, comprising at least the following steps:

   (A) Providing a flat steel product,

   (B) Skin pass the steel flat product from step (A),

   (C) Application of a functional coating to the flat steel product from step (B),

   (D) Forming the steel flat product from step (C) to produce a formed component,

   (E) Removing the functional coating of step (0) from the formed component,

   (F) Application of activation particles to the formed component from step (E), and

   (G) Application of a phosphate coating to the formed component from step (F),

   characterized in that additional activation particles are applied to the flat steel product before and/or during step (B) and/or before and/or during step (C).
2. Process according to claim 1, characterized in that in step (A) a steel flat product with a corrosion-protective coating is provided.
3. Process according to claim 2, characterized in that the corrosion-protective coating is formed by zinc or a zinc alloy.
4. Process according to any one of claims 1 to 3, characterized in that at least one skin pass agent and activation particles are applied to the steel flat product before and/or during step (B).
5. Method according to any one of claims 1 to 4, characterized in that at least one functional coating agent and activation particles are applied before and/or during step (C).
6. Method according to any one of claims 1 to 5, characterized in that the functional coating is an adhesion-promoting layer, a forming aid, a passivation or a combination thereof.
7. Method according to one of claims 1 to 6, characterized in that steps (C), (F) and/or (G) are each carried out by a spraying, dipping or coating process.
8. Process according to any one of claims 1 to 7, characterized in that the activation particles applied in step (F) are selected from the group consisting of powder activations, in particular based on titanium phosphates, or liquid activations, in particular based on zinc phosphates and metal oxides.
9. Process according to one of claims 1 to 8, characterized in that the additional activation particles which are applied to the steel flat product before and/or during step (B) and/or before and/or during step (C) are selected from the group consisting of powder activations, in particular based on titanium phosphates, or liquid activations, in particular based on zinc phosphates and metal oxides.
10. A component manufactured by the method according to any one of claims 1 to 9.
11. Use of a component according to claim 10 in the automotive sector.

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