Method for hot-dip galvanizing components, plant and use

Abstract

Method for hot-dip galvanizing a galvanized iron or steel component, wherein the galvanized iron or steel component is subjected to an activation treatment prior to hot-dip galvanizing such that and / or with the stipulation that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ · cm 2 exhibits, and wherein the galvanized iron or steel component that has undergone activation treatment is subsequently subjected to hot-dip galvanizing, where the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component is determined before the activation treatment, where the activation treatment, depending on the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, comprises only a flux treatment or a pickling treatment and a flux treatment, where the electrical resistance at the surface of the zinc layer is at most 500 kΩ · cm 2 As an activation treatment, at least a flux treatment is carried out and where the electrical resistance at the surface of the zinc layer is more than 500 kΩ · cm 2 As an activation treatment, at least initially a pickling treatment and subsequently a flux treatment are carried out.

Description

[0001] The present invention relates to the technical field of galvanizing iron-based or iron-containing components, in particular steel-based or steel-containing components (steel components), preferably for the automotive industry, the construction industry, the field of general mechanical engineering, the electrical industry and other technical fields of application, by means of hot-dip galvanizing (hot-dip galvanizing).

[0002] In particular, the present invention relates to the technical field of recycling, reuse or reprocessing of previously used components, especially previously used galvanized components, preferably previously used galvanized iron or steel components.

[0003] In particular, the present invention relates to a method and a plant for hot-dip galvanizing (hot-dip galvanizing) of a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, in particular for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component, and the corresponding uses.

[0004] Metallic components of all kinds made from ferrous materials, especially steel components, often require effective corrosion protection due to their application. In particular, steel components for motor vehicles (e.g., cars, trucks, commercial vehicles, etc.), but also for other technical sectors (e.g., construction, mechanical engineering, electrical engineering, etc.), require effective corrosion protection that can withstand long-term stress.

[0005] In this context, it is well known that steel-based components are protected against corrosion by means of galvanizing (galvanizing). During galvanizing, the steel is coated with a generally thin layer of zinc to protect it from corrosion. Various galvanizing processes can be used to galvanize steel components, i.e., to coat them with a metallic zinc coating. These include, in particular, hot-dip galvanizing (also known as hot-dip galvanizing), spray galvanizing (flame spraying with zinc wire), diffusion galvanizing (Sherard galvanizing), electroplating (electrolytic galvanizing), non-electrolytic galvanizing using zinc flake coatings, and mechanical galvanizing.There are significant differences between the aforementioned galvanizing processes, particularly with regard to the execution of the process, but also with regard to the nature and properties of the zinc layers or zinc coatings produced.

[0006] The most important method for corrosion protection of steel using metallic zinc coatings is hot-dip galvanizing. In this process, steel is continuously (e.g., strip and wire) or in sections (e.g., components) immersed in a heated kettle of liquid zinc at temperatures of approximately 400 °C to 600 °C (melting point of zinc: 419.5 °C; zinc alloys may have a higher or lower melting point). This results in the formation of a resistant alloy layer of iron and zinc on the steel surface, and above this, a very firmly adhering layer of pure zinc.

[0007] Hot-dip galvanizing is thus a recognized and proven method for many decades to protect components made of ferrous materials, especially steel, from corrosion. As described above, the typically pre-cleaned or pre-treated component is immersed in a bath of molten zinc, where it reacts with the zinc melt and, as a result, forms a relatively thin zinc layer that is metallurgically bonded to the base material.

[0008] Hot-dip galvanizing is divided into batch galvanizing (see, for example, DIN EN ISO 1461 and DIN 50997) and continuous strip and wire galvanizing (see, for example, DIN EN 10143 and DIN EN 10346). Both batch galvanizing and strip and wire galvanizing are standardized processes. Continuously galvanized steel strip and continuously galvanized wire are semi-finished products that are further processed after galvanizing, particularly by forming, punching, cutting, etc. In contrast, components to be protected by batch galvanizing are generally first manufactured completely or at least partially and only then hot-dip galvanized (thus providing all-around protection against corrosion).Hot-dip galvanizing and coil / wire galvanizing differ depending on the application conditions, particularly in terms of phase structure and the thickness of the resulting zinc coatings. This can lead to different service lives, also depending on the zinc layer thickness. The zinc layer thickness of coil-galvanized sheets is typically in the range of 10 to 35 micrometers, whereas the zinc layer thickness of hot-dip galvanized steel parts is typically in the range of 50 to 200 micrometers and even more.

[0009] Hot-dip galvanizing provides both active and passive corrosion protection. Passive protection is achieved through the barrier effect of the zinc coating. Active corrosion protection results from the cathodic effect of the zinc coating. Compared to more noble metals in the electrochemical series, such as iron, zinc acts as a sacrificial anode, protecting the underlying iron from corrosion until it itself is completely corroded.

[0010] Hot-dip galvanizing, also known as batch galvanizing according to DIN EN ISO 1461, is the process of coating mostly larger steel components and structures. Steel blanks or (semi-)finished workpieces (components) are immersed in a molten zinc bath after pretreatment. This immersion process allows for effective coating of internal surfaces, welds, and other hard-to-reach areas of the workpieces or components.

[0011] Conventional hot-dip galvanizing, particularly immersion galvanizing, is based on immersing iron or steel components in molten zinc, forming a zinc coating on the surface of the components. To ensure adhesion, integrity, and uniformity of the zinc coating, careful surface pretreatment and, if necessary, preparation of the components to be galvanized is generally required beforehand. This typically includes degreasing followed by rinsing, subsequent acid pickling followed by rinsing, and finally flux treatment followed by drying.

[0012] For reasons of process efficiency and cost-effectiveness, in batch galvanizing of identical or similar components (e.g., series production of automotive parts), these are typically grouped together for the entire process (in particular by means of a common workpiece carrier, such as a crossbeam or rack, or a common holding or fastening device for a large number of these identical or similar components). For this purpose, a number of components are attached to the workpiece carrier using holding devices such as slings, ties, or the like. The components, in their grouped state, are then conveyed via the workpiece carrier to the individual treatment steps or stages of hot-dip galvanizing.

[0013] The typical process for conventional hot-dip galvanizing usually proceeds as follows: First, the surfaces of the components in question are degreased to remove residues of fats and oils. Aqueous alkaline or acidic degreasers are typically used for this purpose. After cleaning in the degreasing bath, a rinsing process usually follows, typically by immersion in a water bath, to prevent the degreasing agent from being carried over with the parts to be galvanized into the subsequent pickling process. This is particularly important when switching from alkaline degreasing to acidic pickling.

[0014] The next step is a pickling treatment, which serves primarily to remove inherent impurities, such as rust and scale, from the steel surface. Pickling is usually carried out in diluted hydrochloric acid, with the duration of the pickling process depending, among other things, on the degree of contamination (e.g., rustiness) of the material to be galvanized, as well as the acid concentration and temperature of the pickling bath. To prevent or minimize the transfer of acid and / or salt residues to the material being galvanized, a rinsing process is typically performed after pickling.

[0015] The next step is the so-called fluxing process (also known as flux treatment), in which the previously degreased and pickled steel surface is treated with a flux, typically an aqueous solution of inorganic chlorides, most often a mixture of zinc chloride (ZnCl₂) and ammonium chloride (NH₄Cl). The flux serves two purposes: firstly, to perform a final, intensive cleaning of the steel surface before it reacts with the molten zinc, to dissolve the oxide layer on the zinc surface, and to prevent further oxidation of the steel surface until the galvanizing process; and secondly, to increase the wettability between the steel surface and the molten zinc.After the flux treatment, drying usually takes place to create a solid flux film on the steel surface and to remove adhering water, thus avoiding subsequent undesirable reactions (especially the formation of water vapor) in the liquid zinc dip bath.

[0016] The components pretreated in the aforementioned manner are then hot-dip galvanized by immersion in the molten zinc bath. In hot-dip galvanizing with pure zinc, the zinc content of the melt is at least 98.0 wt.% according to DIN EN ISO 1461. After immersion of the workpiece into the molten zinc (or zinc alloy), it remains in the zinc bath for a sufficient period of time, in particular until the workpiece has reached its temperature and is coated with a zinc layer. Typically, the surface of the zinc bath is cleaned, especially of oxides, zinc ash, flux residues, and the like, before the workpiece is withdrawn from the zinc bath. The hot-dip galvanized component is then subjected to a cooling process (e.g., in air or in a water bath). Finally, any existing holding elements for the component, such as...Lifting equipment, lashing wires or the like, removed.

[0017] Following the galvanizing process, the galvanized components typically undergo post-processing. This involves removing, for example, excess zinc bath residues, especially so-called drips from the zinc solidifying at the edges, as well as oxide or ash residues adhering to the component, as far as necessary.

[0018] One criterion for the quality of hot-dip galvanizing is the thickness of the zinc coating in µm (micrometers). The standard DIN EN ISO 1461 specifies the minimum required coating thicknesses for hot-dip galvanizing, depending on the material thickness. In practice, the coating thicknesses are significantly higher than the minimum thicknesses specified in DIN EN ISO 1461. Generally, zinc coatings produced by hot-dip galvanizing have a thickness in the range of 50 to 200 micrometers and even more.

[0019] During the galvanizing process, a coating of differently composed iron / zinc alloy layers forms on the steel part as a result of the mutual diffusion of liquid zinc with the steel surface. When the hot-dip galvanized objects are removed from the galvanizing process, a layer of zinc—also known as the pure zinc layer—remains adhered to the uppermost alloy layer. This layer's composition corresponds to that of the molten zinc. Due to the high temperatures during the hot-dip galvanizing process, a relatively brittle layer based on an alloy (solid solution) between iron and zinc initially forms on the steel surface, followed by the pure zinc layer. While the relatively brittle iron / zinc alloy layer improves the adhesion to the base material, it makes the galvanized steel more difficult to form. This results in the formation of relatively large overall layer thicknesses.While this allows for a very long corrosion protection period, the risk of the zinc layer flaking off under mechanical stress, especially sudden local impacts, increases with increasing zinc layer thickness, thus compromising the corrosion protection effect. Furthermore, the formed zinc layer is not ductile, limiting further processing options, particularly those that maintain the corrosion protection effect.

[0020] To counteract the previously described problem of the rapidly growing, brittle, and thick iron / zinc alloy layer and to enable thinner layers with simultaneously high corrosion protection during galvanizing, it is known from the prior art to add aluminum to the zinc melt or the liquid zinc bath. For example, adding 5 wt% aluminum to a liquid zinc melt produces a zinc / aluminum alloy with a lower melting point compared to pure zinc. By using a zinc / aluminum melt (Zn / Al melt) or...Using a liquid zinc / aluminium bath (Zn / Al bath), significantly lower layer thicknesses can be achieved for reliable corrosion protection (generally below 50 micrometers); on the other hand, the formation of the brittle iron / zinc alloy layer is prevented, since the aluminum – without adhering to a specific theory – initially forms a barrier layer on the steel surface of the component in question, onto which the actual zinc layer is then deposited.

[0021] Components hot-dip galvanized with a zinc / aluminium melt can therefore be easily formed, but still exhibit improved corrosion protection properties despite the significantly lower layer thickness compared to conventional hot-dip galvanizing with a virtually aluminum-free zinc melt.

[0022] A zinc / aluminum alloy used in hot-dip galvanizing exhibits improved fluidity properties compared to pure zinc. Furthermore, zinc coatings produced by hot-dip galvanizing using such zinc / aluminum alloys offer greater corrosion resistance (two to six times better than that of pure zinc), improved appearance, better formability, and better paintability than zinc coatings made from pure zinc. Moreover, this technology also allows for the production of lead-free zinc coatings.

[0023] Such a hot-dip galvanizing process using a zinc / aluminium melt or a zinc / aluminium hot-dip galvanizing bath is known, for example, from WO 2002 / 042 512 A1 and the relevant publication equivalents to this patent family (e.g., EP 1 352 100 B1, DE 601 24 767 T2 and US 2003 / 0 219 543 A1). Suitable fluxes for hot-dip galvanizing using zinc / aluminium melt baths are also disclosed therein, since flux compositions for zinc / aluminium hot-dip galvanizing baths must differ from those for conventional hot-dip galvanizing with pure zinc. The process disclosed therein enables the production of corrosion protection coatings with very low layer thicknesses (generally well below 50 micrometers and typically in the range of 2 to 20 micrometers) and with very low weight at high cost efficiency, which is why the process described therein is commercially available under the name microZINQ. ®-Procedure is applied.

[0024] Regarding the formation of the zinc layer and its properties, it has been shown that these can be significantly influenced by alloying elements in the zinc melt. Aluminum is one of the most important elements in this regard: It has been shown that even an aluminum content of 100 ppm (weight-based) in the zinc melt improves the appearance of the resulting zinc layer, resulting in a brighter, shinier look. This effect increases steadily with increasing aluminum content in the zinc melt up to 1,000 ppm (weight-based). Furthermore, it has been shown that – as previously described – an aluminum content of 0.12 ppm (weight-based) in the zinc melt significantly improves the appearance of the zinc layer.At a certain aluminum content, an intermetallic Fe / Al phase forms between the iron material and the zinc layer. This inhibits the otherwise typical diffusion processes between the iron and the zinc melt, thus significantly reducing the growth of the Zn / Fe phases. Consequently, the zinc layers are considerably thinner above this aluminum content. Finally, it has been shown that, in general, the corrosion protection effect of the resulting zinc layer increases with increasing aluminum content in the zinc melt. This is because the Zn / Al compounds form significantly more stable surface layers more quickly.

[0025] Well-known examples of the commercial use of aluminum-containing zinc melts include the so-called Galfan. ® -method and the aforementioned microZINQ ®-Process with an aluminum content in the zinc melt typically in the range of 4.2 wt.% to 6.2 wt.%. One advantage of this alloy is that, around the average value of 5 wt.%, the Zn / Al system exhibits a eutectic composition with a melting point of 382 °C, thus enabling a reduction in the operating temperature during the zinc plating process.

[0026] In summary, hot-dip galvanizing layers with different compositions can be applied to iron-based components to provide corrosion protection, whereby the properties, in particular the corrosion protection properties as well as the mechanical and optical properties, of the zinc layer are influenced by its composition.

[0027] However, the corrosion protection provided by the zinc coating (hot-dip galvanizing) can diminish over time, for example, due to weathering, erosion, or damage to the zinc layer. In this context, the zinc coating can be eroded or damaged, particularly by mechanical and / or chemical processes during use. Especially when galvanized components are exposed to environmental influences such as extreme heat and / or cold, salts, etc., or are subjected to mechanical stress, such as deformation, the corrosion protection provided by the zinc coating is affected, and can decrease significantly over time. Reliable corrosion protection can only be guaranteed with an undamaged and continuous zinc coating of a certain minimum thickness, which depends on the composition of the zinc coating.

[0028] Even if the zinc coating is damaged or partially worn away, and therefore no longer provides reliable corrosion protection, the component itself is not necessarily unusable; in particular, the lack of corrosion protection does not necessarily affect the component's technological properties. Consequently, such a component could be reused or reused after reliable corrosion protection has been restored. Components whose corrosion protection properties decrease due to environmental influences or mechanical stress, but which are still functional, can include, for example, scaffolding components, guardrails or crash barriers, body parts, etc. In particular, further use of the component is still possible if it is still functional and no, or at least no technically relevant, corrosion has occurred down to the base material (i.e., down to the component itself).In other words, disposing of or melting down such a component is not necessary, however, a (new) reliable corrosion protection is absolutely essential for further use.

[0029] In current technology, it is therefore common practice to completely dezincify and rezincify components with insufficient corrosion protection, particularly due to a damaged zinc layer. In other words, the remaining zinc layer is completely removed (so-called dezincification), especially through chemical and / or mechanical processes, and then rezincified using a standard hot-dip galvanizing process, particularly one of the processes described above. Before rezincification, repair, correction, and forming work, such as correcting deformations, re-punching holes, cutting threads, adding bores, etc., can be carried out if necessary.

[0030] However, a disadvantage of this process is that the existing zinc layer is completely removed. Furthermore, dezincification is a complex and energy-intensive process. Moreover, dezincification is uneconomical, especially since even minor defects necessitate the removal of the entire zinc layer. Thus, the (complete) removal of the zinc layer and the application of a new one results in high material and energy consumption, which is both economically and environmentally detrimental. In addition, the entire process is complex and time-consuming.

[0031] The previously described state of the art therefore lacks a means of economically, resource-efficiently, and ecologically reprocessing components that are still functional but whose zinc coating no longer provides complete or sufficient corrosion protection, particularly in such a way as to restore reliable corrosion protection. For this purpose, a reliable determination and assessment of the existing or remaining condition and corrosion protection is essential.

[0032] DE 10 2021 117 820 A1 relates to a method and a device for treating already galvanized steel parts that have a zinc layer, in particular for reprocessing used galvanized steel parts.

[0033] EP 3 880 860 B1 relates to a process for producing an aluminum-alloyed or aluminum-containing zinc layer on an iron-based component, wherein the process comprises the following process steps in the order listed below: (a) increasing or adjusting the surface roughness of at least one surface of the iron-based component by mechanical treatment using an abrasive process, wherein the increase or adjustment of the surface roughness is carried out such that the surface has a mean roughness value Ra according to DIN EN ISO 4228:1998-4 in the range of 0.3 to 15 µm; (b) hot-dip galvanizing of the iron-based component in an aluminum-alloyed or aluminum-containing zinc melt, wherein the zinc melt contains at least 0.1 wt% aluminum based on the zinc melt, wherein, after carrying out process step (b), a component provided or coated with the aluminum-alloyed or aluminum-containing zinc layer is produced.A coated iron-based component with a zinc layer thickness in the range of 3 to 30 µm is obtained.

[0034] EP 3 445 889 B1 relates to a process for hot-dip galvanizing an iron or steel component with an aluminum-containing zinc melt, wherein the flux bath comprises an alcohol / water mixture as the liquid phase, the alcohol of the alcohol / water mixture of the flux bath being a water-miscible or water-soluble alcohol selected from the group of linear or branched, saturated, aliphatic, primary, secondary, or tertiary monohydric C1-C4 alcohols and mixtures thereof, and wherein the flux composition comprises as ingredients (i) zinc chloride in an amount in the range of 50 to 95 wt.%, (ii) ammonium chloride in an amount in the range of 5 to 45 wt.%, (iii) at least one alkali and / or alkaline earth salt in an amount in the range of 0.1 to 25 wt.%, and (iv) at least one aluminum salt and / or at least one silver salt in an amount in the range of 5 × 10 -5contains up to 2 wt.%, the flux composition being free of lead chloride and nickel chloride.

[0035] Finally, DE 100 03 680 C2 relates to a process for producing a zinc-coated steel strip, in which the steel strip continuously undergoes the following steps in succession and is subjected to at least two stages of hot-dip galvanizing: continuous annealing of the steel strip before entering the first immersion bath; coating of the steel strip with a base layer in the first stage of hot-dip galvanizing by passing the steel strip for a first immersion period through a first immersion bath of molten zinc with a low aluminum content; cooling of the steel strip coated with the base layer;and applying a top layer to the steel strip coated with the base layer by passing the steel strip coated with the base layer through a second immersion bath for a second immersion time in the second stage of the hot-dip coating process. This second immersion bath consists of a second zinc melt with a higher aluminum content than the first zinc melt.

[0036] The problem underlying the present invention therefore consists in providing a method for hot-dip galvanizing (hot-dip galvanizing) of a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, especially for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component, as well as a corresponding plant for carrying out this method, wherein the disadvantages of the prior art described above are to be avoided at least to a large extent or at least mitigated.

[0037] In particular, a process or system should be provided that enables the restoration of corrosion protection properties without requiring the (complete) removal of the existing zinc layer. This must include a reliable and reproducible determination and assessment of the existing and remaining condition and corrosion protection.

[0038] Furthermore, such a process or system should be provided which is more energy-efficient and resource-saving than conventional processes or systems.

[0039] Furthermore, such a process or facility should be provided which is more sustainable than conventional processes or facilities.

[0040] To solve the problem described above, the present invention proposes – according to a first aspect of the present invention – a method for hot-dip galvanizing (hot-dip galvanizing) of a galvanized iron or steel component according to claim 1; further, in particular special and / or advantageous embodiments of the method according to the invention are the subject of the corresponding dependent method claims.

[0041] Furthermore, according to a second aspect of the present invention, the present invention relates to a system for hot-dip galvanizing of a galvanized iron or steel component according to the independent claim relating to the system (claim 36); further, in particular special and / or advantageous embodiments of the system according to the invention are the subject of the dependent claims relating to the system.

[0042] Finally, according to a third aspect of the present invention, the present invention relates to the use according to the relevant independent use claim; further, in particular special and / or advantageous embodiments of the uses according to the invention are the subject of the relevant dependent use claim.

[0043] It goes without saying that the following explanations state that embodiments, designs, advantages and the like, which are described below for the purpose of avoiding repetition only with regard to one aspect of the invention, naturally also apply to the other aspects of the invention without the need for separate mention.

[0044] With regard to all the relative or percentage weight-related specifications mentioned below, in particular relative quantity or weight specifications, it should also be noted that, within the scope of the present invention, these must be selected by the person skilled in the art in such a way that, in sum, including all components or ingredients, in particular as defined below, they always add up to 100% or 100% by weight; however, this is self-evident to the person skilled in the art.

[0045] Furthermore, it should be noted that the person skilled in the art may, if necessary, deviate from the scope specifications listed below, depending on the application or the specific circumstances, without leaving the scope of the present invention.

[0046] Furthermore, it should be noted that all values ​​or parameters mentioned below, or the like, can generally be determined using standardized or explicitly specified determination methods, or alternatively, using determination or measurement methods that are generally familiar to those skilled in the field.

[0047] Furthermore, for the purposes of describing the present invention, the features of the present invention cited in connection with specific embodiments, configurations, advantages, examples, or the like are also considered disclosed in combination. Thus, higher-order combinations of individual or multiple features cited for specific embodiments, configurations, application examples, or the like are also considered disclosed.

[0048] In particular, with regard to the features characterizing the invention, all possible combinations of these features shall be deemed disclosed, with embodiments of comparable or corresponding preference of the various features in their combination being preferred (e.g. quantities or quantity ranges of the relevant active ingredients and components of the same preference or the like).

[0049] It is particularly important to note that for the following quantities relating to the various ingredients, especially active ingredients, of the composition according to the invention or the like, particularly relative or absolute quantities of the same preference or level of preference, the respective combinations relating to the various ingredients, especially active ingredients, with the corresponding preference or level of preference are also disclosed. Likewise, all other combinations (i.e., combinations based on different preferences or different levels of preference) are also disclosed.

[0050] Having said that, the present invention will now be explained in detail below.

[0051] The subject matter of the present invention – according to a first aspect of the present invention – is thus a method for hot-dip galvanizing (hot-dip galvanizing) of a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, especially for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component. wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subjected to an activation treatment prior to hot-dip galvanizing, in particular an activation treatment comprising a chemical and / or mechanical treatment, preferably an activation treatment comprising at least one chemical and optionally (additionally) a mechanical treatment, such that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ·cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, and wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subsequently subjected to hot-dip galvanizing, where the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component is determined before the activation treatment, wherein the activation treatment, depending on the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, comprises only a flux treatment or a pickling treatment and a flux treatment, where the electrical resistance at the surface of the zinc layer is at most 500 kΩ · cm 2, in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least a flux treatment is carried out and where the electrical resistance at the surface of the zinc layer is more than 500 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least first a pickling treatment and subsequently a flux treatment is carried out, in particular wherein a rinsing process is carried out after the pickling treatment and before the flux treatment, in particular by immersion in a water bath.

[0052] As explained below, the present invention is associated with a multitude of completely unexpected advantages, features and surprising technical effects, the following description of which makes no claim to completeness, but illustrates the inventive character of the present invention: For, as the applicant has now discovered quite unexpectedly, the corrosion protection of an already galvanized iron or steel component can be restored, refurbished or regenerated by the inventive method, in particular the hot-dip galvanizing method, without having to (completely) remove the existing zinc layer.

[0053] In particular, the applicant has discovered, quite unexpectedly, that using the inventive procedure and thus requiring only minimal preparation, it is possible to regenerate, reprocess, or restore the hot-dip galvanizing layer and thus the corrosion protection properties, especially of an already galvanized and used iron or steel component.

[0054] In the context of the present invention, the terms "conventional zinc layer," "pure zinc layer," and "quasi-aluminum-free zinc layer" refer to a zinc layer obtainable by a previously described conventional hot-dip galvanizing process, in particular wherein the zinc content of the melt is at least 98.0 wt.% according to DIN EN ISO 1461. In particular, a conventional zinc layer (i.e., a pure zinc layer or a quasi-aluminum-free zinc layer) in the context of the present invention is to be distinguished from an aluminum-containing or aluminum-alloyed zinc layer. An aluminum-containing or aluminum-alloyed zinc layer in the context of the present invention has, in particular, an aluminum content of at least 2 wt.%. These statements and definitions apply accordingly to the respective zinc baths (i.e., pure zinc baths on the one hand and aluminum-containing or aluminum-alloyed zinc baths on the other).

[0055] Completely unexpectedly, the applicant discovered that the quality of the zinc layer can be determined by measuring its electrical resistance. Based on this quality (material quality), the effort required for the activation treatment can then be precisely determined and adjusted.

[0056] It is particularly advantageous to make the existing zinc layer accessible for further galvanizing. Optimal galvanizing, especially hot-dip galvanizing, and thus the provision of reliable and durable corrosion protection, is especially possible when the hot-dip galvanizing is carried out directly on the existing zinc layer or the base material (i.e., the component material). For this to be successful, the existing zinc layer should be free of impurities, iron corrosion products (i.e., iron oxides), and zinc layer oxidation products (i.e., zinc oxides, zinc hydroxide, zinc oxide hydroxide, zinc bicarbonate, zinc carbonate, etc.).Impurities, corrosion products of the iron, and oxidation products of the zinc layer can be removed within the scope of the activation treatment provided for in the invention, wherein the necessary type, duration, and intensity of the activation treatment depend on the quality and thus the condition of the zinc layer. In particular, for example, a more intensive and / or longer activation treatment is necessary for a lower quality than for a higher quality.

[0057] In the context of the present invention, the term "quality" is to be understood particularly in relation to its suitability for re-hot-dip galvanizing. For example, a high resistance of the existing zinc layer necessitates a more intensive and / or longer activation treatment than a low resistance of the zinc layer, which thus indicates a lower quality within the meaning of the present invention.

[0058] The applicant has discovered that during the galvanizing, in particular hot-dip galvanizing, of galvanized components which have an electrical resistance at the surface of the zinc layer of no more than 500 kΩ · cm 2 have formed uniform and complete zinc layers, which provide high corrosion protection properties and are visually appealing.

[0059] The targeted optimization and adaptation of the activation treatment to the quality of the zinc layer, ensuring a reliable and high-quality hot-dip galvanizing result, is particularly economical, ecological, and sustainable. Specifically, the removal of the existing zinc layer is reduced or minimized, the overall effort is lowered, and the component itself is protected. In particular, the impairment or damage to the component surface caused by the activation treatment can be essentially prevented, thus ensuring that the component's mechanical properties are not compromised. Furthermore, the required amount of new material for galvanizing (i.e., molten zinc) is reduced, and the resulting waste volume is significantly lower compared to the state of the art.

[0060] Adapting the activation treatment to be carried out before galvanizing depending on the quality or electrical resistance of the zinc layer therefore comes with a multitude of advantages; in particular, this approach has economic and technical advantages over a constant activation treatment that is not adapted to the quality of the zinc layer: The inventive method makes the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component more economical, in particular because the activation treatment can be precisely adapted, especially shortened, so that overall productivity is increased.

[0061] Furthermore, by adjusting, and in particular shortening, the activation treatment, as little zinc as possible is removed. This leaves a higher proportion of zinc or zinc layer on the component. The remaining zinc or zinc layer, in turn, provides corrosion protection and, after galvanizing, forms part of the new overall zinc layer, which provides exceptionally high-quality corrosion protection, both mechanically and visually.

[0062] In the process according to the invention, small amounts of zinc are also removed, whereby the removed zinc can subsequently be recovered or recycled (see, for example, so-called ReZINQ). ®-process); however, this recovery is only possible with a limited iron content in the removed zinc. The process according to the invention involves the removal of essentially no iron, or very little iron, from the component itself, thus enabling subsequent recovery or recycling of the necessarily removed zinc. In contrast to the process according to the invention, the prior art—as previously explained—removes the entire zinc layer, inevitably removing larger quantities of iron from the component itself, which often precludes further utilization of the zinc.

[0063] Thus, the inventive procedure is advantageous both compared to complete dezincification and re-galvanizing as well as compared to a constant activation treatment or one that is not individually adjustable to each component before re-galvanizing.

[0064] Furthermore, the zinc layer, in particular the hot-dip galvanizing layer, obtainable from the process according to the invention also offers advantages: In particular, the inventive method provides an at least partially multiphase and / or at least partially layered (overall) hot-dip galvanized coating consisting of Zn / Al / Fe phases. These Zn / Al / Fe phases can, in particular, comprise Zn, ZnAl, ZnFe and / or AlFe phases; this is especially the case when the hot-dip galvanizing is carried out using an aluminum-alloyed or aluminum-containing zinc melt.

[0065] If a non-aluminium alloyed or non-aluminium-containing zinc melt is used in hot-dip galvanizing, a multi-phase and / or at least partially layered (total) hot-dip galvanizing layer is provided, which consists of Zn and ZnFe phases.

[0066] The hot-dip galvanizing layer obtained by the inventive process exhibits high corrosion protection properties and high ductility. Furthermore, this hot-dip galvanizing layer is very bright and therefore visually of particularly high quality.

[0067] Surprisingly, in the inventive process according to a particular embodiment, a hot-dip galvanizing layer containing Zn / Al / Fe phases is formed during hot-dip galvanizing using an aluminum-alloyed or aluminum-containing zinc melt, which is not obtainable by known processes. In the hot-dip galvanizing process of the inventive method, an aluminum-containing zinc layer is not formed on top of the already existing hot-dip galvanizing layer, which typically consists of a hot-dip galvanizing layer with a Zn / Fe phase on the base material and a pure zinc layer arranged above it. Instead, an at least partially multi-phase and / or at least partially layered (new) hot-dip galvanizing layer containing Zn / Al / Fe phases is formed.Hot-dip galvanizing thus not only applies an additional layer, but forms a completely new layer, particularly since the aluminum from the preferably aluminum-alloyed or aluminum-containing zinc bath diffuses at least partially into the existing hot-dip galvanizing layer. This allows for the creation of different hot-dip galvanizing layers, not obtainable with known single-stage processes, which exhibit properties unattainable by such methods.

[0068] In particular, the hot-dip galvanizing layer obtained by the inventive method, especially the hot-dip galvanizing process, is more ductile and therefore less brittle than a pure zinc layer and can therefore be formed or cold-formed, for example bent by 90°, without losing or significantly impairing its corrosion protection properties. At the same time, the hot-dip galvanizing layer obtained by the inventive method, especially the hot-dip galvanizing process, can be provided with a greater layer thickness than a conventional aluminum-containing or aluminum-alloyed zinc layer (i.e., an aluminum-containing or aluminum-alloyed zinc layer which is applied directly or indirectly).directly applied to a component without an existing zinc layer), in particular since the hot-dip galvanizing layer obtainable by the inventive method is not limited by a maximum achievable layer thickness (as in the case of an aluminum-containing or aluminum-alloyed hot-dip galvanizing layer conventional in the art due to the formation of an Fe / Al barrier layer).

[0069] In particular, the thickness of the hot-dip galvanizing layer obtained by the inventive process is essentially unlimited, unlike in the case of an aluminum-containing or aluminum-alloyed hot-dip galvanizing layer obtained by a single-stage process in the prior art. Thus, hot-dip galvanizing layers with a high aluminum content and a thickness significantly exceeding 25 µm can also be produced. At the same time, the hot-dip galvanizing layer obtained by the inventive process also exhibits the advantages of an aluminum-containing or aluminum-alloyed hot-dip galvanizing layer, such as gloss, ductility, and high corrosion protection properties.

[0070] Overall, the inventive process, in particular the hot-dip galvanizing process, is therefore more economical than a processing or recycling process common in the prior art (i.e., a process in which the existing zinc layer is first completely removed and then a new zinc layer is applied) and also more economical than a process in which an activation treatment or pretreatment is not adapted to the quality of the existing zinc layer.

[0071] The hot-dip galvanizing layer resulting from the process according to the invention, in particular the hot-dip galvanizing process, is more ductile and less brittle than a commercial pure zinc layer, and furthermore, the layer thickness is adjustable despite the use of an aluminum-containing or aluminum-alloyed zinc bath. In particular, the process according to the invention produces a hot-dip galvanizing layer that cannot be obtained in a commercial single-stage process, which combines high ductility, an adjustable or controllable layer thickness and layer structure, and high corrosion protection performance.

[0072] The present invention thus provides – as described above – a method for hot-dip galvanizing (hot-dip galvanizing) of a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, especially for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component. wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subjected to an activation treatment prior to hot-dip galvanizing, in particular an activation treatment comprising a chemical and / or mechanical treatment, preferably an activation treatment comprising at least one chemical and optionally (additionally) a mechanical treatment, such that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ·cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, and wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subsequently subjected to hot-dip galvanizing, where the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component is determined before the activation treatment, wherein the activation treatment, depending on the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, comprises only a flux treatment or a pickling treatment and a flux treatment, where the electrical resistance at the surface of the zinc layer is at most 500 kΩ · cm 2, in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least a flux treatment is carried out and where the electrical resistance at the surface of the zinc layer is more than 500 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least first a pickling treatment and subsequently a flux treatment is carried out, in particular wherein a rinsing process is carried out after the pickling treatment and before the flux treatment, in particular by immersion in a water bath.

[0073] Within the scope of the present invention, it is preferred if the zinc melt used in the hot-dip galvanizing contains, based on the zinc melt, at most 98 wt.%, in particular at most 97 wt.%, preferably at most 96 wt.%, zinc.

[0074] Within the scope of the present invention, it may in particular be provided that the zinc melt used in hot-dip galvanizing contains zinc in amounts in the range of 55 wt.% to 98 wt.%, in particular in the range of 65 wt.% to 97 wt.%, preferably in the range of 75 wt.% to 96 wt.%.

[0075] In other words, the present invention does not use a so-called pure zinc melt, nor does it involve galvanizing according to DIN EN ISO 1461. By using a zinc melt with a maximum zinc content of 98 wt.%, at least 2 wt.% of other metals are present in the zinc melt. The selection of these other metals and their corresponding quantities allows the final properties, particularly the optical and mechanical properties as well as the corrosion protection properties, of the zinc layer obtained from hot-dip galvanizing to be adjusted and adapted.

[0076] According to a particular embodiment of the present invention, the zinc melt used in hot-dip galvanizing can be an aluminum-alloyed and / or aluminum-containing zinc melt (“Zn / Al melt”).

[0077] In this context, the zinc melt used in hot-dip galvanizing, in particular the aluminium-alloyed and / or aluminium-containing zinc melt (“Zn / Al melt”), may contain at least 2 wt.%, in particular at least 3 wt.%, preferably at least 4 wt.%, aluminium, based on the zinc melt.

[0078] In particular, the zinc melt used in hot-dip galvanizing, especially the aluminium-alloyed and / or aluminium-containing zinc melt (“Zn / Al melt”), may contain at most 45 wt.%, in particular at most 25 wt.%, preferably at most 8 wt.%, and most preferably at most 6 wt.%, aluminium, based on the zinc melt.

[0079] According to this embodiment, the zinc melt used in hot-dip galvanizing, in particular the aluminium-alloyed and / or aluminium-containing zinc melt (“Zn / Al melt”), based on the zinc melt, can contain aluminium in amounts in the range of 2 wt.% to 45 wt.%, in particular in the range of 2 wt.% to 25 wt.%, preferably in the range of 3 wt.% to 8 wt.%, and most preferably in the range of 4 wt.% to 6 wt.%.

[0080] A so-called aluminum-alloyed and / or aluminum-containing zinc melt ("Zn / Al melt") results in particularly bright and ductile hot-dip galvanizing coatings with high corrosion protection properties. In particular, relatively thin zinc coatings with high corrosion protection properties can be produced when using a zinc melt with the aforementioned amounts of aluminum.

[0081] According to a further particular embodiment of the present invention, the zinc melt used in hot-dip galvanizing can contain, based on the zinc melt, at most 98 wt.% zinc and at least 2 wt.% aluminium.

[0082] According to the present invention, it can be provided in particular that the zinc melt used in the hot-dip galvanizing contains, based on the zinc melt, at most 98 wt.%, in particular at most 97 wt.%, preferably at most 96 wt.%, zinc, and that the zinc melt used in the hot-dip galvanizing contains, based on the zinc melt, at least 2 wt.%, in particular at least 3 wt.%, preferably at least 4 wt.%, aluminium.

[0083] A zinc melt with the ingredients and quantities described above, in particular a maximum of 98 wt.% zinc and at least 2 wt.% aluminum, is in particular a so-called aluminum-alloyed or aluminum-containing zinc melt, from which particularly thin and high-performance zinc layers with a high gloss are produced.

[0084] According to a further particular embodiment of the present invention, the zinc melt used in hot-dip galvanizing can contain zinc in amounts ranging from 55 wt.% to 98 wt.% and aluminum in amounts ranging from 2 wt.% to 45 wt.%.

[0085] Within the scope of the present invention, it can be provided in particular that the zinc melt used in hot-dip galvanizing contains zinc in amounts in the range of 55 wt.% to 98 wt.%, in particular in the range of 65 wt.% to 97 wt.%, preferably in the range of 75 wt.% to 96 wt.%, and that the zinc melt used in hot-dip galvanizing contains aluminum in amounts in the range of 2 wt.% to 45 wt.%, in particular in the range of 2 wt.% to 25 wt.%, preferably in the range of 3 wt.% to 8 wt.%, particularly preferably in the range of 4 wt.% to 6 wt.%.

[0086] According to a particular embodiment of the present invention, the present invention relates to a method for hot-dip galvanizing (hot-dip galvanizing) of a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanized layer, as described above, particularly for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component, wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subjected to an activation treatment, in particular an activation treatment comprising a chemical and mechanical treatment, before hot-dip galvanizing, and wherein the galvanized iron or steel component subjected to the activation treatment, in particular the iron or steel component having a zinc layer, is subsequently subjected to hot-dip galvanizing.wherein the molten zinc used in hot-dip galvanizing contains, based on the total zinc melt, at most 98 wt.% zinc and optionally at least 2 wt.% aluminium.

[0087] According to the invention, the activation treatment is carried out in such a way and / or with the proviso that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ · cm. 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, exhibits.

[0088] With an electrical resistance at the surface of the zinc layer of at most 500 kΩ · cm 2The surface is particularly accessible for hot-dip galvanizing, resulting in the formation of a substantially homogeneous and complete zinc layer. In particular, zinc oxidation products (i.e., oxygen-containing zinc compounds, especially those selected from the group consisting of zinc oxide, zinc hydroxide, zinc oxide hydroxide, zinc hydrogen carbonate, zinc carbonate, and combinations thereof) are present only in small quantities. These oxidation products can interfere with the hot-dip galvanizing process, leading to an incomplete or defective zinc layer and thus less reliable corrosion protection. However, the applicant has surprisingly discovered that with an electrical resistance at the surface of the zinc layer of at most 500 kΩ·cm, 2 a substantially flawless, homogeneous and complete zinc layer is formed in the hot-dip galvanizing process.

[0089] The electrical resistance at the surface can be determined, for example, using a gel electrolyte. Since the gel electrolyte is less reactive than a liquid electrolyte, measurements of the electrical resistance at the surface of the zinc layer using a gel electrolyte – as surprisingly discovered by the applicant – yield more reliable results.

[0090] According to a further particular embodiment of the present invention, the present invention relates to a method as described above for hot-dip galvanizing (hot-dip galvanizing) a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, in particular for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component. wherein the galvanized iron or steel component is subjected to hot-dip galvanizing, wherein the molten zinc used in the hot-dip galvanizing contains, based on the molten zinc, at most 98 wt.% zinc and optionally at least 2 wt.% aluminium.

[0091] According to the invention, the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subjected to an activation treatment, in particular an activation treatment comprising chemical and mechanical treatment, before hot-dip galvanizing, such that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ·cm. 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, exhibits.

[0092] According to a further particular embodiment of the present invention, the present invention relates to a method as described above for hot-dip galvanizing (hot-dip galvanizing) of a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, in particular for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component. wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subjected to an activation treatment prior to hot-dip galvanizing, in particular an activation treatment comprising chemical and mechanical treatment, such that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ·cm2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, and wherein the galvanized iron or steel component that has undergone activation treatment is subsequently subjected to hot-dip galvanizing, wherein the molten zinc used in the hot-dip galvanizing contains, based on the molten zinc, at most 98 wt.% zinc and optionally at least 2 wt.% aluminium.

[0093] Within the scope of the present invention, it may be provided that the zinc melt used in hot-dip galvanizing contains, based on the zinc melt, at most 98 wt.%, in particular at most 97 wt.%, preferably at most 96 wt.%, zinc.

[0094] It may also be provided within the scope of the present invention that the zinc melt used in hot-dip galvanizing contains zinc in amounts in the range of 55 wt.% to 98 wt.%, in particular in the range of 65 wt.% to 97 wt.%, preferably in the range of 75 wt.% to 96 wt.%.

[0095] As previously explained, the present invention does not use so-called pure zinc melt, nor does it involve galvanizing according to DIN EN ISO 1461. By using a maximum of 98 wt.% zinc, at least 2 wt.% of other metals are present in the zinc melt. The selection of these other metals and their corresponding quantities allows the final properties, particularly the optical and mechanical properties as well as the corrosion protection properties, of the zinc layer obtained from hot-dip galvanizing to be adjusted and adapted.

[0096] According to a particular embodiment of the present invention, the zinc melt used in hot-dip galvanizing can be an aluminum-alloyed and / or aluminum-containing zinc melt (“Zn / Al melt”).

[0097] In particular, it may be provided that the zinc melt used in hot-dip galvanizing, especially the aluminium-alloyed and / or aluminium-containing zinc melt (“Zn / Al melt”), contains at least 2 wt.%, in particular at least 3 wt.%, preferably at least 4 wt.%, aluminium, based on the zinc melt.

[0098] In this context, it may also be provided that the zinc melt used in hot-dip galvanizing, in particular the aluminium-alloyed and / or aluminium-containing zinc melt (“Zn / Al melt”), contains at most 45 wt.%, in particular at most 25 wt.%, preferably at most 8 wt.%, and most preferably at most 6 wt.% aluminium, based on the zinc melt.

[0099] Furthermore, in this context it may also be provided that the zinc melt used in hot-dip galvanizing, in particular the aluminium-alloyed and / or aluminium-containing zinc melt (“Zn / Al melt”), based on the zinc melt, contains aluminium in amounts in the range of 2 wt.% to 45 wt.%, in particular in the range of 2 wt.% to 25 wt.%, preferably in the range of 3 wt.% to 8 wt.%, and most preferably in the range of 4 wt.% to 6 wt.%.

[0100] As previously explained, a so-called aluminum-alloyed and / or aluminum-containing zinc melt ("Zn / Al melt") results in particularly bright and ductile hot-dip galvanizing coatings with high corrosion protection properties. In particular, relatively thin zinc coatings with high corrosion protection properties can be produced when using a zinc melt with the aforementioned amounts of aluminum.

[0101] Within the scope of the present invention, it may be preferred if the zinc melt used in the hot-dip galvanizing process contains, based on the zinc melt, at most 98 wt.% zinc and at least 2 wt.% aluminium.

[0102] As previously stated, a zinc melt with the ingredients and quantities described above, in particular a maximum of 98 wt.% zinc and at least 2 wt.% aluminum, is in particular a so-called aluminum-alloyed or aluminum-containing zinc melt, from which particularly thin and high-performance zinc layers with a high gloss are produced.

[0103] In particular, the zinc melt used in hot-dip galvanizing may contain, based on the zinc melt, at most 98 wt.%, in particular at most 97 wt.%, preferably at most 96 wt.%, zinc, and the zinc melt used in hot-dip galvanizing may contain, based on the zinc melt, at least 2 wt.%, in particular at least 3 wt.%, preferably at least 4 wt.%, aluminium.

[0104] According to a particular embodiment of the present invention, the zinc melt used in hot-dip galvanizing can contain zinc in amounts ranging from 55 wt.% to 98 wt.% and aluminum in amounts ranging from 2 wt.% to 45 wt.%.

[0105] Within the scope of the present invention, it may be preferred that the zinc melt used in the hot-dip galvanizing process contains zinc in amounts ranging from 55 wt.% to 98 wt.%, particularly in the range of 65 wt.% to 97 wt.%, preferably in the range of 75 wt.% to 96 wt.%, and that the zinc melt used in the hot-dip galvanizing process contains aluminum in amounts ranging from 2 wt.% to 45 wt.%, particularly in the range of 2 wt.% to 25 wt.%, preferably in the range of 3 wt.% to 8 wt.%, and most preferably in the range of 4 wt.% to 6 wt.%.

[0106] According to a further particular embodiment of the present invention, the aluminium-alloyed and / or aluminium-containing zinc melt (“Zn / Al melt”) used in hot-dip galvanizing can have the following composition, wherein all the quantities mentioned below refer to the aluminium-alloyed and / or aluminium-containing zinc melt (“Zn / Al melt”) and are to be selected such that a total of 100 wt.% results: (i) Zinc (Zn), in particular in amounts in the range of 55 wt.% to 98 wt.%, in particular in the range of 65 wt.% to 97 wt.%, preferably in the range of 75 wt.% to 96 wt.%, (ii) Aluminium (Al), in particular in amounts in the range of 2 wt.% to 45 wt.%, in particular in the range of 3 wt.% to 8 wt.%, preferably in the range of 4 wt.% to 6 wt.%, (iii) optionally magnesium (Mg), in particular in amounts in the range of 0.1 wt.% to 10 wt.%, in particular in the range of 0.1 wt.% to 3 wt.%, preferably in the range of 0.1 wt.% to 2 wt.%; (iii) optionally at least one further metal, in particular in (total) quantities of up to 10 wt.% and / or in particular selected from the group consisting of bismuth (Bi), lead (Pb), tin (Sn), nickel (Ni), silicon (Si) and combinations thereof.

[0107] According to the present invention, the aluminium alloyed and / or aluminium-containing zinc melt (“Zn / Al melt”) used in hot-dip galvanizing may have a temperature in the range of 330 °C to 750 °C, in particular in the range of 340 °C to 600 °C, preferably in the range of 350 °C to 465 °C, and most preferably in the range of 415 °C to 455 °C.

[0108] Within the framework of the inventive method, it has proven particularly advantageous if the galvanized iron or steel component is immersed in the aluminum-alloyed and / or aluminum-containing zinc melt ("Zn / Al melt") used in hot-dip galvanizing, in particular immersed and moved therein, especially for a period of time sufficient to ensure effective hot-dip galvanizing, in particular for a period of time in the range of 0.0001 to 60 minutes, in particular in the range of 0.001 to 45 minutes, preferably in the range of 0.5 to 30 minutes, particularly preferably in the range of 4 to 8 minutes.

[0109] Furthermore, it has proven advantageous within the framework of the inventive method if the galvanized iron or steel component is immersed in the aluminium-alloyed and / or aluminium-containing zinc melt ("Zn / Al melt") used in hot-dip galvanizing, in particular immersed and moved in it, especially for a period of time which is sufficient to ensure effective hot-dip galvanizing (hot-dip galvanizing), in particular for a period of time of at least 0.0001 minutes, preferably at least 0.5 minutes, particularly preferably at least 4 minutes.

[0110] Furthermore, it has proven advantageous within the framework of the inventive method if the galvanized iron or steel component is immersed in the aluminium-alloyed and / or aluminium-containing zinc melt ("Zn / Al melt") used in hot-dip galvanizing, in particular immersed and moved in it, especially for a period of time sufficient to ensure effective hot-dip galvanizing (hot-dip galvanizing), in particular for a period of time of at most 60 minutes, in particular at most 45 minutes, preferably at most 30 minutes, and particularly preferably at most 8 minutes.

[0111] In hot-dip galvanizing with the previously defined duration, a multi-phase or multi-layered overall hot-dip galvanizing layer is formed.

[0112] Within the scope of the present invention, it can be provided in particular that a (total) hot-dip galvanized layer is present after the hot-dip galvanizing.

[0113] In other words, it is specifically intended that a continuous hot-dip galvanizing layer is present after carrying out the process according to the invention, and not two separate layers arranged on top of each other. In particular, a substantially uniform zinc layer with, in particular, a uniform surface and layer thickness is formed.

[0114] In this context, it may be provided that a multi-phase and / or multi-layer, especially multi-phase, (overall) hot-dip galvanizing layer is formed on the base material of the iron or steel component during hot-dip galvanizing.

[0115] Furthermore, in this context it may also be intended that during hot-dip galvanizing an at least partially multi-phase and / or at least partially layered hot-dip galvanizing layer with Zn / Al / Fe phases is formed.

[0116] These Zn / Al / Fe phases may include, in particular, Zn, ZnAl, ZnFe and / or AlFe phases; this is especially the case when hot-dip galvanizing is carried out using an aluminum-alloyed or aluminum-containing zinc melt.

[0117] If a non-aluminium alloyed or non-aluminium-containing zinc melt is used in hot-dip galvanizing, a multi-phase and / or at least partially layered (total) hot-dip galvanizing layer is provided, which consists of Zn and ZnFe phases.

[0118] The hot-dip galvanizing layer obtained by the inventive process exhibits high corrosion protection properties and high ductility. Furthermore, this hot-dip galvanizing layer is very bright and therefore visually of particularly high quality.

[0119] Without limiting ourselves to this theory, the zinc layer still present on the component is permeated by the aluminum-containing or aluminum-alloyed zinc melt from the hot-dip galvanizing process, particularly the aluminum it contains. Specifically, the aluminum-containing or aluminum-alloyed zinc melt, and especially the aluminum it contains, diffuses into the existing hot-dip galvanizing layer, resulting in the formation of a hot-dip galvanizing layer that is at least partially multiphase and / or at least partially layered, containing Zn / Al / Fe phases.

[0120] Furthermore, it may also be provided that the hot-dip galvanizing is carried out in such a way and / or with the stipulation that the aluminium-containing and / or aluminium-alloyed zinc melt ("Zn / Al melt") diffuses at least partially into the existing zinc layer, preferably hot-dip galvanizing layer, of the component.

[0121] It may also be provided that the hot-dip galvanizing is carried out with the stipulation and / or in such a way that a (total) hot-dip galvanizing layer with an aluminium concentration gradient is formed.

[0122] The aluminum concentration gradient – ​​without limiting ourselves to this theory – results primarily from the increased affinity of aluminum for the iron in the iron or steel component. Due to this affinity, the aluminum in the zinc melt used in hot-dip galvanizing, particularly the aluminum-containing or aluminum-alloyed molten zinc, diffuses into the existing zinc layer (hot-dip galvanizing layer). However, according to a particular embodiment, it is important to ensure that the hot-dip galvanizing process does not last so long, or for such a period, that the aluminum completely diffuses through, permeates, and even replaces the entire existing zinc layer. In particular, it may be intended that a new, overall hot-dip galvanizing layer with Zn / Al / Fe phases results.

[0123] According to a particular embodiment of the present invention, the total layer thickness of the (total) hot-dip galvanizing layer resulting after carrying out the process can be at least 30 µm, in particular at least 35 µm, preferably at least 40 µm, particularly preferably at least 45 µm.

[0124] According to a further particular embodiment of the present invention, the total layer thickness of the (total) hot-dip galvanizing layer resulting after carrying out the process can be at most 500 µm, in particular at most 450 µm, preferably at most 400 µm, and particularly preferably at most 300 µm.

[0125] According to a further particular embodiment of the present invention, the total layer thickness of the (total) hot-dip galvanizing layer resulting after carrying out the process can be in the range of 30 µm to 500 µm, in particular in the range of 35 µm to 450 µm, preferably in the range of 40 µm to 400 µm, and particularly preferably in the range of 45 µm to 300 µm.

[0126] According to a further particular embodiment of the present invention, the hot-dip galvanizing can be carried out in such a way and / or with the proviso that the total layer thickness of the (total) hot-dip galvanized layer resulting after carrying out the process is in the range of 30 µm to 500 µm, in particular in the range of 35 µm to 450 µm, preferably in the range of 40 µm to 400 µm, particularly preferably in the range of 45 µm to 300 µm.

[0127] A (total) hot-dip galvanized layer resulting from the process according to the invention, with the previously specified total layer thickness, provides high corrosion protection. At the same time, such a zinc layer can be ductile, particularly if an aluminum-containing or aluminum-alloyed zinc melt is used in the hot-dip galvanizing process; in particular, a corresponding hot-dip galvanized iron or steel component can be formed, especially bent by 90°, without losing its corrosion protection properties or without them being substantially or significantly reduced. In particular, a hot-dip galvanized component that has been galvanized according to the hot-dip galvanizing process according to the invention also exhibits high corrosion protection properties after forming or cold forming (for example, 90° bending).

[0128] Within the scope of the present invention, it may be provided that a cooling treatment takes place after hot-dip galvanizing.

[0129] In other words, it may be planned that the iron or steel component obtained after hot-dip galvanizing will undergo a cooling treatment.

[0130] The optional cooling treatment can be carried out, for example, using air and / or in the presence of air, preferably down to ambient temperature. Cooling makes subsequent handling easier. Furthermore, the cooling treatment strengthens the hot-dip galvanized layer that has formed.

[0131] It may also be provided within the framework of the inventive method that a post-treatment treatment is carried out after hot-dip galvanizing.

[0132] In other words, it may be planned that the iron or steel component obtained after hot-dip galvanizing will undergo a post-processing treatment.

[0133] Possible post-processing steps include, for example, the removal of excess zinc bath residues, especially so-called drips from the zinc solidifying at the edges, as well as oxide or ash residues adhering to the component, and passivating or sealing the surface. Post-processing significantly improves the quality of the hot-dip galvanized coating.

[0134] Within the framework of the inventive method, it has proven advantageous if the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ · cm. 2 , in particular at most 300 kΩ · cm 2 , preferably at most 250 kΩ · cm 2 , particularly preferably at most 200 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, exhibits.

[0135] Furthermore, it has proven particularly advantageous within the framework of the inventive method if the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer in the range of 0.0001 kΩ · cm. 2 up to 500 kΩ · cm 2 , especially in the range of 0.0001 kΩ · cm 2 up to 300 kΩ · cm 2 preferably in the range of 0.0001 kΩ·cm 2 up to 250 kΩ · cm 2 , particularly preferably in the range of 0.0001 kΩ · cm 2 up to 200 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, exhibits.

[0136] When the electrical resistance of the zinc layer surface is within the previously defined upper limit or range, subsequent hot-dip galvanizing yields particularly good results. Specifically, this results in a virtually uniform and defect-free zinc layer, providing reliable corrosion protection.

[0137] Within the scope of the present invention, it can be provided in particular that the electrical resistance is the resistance of the cover layer, in particular the polarization resistance of the cover layer (zinc layer or hot-dip galvanizing layer).

[0138] In this case, the top layer refers specifically to the surface or outer area (edge ​​zone) of the zinc coating or hot-dip galvanizing layer on the component, which interacts with the environment and forms zinc-based compounds through reaction with it. In other words, it is specifically intended that the electrical resistance of the top layer is the electrical resistance of the edge zone of the zinc coating on the iron or steel component.

[0139] According to a particular embodiment of the present invention, the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, can be at least partially, in particular completely, galvanized on at least one surface, in particular having a zinc layer.

[0140] In this context, it is particularly preferred if a full-surface or complete zinc layer is present on the component. With a preferably complete remaining zinc layer, the component is typically not yet corroded. Furthermore, according to a particular embodiment, a new hot-dip galvanizing layer is then provided, which differs from a hot-dip galvanizing layer applied to a component without a zinc layer. In particular, a zinc layer applied to an existing zinc layer using the inventive method is especially ductile and simultaneously provides particularly high corrosion protection. However, it is also possible to carry out the inventive method with a galvanized component on which a complete or full-surface zinc layer is no longer present.

[0141] According to a particular embodiment of the present invention, the activation treatment may comprise a chemical and a mechanical treatment, in particular at least one chemical and optionally (additionally) a mechanical treatment.

[0142] An activation treatment can remove the oxide layer or natural protective layer (which forms automatically on the zinc layer under oxidative conditions) of the existing zinc layer, as well as other impurities and corrosion products (of both zinc and iron), thus exposing the existing zinc layer and activating it for hot-dip galvanizing. This allows for subsequent fast and reliable hot-dip galvanizing.

[0143] In particular, the chemical treatment may include at least pickling and flux treatment.

[0144] In particular, it may be provided that the chemical treatment is carried out using an aqueous saline solution, especially with a pH value of less than 5.

[0145] Furthermore, in this context it may also be provided that the chemical treatment takes place for a duration in the range of 1 second to 60 min, in particular in the range of 5 seconds to 45 min, preferably in the range of 10 seconds to 30 min.

[0146] Chemical treatment lasting this duration removes contaminants, oxide layers or natural coatings formed under oxidative conditions, and iron corrosion products from the remaining zinc layer and any exposed surface of the component. This exposes the existing zinc layer and activates it for hot-dip galvanizing, enabling fast and reliable hot-dip galvanizing. In particular, this duration typically results in the removal or dissolution of the oxide layer and sufficient activation of the existing zinc layer.

[0147] According to a further particular embodiment of the present invention, it may be provided that the chemical treatment is carried out by means of flux treatment in a flux composition in a flux bath.

[0148] Typically, the flux bath of the chemical treatment can comprise an aqueous and / or alcoholic, in particular aqueous, liquid phase, wherein the liquid phase of the flux bath contains the flux composition, in particular in dissolved or dispersed form, preferably in dissolved form.

[0149] In particular, the flux composition of the chemical treatment may include as ingredients salts and optionally wetting agents, in particular wherein the salts are selected from the group of chlorides, preferably from the group of zinc chloride (ZnCl2), ammonium chloride (NH4Cl), alkali and / or alkaline earth chlorides, in particular potassium chloride (KCl) and / or sodium chloride (NaCl), aluminum chloride (AlCl3), silver chloride (AgCl), lead chloride (PbCl2), nickel chloride (NiCl2), bismuth chloride (BiCl3), tin chloride (SnCl2), manganese chloride (MnCl2), cobalt chloride (CoCl2) and combinations thereof.

[0150] In this context, it may be provided that the flux composition of the chemical treatment comprises as ingredients zinc chloride (ZnCl2) and optionally at least one alkali and / or alkaline earth chloride, in particular potassium chloride (KCl) and / or sodium chloride (NaCl), as well as optionally wetting agents and optionally at least one further salt, different from the aforementioned compounds, selected from the group of chlorides, preferably from the group of ammonium chloride (NH4Cl), aluminum chloride (AlCl3), silver chloride (AgCl), lead chloride (PbCl2), nickel chloride (NiCl2), bismuth chloride (BiCl3), tin chloride (SnCl2), manganese chloride (MnCl2), cobalt chloride (CoCl2) and combinations thereof.

[0151] Within the scope of the invention, it has proven advantageous if the flux composition of the chemical treatment comprises salts and optionally wetting agents as ingredients, in particular wherein the flux composition comprises at least zinc chloride (ZnCl2) and at least one alkali and / or alkaline earth chloride, in particular potassium chloride (KCl) and / or sodium chloride (NaCl).

[0152] According to the invention, in a particular embodiment, it can be provided that the flux composition of the chemical treatment is free of ammonium chloride (NH4CI); or that the flux composition of the chemical treatment contains at least substantially no ammonium chloride (NH4CI).

[0153] In particular, the flux bath of the chemical treatment can have a salt content of at least 20 wt.%, in particular at least 30 wt.%, preferably at least 50 wt.%, and most preferably at least 60 wt.%, based on the flux bath.

[0154] Typically, the flux bath used in the chemical treatment can have a salt content of at most 90 wt.%, in particular at most 85 wt.%, preferably at most 80 wt.%, and most preferably at most 75 wt.%, based on the flux bath.

[0155] Within the framework of the process according to the invention, it can be provided that the flux bath of the chemical treatment has a salt content in the range of 20 wt.% to 90 wt.%, in particular in the range of 30 wt.% to 85 wt.%, preferably in the range of 50 wt.% to 80 wt.%, particularly preferably in the range of 60 wt.% to 75 wt.%, based on the flux bath.

[0156] It can also be provided within the framework of the inventive process that the flux bath of the chemical treatment has a salt content in the range of 100 g / l to 800 g / l, in particular in the range of 140 g / l to 720 g / l, preferably in the range of 170 g / l to 670 g / l, and especially preferably in the range of 200 g / l to 600 g / l.

[0157] According to a particular embodiment of the invention, the flux composition of the chemical treatment can comprise the following ingredients, wherein all the quantities mentioned below refer to the flux composition and are to be selected such that a total of 100 wt.% results: (i) Zinc chloride (ZnCl2), in particular in amounts in the range of 50 to 95 wt.%, in particular in the range of 50 to 90 wt.%, preferably in the range of 60 to 85 wt.%, particularly preferably in the range of 65 to 82.5 wt.%, even more preferably in the range of 70 to 82 wt.%, (ii) Ammonium chloride (NH4Cl), particularly in amounts in the range of 0 to 50 wt.%, particularly in the range of 6 to 40 wt.%, preferably in the range of 7 to 35 wt.%, particularly preferably in the range of 8 to 25 wt.%, even more preferably in the range of 10 to 20 wt.%, (iii) Sodium chloride (NaCl), in particular in amounts in the range of 0.1 to 20 wt.%, in particular in the range of 0.5 to 15 wt.%, preferably in the range of 1 to 12.5 wt.%, particularly preferably in the range of 2 to 10 wt.%, even more preferably in the range of 4 to 8 wt.%, and (iv) Potassium chloride (KCl), in particular in amounts in the range of 0.1 to 15 wt.%, preferably in the range of 0.2 to 12.5 wt.%, preferably in the range of 0.4 to 10 wt.%, particularly preferably in the range of 0.5 to 8 wt.%, even more preferably in the range of 0.8 to 6 wt.%.

[0158] According to another embodiment, the chemical treatment can be carried out by means of pickling treatment in a pickling agent.

[0159] In particular, the pickling treatment can be carried out using a chemical treatment containing hydrochloric acid (HCI-containing) and / or hydrochloric acid-based (HCI-based) pickling agent, especially if the pickling agent has a pH value of less than 5.

[0160] In particular, it may be provided within the framework of the inventive process that the pickling treatment of the chemical treatment is carried out with an acidic pickling agent, in particular with a pickling agent with a pH value of less than 5.

[0161] Furthermore, the pickling agent may also contain iron within the framework of the inventive method, in particular in the form of divalent and / or trivalent iron ions.

[0162] In particular, the trivalent iron ions (Fe) can be affected. 3+ -ions) enhance the pickling effect.

[0163] In particular, it may be stipulated in this context that the pickling agent contains zinc with a content of at least 10 g / l.

[0164] In this context, it may also be stipulated that the pickling agent contains zinc with a content of at least 10 g / l and has an iron content of no more than 20% of the zinc content.

[0165] Furthermore, within the framework of the inventive method, it may also be provided that the pickling treatment agent contains at least one additive, in particular at least one pickling additive, in particular selected from the group of corrosion inhibitors, pickling cleaners, pickling accelerators and pickling enhancers as well as combinations thereof.

[0166] In this context, additives can be used to optimize the pickling effect. Possible pickling additives include inhibitors to prevent excessive attack and / or to protect the base material, or pickling enhancers to increase the attack. Commercial products are available, for example, from STOCKMEIER Holding GmbH, such as the Lerapas products. ® BP, Leraclen ® Pickling fats or Leraclen ® 1227.

[0167] According to a further particular embodiment, the pickling agent and / or the flux bath of the chemical treatment can contain at least one wetting agent and / or surfactant, in particular at least one ionic or non-ionic wetting agent and / or surfactant, preferably at least one non-ionic wetting agent and / or surfactant.

[0168] In particular, the pickling agent and / or the flux bath of the chemical treatment can contain the at least one wetting agent and / or surfactant in amounts of 0.0001 to 15 wt.%, preferably in amounts of 0.001 to 10 wt.%, more preferably in amounts of 0.01 to 8 wt.%, even more preferably in amounts of 0.01 to 6 wt.%, most preferably in amounts of 0.05 to 3 wt.%, even more preferably in amounts of 0.1 to 2 wt.%, based on the pickling agent and / or flux bath.

[0169] According to yet another embodiment, the chemical treatment can be carried out by means of a pickling treatment and a flux treatment.

[0170] The combination of pickling and flux treatment leads to a particularly efficient and essentially complete removal of the oxide layer and other impurities, such as corrosion products, and thus to a particularly uniform and flawless hot-dip galvanizing.

[0171] In this context, pickling treatment can be carried out first, followed by flux treatment, with at least one rinsing process taking place after pickling treatment and before flux treatment, in particular by immersion in a water bath.

[0172] It has proven effective if the pickling treatment of the chemical treatment and the flux treatment of the chemical treatment each take place for a duration in the range of 1 second to 60 min, in particular in the range of 5 seconds to 45 min, preferably in the range of 10 seconds to 30 min.

[0173] As previously explained, the processing time should be adjusted to the quality of the zinc surface to ensure the complete removal of impurities such as the oxide layer and corrosion products of the zinc and / or iron. At the same time, both the flux treatment and the pickling treatment should be as short as possible to avoid removing any or virtually no zinc layer.

[0174] Within the framework of the inventive process, it may be provided that the chemical treatment, in particular the flux treatment and / or the pickling treatment, takes place at an elevated temperature.

[0175] In particular, flux treatment and / or pickling treatment can be carried out at a temperature in the range of 20 °C to 90 °C, especially in the range of 25 °C to 80 °C.

[0176] As previously stated, mechanical treatment can be performed as part of the activation treatment.

[0177] According to a particular embodiment, the mechanical treatment can include an abrasive treatment.

[0178] In particular, the abrasive treatment may be selected from the group of blasting methods, especially sandblasting, water blasting and / or dry ice blasting, grinding, brushing, lasers and combinations thereof.

[0179] It may also be possible to carry out the chemical treatment using a flow.

[0180] According to the present invention, the electrical resistance on the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is determined before the activation treatment.

[0181] In this context, the type and / or duration and / or intensity of the activation treatment can depend on the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer.

[0182] This method is particularly advantageous because the activation treatment effort can be precisely adjusted in advance, making the process especially economical, environmentally friendly, material-conserving, and resource-efficient. In particular, the amount of material removed can be reduced, and the activation treatment effort can be optimized. Thus, the activation treatment effort can be adjusted beforehand so that, after the activation treatment, the electrical resistance at the surface of the zinc layer is no more than 500 kΩ·cm. 2 amounts.

[0183] Depending on the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, the activation treatment comprises either only a flux treatment or a pickling treatment and a flux treatment.

[0184] As previously explained, this approach makes it possible to precisely control and optimize the intensity and effort of the activation treatment. Particularly with excessive intensity (for example, due to an excessively long or intensive pickling treatment), the surface, especially the component surface and / or the zinc coating, can be excessively attacked or worn away. Within the framework of the inventive method, it is specifically intended that as little material as possible is removed from the galvanized iron or steel component. Thus, the electrical resistance is a key measure of the necessary activation treatment.

[0185] In this context, it is stipulated that if the electrical resistance at the surface of the zinc layer is no more than 500 kΩ · cm, 2, in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, at least a flux treatment is carried out as an activation treatment.

[0186] It is also stipulated that if the electrical resistance at the surface of the zinc layer exceeds 500 kΩ · cm, 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least first a pickling treatment and subsequently a flux treatment is carried out, in particular wherein a rinsing process is carried out after the pickling treatment and before the flux treatment, in particular by immersion in a water bath.

[0187] The oxidation products of zinc, especially zinc oxide, zinc hydroxide, zinc oxide hydroxide, zinc hydrogen carbonate and zinc carbonate, increase the electrical resistance compared to pure zinc, so that by removing these oxidation products and thus the natural top layer, the electrical resistance of the surface of the zinc layer typically also decreases.

[0188] According to a particular embodiment of the present invention, the present invention relates to a method as described above for hot-dip galvanizing a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, in particular for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component. wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subjected to an activation treatment prior to hot-dip galvanizing, in particular an activation treatment comprising chemical and mechanical treatment, such that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ·cm 2 , in particular at most 300 kΩ · cm 2 , preferably at most 250 kΩ · cm 2 , particularly preferably at most 200 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, and wherein the galvanized iron or steel component undergoing the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ · cm 2, in particular at most 300 kΩ · cm 2 , preferably at most 250 kΩ · cm 2 , particularly preferably at most 200 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, exhibits, wherein the galvanized iron or steel component that has undergone activation treatment is subsequently subjected to hot-dip galvanizing, wherein the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is determined before the activation treatment, wherein the activation treatment, depending on the electrical resistance on the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, comprises only a flux treatment or a pickling treatment and a flux treatment.

[0189] According to a further particular embodiment of the present invention, the present invention relates to a method as described above for hot-dip galvanizing (hot-dip galvanizing) a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, in particular for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component. wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subjected to an activation treatment prior to hot-dip galvanizing, in particular an activation treatment comprising chemical and mechanical treatment, such that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ·cm 2 , in particular at most 300 kΩ · cm 2 , preferably at most 250 kΩ · cm 2 , particularly preferably at most 200 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, exhibits, wherein the galvanized iron or steel component that has undergone activation treatment is subsequently subjected to hot-dip galvanizing, wherein the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is determined before the activation treatment, wherein the activation treatment, depending on the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, comprises only a flux treatment or a pickling treatment and a flux treatment, where the electrical resistance at the surface of the zinc layer is at most 500 kΩ · cm 2 , in particular determined according to DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, at least a flux treatment is carried out as an activation treatment and wherein, in the case of an electrical resistance at the surface of the zinc layer of more than 500 kΩ · cm2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least first a pickling treatment and subsequently a flux treatment is carried out, in particular wherein a rinsing process is carried out after the pickling treatment and before the flux treatment, in particular by immersion in a water bath.

[0190] According to the present invention, it may be provided that the composition of the zinc layer, in particular the hot-dip galvanized layer, is determined before the electrical resistance is determined, in particular by means of laser-induced plasma spectroscopy (LIBS).

[0191] Determining a composition using laser-induced plasma spectroscopy (LIBS) is well known to those skilled in the art and thus constitutes general technical knowledge. This procedure is also described in DE 10 2014 013 160 A1 and on Wikipedia, particularly in the secondary sources cited therein, such as a corresponding article from TU Clausthal or on the website of SECOPTA analytics GmbH. In this regard, full reference is made to the relevant explanations in the aforementioned documents and sources, which are hereby expressly incorporated into the present application.

[0192] In particular, the measurement and / or the measurement parameters of the electrical resistance can be adapted to the composition of the zinc layer, especially the hot-dip galvanized layer.

[0193] According to a particular embodiment, the galvanized iron or steel component that has undergone activation treatment can be subjected to a drying treatment.

[0194] Performing a drying treatment after the activation treatment, and especially immediately before hot-dip galvanizing, has the advantage that no liquid is carried into the zinc bath.

[0195] The drying treatment can be carried out at a temperature in the range of 30 °C to 400 °C, in particular in the range of 35 °C to 375 °C, preferably in the range of 40 °C to 350 °C, and most preferably in the range of 50 °C to 325 °C.

[0196] In this context, it has proven advantageous if the drying treatment is carried out for a duration in the range of 0.1 seconds to 60 minutes, particularly in the range of 1 second to 45 minutes, preferably in the range of 10 seconds to 35 minutes, especially preferably in the range of 20 seconds to 30 minutes, and even more preferably in the range of 20 seconds to 15 minutes.

[0197] The drying treatment can be carried out in the presence of and / or using air.

[0198] Typically, in this context, the drying treatment takes place in at least one drying facility, in particular in at least one oven.

[0199] According to a further particular embodiment of the present invention, it may be provided that the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, is subjected to an inspection before the activation treatment.

[0200] According to a further particular embodiment of the present invention, it may be provided that the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, is checked for suitability for regeneration and / or reprocessing and / or reuse before the activation treatment.

[0201] In particular, the inspection can be carried out using optical and / or mechanical and / or inductive and / or electrical and / or chemical methods.

[0202] By checking the galvanized iron or steel component beforehand for suitability for regeneration and / or reprocessing and / or reuse, components can already be sorted out which cannot be used even after regeneration and / or reprocessing and / or reuse according to the invention.

[0203] In particular, it may be provided that the galvanized iron or steel component, especially the iron or steel component having a zinc layer, preferably a hot-dip galvanized layer, is checked with regard to at least one specific property and / or a specific test parameter, in particular selected from the group of: condition and / or type of the existing zinc layer; composition and / or grade and / or thickness of the steel part; degree of corrosion and / or wear of the steel part; optical condition of the steel part; deformation of the steel part from its original shape; degree of contamination of the existing zinc layer; type and / or concentration of oxidation products of the zinc layer (hot-dip galvanized layer); type and / or concentration of deposits, in particular of salts, oxides, hydroxides and greases; marking of the steel part;Presence and / or condition of fastening options, in particular holes, threads and / or openings; and presence of foreign coating materials.

[0204] Furthermore, in this context it may also be provided that the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, is prepared depending on the inspection, in particular by degreasing, correction forming, pressing, rolling, bending, drilling and / or cutting.

[0205] It is therefore possible to prepare a galvanized iron or steel component, which is not suitable for regeneration and / or reprocessing and / or reuse upon initial assessment, in such a way as to establish its suitability.

[0206] Furthermore, within the scope of the present invention, it may also be provided that the activation treatment, in particular the abrasive treatment, of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, is carried out depending on the inspection, in particular in such a way that existing dirt, deposits and / or corrosion products are removed.

[0207] It is therefore possible to prepare a galvanized iron or steel component that, upon initial assessment, is not suitable for regeneration, reprocessing, and / or reuse, in such a way as to make it suitable. This can involve repairing deformations as well as removing contaminants, deposits, and / or corrosion products, thus making the surface of the galvanized iron or steel component accessible to the process according to the invention. However, such preparation is not possible for every unsuitable component; in cases of excessive deformation or a high proportion or difficult-to-remove contaminants, deposits, and / or corrosion products, it is possible that even during preparation the surface cannot be made sufficiently accessible to provide adequate corrosion protection properties within the framework of the process according to the invention.It is also possible that the component itself is already too heavily corroded, so that it no longer meets the mechanical requirements necessary for its intended use. In such cases, the component can, for example, be recycled using conventional methods.

[0208] According to a particular embodiment, the method may comprise the following process steps in the order listed below: (a) Check the galvanized iron or steel component; then (b) Prepare the galvanized iron or steel component checked in step (a); then (c) Measurement of the resistance of the galvanized iron or steel component checked in process step (a) and prepared in process step (b); then (d) Activation of the galvanized iron or steel component checked in process step (a) and prepared in process step (b); then (e) Drying treatment of the galvanized iron or steel component activated in process step (d); then (f) Hot-dip galvanizing of the galvanized iron or steel component activated in process step (d) and dried in process step (e); then (g) Cooling treatment of the iron or steel component hot-dip galvanized in process step (f); then (h) Post-processing of the iron or steel component which has been hot-dip galvanized in process step (f) and cooled in process step (g).

[0209] As a result, the present invention provides an efficient, economical, ecological and sustainable method for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component.

[0210] A further object – according to a second aspect of the present invention – is a plant (system) for hot-dip galvanizing (thermal immersion galvanizing) of a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, especially for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component, for carrying out a previously described process, the plant comprises the following devices in the order listed below: - an activation device for activating the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer; arranged downstream and / or in the process sequence for this purpose - a hot-dip galvanizing device for hot-dip galvanizing the iron or steel component obtained after activation in a zinc melt; wherein the device comprises at least one measuring device arranged downstream of the activation device and upstream of the hot-dip galvanizing device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, and wherein a further measuring device for measuring an electrical resistance on the surface of the zinc layer is arranged upstream of the activation device.

[0211] According to the invention, the measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, is arranged upstream of the hot-dip galvanizing device.

[0212] According to the invention, it is further provided that the measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanized layer, is arranged downstream of the activation device.

[0213] In other words, according to the invention, the measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, is arranged upstream of the hot-dip galvanizing device and downstream of the activation device.

[0214] Within the scope of the present invention, it is therefore provided that the measuring device is arranged between the hot-dip galvanizing device and the activation device.

[0215] Within the scope of the present invention, it can be provided in particular that the measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, is designed for measuring the surface layer resistance, in particular the polarization resistance of the surface layer (zinc layer or hot-dip galvanizing layer).

[0216] The electrical resistance at the surface can be determined, for example, using a gel electrolyte. Since the gel electrolyte is less reactive than a liquid electrolyte, measurements of the electrical resistance at the surface of the zinc layer using a gel electrolyte – as surprisingly discovered by the applicant – yield more reliable results.

[0217] Within the scope of the present invention, as previously described, a further measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanized layer, is arranged upstream of the activation device.

[0218] In particular, the further measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, is designed for measuring the surface layer resistance, in particular the polarization resistance of the surface layer (zinc layer or hot-dip galvanizing layer).

[0219] According to the invention, it is therefore provided that the system according to the invention has two or more measuring devices for measuring an electrical resistance.

[0220] Furthermore, within the scope of the present invention, it may be provided that the activation device comprises at least one flux device and pickling device and optionally a mechanical activation device.

[0221] In particular, the flux device can be arranged downstream of the pickling device and the pickling device downstream of the mechanical activation device.

[0222] According to a particular embodiment of the present invention, the invention also relates to a system as described above for hot-dip galvanizing of a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, in particular for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component, for carrying out a process as described above. the plant comprises the following devices in the order listed below: - an activation device for activating the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer; arranged downstream and / or in the process sequence for this purpose - a hot-dip galvanizing device for hot-dip galvanizing the iron or steel component obtained after activation in a zinc melt; wherein the device comprises at least one measuring device arranged downstream of the activation device and upstream of the hot-dip galvanizing device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, and wherein a further measuring device for measuring an electrical resistance on the surface of the zinc layer is arranged upstream of the activation device, wherein the activation device comprises at least a fluxing device and pickling device and a mechanical activation device.

[0223] Within the scope of the present invention, the measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, is arranged, in particular, upstream of the hot-dip galvanizing device.

[0224] According to the invention, the measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanized layer, is arranged particularly downstream of the activation device.

[0225] Furthermore, according to the invention, the measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, is arranged upstream of the hot-dip galvanizing device and downstream of the activation device.

[0226] Furthermore, according to the invention, the measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, is designed to measure the surface layer resistance, in particular the polarization resistance of the surface layer (zinc layer or hot-dip galvanizing layer).

[0227] According to the present invention, a further measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanized layer, is arranged upstream of the activation device, as previously described.

[0228] In particular, the further measuring device for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, can be designed to measure the surface layer resistance, in particular the polarization resistance of the surface layer (zinc layer or hot-dip galvanizing layer).

[0229] The system according to the invention thus has several measuring devices for measuring electrical resistance.

[0230] It may also be provided within the scope of the present invention that a cooling device is arranged downstream of the hot-dip galvanizing device.

[0231] The optional cooling device can, for example, be designed for cooling with air and / or in the presence of air, preferably cooling to ambient temperature. Cooling facilitates subsequent handling and hardens the resulting hot-dip galvanized layer.

[0232] Furthermore, a post-processing device can be arranged downstream of the hot-dip galvanizing device in the system according to the invention.

[0233] In particular, the post-processing device can be arranged downstream of the cooling device.

[0234] Consequently, it may be provided in particular that the post-processing device is arranged downstream of the hot-dip galvanizing device and downstream of the cooling device in the process sequence.

[0235] The post-processing device can be designed, for example, to remove excess zinc bath residues, especially so-called drips from the zinc solidifying at the edges, as well as oxide or ash residues adhering to the component, and to passivate or seal the surface. Post-processing significantly improves the quality of the hot-dip galvanized coating.

[0236] According to a further special embodiment, the system according to the invention can be designed in such a way that, in particular upstream to the measuring device and / or to the further measuring device, a spectroscopy device is also arranged.

[0237] In particular, the spectroscopy device can be designed to perform a measurement using laser-induced plasma spectroscopy (LIBS).

[0238] In this context, the spectroscopy device can comprise at least one laser and at least one detector, in particular a spectrometer.

[0239] As previously explained in connection with the method according to the invention, the composition of the zinc layer can be determined by means of laser-induced plasma spectroscopy (LIBS), whereby the measurement and / or the measurement parameters of the electrical resistance are subsequently adapted to the composition of the zinc layer.

[0240] In the context of the present invention, it may also be provided that a drying device, in particular an oven, is arranged downstream of the activation device.

[0241] According to yet another particular embodiment of the present invention, a verification device can be arranged upstream of the activation device.

[0242] In particular, the inspection device can be designed for the optical and / or mechanical and / or inductive and / or electrical and / or chemical inspection of the galvanized iron or steel component, especially the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer.

[0243] Furthermore, the inspection device may include at least one device for optical and / or mechanical and / or inductive and / or electrical and / or chemical inspection of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer.

[0244] According to a further special embodiment, the system can include the following devices and equipment in the order listed below: (ÜV) at least one inspection device; arranged downstream and / or in the process flow for this purpose (SV) a spectroscopy device; arranged downstream and / or in the process flow (MV') another measuring device; arranged downstream and / or in the process flow for this purpose (AV) at least one activation device, wherein the activation device comprises at least one flux device and pickling device and optionally a mechanical activation device, wherein the flux device is arranged downstream of the pickling device and the pickling device is arranged in particular downstream of the mechanical activation device; arranged downstream and / or in the process sequence downstream therefrom (TE) at least one drying device, in particular an oven; arranged downstream and / or in the process flow (SV) a spectroscopy device; arranged downstream and / or in the process flow (MV) at least one measuring device; arranged downstream and / or in the process flow for this purpose (FZ) at least one hot-dip galvanizing device; arranged downstream and / or in the process sequence (AK) at least one cooling device; arranged downstream and / or in the process flow for this purpose (NV) at least one post-processing device.

[0245] For further details regarding the system according to the second aspect of the invention, reference can be made to the above statements relating to the first aspect of the invention, which also apply accordingly to the system according to the second aspect of the invention.

[0246] Furthermore, a hot-dip galvanized iron or steel component is described, obtainable according to a previously described process and / or available in a previously described plant.

[0247] Also described is a hot-dip galvanized (hot-dip galvanized) iron or steel component, in particular a hot-dip galvanized iron or steel component as described above, wherein the hot-dip galvanized iron or steel component is obtainable by subjecting a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanized layer, to an activation treatment, in particular an activation treatment comprising a chemical and mechanical treatment, such that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ·cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, and where the galvanized iron or steel component that has undergone activation treatment has subsequently been subjected to hot-dip galvanizing.

[0248] In particular, it may be provided that the hot-dip galvanized iron or steel component has a (total) hot-dip galvanizing layer.

[0249] It may be provided that the hot-dip galvanized iron or steel component has a multi-phase and / or multi-layered, in particular multi-phase, (overall) hot-dip galvanizing layer on the base material of the iron or steel component.

[0250] Consequently, a uniform hot-dip galvanized coating is typically not present. In particular, several layers or intermetallic phases are contained within this coating. In the context of the present invention, this specifically means that there is no uniform composition within this coating, but rather different areas (i.e., layers or phases) with different compositions, especially different amounts of the individual components (i.e., different amounts of zinc, aluminum, iron, and optionally other metals).

[0251] It may also be stipulated in this context that the hot-dip galvanized iron or steel component has a hot-dip galvanizing layer that is at least partially multi-phase and / or at least partially layered, containing Zn / Al / Fe phases. These Zn / Al / Fe phases may include, in particular, Zn, ZnAl, ZnFe, and / or AlFe phases; this is especially the case if the hot-dip galvanizing is carried out using an aluminum-alloyed or aluminum-containing zinc melt.

[0252] If the hot-dip galvanizing process uses a non-aluminium alloyed or non-aluminium-containing zinc melt, a multi-phase and / or at least partially layered (total) hot-dip galvanizing coating is provided, which consists of Zn and ZnFe phases.

[0253] The hot-dip galvanizing layer obtained by the inventive process exhibits high corrosion protection properties and high ductility. Furthermore, this hot-dip galvanizing layer is very bright and therefore visually of particularly high quality.

[0254] Furthermore, in this context it may be provided that the hot-dip galvanized iron or steel component has a (total) hot-dip galvanizing layer with an aluminum concentration gradient.

[0255] Furthermore, in this context it may be provided that the multi-phase and / or multi-layer, in particular multi-phase, (total) hot-dip galvanizing layer has an aluminium concentration gradient.

[0256] In this context, the term "aluminum concentration gradient" used according to the invention refers in particular to the fact that the concentration of aluminum in the (total) hot-dip galvanized layer is irregularly distributed or not uniform throughout, specifically such that a particularly high amount of aluminum is present on the outer layers, and furthermore, an increased amount of aluminum is also present directly or immediately adjacent to the base material. The increased amount of aluminum at the base material is primarily due to the high affinity between aluminum and iron—without limiting ourselves to this theory—so that some of the aluminum diffuses into the base material. In other words, the aluminum concentration is relatively low, particularly in the interior or "middle" of the (total) hot-dip galvanized layer.

[0257] The (total) layer thickness of the (total) hot-dip galvanizing layer of the hot-dip galvanized iron or steel component can vary in other areas: In particular, the hot-dip galvanized iron or steel component can have a (total) hot-dip galvanizing layer with a total layer thickness of at least 30 µm, in particular at least 35 µm, preferably at least 40 µm, particularly preferably at least 45 µm.

[0258] Furthermore, the hot-dip galvanized iron or steel component can have a (total) hot-dip galvanizing layer with a total layer thickness of at most 500 µm, in particular at most 450 µm, preferably at most 400 µm, and especially preferably at most 300 µm.

[0259] Furthermore, the hot-dip galvanized iron or steel component can have a (total) hot-dip galvanizing layer with a total layer thickness in the range of 30 µm to 500 µm, in particular in the range of 35 µm to 450 µm, preferably in the range of 40 µm to 400 µm, and especially preferably in the range of 45 µm to 300 µm.

[0260] According to a particular embodiment of the present invention, the hot-dip galvanized iron or steel component can be designed to be bendable at 90° at least substantially without impairing the corrosion protection performance.

[0261] This means, in particular, that the corrosion protection performance of the hot-dip galvanized component does not decrease, or at least not substantially decreases, after a 90° bend. Specifically, the hot-dip galvanized component exhibits very high corrosion protection performance even after a 90° bend.

[0262] According to a further particular embodiment, the hot-dip galvanized iron or steel component, in particular with a base material thickness of the iron or steel component of at least 2 mm and a total layer thickness of the (total) hot-dip galvanizing layer of at least 30 µm, after 90° bending with a residence time of at least 1,000 h, in particular at least 1,250 h, preferably at least 1,500 h, particularly preferably at least 1,750 h, most preferably at least 2,000 h, in the salt spray test, in particular according to DIN EN ISO 9227, exhibits at least substantially no red rust formation, preferably no red rust formation at all.

[0263] A previously mentioned residence time in the salt spray test without red rust formation demonstrates a high level of corrosion protection.

[0264] Red rust consists primarily of corrosion products of iron and steel (iron oxides) and indicates damage to the substrate that the hot-dip galvanizing layer is intended to protect. Red rust therefore forms when corrosion protection is inadequate.

[0265] In particular, the hot-dip galvanized iron or steel component, especially with a total hot-dip galvanizing layer of at least 350 g / m², exhibits 2 , with a residence time of at least 1,000 h, in particular at least 2,000 h, preferably at least 5,000 h, particularly preferably at least 8,000 h, most preferably at least 10,000 h, in the salt spray test, in particular according to DIN EN ISO 9227, at least substantially no red rust formation, preferably no red rust formation, occurs.

[0266] In comparison, state-of-the-art hot-dip galvanized iron or steel components can only withstand approximately 800 hours in the salt spray test according to DIN EN ISO 9227 without red rust formation, even with a hot-dip galvanizing layer of 550 g / m². 2 . Thus, the hot-dip galvanized iron or steel components according to the invention can remain in the salt spray test according to DIN EN ISO 9227 for a longer period of time without red rust formation, and even with a lower layer thickness of the hot-dip galvanizing layer.

[0267] Without wishing to limit ourselves to this theory, this improvement in corrosion protection performance is due to the special multi-layered or multi-phase structure of the (total) hot-dip galvanizing layer of the described hot-dip galvanized iron or steel component, in particular to the presence of an at least partially multi-phase and / or at least partially layered hot-dip galvanizing layer with Zn / Al / Fe phases.

[0268] The described hot-dip galvanized iron or steel component also has a multitude of completely unexpected advantages, special features and surprising technical effects, the following description of which makes no claim to completeness, but illustrates the inventive character of the present invention: For, as the applicant has now discovered quite unexpectedly, the described hot-dip galvanized iron or steel component has a higher corrosion protection with the same thickness of the hot-dip galvanizing layer compared to a conventional pure zinc layer.

[0269] In particular, the described hot-dip galvanized iron or steel component has a hot-dip galvanizing layer that is at least partially multi-phase and / or at least partially layered, consisting of Zn / Al / Fe phases. The hot-dip galvanizing layer exhibits high corrosion protection properties and high ductility. Furthermore, the hot-dip galvanizing layer is very bright and therefore visually of particularly high quality.

[0270] These Zn / Al / Fe phases may include, in particular, Zn, ZnAl, ZnFe and / or AlFe phases; this is especially the case when hot-dip galvanizing is carried out using an aluminum-alloyed or aluminum-containing zinc melt.

[0271] If a non-aluminium alloyed or non-aluminium-containing zinc melt is used in hot-dip galvanizing, a multi-phase and / or at least partially layered (total) hot-dip galvanizing layer is provided, which consists of Zn and ZnFe phases.

[0272] The hot-dip galvanizing layer according to the invention exhibits high corrosion protection properties and high ductility. In addition, this hot-dip galvanizing layer is very bright and therefore visually of particularly high quality.

[0273] Surprisingly, the hot-dip galvanizing layer containing Zn / Al / Fe phases of the described hot-dip galvanized component cannot be obtained by known methods. The hot-dip galvanizing layer of the described hot-dip galvanized component thus offers different properties that are not achievable by known hot-dip galvanizing layers obtained in single-stage processes.

[0274] In particular, the hot-dip galvanizing layer of the described hot-dip galvanized component is more ductile and therefore less brittle than a pure zinc layer and can thus be formed or cold-formed, for example bent by 90°, without losing or significantly impairing its corrosion protection properties. At the same time, the hot-dip galvanizing layer of the described hot-dip galvanized component can be provided with a greater thickness than a conventional aluminum-containing or aluminum-alloyed zinc layer (i.e., an aluminum-containing or aluminum-alloyed zinc layer that is applied directly to a component without an existing zinc layer), especially since the hot-dip galvanizing layer of the described hot-dip galvanized component is not limited by a maximum achievable thickness (as is the case with a conventional aluminum-containing or aluminum-alloyed zinc layer).aluminium alloy hot-dip galvanizing layer through the formation of an Fe / Al barrier layer).

[0275] In particular, the thickness of the hot-dip galvanizing layer of the described hot-dip galvanized component is essentially unlimited, unlike in the case of a conventional aluminum-containing or aluminum-alloyed hot-dip galvanizing layer obtained through a single-stage process. This allows for the production of hot-dip galvanizing layers with a high aluminum content and a thickness significantly exceeding 25 µm. At the same time, the hot-dip galvanizing layer of the described component also exhibits the advantages of an aluminum-containing or aluminum-alloyed hot-dip galvanizing layer, such as gloss, ductility, and high corrosion protection properties.

[0276] For further details regarding the described hot-dip galvanized iron or steel component, reference can be made to the above statements relating to the first and second aspects of the invention, which also apply accordingly to the described hot-dip galvanized iron or steel component.

[0277] Finally, a further subject of the present invention – according to a third aspect of the present invention – is its use in connection with a hot-dip galvanizing process according to the present invention.

[0278] According to the invention, the present invention relates to the use of a hot-dip galvanizing process for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component, wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subjected to an activation treatment, in particular an activation treatment comprising chemical and mechanical treatment, before hot-dip galvanizing, such that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ·cm. 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, and wherein the galvanized iron or steel component that has undergone activation treatment is subsequently subjected to hot-dip galvanizing, where the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component is determined before the activation treatment, where the electrical resistance at the surface of the zinc layer is at most 500 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, where at least a flux treatment is carried out as an activation treatment; and / or where the electrical resistance at the surface of the zinc layer is more than 500 kΩ · cm 2, in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least first a pickling treatment and subsequently a flux treatment is carried out, in particular wherein a rinsing process is carried out after the pickling treatment and before the flux treatment, in particular by immersion in a water bath.

[0279] Within the scope of the present invention, a galvanized iron or steel component can thus be regenerated, reprocessed, or reused, particularly without the need to completely remove the existing zinc layer. As previously explained, this process is especially economical, environmentally friendly, and resource-efficient, conserving material and resources, and requiring minimal effort.

[0280] Also described is the use of the electrical resistance at the surface of a zinc layer of a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, for adjusting an activation treatment, in particular an activation treatment comprising a chemical and mechanical treatment, for preparing the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, for hot-dip galvanizing. in particular wherein the type and / or duration and / or intensity of the activation treatment depends on the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, where the electrical resistance at the surface of the zinc layer is at most 500 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, where at least a flux treatment is carried out as an activation treatment; and / or where the electrical resistance at the surface of the zinc layer is more than 500 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least first a pickling treatment and subsequently a flux treatment is carried out, in particular wherein a rinsing process is carried out after the pickling treatment and before the flux treatment, in particular by immersion in a water bath.

[0281] It is intended that the electrical resistance at the surface of the zinc layer will not exceed 500 kΩ·cm. 2, in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, at least a flux treatment is carried out as an activation treatment.

[0282] It is also stipulated that if the electrical resistance at the surface of the zinc layer exceeds 500 kΩ · cm, 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least first a pickling treatment and subsequently a flux treatment is carried out, in particular wherein a rinsing process is carried out after the pickling treatment and before the flux treatment, in particular by immersion in a water bath.

[0283] By adjusting the activation treatment based on the electrical resistance of the zinc layer's surface, the entire process can be made particularly sustainable. In this context, the electrical resistance is a measure of the zinc layer's quality and thus a measure of the necessary extent of the activation treatment.

[0284] Also described in more detail is the use of the electrical resistance on the surface of a zinc layer of a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanized layer, for determining the condition and / or quality of the zinc layer, preferably a hot-dip galvanized layer, for the regeneration and / or reprocessing and / or reuse of the iron or steel component having the zinc layer, preferably a hot-dip galvanized layer, by means of subsequent hot-dip galvanizing (hot-dip galvanizing). wherein the galvanized iron or steel component is subjected to an activation treatment, in particular an activation treatment comprising chemical and mechanical treatment, in preparation for hot-dip galvanizing, wherein the electrical resistance at the surface of a zinc layer is used and / or taken into account to adjust the activation treatment, where the electrical resistance at the surface of the zinc layer is at most 500 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, where at least a flux treatment is carried out as an activation treatment; and / or where the electrical resistance at the surface of the zinc layer is more than 500 kΩ · cm 2, in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least first a pickling treatment and subsequently a flux treatment is carried out, in particular wherein a rinsing process is carried out after the pickling treatment and before the flux treatment, in particular by immersion in a water bath.

[0285] It is intended that the galvanized iron or steel component will be subjected to an activation treatment, in particular an activation treatment comprising chemical and mechanical treatment, in preparation for hot-dip galvanizing, whereby the electrical resistance at the surface of a zinc layer is used and / or taken into account to adjust the activation treatment.

[0286] In particular, the type and / or duration and / or intensity of the activation treatment can depend on the electrical resistance on the surface of the zinc layer of the galvanized iron or steel component, especially the iron or steel component having a zinc layer, preferably a hot-dip galvanized layer.

[0287] With an electrical resistance at the surface of the zinc layer of at most 500 kΩ · cm 2 , in particular determined according to DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, at least a flux treatment is carried out as an activation treatment.

[0288] If the electrical resistance at the surface of the zinc layer is more than 500 kΩ · cm 2, in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, as activation treatment at least first a pickling treatment and subsequently a flux treatment, in particular wherein after the pickling treatment and before the flux treatment a rinsing process, in particular by immersion in a water bath.

[0289] For further details on the uses according to the third aspect of the invention, reference can be made to the above statements relating to the preceding aspects of the invention, which also apply accordingly to the uses according to the third aspect of the invention.

[0290] Further features, advantages, and applications of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawings and the drawings themselves. All features described and / or illustrated, individually or in any combination, constitute the subject matter of the present invention, irrespective of their compilation in the claims and their cross-references.

[0291] It shows: Fig. 1 a hot-dip galvanized iron or steel component obtainable by the inventive method according to a particular embodiment, Fig. 2 a schematic representation of a system according to the invention in a particular embodiment of the present invention.

[0292] In Fig.1 is a hot-dip galvanized iron or steel component 1 obtainable by the inventive method according to a particular embodiment, wherein the iron or steel component 1 has a multi-layered (overall) hot-dip galvanizing layer 3 applied to the base material of the iron or steel component 2. The multi-layered or multi-phase hot-dip galvanizing layer 3 comprises an at least partially multi-phase and / or at least partially layered hot-dip galvanizing layer with Zn / Al / Fe phases. For further details, reference can be made to the above descriptions.

[0293] Fig.Figure 2 shows a hot-dip galvanizing plant AZ according to a particular embodiment, wherein the devices are depicted in the corresponding sequence of the process steps to be carried out (i.e., in the sequence of the process direction): The hot-dip galvanizing plant AZ initially comprises a testing device ÜV, a spectroscopy device SV, a further measuring device MV', an activation device AV, a drying device TE, a spectroscopy device SV, a measuring device MV, and a measuring device SV.A hot-dip galvanizing device FZ is installed downstream and / or arranged in the process flow, as is a cooling device AK, and a finishing device AV is installed downstream and / or arranged in the process flow. For further details, please refer to the above explanations.

[0294] Further embodiments, modifications and variations of the present invention are readily apparent and feasible to the person skilled in the art when reading the description, without leaving the scope of the present invention.

[0295] The present invention is illustrated by the following exemplary embodiments, which are not intended to limit the present invention in any way, but merely to explain exemplary and non-limiting implementations and embodiments. EXECUTION EXAMPLES Example 1: Influence of activation treatment on zinc layer thickness

[0296] To investigate the influence of activation treatment on zinc layer thickness, hot-dip galvanized steel sheets measuring 100 mm x 200 mm x 2 mm are subjected to different activation treatments. In particular, the removal of the zinc layer is examined.

[0297] The hot-dip galvanized steel sheets were galvanized in a so-called pure zinc bath in accordance with DIN EN ISO 1461 and DASt guideline 022.

[0298] This is followed by an activation treatment in one of the subsequent baths A to C and the zinc layer thickness over time is determined. Table 1: Activation baths used Ingredients Bad A Bad B Bad C HCl[g / l] 30,6 13,5 42,3 HCl[%] 3,0 1,4 4,2 Fe [g / l] 3,42 1,73 13,4 Zn [g / l] 34,3 14,1 1,1

[0299] Bath A corresponds to a typical dezincification bath with low acid and high zinc concentration. To determine the removal rate, galvanized steel sheets (treated in a pure zinc bath) are immersed in Bath A, and the layer thickness is measured at time intervals. The corresponding results are shown in Table 2. Table 2: Zinc layer thickness as a function of time during immersion in bath A Time [min] Layer thickness [µm] 0 76,34 3 74,76 6 73,14 9 69,86 12 68,00

[0300] Bath B is a less intensive version of Bath A. To determine the corrosion rate, steel sheets galvanized in a pure zinc bath are immersed in Bath B, and the layer thickness is measured at time intervals. The corresponding results are shown in Table 3. Table 3: Zinc layer thickness as a function of time during immersion in bath B Time [min] Layer thickness [µm] 0 73,90 3 72,22 6 71,66 9 69,86 12 68,02

[0301] Bath C corresponds to a pickling solution used in conventional galvanizing processes (i.e., high iron and low zinc content). To determine the removal rate, steel sheets galvanized in a pure zinc bath are immersed in Bath C, and the layer thickness is measured at time intervals. The corresponding results are shown in Table 4. Table 4: Zinc layer thickness as a function of time during immersion in bath C Time [min] Layer thickness [µm] 0 56,21 1 52,56 2 51,90 3 50,94 4 48,86

[0302] Overall, the following wear rates can be determined from the tests carried out: Table 5: Abrasion rates Bad A Bad B Bad C Removal rate [µm / min] 0,695 0,49 1,825

[0303] Overall, baths A and B allow for precise and targeted pickling and stripping of galvanized components. Using bath C, precise and targeted pickling and stripping of galvanized components is more difficult. However, bath C allows for the removal of larger quantities of contaminants in a shorter time. Example 2: Dependence of the galvanizing result on electrical resistance

[0304] The relationship between the electrical resistance of the surface of the zinc layer and the galvanizing result of both hot-dip galvanizing in a pure zinc bath according to DIN 1461 and in an aluminum-containing or aluminum-alloyed zinc bath according to DIN 50997 is investigated.

[0305] Steel sheets measuring 150 mm x 200 mm x 2 mm are zinc-plated in a pure zinc bath according to DIN 1461. The steel sheets are then exposed to oxidative and, if necessary, corrosive conditions. Before a second zinc plating, either in a pure zinc bath according to DIN 1461 or in an aluminum-containing or aluminum-alloyed zinc bath according to DIN 50997, the surface layer resistance is determined according to DIN EN ISO 17475 and DIN 50918 using potentiostatic polarization measurement and a gel electrolyte, and an activation treatment is carried out.

[0306] The activation treatment consists of either a flux treatment alone or a flux treatment combined with a pickling treatment and an intermediate rinsing step. The flux used in the flux treatment is aqueous-based and contains the following ingredients (weight values ​​based on dry weight): 60% by weight zinc chloride and 40% by weight ammonium chloride, with the flux bath having a pH of less than 5. The pickling treatment is carried out with a hydrochloric acid-based pickling solution with a pH of less than 5.

[0307] The resulting zinc layer is then assessed for defects, in particular whether the zinc layer is uniform and free of defects. Table 6: Galvanizing results Attempt Resistance [kΩcm] 2 ] Activation treatment galvanizing bath Zinc layer V1 44,53 flux Pure zinc DIN 1461 without defects V2 81,08 flux Pure zinc DIN 1461 without defects V3 131,553 flux Pure zinc DIN 1461 without defects V4 30,98 flux Zn / Al DIN 50997 without defects V5 105,06 flux Zn / Al DIN 50997 without defects V6 178,117 flux Zn / Al DIN 50997 without defects V7 504,53 pickling agents and fluxes Pure zinc DIN 1461 without defects V8 581,08 pickling agents and fluxes Pure zinc DIN 1461 without defects V9 631,553 pickling agents and fluxes Zn / Al DIN 50997 without defects V10 530,98 pickling agents and fluxes Zn / Al DIN 50997 without defects V11 605,06 pickling agents and fluxes Zn / Al DIN 50997 without defects V12 678,117 pickling agents and fluxes Zn / Al DIN 50997 without defects V13 504,53 flux Pure zinc DIN 1461 inadequate V14 581,08 flux Pure zinc DIN 1461 inadequate V15 631,553 flux Zn / Al DIN 50997 inadequate V16 530,98 flux Zn / Al DIN 50997 inadequate V17 605,06 flux Zn / Al DIN 50997 inadequate V18 678,117 flux Zn / Al DIN 50997 inadequate

[0308] A flawless galvanizing process, whether in a pure zinc bath according to DIN 1461 or in an aluminum-containing or aluminum-alloyed zinc bath according to DIN 50997 with only a flux treatment as activation treatment, is only possible with a surface layer resistance according to DIN EN ISO 17475 and DIN 50918 of less than 500 kΩ · cm. 2 Possible. With a surface layer resistance according to DIN EN ISO 17475 and DIN 50918 above 500 kΩ·cm. 2 Pickling and flux treatment are necessary to obtain a zinc layer without defects. Example 2: Corrosion protection performance

[0309] To verify the corrosion protection performance of the hot-dip galvanized coatings obtained according to the inventive method, steel sheets measuring 100 mm x 200 mm x 2 mm, hot-dip galvanized in a pure zinc bath according to DIN 1461, are hot-dip galvanized again after storage under oxidative conditions for 48 h according to the inventive method using an aluminum-containing or aluminum-alloyed zinc bath according to DIN 50997. Since the steel sheets each have an electrical resistance at the surface of the zinc layer of no more than 500 kΩ·cm, 2 For products meeting the requirements of DIN EN ISO 17475 and DIN 50918, only flux treatment is carried out before hot-dip galvanizing. The flux used in this treatment is aqueous and contains the following ingredients (weight values ​​based on dry weight): 60 wt% zinc chloride and 40 wt% ammonium chloride, with the flux bath having a pH value of less than 5.

[0310] Microscopic analyses show that the steel sheets regenerated or reprocessed according to the inventive method do not have two different or separate hot-dip galvanizing layers on top of each other, but rather that the aluminum-containing or aluminum-alloyed zinc melt diffuses into the existing hot-dip galvanizing zinc layer. Overall, a multi-layered (total) hot-dip galvanizing layer is thus present on the base material of the iron or steel component, wherein at least a partially multi-phase and / or at least partially layered hot-dip galvanizing layer with Zn / Al / Fe phases is present, and an aluminum gradient is present.

[0311] Furthermore, new (i.e., without a zinc coating) steel sheets measuring 100 mm x 200 mm x 2 mm are hot-dip galvanized according to standard procedures in a pure zinc bath according to DIN 1461 or in an aluminum-containing or aluminum-alloyed zinc bath according to DIN 50997. Prior to this, the steel sheets are degreased, rinsed, pickled, rinsed again, treated with a flux, and dried according to standard procedures.

[0312] Then all zinc sheets are coated with a ZINQ ® duropass passivation treatment (passivation with chromium(III)).

[0313] To verify the corrosion protection performance, the steel sheets are tested in their straight, unprocessed form on the one hand, and after being bent by 90° (i.e., after cold forming) on ​​the other, each time using a salt spray test according to DIN EN ISO 9227 for 1008 hours. The amount of white rust and red rust formed on the surface is then determined, and the proportion of the surface area exhibiting white rust and red rust, respectively, is specified. Table 7: Results for the straight sheets Proceedings Regeneration of the zinc layer (according to the invention) Zinc melt (DIN 1461) Zn / Al melt (DIN 50997) Layer thickness 76,5 µm 68,6 µm 6,9 µm White rust 40 - 50 % 90 - 95 % 5 - 10 % Red rust 0 % 0,5 - 1 % ≤ 0,5 % Table 8: Results of the sheets bent by 90° Proceedings Regeneration of the zinc layer (according to the invention) Zinc melt (DIN 1461) Zn / Al melt (DIN 50997) Layer thickness 46,2 µm 68,2 µm 6,8 µm White rust 20 % 90 - 95 % 5 - 10 % Red rust 0 % 1 - 2,5 % 5%

[0314] The white rust that forms consists of zinc corrosion products (zinc oxide, zinc hydroxide, zinc carbonate, and the like). This only affects the appearance; it does not represent material damage, as the base material remains intact and uncorroded. In contrast, the red rust that forms consists of the corrosion products of the iron- or steel-based base material or component (namely, iron oxides), which indicates material damage. Red rust therefore only forms when corrosion protection is inadequate.

[0315] As can be seen from the results in Tables 7 and 8, neither the straight nor the shaped components regenerated or reprocessed using the hot-dip galvanizing process according to the invention exhibit red rust after 1,008 h in the salt spray test. In contrast, red rust forms on the surface of both the straight and the shaped components hot-dip galvanized in the zinc melt and the zinc / aluminum melt. This is attributable—without limiting ourselves to this theory—to the specific layer structure described above.

Claims

[1] Method for hot-dip galvanizing a galvanized iron or steel component, wherein the galvanized iron or steel component is subjected to an activation treatment prior to hot-dip galvanizing such that and / or with the stipulation that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ · cm 2 exhibits, wherein the galvanized iron or steel component that has undergone activation treatment is subsequently subjected to hot-dip galvanizing, where the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component is determined before the activation treatment, where the activation treatment, depending on the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, comprises only a flux treatment or a pickling treatment and a flux treatment, where the electrical resistance at the surface of the zinc layer is at most 500 kΩ · cm 2 As an activation treatment, at least a flux treatment is carried out and where the electrical resistance at the surface of the zinc layer is more than 500 kΩ · cm 2 As an activation treatment, at least initially a pickling treatment and subsequently a flux treatment are carried out. [2] Method according to claim 1, wherein the molten zinc used in hot-dip galvanizing contains, based on the total zinc melt, at most 98 wt.%, in particular at most 97 wt.%, preferably at most 96 wt.%, zinc; and / or wherein the zinc melt used in hot-dip galvanizing contains zinc in amounts ranging from 55 wt.% to 98 wt.%, in particular from 65 wt.% to 97 wt.%, preferably from 75 wt.% to 96 wt.%, based on the zinc melt. [3] Method according to claim 1 or claim 2, wherein the zinc melt used in hot-dip galvanizing is an aluminum-alloyed and / or aluminum-containing zinc melt; in particular wherein the molten zinc used in hot-dip galvanizing contains at least 2 wt.%, in particular at least 3 wt.%, preferably at least 4 wt.%, aluminium, based on the molten zinc; and / or in particular wherein the molten zinc used in hot-dip galvanizing contains, based on the molten zinc, at most 45 wt.%, in particular at most 25 wt.%, preferably at most 8 wt.%, particularly preferably at most 6 wt.%, aluminium; and / or in particular wherein the molten zinc used in hot-dip galvanizing contains, based on the molten zinc, aluminium in amounts in the range of 2 wt.% to 45 wt.%, in particular in the range of 2 wt.% to 25 wt.%, preferably in the range of 3 wt.% to 8 wt.%, most preferably in the range of 4 wt.% to 6 wt.%. [4] Method according to any of the preceding claims, wherein the molten zinc used in the hot-dip galvanizing process contains, based on the molten zinc, at most 98 wt.% zinc and at least 2 wt.% aluminium. [5] Method according to any of the preceding claims, wherein the zinc melt used in hot-dip galvanizing contains, based on the zinc melt, at most 98 wt.%, in particular at most 97 wt.%, preferably at most 96 wt.%, zinc and wherein the molten zinc used in hot-dip galvanizing contains at least 2 wt.%, in particular at least 3 wt.%, preferably at least 4 wt.%, aluminium, based on the molten zinc. [6] Method according to any of the preceding claims, wherein the zinc melt used in the hot-dip galvanizing process contains, based on the zinc melt, zinc in amounts ranging from 55 wt.% to 98 wt.% and aluminium in amounts ranging from 2 wt.% to 45 wt.%. [7] Method according to any of the preceding claims, wherein the zinc melt used in hot-dip galvanizing contains zinc in amounts ranging from 55 wt.% to 98 wt.%, in particular from 65 wt.% to 97 wt.%, preferably from 75 wt.% to 96 wt.%, based on the zinc melt wherein the molten zinc used in hot-dip galvanizing contains, based on the molten zinc, aluminium in amounts in the range of 2 wt.% to 45 wt.%, in particular in the range of 2 wt.% to 25 wt.%, preferably in the range of 3 wt.% to 8 wt.%, particularly preferably in the range of 4 wt.% to 6 wt.%. [8] Method for hot-dip galvanizing a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, in particular for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component, according to one of the preceding claims, wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subjected to an activation treatment prior to hot-dip galvanizing, in particular an activation treatment comprising a chemical and / or mechanical treatment, preferably an activation treatment comprising at least one chemical and optionally one mechanical treatment, and wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subsequently subjected to hot-dip galvanizing, wherein the zinc melt used in the hot-dip galvanizing contains, based on the zinc melt, at most 98 wt.% zinc and optionally at least 2 wt.% aluminium. [9] Method for hot-dip galvanizing a galvanized iron or steel component, in particular an iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, in particular for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component, according to one of the preceding claims, wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is subjected to an activation treatment prior to hot-dip galvanizing, in particular an activation treatment comprising a chemical and / or mechanical treatment, preferably an activation treatment comprising at least one chemical and optionally one mechanical treatment, such that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ·cm2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, and wherein the galvanized iron or steel component that has undergone activation treatment is subsequently subjected to hot-dip galvanizing, wherein the molten zinc used in the hot-dip galvanizing contains, based on the molten zinc, at most 98 wt.% zinc and optionally at least 2 wt.% aluminium. [10] Method according to any of the preceding claims, wherein the aluminium alloyed and / or aluminium-containing zinc melt used in hot-dip galvanizing has the following composition, wherein all the quantities specified below refer to the aluminium alloyed and / or aluminium-containing zinc melt and are to be selected such that a total of 100 wt.% results: (i) Zinc, in particular in amounts in the range of 55 wt.% to 98 wt.%, in particular in the range of 65 wt.% to 97 wt.%, preferably in the range of 75 wt.% to 96 wt.%, (ii) Aluminium, in particular in amounts in the range of 2 wt.% to 45 wt.%, in particular in the range of 3 wt.% to 8 wt.%, preferably in the range of 4 wt.% to 6 wt.%, (iii) optionally magnesium, in particular in amounts in the range of 0.1 wt.% to 10 wt.%, in particular in the range of 0.1 wt.% to 3 wt.%, preferably in the range of 0.1 wt.% to 2 wt.%; (iii) optionally at least one further metal, in particular in amounts up to 10 wt.% and / or in particular selected from the group consisting of bismuth, lead, tin, nickel, silicon and combinations thereof. [11] Method according to one of the preceding claims, wherein the aluminium alloyed and / or aluminium-containing zinc melt used in hot-dip galvanizing has a temperature in the range of 330 °C to 750 °C, in particular in the range of 340 °C to 600 °C, preferably in the range of 350 °C to 465 °C, particularly preferably in the range of 415 °C to 455 °C. [12] Method according to any of the preceding claims, wherein the galvanized iron or steel component is immersed, and in particular immersed and moved, in the aluminum-alloyed and / or aluminum-containing zinc melt used in the hot-dip galvanizing process, particularly for a period of time sufficient to ensure effective hot-dip galvanizing, in particular for a period of time in the range of 0.0001 to 60 minutes, in particular in the range of 0.001 to 45 minutes, preferably in the range of 0.5 to 30 minutes, and most preferably in the range of 4 to 8 minutes; and / or wherein the galvanized iron or steel component is immersed, in particular immersed and moved, in the aluminum-alloyed and / or aluminum-containing zinc melt used in the hot-dip galvanizing process, particularly for a period of time sufficient to achieve effective hot-dip galvanizing, in particular for a period of time of at least 0.0001 minutes, preferably at least 0.5 minutes, and most preferably at least 4 minutes; and / or wherein the galvanized iron or steel component is immersed in the aluminium alloyed and / or aluminium-containing zinc melt used in hot-dip galvanizing, in particular immersed and moved therein, in particular for a period of time sufficient to ensure effective hot-dip galvanizing, in particular for a period of time of at most 60 minutes, in particular at most 45 minutes, preferably at most 30 minutes, particularly preferably at most 8 minutes. [13] Method according to any of the preceding claims, where a hot-dip galvanizing layer is present after hot-dip galvanizing; in particular where, in hot-dip galvanizing, a multi-phase and / or multi-layer, especially multi-phase, hot-dip galvanizing layer is formed on the base material of the iron or steel component; and / or in particular where, in hot-dip galvanizing, an at least partially multi-phase and / or at least partially layered hot-dip galvanizing layer with Zn / Al / Fe phases is formed; and / or in particular wherein the hot-dip galvanizing is carried out in such a way and / or with the proviso that the aluminum-containing and / or aluminum-alloyed zinc melt diffuses at least partially into the existing zinc layer, preferably hot-dip galvanizing layer, of the component; and / or in particular, wherein the hot-dip galvanizing is carried out with the stipulation and / or in such a way that a hot-dip galvanizing layer with an aluminium concentration gradient is formed. [14] Method according to any of the preceding claims, wherein the total thickness of the hot-dip galvanized layer resulting from the process is at least 30 µm, in particular at least 35 µm, preferably at least 40 µm, and most preferably at least 45 µm; and / or wherein the total thickness of the hot-dip galvanized layer resulting from the process is at most 500 µm, in particular at most 450 µm, preferably at most 400 µm, and most preferably at most 300 µm; and / or wherein the total thickness of the hot-dip galvanized layer resulting from the process is in the range of 30 µm to 500 µm, in particular in the range of 35 µm to 450 µm, preferably in the range of 40 µm to 400 µm, and most preferably in the range of 45 µm to 300 µm; and / or wherein the hot-dip galvanizing is carried out in such a manner and / or with the stipulation that the total layer thickness of the hot-dip galvanizing layer resulting after carrying out the process is in the range of 30 µm to 500 µm, in particular in the range of 35 µm to 450 µm, preferably in the range of 40 µm to 400 µm, particularly preferably in the range of 45 µm to 300 µm. [15] Method according to any of the preceding claims, wherein a cooling treatment is carried out after hot-dip galvanizing; and / or wherein the iron or steel component obtained after hot-dip galvanizing is subjected to a cooling treatment; and / or wherein a post-treatment treatment is carried out after hot-dip galvanizing; and / or wherein the iron or steel component obtained after hot-dip galvanizing is subjected to a post-treatment treatment. [16] Method according to any of the preceding claims, wherein the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer in the range of 0.0001 kΩ · cm 2 up to 500 kΩ · cm 2 , especially in the range of 0.0001 kΩ · cm 2 up to 300 kΩ · cm 2 preferably in the range of 0.0001 kΩ·cm 2 up to 250 kΩ · cm 2 , particularly preferably in the range of 0.0001 kΩ · cm 2 up to 200 kΩ · cm 2 , in particular determined in accordance with DIN EN ISO 17475 and / or DIN 50918, in particular by means of potentiostatic polarization measurement, exhibits. [17] Method according to any of the preceding claims, wherein the electrical resistance is the surface layer resistance, in particular the polarization resistance of the surface layer. [18] Method according to one of the preceding claims, wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, is at least partially, in particular completely, galvanized on at least one surface, in particular having a zinc layer. [19] Method according to any of the preceding claims, wherein the activation treatment includes at least one chemical and, if applicable, one mechanical treatment; the chemical treatment includes at least a flux treatment and, if necessary, a pickling treatment; in particular wherein the chemical treatment is carried out by an aqueous saline solution, in particular with a pH value of less than 5; and / or in particular wherein the chemical treatment is carried out for a period of time in the range of 1 second to 60 min, in particular in the range of 5 seconds to 45 min, preferably in the range of 10 seconds to 30 min. [20] Method according to claim 19, wherein the chemical treatment is carried out by means of flux treatment in a flux composition in a flux bath; in particular wherein the flux bath of the chemical treatment comprises an aqueous and / or alcoholic, in particular aqueous, liquid phase, wherein the liquid phase of the flux bath contains the flux composition, in particular in dissolved or dispersed form, preferably in dissolved form, and / or in particular wherein the flux composition of the chemical treatment comprises as ingredients salts and optionally wetting agents, in particular wherein the salts are selected from the group of chlorides, preferably from the group of zinc chloride, ammonium chloride, alkali and / or alkaline earth chlorides, in particular potassium chloride and / or sodium chloride, aluminum chloride, silver chloride, lead chloride, nickel chloride, bismuth chloride, tin chloride, manganese chloride, cobalt chloride and combinations thereof; and / or in particular wherein the flux composition of the chemical treatment comprises as ingredients zinc chloride and optionally at least one alkali and / or alkaline earth chloride, in particular potassium chloride and / or sodium chloride, as well as optionally wetting agents and optionally at least one further salt, different from the aforementioned compounds, selected from the group of chlorides, preferably from the group of ammonium chloride, aluminium chloride, silver chloride, lead chloride, nickel chloride, bismuth chloride, tin chloride, manganese chloride, cobalt chloride and combinations thereof; and / or in particular wherein the flux composition of the chemical treatment comprises as ingredients salts and optionally wetting agents, in particular wherein the flux composition comprises at least zinc chloride and at least one alkali and / or alkaline earth chloride, in particular potassium chloride and / or sodium chloride; and / or in particular wherein the flux composition of the chemical treatment is free of ammonium chloride; and / or in particular wherein the flux composition of the chemical treatment contains at least substantially no ammonium chloride; and / or in particular wherein the flux bath of the chemical treatment has a salt content of at least 20 wt.%, in particular at least 30 wt.%, preferably at least 50 wt.%, most preferably at least 60 wt.%, based on the flux bath; and / or in particular wherein the flux bath of the chemical treatment has a salt content of at most 90 wt.%, in particular at most 85 wt.%, preferably at most 80 wt.%, most preferably at most 75 wt.%, based on the flux bath; and / or in particular wherein the flux bath of the chemical treatment has a salt content in the range of 20 wt.% to 90 wt.%, particularly in the range of 30 wt.% to 85 wt.%, preferably in the range of 50 wt.% to 80 wt.%, most preferably in the range of 60 wt.% to 75 wt.%, based on the flux bath; and / or in particular wherein the flux bath of the chemical treatment has a salt content in the range of 100 g / l to 800 g / l, particularly in the range of 140 g / l to 720 g / l, preferably in the range of 170 g / l to 670 g / l, most preferably in the range of 200 g / l to 600 g / l. [21] Method according to claim 20, wherein the flux composition of the chemical treatment comprises the following ingredients, wherein all quantities listed below refer to the flux composition and are to be selected in such a way as to result in a total of 100 wt.%: (i) Zinc chloride, in particular in amounts in the range of 50 to 95 wt.%, in particular in the range of 50 to 90 wt.%, preferably in the range of 60 to 85 wt.%, particularly preferably in the range of 65 to 82.5 wt.%, even more preferably in the range of 70 to 82 wt.%, (ii) Ammonium chloride, in particular in amounts in the range of 0 to 50 wt.%, in particular in the range of 6 to 40 wt.%, preferably in the range of 7 to 35 wt.%, particularly preferably in the range of 8 to 25 wt.%, even more preferably in the range of 10 to 20 wt.%, (iii) Sodium chloride, in particular in amounts in the range of 0.1 to 20 wt.%, in particular in the range of 0.5 to 15 wt.%, preferably in the range of 1 to 12.5 wt.%, particularly preferably in the range of 2 to 10 wt.%, even more preferably in the range of 4 to 8 wt.%, and (iv) Potassium chloride, in particular in amounts in the range of 0.1 to 15 wt.%, preferably in the range of 0.2 to 12.5 wt.%, preferably in the range of 0.4 to 10 wt.%, particularly preferably in the range of 0.5 to 8 wt.%, even more preferably in the range of 0.8 to 6 wt.%. [22] Method according to claim 19, where the chemical treatment is carried out by means of pickling treatment in a pickling agent; in particular wherein the pickling treatment is carried out using a hydrochloric acid-containing and / or hydrochloric acid-based pickling agent, in particular wherein the pickling agent has a pH value of less than 5; and / or in particular, wherein the pickling treatment is carried out using an acidic pickling agent, especially a pickling agent with a pH value of less than 5; and / or in particular wherein the pickling agent contains iron, especially in the form of divalent and / or trivalent iron ions; and / or in particular wherein the pickling agent contains zinc at a level of at least 10 g / l; and / or in particular wherein the pickling agent contains zinc with a content of at least 10 g / l and has an iron content of no more than 20% of the zinc content; and / or in particular wherein the pickling agent contains at least one additive, in particular at least one pickling additive, in particular selected from the group of corrosion inhibitors, pickling cleaners, pickling accelerators and pickling enhancers and combinations thereof. [23] Method according to claim 21 or claim 22, wherein the pickling agent and / or the flux bath of the chemical treatment contains and / or includes at least one wetting agent and / or surfactant, in particular at least one ionic or non-ionic wetting agent and / or surfactant, preferably at least one non-ionic wetting agent and / or surfactant; in particular wherein the pickling agent and / or the flux bath of the chemical treatment contains and / or includes the at least one wetting agent and / or surfactant in amounts of 0.0001 to 15 wt.%, preferably in amounts of 0.001 to 10 wt.%, preferably in amounts of 0.01 to 8 wt.%, even more preferably in amounts of 0.01 to 6 wt.%, most preferably in amounts of 0.05 to 3 wt.%, even more preferably in amounts of 0.1 to 2 wt.%, based on the pickling agent and / or flux bath. [24] Method according to any one of the preceding claims 19 to 23, the chemical treatment is carried out by means of a pickling treatment and a flux treatment; in particular wherein the pickling treatment of the chemical treatment and the flux treatment of the chemical treatment each take place for a duration in the range of 1 second to 60 min, in particular in the range of 5 seconds to 45 min, preferably in the range of 10 seconds to 30 min; and / or in particular wherein the pickling treatment is carried out first and then the flux treatment, wherein a rinsing process takes place after the pickling treatment and before the flux treatment, in particular by immersion in a water bath. [25] Method according to any one of the preceding claims 19 to 24, wherein the chemical treatment, in particular the flux treatment and / or the pickling treatment, takes place at elevated temperature; in particular where the flux treatment and / or pickling treatment takes place at a temperature in the range of 20 °C to 90 °C, especially in the range of 25 °C to 80 °C. [26] Method according to any of the preceding claims Claims 19 to 25, wherein the mechanical treatment includes an abrasive treatment; in particular wherein the abrasive treatment is selected from the group of blasting, in particular sandblasting, water blasting and / or dry ice blasting, grinding, brushing, lasering and combinations thereof. [27] Method according to any of the preceding claims, wherein the type and / or duration and / or intensity of the activation treatment depends on the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer. [28] Method according to any of the preceding claims, wherein, prior to determining the electrical resistance, the composition of the zinc layer, in particular the hot-dip galvanizing layer, is determined, in particular by means of laser-induced plasma spectroscopy; in particular where the measurement and / or measurement parameters of the electrical resistance are adapted to the composition of the zinc layer, especially the hot-dip galvanizing layer. [29] Method according to any of the preceding claims, wherein the galvanized iron or steel component undergoing activation treatment is subjected to a drying treatment; in particular wherein the drying treatment is carried out at a temperature in the range of 30 °C to 400 °C, particularly in the range of 35 °C to 375 °C, preferably in the range of 40 °C to 350 °C, most preferably in the range of 50 °C to 325 °C; and / or in particular wherein the drying treatment is carried out for a duration in the range of 0.1 seconds to 60 minutes, particularly in the range of 1 second to 45 minutes, preferably in the range of 10 seconds to 35 minutes, particularly preferably in the range of 20 seconds to 30 minutes, and even more preferably in the range of 20 seconds to 15 minutes; and / or in particular wherein the drying treatment is carried out in the presence of and / or by means of air; and / or in particular wherein the drying treatment takes place in at least one drying device, in particular in at least one oven. [30] Method according to any of the preceding claims, wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, is subjected to an initial inspection before the activation treatment; and / or wherein the galvanized iron or steel component, in particular the one having a zinc layer, preferably hot-dip galvanized, iron or steel component, is checked for suitability for regeneration and / or reprocessing and / or reuse before activation treatment; in particular, the initial inspection is carried out by optical and / or mechanical and / or inductive and / or electrical and / or chemical methods. [31] Method according to claim 30, wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanized layer, is inspected during the initial inspection with regard to at least one specific property and / or one specific test parameter, in particular selected from the group of: condition and / or type of the existing zinc layer; composition and / or grade and / or thickness of the steel part; degree of corrosion and / or wear of the steel part; optical condition of the steel part; deformation of the steel part from its original shape; degree of contamination of the existing zinc layer; type and / or concentration of oxidation products of the zinc layer; type and / or concentration of deposits, in particular of salts, oxides, hydroxides and greases; marking of the steel part; presence and / or condition of fastening options, in particular holes, threads and / or openings;and the presence of foreign coating materials.; [32] Method according to claim 30 or claim 31, wherein the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer, is prepared depending on the initial inspection, in particular by degreasing, reshaping, pressing, rolling, bending, drilling and / or cutting; and / or wherein the activation treatment, in particular the abrasive treatment, of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably hot-dip galvanizing layer, is carried out depending on the initial inspection, in particular in such a way that existing dirt, deposits and / or corrosion products are removed. [33] Method according to any of the preceding claims, wherein the method comprises the following process steps in the order listed below: (a) initial inspection of the galvanized iron or steel component; then (b) Prepare the galvanized iron or steel component checked in step (a); then (c) Measurement of the resistance of the galvanized iron or steel component checked in process step (a) and prepared in process step (b); then (d) Activation of the galvanized iron or steel component inspected in process step (a) and prepared in process step (b); then (e) Drying treatment of the galvanized iron or steel component activated in process step (d); then (f) Hot-dip galvanizing of the galvanized iron or steel component activated in process step (d) and dried in process step (e); then (g) Cooling treatment of the iron or steel component hot-dip galvanized in process step (f); then (h) Post-processing of the iron or steel component which was hot-dip galvanized in process step (f) and cooled in process step (g). [34] Plant (AF) for hot-dip galvanizing an iron or steel component having a zinc layer for carrying out a method according to one of the preceding claims, wherein the plant comprises the following devices in the following order: - an activation device (AD) for activating the galvanized iron or steel component; arranged downstream and / or in the process flow for this purpose - a hot-dip galvanizing device (FZ) for hot-dip galvanizing the iron or steel component obtained after activation in a zinc melt; wherein the system comprises at least one measuring device (MV) arranged downstream of the activation device (AV) and upstream of the hot-dip galvanizing device (FZ) for measuring an electrical resistance on the surface of the zinc layer and wherein a further measuring device (MV') for measuring an electrical resistance on the surface of the zinc layer is arranged upstream of the activation device (AV). [35] System according to claim 34, wherein the measuring device (MV) for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, is designed to measure the surface layer resistance, in particular the polarization resistance of the surface layer. [36] Apparatus according to claim 34 or claim 35, wherein the further measuring device (MV') for measuring an electrical resistance on the surface of the zinc layer, preferably hot-dip galvanizing layer, is designed to measure the surface layer resistance, in particular the polarization resistance of the surface layer. [37] Plant according to any of the preceding claims, wherein the activation device (AD) comprises at least one flux device (FD) and one pickling device (PD) and optionally a mechanical activation device (MD); in particular wherein the flux device (FE) is arranged downstream of the pickling device (BE) and the pickling device (BE) is arranged downstream of the mechanical activation device (MA). [38] Plant according to one of the preceding claims, wherein a cooling device (AK) is arranged downstream of the hot-dip galvanizing device (FZ). [39] Plant according to any of the preceding claims, wherein a post-processing device (NV) is arranged downstream of the hot-dip galvanizing device (FZ); in particular wherein the post-processing device (NV) is arranged downstream of the cooling device (AK). [40] Plant according to any of the preceding claims, wherein, in particular upstream of the measuring device (MV) and / or the further measuring device (MV'), a spectroscopy device (SV) is also arranged; in particular wherein the spectroscopy device (SV) is configured to perform a measurement using laser-induced plasma spectroscopy; and / or in particular wherein the spectroscopy device (SV) comprises at least one laser and at least one detector, in particular a spectrometer. [41] Plant according to one of the preceding claims, wherein a drying device (TE), in particular an oven, is arranged downstream of the activation device (AV). [42] Plant according to any of the preceding claims, wherein a verification device (V) is arranged upstream of the activation device (AV); in particular wherein the inspection device (ID) is designed for the optical and / or mechanical and / or inductive and / or electrical and / or chemical inspection of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer; and / or in particular wherein the inspection device (ID) comprises at least one device for optical and / or mechanical and / or inductive and / or electrical and / or chemical inspection of the galvanized iron or steel component, in particular the iron or steel component having a zinc layer, preferably a hot-dip galvanizing layer. [43] Plant according to any of the preceding claims, wherein the plant comprises the following devices and equipment in the following order: (ÜV) at least one inspection device (ÜV); arranged downstream and / or in the process flow for this purpose (SV) a spectroscopy device (SV); arranged downstream and / or in the process flow (MV') a further measuring device (MV'); arranged downstream and / or in the process flow (AV) at least one activation device (AV), wherein the activation device (AV) comprises at least one flux device (FE) and pickling device (BE) and optionally a mechanical activation device (MA), wherein the flux device (FE) is arranged downstream of the pickling device (BE) and the pickling device (BE) is arranged in particular downstream of the mechanical activation device (MA); downstream and / or arranged downstream in the process sequence thereto (TE) at least one drying device (TE), in particular an oven; arranged downstream and / or in the process flow (SV) a spectroscopy device (SV); arranged downstream and / or in the process flow (MV) at least one measuring device (MV); arranged downstream and / or in the process flow. (FZ) at least one hot-dip galvanizing device (FZ); arranged downstream and / or in the process sequence (AK) at least one cooling device (AK); arranged downstream and / or in the process flow. (NV) at least one post-processing device (AV). [44] Use of a hot-dip galvanizing process for the regeneration and / or reprocessing and / or reuse of a galvanized iron or steel component, wherein the galvanized iron or steel component is subjected to an activation treatment prior to hot-dip galvanizing such that and / or with the stipulation that the galvanized iron or steel component subjected to the activation treatment has an electrical resistance at the surface of the zinc layer of no more than 500 kΩ · cm 2 exhibits, wherein the galvanized iron or steel component that has undergone activation treatment is subsequently subjected to hot-dip galvanizing, where the electrical resistance at the surface of the zinc layer of the galvanized iron or steel component is determined before the activation treatment, where the electrical resistance at the surface of the zinc layer is at most 500 kΩ · cm 2 As an activation treatment, at least a flux treatment is performed; and / or where the electrical resistance at the surface of the zinc layer is more than 500 kΩ · cm 2 As an activation treatment, at least initially a pickling treatment and subsequently a flux treatment are carried out. [45] Use according to claim 44, wherein the hot-dip galvanizing process for regeneration and / or reprocessing and / or reuse of the galvanized iron or steel component is characterized by one or more of the features of claims 1 to 33.

Images