EP3411510B1 - Hot-dip galvanization system and hot-dip galvanization method - Google Patents

Description

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 or motor vehicle industry, by means of hot-dip galvanizing (hot-dip galvanizing).

The present invention relates to a system and a method for hot-dip galvanizing (hot-dip galvanizing) of components (ie of iron-based or iron-containing components, in particular steel-based or steel-containing components (steel components)), for large-scale hot-dip galvanizing of a large number of identical or similar components (e.g. Motor vehicle components) according to claims 1 and 10.

Furthermore, the present invention relates to the use of the system according to the invention or the method according to the invention for hot-dip galvanizing (hot-dip galvanizing) of components (ie of iron-based or iron-containing components, in particular steel-based or steel-containing components (steel components)) for large-scale hot-dip galvanizing of a large number of identical or similar components (e.g. automotive components) according to claim 15.

Metallic components of any kind made of ferrous material, especially components made of steel, often require efficient protection against corrosion due to the application. In particular, components made of steel for motor vehicles (motor vehicles), such as. B. cars, trucks, commercial vehicles, etc., require efficient corrosion protection that can withstand long-term loads.

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

The most important method for protecting steel from corrosion by means of metallic zinc coatings is hot-dip galvanizing (hot-dip galvanizing). Steel is immersed continuously (e.g. strip and wire) or piece by piece (e.g. components) at temperatures of around 450 ° C to 600 ° C in a heated boiler with liquid zinc (melting point of zinc: 419.5 ° C), so that a resistant alloy layer of iron and zinc is formed on the steel surface and above that a very firmly adhering pure zinc layer.

In hot-dip galvanizing, a distinction is made between discontinuous piece galvanizing (see e.g. DIN EN ISO 1461) and continuous strip galvanizing (DIN EN 10143 and DIN EN 10346). Both piece galvanizing and strip galvanizing are standardized processes. Strip-galvanized steel is a preliminary or intermediate product (semi-finished product), which is further processed after galvanizing, in particular by forming, punching, cutting, etc., whereas components to be protected by piece galvanizing are first completely manufactured and only then hot-dip galvanized (which means that the components all around protected against corrosion). Bulk galvanizing and strip galvanizing also differ in terms of the zinc layer thickness, which results in different protection periods. The zinc layer thickness of galvanized sheet metal is usually at most 20 to 25 micrometers, whereas the zinc layer thickness of galvanized steel parts is usually in the range of 50 to 200 micrometers and even more.

Hot-dip galvanizing provides both active and passive corrosion protection. Passive protection is provided by the barrier effect of the zinc coating. Active corrosion protection arises due to the cathodic effect of the zinc coating. Compared to nobler metals of the electrochemical series, such as. As iron, zinc serves as a sacrificial anode, which protects the iron underneath from corrosion until it is completely corroded.

In so-called piece galvanizing according to DIN EN ISO 1461, hot-dip galvanizing of mostly larger steel components and structures takes place. Steel-based blanks or finished workpieces (components) are immersed in the zinc bath after pretreatment. Dipping in particular also makes it easy to reach inner surfaces, weld seams and hard-to-reach places on the workpieces or components to be galvanized.

Conventional hot-dip galvanizing is based in particular on the immersion of iron or steel components in a zinc melt with the formation of a zinc coating or a zinc coating on the surface of the components. In order to ensure the adherence, the integrity and the uniformity of the zinc coating, a thorough surface preparation of the components to be galvanized is generally required in advance, which usually involves degreasing with subsequent rinsing, a subsequent acidic pickling with subsequent rinsing and finally a flux treatment (i.e. a so-called fluxing ) with subsequent drying process.

The typical procedure for conventional piece galvanizing using hot-dip galvanizing is usually as follows. For reasons of process economy and cost-effectiveness, the galvanizing of identical or similar components (e.g. series production of motor vehicle components) is typically combined or grouped for the entire process (in particular by means of a common product carrier or, for example, a crossbar or frame) a common holding or fastening device for a large number of these identical or similar components). For this purpose, a plurality of components on the goods carrier via holding means, such as. B. attached sling, connecting wires or the like. The components are then fed into the subsequent treatment steps or stages in the grouped state via the product carrier.

First, the component surfaces of the grouped components are subjected to degreasing in order to remove residues of fats and oils, usually using aqueous alkaline or acidic degreasing agents as degreasing agents. After cleaning in the degreasing bath, there is usually a rinsing process, typically by immersion in a water bath, in order to prevent the degreasing agents from being carried over with the galvanized material in the subsequent process step of pickling, in particular when changing from alkaline degreasing to an acid base is of great importance.

This is followed by a pickling treatment (pickling), which in particular for removing species-specific impurities, such as. B. rust and scale, from the steel surface. Pickling is usually done in dilute hydrochloric acid, whereby the duration of the pickling process depends, among other things, on the state of contamination (e.g. degree of rusting) of the galvanized material and the acid concentration and temperature of the pickling bath. To avoid or minimize Carryover of acid and / or salt residues with the galvanized material usually takes place after the pickling treatment, a rinsing process (rinsing step).

This is followed by the so-called fluxing (flux treatment), the previously degreased and pickled steel surface using a so-called flux, which is typically an aqueous solution of inorganic chlorides, most often with a mixture of zinc chloride (ZnCl ₂ ) and ammonium chloride (NH ₄ Cl), includes. On the one hand, it is the job of the flux to carry out a final intensive fine cleaning of the steel surface before the reaction of the steel surface with the molten zinc and to dissolve the oxide skin of the zinc surface and to prevent renewed oxidation of the steel surface until the galvanizing process. On the other hand, the flux increases the wettability between the steel surface and the molten zinc. After the flux treatment, drying is usually carried out in order to produce a solid flux film on the steel surface and to remove adhering water, so that undesired reactions (in particular the formation of water vapor) in the liquid zinc dip bath are subsequently avoided.

The components pretreated in the aforementioned manner are then hot-dip galvanized by immersion in the molten zinc. In hot-dip galvanizing with pure zinc, the zinc content of the melt according to DIN EN ISO 1461 is at least 98.0% by weight. After immersing the galvanized material in the molten zinc, it remains in the molten zinc bath for a sufficient period of time, in particular until the galvanized material has reached its temperature and is coated with a zinc layer. Typically, the surface of the zinc melt is cleaned, in particular, of oxides, zinc ash, flux residues and the like before the galvanized material is then pulled out of the zinc melt again. The hot-dip galvanized component is then subjected to a cooling process (e.g. in air or in a water bath). Finally, the holding means for the component, such as. B. sling, connecting wires or the like, removed. The galvanizing process is usually followed by a sometimes complex post-processing or post-treatment. Excess zinc residues, in particular so-called drip noses of the zinc solidifying at the edges, and oxide or ash residues adhering to the component are removed as far as possible.

A criterion for the quality of hot-dip galvanizing is the thickness of the zinc coating in µm (micrometers). The DIN EN ISO 1461 standard specifies the minimum values for the required coating thicknesses, which are to be supplied depending on the material thickness for piece galvanizing. In practice, the layer thicknesses are significantly higher than the minimum layer thicknesses specified in DIN EN ISO 1461. In general, zinc coatings made by bar galvanizing have a thickness in the range of 50 to 200 micrometers and even more.

During the galvanizing process, as a result of a mutual diffusion of the liquid zinc with the steel surface on the steel part, a coating of differently composed iron-zinc alloy layers is formed. When the hot-dip galvanized objects are pulled out, a layer of zinc - also referred to as a pure zinc layer - remains on the top alloy layer, the composition of which corresponds to the zinc melt. Because of the high temperatures during hot-dip immersion, a relatively brittle layer based on an alloy (mixed crystals) is formed between iron and zinc on the steel surface and only the pure zinc layer. The relatively brittle iron-zinc alloy layer improves the adhesive strength with the base material, but complicates the formability of the galvanized steel. Higher silicon contents in the steel, as are used in particular to soothe the steel during its manufacture, lead to an increased reactivity between the molten zinc and the base material and consequently to a strong growth of the iron-zinc alloy layer. In this way, relatively large total layer thicknesses are formed. Although this enables a very long period of corrosion protection, the risk increases that the layer will flake off under mechanical stress, in particular local, sudden effects, and the corrosion protection effect will be disturbed as a result of increasing zinc layer thickness.

In order to counteract the previously described problem of the appearance of the rapidly growing, brittle and thick iron-zinc alloy layer and also to enable smaller layer thicknesses with high corrosion protection during galvanizing, it is known from the prior art that the zinc melt or the liquid zinc bath add aluminum. For example, by adding 5% by weight aluminum to a liquid zinc melt, a zinc-aluminum alloy with a lower melting temperature compared to pure zinc is produced. By using a zinc-aluminum melt (Zn-Al melt) or a liquid zinc-aluminum bath (Zn-Al bath), on the one hand, significantly smaller layer thicknesses can be achieved for reliable corrosion protection realize (generally below 50 microns); on the other hand, the formation of the brittle iron-tin alloy layer does not take place, since the aluminum - without being based on 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. With a zinc-aluminum melt, hot-dip galvanized components can therefore be easily formed, but nevertheless have improved corrosion protection properties - despite the significantly smaller layer thickness compared to conventional hot-dip galvanizing with a quasi aluminum-free zinc melt. A zinc-aluminum alloy used in the hot-dip galvanizing bath has improved fluidity properties compared to pure zinc. In addition, zinc coatings produced by hot-dip galvanizing using such zinc-aluminum alloys have greater corrosion resistance (which is two to six times better than that of pure zinc), improved formability and better paintability than zinc coatings formed from pure zinc. This technology can also be used to produce lead-free zinc coatings.

Such a hot-dip galvanizing process using a zinc-aluminum melt or using a zinc-aluminum hot-dip galvanizing bath is known, for example, from US Pat WO 2002/042512 A1 and the relevant document equivalents for this patent family (e.g. EP 1 352 100 B1 . DE 601 24 767 T2 and US 2003/0219543 A1 ). Suitable fluxes for hot-dip galvanizing using zinc-aluminum hot-dip baths are also disclosed there, since flux compositions for zinc-aluminum hot-dip galvanizing baths are different from those for conventional hot-dip galvanizing with pure zinc. With the method disclosed there, corrosion protection coatings can be produced with very small layer thicknesses (generally significantly below 50 micrometers and typically in the range from 2 to 20 micrometers) and with very low weight with high cost efficiency, which is why the method described there is commercially available under the name microZINQ ® method is applied.

In the case of hot-dip galvanizing of components in zinc-aluminum melt baths, there is a large number of identical or similar components in large-volume hot-dip galvanizing (e.g. large-volume hot-dip galvanizing of automotive components or in the automotive industry) due to the more difficult wettability of the steel with the zinc-aluminum melt as well The small thickness of the zinc coatings or zinc coatings is a problem in subjecting the identical or similar components to identical process conditions and process sequences with an economical process sequence, in particular reliably and perform reproducible high-precision hot-dip galvanizing, which provides identical dimensional accuracy for all identical or similar components. This is done in the prior art - in addition to a complex pretreatment, in particular with the selection of special fluxes - typically in particular by special process control during the galvanizing process, such as. B. extended immersion times of the components in the zinc-aluminum melt, since this is the only way to ensure that there are no imperfections in the relatively thin zinc coatings or no areas that are not or incompletely coated.

In order to economically design the process sequence in the known hot-dip galvanizing of identical or similar components, in the case of large-scale batch hot-dip galvanizing, and to ensure an identical process sequence, the state of the art is such that a large number of the identical or similar components to be galvanized, e.g. B. summarized on a common goods carrier or the like or grouped and performed in the grouped state through the individual process steps.

The known hot-dip galvanizing, however, has several disadvantages. In the case of a multilayer hanging of the goods carrier and in particular with the same immersion and removal movement of the goods carrier, the components or component areas do not necessarily linger in the zinc melt for the same length of time. This results in reaction times of different lengths between the material of the components and the zinc melt and, as a result, different zinc layer thicknesses on the components. Furthermore, act on high-temperature sensitive components, particularly high-strength and high-strength steels such as. B. for spring steels, chassis and body components and press-hardened formed parts, different residence times in the zinc melt on the mechanical characteristics of the steel. With regard to the guarantee of defined characteristic values of the components, compliance with defined process parameters for each individual component is inevitable.

Furthermore, when the components are pulled out of the zinc melt, the zinc inevitably flows off and drips off at the component edges and corners. This creates zinc noses on the component. The subsequent elimination of these zinc noses, which is usually done manually, represents a considerable cost factor, especially when it comes to galvanizing large quantities and / or complying with high demands on tolerances. With a fully loaded goods carrier, it is usually not possible to reach all components and individually remove the zinc noses there at the galvanizing point. Usually, the galvanized components have to be removed from the product carrier after the galvanizing and have to be individually examined and reworked individually, which is very complex.

Furthermore, it is the case with the known hot-dip galvanizing that the immersion and removal movement of the goods carrier in and out of the galvanizing bath takes place at the same point. Due to the process-related occurrence of zinc ash as a reaction product from the flux and the zinc melt after immersing the components that accumulate on the surface of the zinc bath, it is imperative to remove the zinc ash from the surface by pulling it off or rinsing it off before it is removed to avoid sticking to the galvanized components when pulling them out so that there is as little contamination as possible on the galvanized component. In view of the large number of components in the zinc bath and the comparatively poor accessibility of the surface of the galvanizing bath, the removal of the zinc ash from the bath surface regularly turns out to be very complex and sometimes problematic. On the one hand, the removal of the zinc ash from the surface results The galvanizing bath delays the process while reducing productivity and is also a source of errors with regard to the galvanizing quality of the individual components.

Ultimately, contamination and zinc noses remain on the galvanized components in the conventional hot-dip galvanizing, which can be removed by manual reworking. This rework is regularly very costly and time-consuming. In this regard, it should be noted that rework does not only mean cleaning or repairing, but in particular also includes visual inspection. Due to the process, all components are at risk of contamination or zinc noses that need to be removed. Accordingly, all components must be inspected individually. This test alone, without any necessary subsequent work steps, represents a very high cost, particularly in the area of large series with a large number of components to be tested and very high quality requirements.

The US 3639142 A relates to an elongated steel component which is passed in a continuously longitudinally oriented process through a spray washer and a blasting chamber, an acid being sprayed onto the surface of the elongated steel component first and then blown off. A chloride flux is also sprayed onto the surface of the component and then blown off so that no excess flux adheres to the component surface. The components are then placed in an oven for preheating and drying the flux and then immersed in a hot liquid zinc melt.

Furthermore, the US 5853806 A a fire coating process for a steel component, a molten aluminum alloy according to a one-step coating process being provided as the melt. According to the process, it is in the US 5853806 A It is provided that a flux is applied before immersion in the coating bath containing the melt. The flux should be designed so that the oxide layer on the steel component surface is avoided. The bath surface has an application or coating of a fluoride-containing flux. Alternatively, the oxide layer on the steel component surface can also be removed, the steel component being immersed in a molten aluminum-zinc-silicon alloy or an aluminum-silicon alloy, the coating bath being provided on the top with a flux containing an iron compound on the melt.

In addition, the US 2940870 A a method for hot-dip galvanizing of metallic components, whereby an improved flux is to be used for application to the iron-containing component for a uniform application of zinc. The method includes wetting the iron-containing component with an aqueous flux solution based on an ammonia zinc chloride-containing flux solution and drying this solution on the component surface, after the component has dried it is immersed in a molten zinc bath, a salt-containing fluoride being applied to the top of the zinc bath, which is free of ammonia.

Furthermore, the GB 830258 A a process for electroplating, the melt comprising aluminum and the components being treated with an aqueous flux solution before immersion in the galvanizing bath. The flux solution either contains a dissolved aluminum compound or the components that have already been treated with a flux are immersed in an aqueous solution containing an aluminum compound and then dried before they are immersed in the molten zinc bath. The flux preferably contains 25 to 30% of the zinc ammonium chloride.

Otherwise concerns the DE 20 25801 A1 a device for coating components to be tinned with a flux, the dissolved flux in a dispenser container being under a controllable excess pressure and the flux outlet of the dispenser container having an adjustable nozzle which sprays the flux solution emerging from the container in individual jets onto the surfaces to be tinned of the moving components.

In addition, the CN 103290348 B a zinc coating process. The process includes an automatic control system and other various transport devices for the component to be galvanized. The method is to be carried out in such a way that the process flow is to take place automatically on the basis of characteristic values.

The problem underlying the present invention therefore consists in the provision of a system or a method for the piece galvanizing of iron-based or iron-containing components, in particular steel-based or steel-containing components (steel components) by means of hot-dip galvanizing (hot-dip galvanizing) in a zinc-aluminum melt (ie in a liquid zinc-aluminum bath) for the large-scale hot-dip galvanizing of a large number of identical or similar components (e.g. motor vehicle components), the disadvantages of the prior art described above being at least largely avoided or at least mitigated.

In particular, such a system or such a method is to be provided, which (s) enable improved process economy and a more efficient, in particular more flexible process flow compared to conventional hot-dip galvanizing systems or methods.

To solve the problem described above, the present invention proposes - according to a first aspect of the present invention - a hot-dip galvanizing plant according to claim 1; further, in particular special and / or advantageous, configurations of the system according to the invention are the subject of the relevant system subclaims.

Furthermore, the present invention relates - according to a second aspect of the present invention - to a method for hot-dip galvanizing according to the independent method claim; further, in particular special and / or advantageous, configurations of the method according to the invention are the subject of the relevant method subclaims.

Furthermore, the present invention relates - according to a third aspect of the present invention - to the use of the system according to the invention and / or the method according to the invention according to the independent use claim.

It goes without saying in the following explanations that configurations, embodiments, advantages and the like, which are subsequently carried out for the purpose of avoiding repetitions for only one aspect of the invention, of course also apply correspondingly to the other aspects of the invention, without this being a separate one Mention is required.

In the case of all the relative or percentage weight-related information mentioned below, in particular relative quantity or weight information, it should further be noted that within the scope of the present invention, these are to be selected by the person skilled in the art in such a way that they include all components or ingredients, in particular as defined below, always add or add 100% or 100% by weight; this goes without saying for the expert.

In addition, it applies that the person skilled in the art - depending on the application or on a case-by-case basis - can deviate from the range specifications listed below if necessary without leaving the scope of the present invention.

In addition, it is true that all of the values or parameters specified below or the like can in principle be determined or determined using standardized or standardized or explicitly specified determination methods or otherwise using determination or measurement methods which are per se familiar to the person skilled in the art in this field.

With that in mind, the present invention will now be explained in detail below.

According to a first aspect of the invention, the invention therefore relates to a system for hot-dip galvanizing components for large-scale hot-dip galvanizing of a large number of identical or similar components with a conveyor device with at least one product carrier for conveying the components, a flux application device for applying a flux to the surface of the components and a hot-dip galvanizing device for hot-dip galvanizing the components with a galvanizing bath having a molten zinc-aluminum alloy, the goods carrier being designed for receiving and transporting at least one individual component, the flux application device having a spray device for automated spray application of the flux onto the surface of the individual component,
wherein a control device coupled to the spray device for the automatic spray application of the flux is provided for automated control of the spray order depending on the shape and / or type and / or the material and / or the surface quality of the component,
wherein the control device is designed in such a way that a homogeneous and / or individually adapted spray application results
and wherein the control device for automated control of the thickness of the spray application on the component and / or the concentration of the flux and / or the spray duration of the spray application per component and / or the spray duration of the spray application of different areas of a component and / or the simultaneous spray application of different fluxes and / or different flux components are provided,
wherein the spray device has a plurality of spray heads, at least one spray head being movable relative to the component in the X direction and / or in the Y direction and / or in the Z direction.

According to the method, the invention thus relates - according to a second aspect of the invention - to a method for hot-dip galvanizing at least one component using a molten zinc-aluminum alloy for large-scale hot-dip galvanizing of a large number of identical or similar components, the component in the separated state on a product carrier to a flux application device Flux application is transported, the component is provided in the separated state by an automated spray application of a spray device with the flux and then that on its surface with the Flux-provided component is subjected to hot-dip galvanizing in a galvanizing bath containing the molten zinc-aluminum alloy,
the automated spray application being carried out homogeneously and / or individually adapted to the component;
wherein the spray application is controlled automatically depending on the shape, type, material and / or surface quality of the component, the concentration of the flux and / or the spray duration of the spray application per component and / or the spray duration of the spray application of different areas of a component and / or the thickness of the spray application on the component and / or a simultaneous spray application of different fluxes is set; and
wherein the distance and / or the direction of a spray head of the spray device to the component is changed when the flux is sprayed onto a component.

According to the use, the invention thus relates - according to a third aspect of the invention - to the use of a system according to the invention and / or a method according to the invention for large-batch hot-dip galvanizing of a large number of identical or similar components, preferably piece galvanizing.

In connection with the creation of the present invention, it has been recognized that the spray application of the flux on the components to be galvanized has a considerable influence on the entire galvanizing process, although the spray application of the flux, in particular in the context of large-scale production, at first glance compared to fluxing in one Flux immersion bath appears to be uneconomical. In connection with the invention, however, it has been found that applying the flux by immersing the component in a flux bath has a number of disadvantages. In so-called immersion fluxing, when the components are pulled out of the immersion bath, there is an uneven layer of the flux on the components to be galvanized. While the component has a rather thin layer thickness of the flux in the upper region, there is an increased layer thickness of the flux in the lower region. In addition, flux residues accumulate in corners and on the edges of the components to be galvanized.

In the galvanizing process that follows the fluxing process, the flux reacts with the zinc melt. Due to the different thickness of the flux layer on the component to be galvanized, a different thickness of the zinc layer on the component can also result. The different zinc layer thickness on the component thus represents, among other things, the result of the uneven layer thickness of the flux.

Furthermore, energy and radiation losses inevitably arise in an immersion bath, since the immersion bath generally has to be kept at a constant temperature in the range between 60 ° C. and 80 ° C. If the temperature falls below a certain value, reheating is necessary. This is not only expensive; the constant temperature control puts a strain on the flux solution. Because of the permanent temperature treatment, various chemicals in the flux can decompose. Since an immersion bath is an open bath, a loss of solvent (water) can also occur. This inevitably changes the flux composition. For this reason, in particular in the case of immersion baths which are heated over a long period of time, there is a risk that the flux will not be applied to the component to be galvanized with the desired and originally set composition.

The aforementioned disadvantages are avoided by the spray application according to the invention. First of all, the spray application is more economical in terms of energy, since no bath has to be kept at a higher temperature. Due to the lack of a bath, energy and radiation losses are avoided. Furthermore, the concentration of the flux can be kept constant at a constant level, since in contrast to an open bath there is no loss of solvent. Since there is no bathroom with inevitably inhomogeneities, the spray application is more homogeneous. Furthermore, the quality and the layer thickness of the flux can be precisely controlled by a predetermined concentration control of the flux and a precise control of the thickness of the application. A defined amount of the flux can be applied as part of the spray application. Furthermore, the spray application makes it possible to avoid flux accumulation at corners, edges, folds or the like. Ultimately, all of this means that homogeneous galvanizing with a constant layer thickness is made possible in the galvanizing bath.

Furthermore, it has been found that the spray application results in improved drainage behavior of the applied flux due to the defined amount of spray. A precisely metered application of the flux during the spray application can prevent a concentrated solution of the flux from getting stuck at the aforementioned corners and edges, but in any case it can be reduced. As a result of the reduced and, in particular, even application of the flux compared to a dip coating, no superfluous flux is ultimately introduced into the galvanizing bath.

Another significant advantage of the spray application according to the invention over the dip coating is that it is easier to use different fluxes for different applications. The spray technology increases individual adaptability and ensures improved flexibility.

In order to be able to guarantee a complete spray application of the component to be galvanized, the component must be accessible from all sides as part of the automation of the process. For this reason, the component in question is either attached as a single component to the goods carrier and guided through the spraying device. When the component is completely separated, with only a single component attached to the goods carrier, every area of the component is accessible and can be sprayed accordingly.

Alternatively, depending on the size and design of the goods carrier, it is also possible to fasten a small group, ie up to a maximum of 10 components, preferably up to 5 components, these components being arranged, in particular, in a row next to or behind one another, in such a way that that they don't touch The distance between the components of the small group attached to the carrier should preferably be at least 10 cm, preferably at least 50 cm and in particular more than 1 m from one another. With such an arrangement and / or spacing of the individual components of the small group on the product carrier, there is a separation of the component in the sense of the present invention, since with such a distance of the separated components, access to any area of the components for the automated spray application is ensured.

According to the invention, a control device coupled to the spray device for the automated spray application of the flux is provided. The control device, by means of which in particular the spraying times and / or spray quantity and / or spraying duration and / or spraying direction per unit area of the component can be set, results in a homogeneous and / or individual response to the Component-adapted spray application and from this a defined layer thickness of the flux on the component to be galvanized. In this context, the control device is designed such that the automated spray application takes place as a function of the shape and / or the type and / or the material and / or the surface quality, in particular the surface roughness of the component. For example, different materials and / or different surface properties can result in different layer thicknesses, concentrations or else compositions of the flux. The spray application is automated via the control device such that the concentration of the flux and / or the spray duration of the spray application per component and / or the spray duration of the spray application indicate different areas of the component and / or the thickness of the spray application on the component, in particular different thicknesses of the spray application a component and / or a simultaneous spray application of different flux and / or different flux components is adjustable.

In order to be able to apply the flux to the surface of the separated component as precisely as possible by spraying, the spraying device has a plurality of spray heads with which preferably different areas of the component can be sprayed. In this context, at least one spray head can be moved relative to the component in the X direction and / or in the Y direction and / or in the Z direction. The movement of the spray head in question, which can preferably be moved in all three directions, takes place in terms of control technology via the control device. The aforementioned measure ultimately makes it possible for the distance and / or the direction of a spray head of the spray device to the component to be changed when the flux is sprayed onto a component. In particular, it can be ensured in this way that areas of the component which are not directly accessible can be easily reached by appropriate alignment of the spray head and can be provided with the layer thickness of the flux provided exactly for this area.

In addition, the spray device is preferably designed to spray different fluxes and / or different flux components simultaneously. In this connection, it is structurally provided in a preferred embodiment that at least one spray head has at least two spray lines for different fluxes and / or different flux components. According to the method, this means that different fluxes and / or different flux components during the spraying process either simultaneously or at different times during a spraying process can be applied to the component in question. This embodiment has the advantage that different areas of a component can be sprayed with a different flux or different flux components. This can influence the subsequent hot-dip galvanizing in a corresponding manner. In principle, however, it is also possible to spray immediately successive components of the galvanizing process with different fluxes / flux components without interrupting the production process.

A drying device is preferably connected to the spraying device of the flux application device. This drying device is designed in particular for drying the sprayed-on flux in the separated state of the component. Since a precisely defined amount of flux is applied to the component by the spray application, the drying step can be carried out relatively quickly and therefore relatively inexpensively, which is not possible in comparison to drying after an immersion bath.

In the device according to the invention and also in the method according to the invention, the flux application is preferably preceded by a surface treatment and in particular degreasing. According to the system, a surface treatment device, in particular pickling device, upstream of the flux application device is preferably provided for the chemical, in particular wet-chemical, surface treatment of the components by means of a surface treatment agent, preferably for pickling the surfaces of the components by means of a pickling agent. In particular, it makes sense for the surface treatment device to have a spray device for spraying the surface treatment agent, in particular the pickling agent, onto the surface of the individual component. In connection with the spray application of the surface treatment agent, the same basic advantages apply as for the spray application of the flux. In particular, when the surface treatment agent is sprayed on, it can be ensured that certain areas of the component are sprayed more strongly and / or longer than other areas. In order to be able to spray the component with the surface treatment agent in a corresponding manner in all areas, the separation of the component is also particularly suitable for surface treatment.

Otherwise, it goes without saying that the spray device for spraying the surface treatment agent can be designed in a corresponding manner in a constructive manner as the spray device for the spray application of the flux. Here, too, adjustable spray heads and the use of different spray lines for different surface treatment agents and / or different surface treatment agent components can be provided.

According to the system, it is also advantageous if the surface treatment device is preceded by a degreasing device for degreasing the components by means of a degreasing agent. Degreasing is preferably also carried out by spraying the degreasing agent onto the surface of the separated component. In this regard, the advantages mentioned for spraying on the surface treatment agent apply in the same way. Furthermore, the spray device for the degreasing agent is preferably constructed in the same way as the spray device for the surface treatment agent, so that reference can expressly be made to this. In particular, one or more adjustable spray heads are provided and different degreasing agents or components can be sprayed on via at least two separate spray lines per spray head.

In order to prevent a treatment agent from entering the next process stage, at least one rinsing device for rinsing the components with a detergent is provided in a preferred embodiment of the system according to the system. In particular, a rinsing device is provided after the degreasing device and / or after the surface treatment device. In each case, a rinsing device is preferably provided after the degreasing device and after the surface treatment device.

In connection with the rinse it can be provided that this is also done by spraying with the relevant detergent. As an alternative or in addition, an immersion rinse can also be provided. In all cases, however, it is particularly preferred to carry out the rinsing processes in the separated state of the component, since this provides access to all areas of the component.

In a preferred embodiment of the invention, it is provided that the spray device, preferably each spray device in connection with the system according to the invention, is assigned a housing which is in particular closed on all sides. It goes without saying that one or more feed and discharge openings for the goods carrier and the component (s) isolated thereon can be provided in the housing. The housing ultimately prevents the environment from being exposed to vapors and / or chemicals which are used or are produced during spraying. In addition, an enclosure makes it possible to collect the spray in question, in particular by means of appropriate floor drains of the enclosure, and to recycle it for reuse. If necessary, appropriate preparation of the respective spray is provided.

In a preferred embodiment of the invention, in addition to the individual fluxing, individual galvanizing of the components, that is to say of a component isolated on the goods carrier, is provided. The invention provides two alternatives for this. In a first alternative, a separating device is provided for the preferably automated feeding, immersion and removal of a component separated from the goods carrier into the galvanizing bath of the hot-dip galvanizing device. In the alternative embodiment to this, the conveying device and the hot-dip galvanizing device are designed in such a way that the component isolated on the goods carrier is guided through the galvanizing bath in the separated state.

In connection with the invention, it has been recognized that, in particular for certain components, such as high-strength and high-strength steels, which are temperature-sensitive, targeted and optimized handling of the components is necessary in the actual galvanizing process. In the case of individual galvanizing in connection with the system according to the invention or the method according to the invention, it can easily be ensured that the components are each subject to identical process parameters. Especially for spring steels or chassis and body components made of high-strength and high-strength steels, such as B. press-hardened formed parts, this plays a significant role. By separating the components for galvanizing, it is possible that the reaction times between the steel and the molten zinc are the same. Ultimately, this always results in the same zinc layer thickness. In addition, the characteristic values of the components are influenced in an identical manner by the galvanizing, since the invention ensures that the components have been exposed to identical process parameters.

A further, considerable advantage of the invention, in particular in connection with the separating device, results from the fact that each component can be manipulated and treated exactly in the separating device according to the invention, for example by special turning and steering movements of the component when it is pulled out of the melt. As a result, the post-processing effort can be significantly reduced or even partially avoided. Furthermore, the invention offers the possibility that zinc ash buildup can be significantly reduced and in some cases even avoided. This is possible because the process according to the invention can be controlled in such a way that a component to be galvanized, after being immersed, is moved away from the immersion location and moved to a location remote from the immersion location. Subsequently, the immersion takes place. While the zinc ash rises in the area of the immersion point and is located on the surface of the immersion point, there are few or no zinc ash residues at the immersion point. This special technique allows zinc ash build-up to be significantly reduced or avoided.

In connection with the present invention, it has also been found that, taking into account the post-processing that is sometimes no longer necessary in the invention, the total production time in the production of galvanized components can even be reduced compared to the prior art, that is, the invention ultimately a higher productivity provides, especially because the manual post-processing is very time consuming in the prior art.

Another advantage in terms of system technology with a single galvanizing is that no wide and deep, only a narrow galvanizing tank is necessary. This reduces the surface of the galvanizing bath, which can be better shielded in this way, so that the radiation losses can be significantly reduced.

As a result, the invention with the isolated galvanizing results in components with a higher quality and cleanliness on the surface, the components as such being exposed to identical process conditions and thus having the same component characteristics. The invention also offers economic advantages over the prior art from an economic point of view, since the production time can be reduced by up to 20%, taking into account the post-processing that is no longer necessary or in some cases very limited.

According to the device, the alternative with the separating device provides that the separating device has at least one separating means arranged between the flux application device and the hot-dip galvanizing device. This separating means is then preferably designed in such a way that it either removes a separated component from the goods carrier or several components as a small group, although these are separated from one another, that is to say sufficiently spaced apart, and the separated component or the small group is removed from one another then feeds individual components to the hot-dip galvanizing device for hot-dip galvanizing. The separating means can remove or remove the component directly from the product carrier or remove the component from the component group that has already been placed by the product carrier. It goes without saying that in principle it is also possible for more than one separating means to be provided, that is to say at the same time a plurality of separated components are hot-dip galvanized in the separated state. In this context, it goes without saying that at least the galvanizing process of the individual components is carried out in an identical manner, even if components of different individualizing means are guided simultaneously or at different times and independently of one another through the hot-dip galvanizing device or the galvanizing bath.

In a further preferred embodiment of the invention, the separating means is designed in such a way that a separated component is immersed in an immersion area of the bath, then moved from the immersion area to an adjacent immersion area and is subsequently immersed in the immersion area. The above-mentioned movement can also be achieved, if the separator is not used, but instead the component is fastened to the goods carrier in the separated state and fed to the galvanizing bath via the goods carrier, immersed in the immersion area, moved to the immersion area and immersed there becomes. As previously stated, zinc ash is formed on the surface of the immersion area as a reaction product of the flux with the zinc melt. Due to the movement of the component immersed in the zinc melt from the immersion area to the immersion area, there is little or no zinc ash on the surface of the immersion area. In this way, the surface of the dipped galvanized component remains free or at least essentially free of zinc ash buildup. It goes without saying that the immersion area is adjacent to the immersion area, that is to say it is spatially spaced apart and in particular non-overlapping areas of the galvanizing bath.

In a preferred embodiment of the aforementioned inventive concept, it is also provided that the component remains in the immersion area of the galvanizing bath at least until the reaction time between the component surface and the zinc-aluminum alloy of the galvanizing bath has ended. This ensures that the zinc ash, which moves upward within the melt, only spreads out on the surface of the immersion area. The component can then be moved into the replacement area, which is essentially free of zinc ash, and can be replaced there.

In tests which have been carried out in connection with the invention, it has been found that it is expedient if the component remains between 20% and 80%, preferably at least 50% of the galvanizing time in the area of the immersion area and only then moves into the immersion area becomes. In terms of system engineering, this means that the separating device or the associated separating means or the conveying device are designed and, if necessary, matched to one another by means of a corresponding control so that the aforementioned process sequence can be carried out without problems.

In particular in the case of components made of temperature-sensitive steels and in the case of customer-specific requirements for components with product properties that are as identical as possible, it is provided according to the system and method that the conveying device or the separating means is designed in such a way that all components in an identical manner, in particular with an identical movement, in an identical arrangement and / or with an identical time through the galvanizing bath. Ultimately, this can easily be achieved by a corresponding control of the conveying device or the at least one assigned separating means. Due to the identical handling, identical components, that is to say components which each consist of the same material and have the same shape, each have identical product properties. This includes not only the same zinc layer thicknesses, but also identical characteristic values of the galvanized components, since they were each led through the galvanizing bath in an identical manner.

Furthermore, according to the system and method, the invention offers the advantage of being isolated during hot-dip galvanizing that zinc noses can be avoided more easily. For this purpose, according to the system, a stripping device is provided in connection with the replacement area, the conveying device or the separating means being preferred in a preferred embodiment of this inventive concept is designed in such a way that all components are guided past the stripping device for stripping liquid zinc in an identical manner. In an alternative embodiment in connection with the separating means, which, however, can also be implemented in combination with the stripping device, it is provided that all components are moved in an identical manner after being removed in such a way that dripping noses of liquid zinc are removed, in particular dripping and / or evenly distributed on the component surfaces. As a result of the invention, it is thus possible for each individual component to be defined not only by the galvanizing bath, but also either in a specific positioning, for example an inclined position of the component, and to move past one or more scrapers and / or the component by means of special ones To move rotary and / or steering movements after the immersion so that zinc noses are at least substantially avoided.

In a preferred development of the invention, a cooling device, in particular a quenching device, is provided after the hot-dip galvanizing device, on which the component is cooled or quenched after the hot-dip galvanizing.

Furthermore, an aftertreatment device can be provided in particular after the cooling device. The aftertreatment device serves in particular to passivate, seal or color the galvanized components. The post-treatment step can also include post-processing, in particular the removal of impurities and / or the removal of zinc noses. As has been explained above, the post-processing step in the invention is, however, considerably reduced compared to the method known in the prior art and in some cases even unnecessary.

It is particularly advantageous if the control device is coupled not only to the individual spray devices, but also to the conveyor device. This makes it possible to change the transport speed of the individual goods carriers as required. For example, it is possible to change the transport speed of a product carrier at least in regions relative to the transport speed of another product carrier. This makes it possible to adapt certain process steps, which take more time than others, to the respective requirements, if necessary. As a result, the entire process sequence of the method according to the invention is optimized and thus shortened.

In a particularly preferred embodiment of the invention, the conveying device has a circumferential, closed transport route with a plurality of goods carriers, which leads at least along the surface treatment device, the flux application device and the hot-dip galvanizing device. In particular, the transport route extends along all process steps of the system according to the invention. As a result, continuous piece galvanizing of the components in the separated state of the components is made possible.

The conveyor can basically be designed as a crane system. In this case, the individual components are then transported hanging. In principle, however, it is also possible to design the conveyor as a floor conveyor. In this case, the goods carriers move on the floor. In this case, the transport route can be designed as a rail guide. In principle, it is also possible in this connection to provide a combination of a crane system with supplementary floor conveyors.

1. (i) Zink, insbesondere in Mengen im Bereich von 55 bis 99,999 Gew.-%, vorzugsweise 60 bis 98 Gew.-%,
2. (ii) Aluminium, insbesondere in Mengen ab 0,001 Gew.-%, vorzugsweise ab 0,005 Gew.-%, weiter bevorzugt im Bereich von 0,03 bis 45 Gew.-%, weiter bevorzugt zwischen 0,1 bis 45 Gew.-%, vorzugsweise zwischen 2 bis 40 Gew.-%, wobei der Zinkgehalt dann jeweils entsprechend angepasst ist,
3. (iii) gegebenenfalls Silizium, insbesondere in Mengen im Bereich von 0,0001 bis 5 Gew.-%, vorzugsweise 0,001 bis 2 Gew.-%;
4. (iv) gegebenenfalls mindestens ein weiterer Inhaltsstoff und/oder gegebenenfalls mindestens eine Verunreinigung, insbesondere aus der Gruppe der Alkalimetalle wie Natrium und/oder Kalium, Erdalkalimetalle wie Kalzium und/oder Magnesium und/oder Schwermetalle wie Cadmium, Blei, Antimon, Wismut, insbesondere in Gesamtmengen im Bereich von 0,0001 bis 10 Gew.-%, vorzugsweise 0,001 bis 5 Gew.-%.

Furthermore, the invention relates to a system and / or a method of the aforementioned type, the components being iron-based and / or iron-containing components, in particular steel-based and / or steel-based components, so-called steel components, preferably automotive components or components for the automotive sector. Alternatively or in addition, the galvanizing bath contains zinc and aluminum in a zinc-aluminum weight ratio in the range from 55-99.999: 0.001-45, preferably 55-99.97: 0.03-45, in particular 60-98: 2-40, preferably 70-96: 4-30. Alternatively or additionally, the galvanizing bath has the following composition, in which the weight data are based on the galvanizing bath and the sum of all components of the composition results in 100% by weight:

1. (i) zinc, in particular in amounts in the range from 55 to 99.999% by weight, preferably 60 to 98% by weight,
2. (ii) aluminum, in particular in amounts from 0.001% by weight, preferably from 0.005% by weight, more preferably in the range from 0.03 to 45% by weight, more preferably between 0.1 to 45% by weight , preferably between 2 to 40% by weight, the zinc content then being adjusted accordingly,
3. (iii) optionally silicon, in particular in amounts in the range from 0.0001 to 5% by weight, preferably 0.001 to 2% by weight;
4. (iv) optionally at least one further ingredient and / or optionally at least one impurity, in particular from the group of alkali metals such as sodium and / or potassium, alkaline earth metals such as calcium and / or magnesium and / or heavy metals such as cadmium, lead, antimony, bismuth, in particular in total in the range of 0.0001 to 10% by weight, preferably 0.001 to 5% by weight.

In connection with tests that have been carried out, it has been found that very thin and very homogeneous coatings on the component can be achieved with zinc baths with the previously specified composition, which in particular meet the high requirements for component quality in motor vehicle construction.

1. (i) Zinkchlorid (ZnCl₂), insbesondere in Mengen im Bereich von 50 bis 95 Gew.-%, vorzugsweise 58 bis 80 Gew.-%;
2. (ii) Ammoniumchlorid (NH₄Cl), insbesondere in Mengen im Bereich von 5 bis 50 Gew.-%, vorzugsweise 7 bis 42 Gew.-%;
3. (iii) gegebenenfalls mindestens ein Alkali- und/oder Erdalkalisalz, bevorzugt Natriumchlorid und/oder Kaliumchlorid, insbesondere in Gesamtmengen im Bereich von 1 bis 30 Gew.-%, vorzugsweise 2 bis 20 Gew.-%;
4. (iv) gegebenenfalls mindestens ein Metallchlorid, bevorzugt Schwermetallchlorid, vorzugsweise ausgewählt aus der Gruppe von Nickelchlorid (NiCl₂), Manganchlorid (MnCl₂), Bleichlorid (PbCl₂), Cobaltchlorid (CoCl₂), Zinnchlorid (SnC1₂), Antimonchlorid (SbCl₃) und/oder Bismutchlorid (BiCl₃), insbesondere in Gesamtmengen im Bereich von 0,0001 bis 20 Gew.-%, vorzugsweise 0,001 bis 10 Gew.-%;
5. (v) gegebenenfalls mindestens ein weiteres Additiv, vorzugsweise Netzmittel und/oder Tensid, insbesondere in Mengen im Bereich von 0,001 bis 10 Gew.-%, vorzugsweise 0,01 bis 5 Gew.-%.

Alternatively or additionally, the flux has the following composition, the weight data being based on the flux and resulting in the sum of all components of the composition 100% by weight:

1. (i) zinc chloride (ZnCl ₂ ), in particular in amounts in the range from 50 to 95% by weight, preferably 58 to 80% by weight;
2. (ii) ammonium chloride (NH ₄ Cl), in particular in amounts in the range from 5 to 50% by weight, preferably 7 to 42% by weight;
3. (iii) optionally at least one alkali and / or alkaline earth metal salt, preferably sodium chloride and / or potassium chloride, in particular in total amounts in the range from 1 to 30% by weight, preferably 2 to 20% by weight;
4. (iv) optionally at least one metal chloride, preferably heavy metal chloride, preferably selected from the group consisting of nickel chloride (NiCl ₂ ), manganese chloride (MnCl ₂ ), lead chloride (PbCl ₂ ), cobalt chloride (CoCl ₂ ), tin chloride (SnC1 ₂ ), antimony chloride (SbCl ₃ ) and / or bismuth chloride (BiCl ₃ ), in particular in total amounts in the range from 0.0001 to 20% by weight, preferably 0.001 to 10% by weight;
5. (v) optionally at least one further additive, preferably wetting agent and / or surfactant, in particular in amounts in the range from 0.001 to 10% by weight, preferably 0.01 to 5% by weight.

As an alternative or in addition, it is provided that the flux application device, in particular the flux bath of the flux application device, contains the flux in preferably aqueous solution, in particular in amounts and / or concentrations of the flux in the range from 200 to 700 g / l, in particular 350 to 550 g / l , preferably 500 to 550 g / l, and / or that the flux is used as a preferably aqueous solution, in particular with amounts and / or concentrations of the flux in the range from 200 to 700 g / l, in particular 350 to 550 g / l, preferably 500 to 550 g / l.

In experiments with a flux in the aforementioned composition and / or concentration, in particular in connection with the zinc-aluminum alloy described above, it has been found that very small layer thicknesses, in particular less than 20 μm, result, with a low weight and reduced costs goes along. These are essential criteria, particularly in the automotive sector.

Further features, advantages and possible uses of the present invention, as defined in the claims, result from the following description of exemplary embodiments with reference to the drawing and the drawing itself.

Fig. 1

einen schematischen Verfahrensablauf der einzelnen Stufen des erfindungsgemäßen Verfahrens,

Fig. 2

eine schematische Darstellung einer erfindungsgemäßen Anlage und des Ablaufs des erfindungsgemäßen Verfahren bei einem Verfahrensschritt,

Fig. 3

eine schematische Darstellung einer erfindungsgemäßen Anlage und des Ablaufs des erfindungsgemäßen Verfahren bei einem weiteren Verfahrensschritt und

Fig. 4

eine schematische Darstellung einer erfindungsgemäßen Anlage und des Ablaufs des erfindungsgemäßen Verfahren bei einem weiteren Verfahrensschritt.

It shows:

Fig. 1

a schematic process flow of the individual stages of the method according to the invention,

Fig. 2

1 shows a schematic representation of a system according to the invention and the sequence of the method according to the invention in one method step,

Fig. 3

a schematic representation of a system according to the invention and the sequence of the method according to the invention in a further method step and

Fig. 4

a schematic representation of a system according to the invention and the sequence of the method according to the invention in a further process step.

In Fig. 1 a sequence of the method according to the invention is shown schematically in a system 1 according to the invention. In this context, it should be pointed out that the flowchart shown is a method possible according to the invention, but individual method steps can also be omitted or can be provided in a different order than shown and described below. Further method steps can also be provided. For the rest, it is the case that not all process stages have to be provided in a spatially combined system 1. Decentralized implementation of individual process stages is also possible. In particular, the entire process can be cycled.

In the in Fig. 1 The flow diagram shown denotes stage A, the delivery and storage of components 2 to be galvanized at a connection point. In the present example, the components 2 have already been mechanically surface-treated, in particular sandblasted. This can, but does not have to be provided.

In stage B, the components 2 are connected in the separated state to a goods carrier 7 of a conveyor 3. In the illustrated embodiment, only a single component 2 is attached to the goods carrier 7. It is also possible for the goods carrier 7 to have a basket, a frame or the like in which or in which the component 2 is inserted. It is not shown that in principle it is also possible to fasten a plurality of components 2 to the goods carrier 7 in the manner of a small group. The components 2 are then sufficiently spaced from one another, so that ultimately there is an isolated state.

Degreasing of component 2 takes place in stage C. Alkaline or acidic degreasing agents 11 are used here to remove residues of fats and oils on component 2.

In stage D, a rinse, in particular with water, of the degreased component 2 is provided. The residues of degreasing agent 11 are rinsed off the component 2.

In method specification E, the surface of component 2 is pickled, that is, a wet-chemical surface treatment. Pickling is usually done with dilute hydrochloric acid.

Stage F is followed by stage F, which in turn involves rinsing, in particular with water, in order to prevent the pickling agent from being carried over into the subsequent process stages.

The correspondingly cleaned and pickled component 2 to be galvanized is then fluxed, namely subjected to a flux treatment. The flux treatment in stage H is carried out in the present case with an aqueous flux solution. Subsequently, the goods carrier 7 with the component 2 is fed to a drying stage I in order to produce a solid flux film on the surface of the component 2 and to remove adhering water.

In method step J, the component 2 is removed from the goods carrier 7. The component can be temporarily stored at this point.

In stage K, component 2 is hot-dip galvanized. For this purpose, the component 2 is immersed in a galvanizing bath 28 and then immersed again after a predetermined dwell time.

The galvanizing in process step K is followed by dripping of the still liquid zinc in stage L. The dripping takes place, for example, by moving along the component 2, which is galvanized in the separated state, on one or more scrapers of a stripping device and / or by predetermined pivoting and rotating movements of the component 2, which either leads to dripping or to the even distribution of the zinc on the component surface.

The galvanized component is then quenched in step M.

The quenching in method step M is followed by an aftertreatment in stage N, which can be, for example, passivation, sealing or organic or inorganic coating of the galvanized component 2. The aftertreatment also includes a possible postprocessing of the component 2.

In the 2 to 4 An embodiment of a system 1 according to the invention is shown schematically.

In the 2 to 4 an embodiment of a system 1 according to the invention for hot-dip or hot-dip galvanizing of components 2 is shown in a schematic representation. The system 1 is intended for hot-dip galvanizing a large number of identical components 2 in discontinuous operation, the so-called piece galvanizing. In particular, system 1 is designed and suitable for hot-dip galvanizing of components 2 in large series. Large-volume galvanizing denotes a galvanizing process in which more than 100, in particular more than 1000 and preferably more than 10,000, identical components 2 are galvanized in succession without components 2 of different shape and size being galvanized in between.

The system 1 has a conveyor 3 for conveying the components 2. The conveying device 3 is in the present case a crane runway with a rail guide 4 on which a trolley 5 with a lifting mechanism can be moved. A goods carrier 7 is connected to the trolley 5 via a hoist rope 6. The goods carrier 7 serves to hold and fasten the components 2 in the separated state. The connection of the components 2 to the goods carrier 7 usually takes place at a connection point 8 of the system, at which the components 2 are arranged for connection to the goods carrier 7.

A degreasing device 9 connects to the connection point 8. The degreasing device 9 has a degreasing chamber 10 with a spray device 10a with a plurality of spray heads 10b for spraying on a degreasing agent 11. The degreasing chamber 10 represents an at least substantially complete housing for the spray device 10a, so that sprayed degreasing agent 11 remains in the degreasing chamber 10 as far as possible and does not escape from the chamber during spraying. The degreasing agent 11 can be acidic or basic.

The degreasing device 9 is followed by a rinsing device 12 which has a sink 13 with detergent 14 therein. The detergent 14 is water in the present case.

A surface treatment device designed as a pickling device 15 for wet-chemical surface treatment of the components 2 is connected to the flushing device 12, that is to say downstream in the process direction. The pickling device 15 has a pickling chamber 16 with a spray device 16a and a plurality of spray heads 16b for spraying on a pickling agent 17 . The pickling chamber 16 represents an essentially closed housing for the spray device 16a, so that sprayed pickling agent 17 does not escape from the pickling chamber 16 during the spraying process. The pickling agent 17 in the present case is dilute hydrochloric acid.

Following the pickling device 15, a rinsing device 18 with a sink 19 and detergent 20 located therein is again provided. The detergent 20 is again water.

In the process direction behind the flushing device 18 there is a flux application device 21 with a flux chamber 22 with a spray device 22a with a plurality of spray heads 22b for spraying on a flux 23. The flux chamber 22 also represents an essentially closed housing for the spray device 22a, so that the spray medium cannot exit from the flux chamber 22 during the spraying process. In a preferred embodiment, the flux contains zinc chloride (ZnCl ₂ ) in an amount of 58 to 80% by weight and ammonium chloride (NH ₄ Cl) in an amount of 7 to 42% by weight. Furthermore, if necessary, a small amount of alkali and / or alkaline earth salts and, if necessary, a heavy metal chloride are provided in a further reduced amount. Furthermore, a wetting agent may also be provided in small amounts. It goes without saying that the aforementioned weight specifications are based on the flux 23 and make up 100% by weight in the sum of all components of the composition. Otherwise, the flux 23 is present in an aqueous solution, specifically in a concentration in the range from 500 to 550 g / l.

A drying device 24 is connected to the flux application device 21 in order to remove adhering water from the flux film, which is located on the surface of the component 2.

Furthermore, the system 1 has a hot-dip galvanizing device 25 in which the components 2 are hot-dip galvanized in the separated state. The hot-dip galvanizing device 25 has a galvanizing basin 26, optionally with a housing 27 provided on the top side. In the galvanizing basin 26 there is a galvanizing bath 28 which contains a zinc-aluminum alloy. Specifically, the galvanizing bath has 60 to 98% by weight of zinc and 2 to 40% by weight of aluminum. Furthermore, small amounts of silicon and optionally a small amount of alkali and / or alkaline earth metals and heavy metals are provided, if necessary in further reduced proportions. It goes without saying that the aforementioned weight specifications are based on the galvanizing bath 28 and make up 100% by weight in the sum of all components of the composition.

In the process direction after the hot-dip galvanizing device 25 there is a cooling device 29 which is provided for quenching the components 2 after the hot-dip galvanizing. Finally, after the cooling device 29, a post-treatment device 30 is provided, in which the hot-dip galvanized components 2 can be post-treated and / or post-processed.

Between the drying device 24 and the hot-dip galvanizing device 25 there is a separating device 31 which is provided for the automated feeding, immersion and removal of a component 2 separated from the goods carrier 7 into the galvanizing bath 28 of the hot-dip galvanizing device 25. In the exemplary embodiment shown, the separating device 31 has a separating means 32 which is provided for handling the component 2, namely for removing the component 2 from the product carrier 7 and for feeding, immersing and immersing the separated component 2 into the galvanizing bath 28.

For the separation, there is a transfer point 33 between the separation means 32 and the drying device 24, at which the component 2 is either deposited or, in particular, can be removed from the goods carrier 7 in the hanging state. For this purpose, the separating means 32 is preferably designed such that it can be moved in the direction of the transfer point 33 and away from it and / or in the direction of the galvanizing device 25 and can be moved away from it.

Otherwise, the separating means 32 is designed in such a way that it moves a component 2, which is individually immersed in the galvanizing bath 28, from the immersion area to an adjacent immersion area and subsequently immerses in the immersion area. The immersion area and the immersion area are spaced apart from one another, ie they do not correspond to one another. In particular, the two areas do not overlap. The movement from the immersion area to the immersion area takes place only after a predetermined period of time has elapsed, namely after the reaction time of the flux 23 with the surface of the components 2 to be galvanized has ended.

Furthermore, a control device 34 is assigned to the separating device 31 and / or the separating means 32, according to which the separating means 32 is moved such that all the components 2 separated by the goods carrier 7 pass through the galvanizing bath 28 with identical movement, in an identical arrangement and with an identical time become.

The control device 34 is not only coupled to the separating means 32 of the separating device 31, but also to the spraying devices 10a, 16a and 22a and also to the trolley 5. The control device 34 thus makes it possible to determine the transport speed of the trolley 5 and thus to control the goods carrier 7 from one process stage to the next and also to control the dwell time in the respective process stage. Furthermore, the spray application can also be controlled in the respective process stages via the control device 34.

It is not shown that above the galvanizing bath 28 and still inside the housing 27 there is a stripper of a stripping device, not shown, which is provided for stripping liquid zinc. In addition, the separating means 32 can also be controlled via the associated control device such that an already galvanized component 2 is still moved within the housing 27, for example by corresponding rotary movements, in such a way that excess zinc drips off and / or alternatively is evenly distributed on the component surface.

In the 2 to 4 Various states are now shown when operating system 1. Fig. 2 shows a state in which a plurality of components 2 to be galvanized are stored at the connection point 8. The goods carrier 7 is located above the group of components 2. After the goods carrier 7 has been lowered, a component 2 is fastened to the goods carrier 7. Is shown schematically in Fig. 2 that the spray devices 10a, 16a and 22a each spray the respective spray. In fact, however, spraying only takes place when component 2 located on goods carrier 7 is actually located in the respective spray chamber. Ultimately, this is controlled by the control device 34.

In Fig. 3 component 2 is located above the pickling device 15. Steps C and D, namely degreasing and rinsing, have already been carried out.

In Fig. 4 component 2 has been deposited at transfer point 33. The trolley 5 is on the way back to the connection point 8 to accommodate a new component 2. The component deposited at the transfer point 33 has already been picked up by the separating means 32, so that this component 2 is shortly before being fed into the hot-dip galvanizing device 25.

The embodiment shown is only one possible embodiment of the system 1 according to the invention. In principle, it is possible for the conveying device 3 to have a circumferential rail guide 4. The rail guide 4 here represents a closed path. In this embodiment, it is possible for a plurality of goods carriers 7 to be provided. The rail guide 4 then forms a closed circuit. Otherwise, it is possible that the conveyor 3 is not designed as a crane runway but as a floor conveyor. One or more goods carriers 7 then move on the floor, possibly along a rail guide, and in doing so move to the individual process stages. Several goods carriers 7 can also be provided here.

In addition, it is possible - in deviation from the exemplary embodiment shown - to transport a plurality of individual components 2 as a small group. It is then decisive here that the individual components 2 on the goods carrier 7 are sufficiently spaced from one another so that the components 2 fastened to the respective goods carrier 7 are accessible from all sides.

If the component 2 is sprayed, recycling, not shown, is provided. The spray which drips from component 2 in the respective chamber and does not remain on component 2 is collected and recycled in particular at the bottom of the respective chamber. Before recycling, the respective spray agent is preferably processed, in particular cleaned.

Furthermore, it is not shown that the flushing devices 12, 18 can also have a spraying device of the type described above, provided in a corresponding spraying chamber. The rinsing does not necessarily have to be done by immersion rinsing.

It is also not shown that the individual spray devices 10a, 16a, 22a have adjustable spray heads 10b, 16b, 22b. Each spray head 10b, 16b, 22b can be adjustable individually or else a group of spray heads 10b, 16b, 22b. In particular, the respective spraying device can be designed in such a way that spraying on of the respective spraying agent with different concentrations is possible. This can be done, for example, by supplying a highly concentrated spray medium via one spray line, while a diluent, for example water, is supplied via another spray line.

Instead of the separating device 31 shown, it is also possible for the components 2 to be guided through the hot-dip galvanizing device 25 on the goods carrier 7 in the separated state. Transport to the subsequent process steps, which follow the hot-dip galvanizing, can also take place via the conveyor 3.

Reference symbol list:

1

investment

2

component

3

Conveyor

4

Rail guide

5

Trolley

6

Hoist rope

7

Goods carrier

8th

Liaison

9

Degreasing device

10

Degreasing chamber

10a

Flushing device

10b

spray nozzle

11

Degreasing agent

12th

Flushing device

13

Sink

14

Detergent

15

Pickling device

16

Pickling chamber

16a

Flushing device

16b

Rinsing head

17

Mordants

18th

Flushing device

19

Sink

20th

Detergent

21

Flux application device

22

Flux chamber

22a

Flushing device

22b

spray nozzle

23

Flux

24

Drying facility

25

Hot-dip galvanizing facility

26

Galvanizing basin

27

Enclosure

28

Galvanizing bath

29

Cooling device

30

Aftertreatment facility

31

Separation device

32

Separating agent

33

Transfer point

34

Control device

Claims (15)

1. A system (1) for the hot-dip galvanization of components (2) for large-scale hot-dip galvanization comprising a plurality of identical or similar components (2) with a conveyor device (3) having at least one goods carrier (7) for conveying the components (2), a flux application device (21) for the application of a flux (23) on the surface of the components (2) and a hot-dip galvanization device (25) for the hot-dip galvanization of the components (2) with a galvanization bath (28) comprising a molten zinc-aluminium alloy, wherein the goods carrier (7) is designed for the receiving and for the transport of at least one separated component (2), wherein the flux application device (21) comprises a spraying device (22a) for the automated spray application of the flux (23) onto the surface of the separated component (2),
   wherein a control device (34) which is coupled to the spraying device (22a) for the automatic spraying of the flux (23) is provided for the automated control of the spray application depending on the shape and/or type and/or material and/or surface quality of the component (2),
   wherein the control device (34) is designed so that the spray application is homogeneous and/or is individually adapted to the component (2)
   and wherein the control device (34) is provided for the automated control of the thickness of the spray application on the component (2) and/or the concentration of the flux (23) and/or the spraying duration of the spray application per component (2) and/or the spraying duration of the spray application for different areas of a component (2) and/or the simultaneous spray application of different flux (23) and/or different flux components,
   wherein the spraying device (22a) comprises a plurality of spray heads (22b), wherein at least one spray head (22a) is movable in the X direction and/or in the Y direction and/or in the Z direction relative to the component (2).
2. The system according to claim 1, characterized in that the goods carrier (7) is designed and provided for the receiving and the transporting of only a single separated component (2) or that the goods carrier (7) is designed and provided for the receiving and the transporting of a small group of separated components (2).
3. The system according to one of the preceding claims, characterized in that the spraying device (22a) is designed for the simultaneous spraying of different fluxes (23) and/or different flux components.
4. The system according to one of the preceding claims, characterized in that a drying device (24) is provided downstream of the flux application device (21)
   and in that upstream of the flux application device (21) a surface treatment device is provided for the chemical surface treatment of the components (2) by means of a surface treatment agent
   and in that upstream of the surface application device and/or the surface treatment device a degreasing device (9) is provided for the degreasing of the components (2) by means of a degreasing agent (11).
5. The system according to one of the preceding claims, characterized in that a separating device (31) is provided for the feeding, immersion, and removal of a component (2) separated from the goods carrier (7) into/from the galvanisation bath (28) of the hot-dip galvanization device (25), or in that the conveyor device (3) and the hot-dip galvanisation device (25) are designed such that the component (2) fastened to the goods carrier (7) is guided in the separated state through the galvanization bath (28).
6. The system according to one of the preceding claims, characterized in that the conveyor device (3) is designed such that all components (2) are guided in an identical manner through the galvanization bath (28), or in that the separating means (31) is designed such that all components (2) separated from the goods carrier (7) are guided in an identical manner through the galvanization bath (28).
7. The system according to one of the preceding claims, characterized in that a stripping device is provided downstream of the removal region of the galvanization bath (28).
8. The system according to one of the preceding claims, characterized in that the control device (34) is coupled with the conveyor device (3) for changing the transport speed of at least one goods carrier (7).
9. The system according to one of the preceding claims, characterized in that the conveying device (3) comprises a circumferential, closed transport path with a plurality of goods carriers (7).
10. A method for the hot-dip galvanization of at least one component (2) using a molten zinc-aluminium alloy for large-scale hot-dip galvanization of a plurality of identical or similar components (2), wherein the component (2) in the separated state is transported on a goods carrier (7) to a flux application device (21) for the flux application, wherein the component (2) in the separated state is provided with the flux (23) through an automated spray application of a spraying device (22a) and then the component (2) provided on the surface thereof with the flux (23) undergoes a hot-dip galvanization in a galvanization bath (28) comprising the molten zinc-aluminium alloy,
    wherein the automated spray application takes place homogeneously and/or is individually adapted to the component;
    wherein the spray application is automatically controlled depending on the shape, the type, the material and/or the surface condition of the component (2), wherein the concentration of the flux (23) and/or the spraying duration of the spray application is set per component (2) and/or the spraying duration of the spray application is set for different areas of a component (2) and/or the thickness of the spray application is set on the component (2) and/or a simultaneous spray application of different fluxes (23) is set; and
    wherein the distance and/or the direction of a spray head (22b) of the spray device (22a) to the component (2) is changed when spraying the flux (23) onto a component (2).
11. The method according to claim 10, characterized in that the component (2) in the separated state is attached to the product carrier (7) as a single component (2) and is transported by the goods carrier (7) or that a small group of components (2) is attached on the product carrier (7) and is transported by the goods carrier (7).
12. The method according to one of the preceding claims, characterized in that a separated component (2) is immersed in an immersion region of the galvanization bath (28), then moves from the immersion region to an adjacent removal region and is subsequently removed in the removal region.
13. The method according to one of the preceding claims, characterized in that all separated components (2) are guided in an identical manner through the galvanization bath (28); and/or in that after removal all separated components (2) are guided along in an identical manner to a stripping device for the stripping of the liquid zinc-aluminium alloy; and/or in that all the separated components (2) are moved in an identical manner after removal in such a way that drips of the liquid zinc-aluminium alloy are removed and/or in that the flux (23) is dried after application to the surface of the components and/or in that the components (2) are dried after application of the flux (23) and/or in that the component (2) is cooled after the hot-dip galvanization and/or in that the component (2) is post-treated after the hot-dip galvanization.
14. The method according to one of the preceding claims, characterized in that the goods carrier (7) of the conveyor device (3) is moved at different transport speeds during the method and/or in that the goods carrier (7) is moved along a circumferential, closed transport path during the method.
15. A use of the system according to one of claims 1 to 9 and/or of the method according to one of claims 10 to 14 for the large-scale hot-dip galvanization of a large number of identical or similar components (2), in particular for batch galvanization.

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