EP3400318A1

EP3400318A1 - Hot-dip galvanization system and hot-dip galvanization method

Info

Publication number: EP3400318A1
Application number: EP17701042.8A
Authority: EP
Inventors: Thomas PINGER; Lars Baumgürtel
Original assignee: Fontaine Holdings NV
Current assignee: Fontaine Holdings NV
Priority date: 2016-03-09
Filing date: 2017-01-09
Publication date: 2018-11-14
Anticipated expiration: 2037-01-09
Also published as: CN108884543A; WO2017153062A1; DE102016106660A1; SI3400318T1; CA3015539A1; US20190048452A1; US11549166B2; ES2758519T3; PL3400318T3; BR112018068229A2; CA3015539C; CN108884543B; EP3400318B1; DK3400318T3; BR112018068229B1; MX2018010835A; HUE047635T2

Abstract

The invention relates to a system and a method for the hot-dip galvanization of components, preferably for mass-production hot-dip galvanization of a plurality of identical or similar components, in particular in batches, preferably for batch galvanization.

Description

Plant for hot-dip galvanizing and hot dip galvanizing

The present invention relates to the technical field of galvanizing iron-based or iron-containing components, in particular steel-based or stahlhal- term components (steel components), preferably for the automotive or automotive industry by means of hot dip galvanizing (hot dip galvanizing).

In particular, the present invention relates to a plant and a process for hot dip galvanizing (hot dip galvanizing) of components (ie of iron-based or iron-containing components, especially steel-based or steel-containing components (steel components)), especially for large-scale hot-dip galvanizing a variety of identical or similar Components (eg motor vehicle components) in discontinuous operation (so-called piece galvanizing). Metallic components of any kind made of ferrous material, in particular components made of steel, often require an efficient protection against corrosion due to the application. In particular, components made of steel for motor vehicles (motor vehicles), such. As cars, trucks, commercial vehicles, etc., require efficient corrosion protection, which also withstands long-term stress.

In this context, it is known to protect steel-based components by means of galvanizing (galvanizing) against corrosion. In galvanizing, the steel is provided with a generally thin layer of zinc to protect the steel from corrosion. Various galvanizing can be used to galvanize steel components, ie to coat with a metallic coating of zinc, in particular the hot dip galvanizing (synonymously also referred to as hot dip galvanizing), the spray galvanizing (flame spraying with zinc wire), the 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 abovementioned galvanizing processes, in particular with regard to the process implementation, but also with regard to the nature and properties of the zinc coatings or zinc coatings produced. Probably the most important process for corrosion protection of steel by metallic zinc coatings is the hot dip galvanizing (hot dip galvanizing). Steel is continuously immersed (eg strip and wire) or piecewise (eg components) at temperatures of about 450 ° C to 600 ° C in a heated vessel with molten zinc (melting point of zinc: 419.5 ° C), so that forms on the steel surface, a resistant alloy layer of iron and zinc and above a very firmly adhering pure zinc layer.

In hot-dip galvanizing, a distinction is made between discontinuous piece galvanizing (cf., for example, DIN EN ISO 1461) and continuous strip galvanizing (DIN EN 10143 and DIN EN 10346). Both galvanizing and strip galvanizing are standardized or standardized processes. Strip-galvanized steel is a preliminary or intermediate product (semi-finished product), which is further processed after galvanizing, in particular by forming, stamping, cutting, etc., whereas components to be protected by hot-dip galvanizing are first completely manufactured and then hot-dip galvanized (whereby the Components are completely protected against corrosion). Piece galvanizing and strip galvanizing also differ in terms of zinc layer thickness, resulting in different periods of protection. The zinc layer thickness of strip-galvanized sheet metal is usually at most 20 to 25 micrometers, whereas the zinc layer thicknesses of piece-galvanized steel parts are 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. The active corrosion protection is due to the cathodic effect of the zinc coating. Compared to nobler metals of the electrochemical series, such. As iron, zinc serves as a sacrificial anode, which protects the underlying iron from corrosion until it is completely corroded itself.

In so-called piece galvanizing according to DIN EN ISO 1461, hot-dip galvanizing is carried out on mostly larger steel components and constructions. Here, steel-based blanks or finished workpieces (components) are immersed in the molten zinc bath after pretreatment. In particular, inner surfaces, weld seams and hard-to-reach areas of the workpieces or components to be galvanized can be easily achieved by diving. Conventional hot-dip galvanizing is based, in particular, on the dipping of iron or steel components into a molten zinc to form a zinc coating or a zinc coating on the surface of the components. In order to ensure the adhesion, the integrity and the uniformity of the zinc coating, a thorough surface preparation of the components to be galvanized is generally required beforehand, which usually involves degreasing with subsequent rinsing, subsequent acid pickling followed by rinsing and finally fluxing (ie, so-called fluxing ) with subsequent drying process.

The typical process sequence in conventional piece galvanizing by means of hot-dip galvanizing is usually as follows. For reasons of process economics and economic efficiency, identical or similar components (eg mass production of motor vehicle components) are typically combined or grouped together for the entire process in the case of piece galvanizing (in particular by means of a common, for example designed as traverse or frame) Goods carrier or a common holding or fastening device for a plurality of identical or similar components). For this purpose, a plurality of components on the goods carrier via holding means, such. As slings, Anbindehähte or the like attached. Subsequently, the components are supplied in the grouped state on the goods carrier the subsequent treatment steps or stages.

First, the component surfaces of the grouped components are subjected to degreasing in order to remove residues of fats and oils, wherein the degreasing agents used are usually aqueous alkaline or acid degreasing agents. After cleaning in the degreasing bath, a rinsing process usually follows, typically by immersion in a water bath, in order to avoid carryover of degreasing agents with the galvanizing material into the subsequent process step of pickling, in particular when changing from alkaline degreasing to an acidic one Base is of high importance.

This is followed by a pickling (pickling), which in particular for the removal of inherent impurities such. As rust and scale, is used by the steel surface. The pickling is usually carried out in dilute hydrochloric acid, wherein the duration of the pickling process, among other things, the impurity state (eg, degree of rusting) of the zinc and the acid concentration and Temperature of the pickling bath is dependent. To avoid or minimize the carryover of acid and / or salt residues with the galvanizing material, a rinsing process (rinsing step) usually takes place after the pickling treatment. Subsequently, then the so-called fluxing (flux treatment), wherein the previously degreased and pickled steel surface with 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 task of the flux, before the reaction of the steel surface with the molten zinc, to carry out a final intensive ultrafine cleaning of the steel surface 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 to produce a solid flux film on the steel surface and to remove adhering water so as to subsequently avoid undesirable reactions (especially the formation of water vapor) in the liquid zinc immersion bath. The pre-treated in the above manner components are then hot dip galvanized by immersion in the liquid zinc melt. In galvanizing with pure zinc, the zinc content of the melt in accordance with DIN EN ISO 1461 is at least 98.0% by weight. After immersion of the galvanized in the molten zinc this remains for a sufficient period of time in the zinc melt bath, especially until the galvanized has assumed its temperature and coated with a layer of zinc. Typically, the surface of the molten zinc is in particular cleaned of oxides, zinc ash, flux residues and the like, before the galvanized material is then withdrawn from the molten zinc. The hot dip galvanized component is then subjected to a cooling process (eg in the air or in a water bath). Finally, the holding means for the component, such. As slings, Anbindedräh- te or the like, away. Following the galvanizing process, a sometimes complicated post-processing or aftertreatment usually takes place. In so doing, excess zinc residues, in particular so-called drip stains of the zinc which solidifies on the edges, and oxide or ash residues which adhere to the component are removed as far as possible. A criterion for the quality of a hot-dip galvanizing is the thickness of the zinc coating in μιη (microns). The standard DIN EN ISO 1461 specifies the minimum values of the required coating thicknesses, which, depending on the material thickness, are to be supplied in the case of hot-dip galvanizing. In practice, the layer thicknesses are significantly higher than the minimum layer thicknesses specified in DIN EN ISO 1461. In general, zinc plated zinc plating has a thickness in the range of 50 to 200 microns and even more.

In the galvanizing process, a coating of variously composed iron / zinc alloy layers is formed as a result of mutual diffusion of the liquid zinc with the steel surface on the steel part. When pulling out the hot-dip galvanized objects remains on the uppermost alloy layer still adhere - also referred to as pure zinc layer - layer of zinc, which corresponds in composition to the molten zinc. Because of the high temperatures during hot dipping, a relatively brittle layer based on an alloy (mixed crystals) between iron and zinc initially forms on the steel surface, and above that only the pure zinc layer. Although the relatively brittle iron / zinc alloy layer improves the adhesive strength with the base material, it complicates the formability of the galvanized steel. Higher silicon contents in the steel, which are used in particular for so-called calming of the steel during its production, 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, it comes to the formation of relatively large total layer thicknesses. Although this allows a very long corrosion protection period, however, the danger also increases with increasing zinc layer thickness that the layer flakes off under mechanical stress, in particular local, sudden effects, and the corrosion protection effect is thereby disturbed. In order to counteract the problem described above of the occurrence of the rapidly growing, brittle and thick iron / zinc alloy layer and also to allow lower layer thicknesses with simultaneously high corrosion protection during galvanizing, it is known from the prior art, the zinc melt or the liquid zinc bath additionally add aluminum. For example, by adding 5% by weight of aluminum to a liquid molten zinc, a zinc / aluminum alloy having a lower melting temperature than pure zinc is produced. By using a zinc / aluminum melt (Zn / Al melt) or a liquid zinc / aluminum bath (Zn / Al bath) leave On the one hand realize significantly lower layer thicknesses for reliable corrosion protection (generally below 50 microns); On the other hand, the formation of the brittle iron / tin alloy layer is omitted because the aluminum, so to speak, first forms a barrier layer on the steel surface of the relevant component, onto which the actual zinc layer is then deposited. Hot-dip galvanized components can therefore be easily formed with a zinc / aluminum melt, but nevertheless have improved corrosion protection properties despite the significantly lower layer thickness in comparison to conventional hot-dip galvanizing with a virtually aluminum-free molten 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 performed using such zinc / aluminum alloys have greater corrosion resistance (which is two to six times better than Reinzink's), improved formability, and better paintability than zinc coatings formed from pure zinc. Moreover, this technology can also 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 WO 2002/042512 A1 and the corresponding reference numerals to this patent family (eg EP 1 352 100 B1, DE 601 24 767 T2 and US 2003/0219543 A1). It also discloses suitable fluxes for hot dip galvanizing by means of zinc / aluminum molten baths, since flux compositions for zinc / aluminum hot dip galvanizing baths are different from those for conventional hot dip galvanizing. With the process disclosed therein corrosion protection coatings can be produced with very low layer thicknesses (generally well below 50 microns and typically in the range of 2 to 20 microns) and with very low weight with high cost efficiency, which is why the process described therein commercially under the name microZINQ ^® method is applied.

In the case of hot-dip galvanizing of components in zinc / aluminum molten baths, a large number of identical or similar components (eg large-scale backfire galvanizing of motor vehicle components or in the automotive industry) exist, in particular in the case of large-scale hot-dip galvanizing, because of the more difficult wettability of the steel with the zinc / aluminum melt as well as the small thickness of Zinc coatings or zinc coatings a problem in the economical process, the identical or similar components always subject to identical process conditions and processes, in particular reliably and reproducibly perform 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, especially with the selection of special flux - typically in particular by special process control during the galvanizing process, such. B. extended immersion times of the components in the zinc / aluminum melt, since only in this way it is ensured that no defects in the relatively thin zinc coatings or no or incomplete coated areas occur.

In order to make the process in the known piece hot-dip galvanizing of identical or similar components, especially in the Großserienstückfeuerverzin- economic and to ensure an identical process flow, it is in the prior art so that a variety of identical or identical components to be galvanized z. B. on a common goods carrier or the like summarized or grouped and guided in the grouped state by the individual process steps, and in particular the galvanizing.

However, the known piece of fire galvanizing has several disadvantages. In the case of a multi-layered suspension of the product carrier and in particular in the case of the same immersion and exchange movement of the product carrier, the components or component regions inevitably do not remain in the molten zinc for the same length. This results in different reaction times between the material of the components and the molten zinc and thus different zinc layer thicknesses on the components. Furthermore, in the case of high-temperature-sensitive components, in particular in the case of high-strength and ultrahigh-strength steels, such as, for example, For example, spring steel, chassis and body components and press-hardened formed parts, different residence times in the molten zinc on the mechanical characteristics of the steel. With regard to the guarantee of defined characteristic values of the components, the observance of defined process parameters is inevitably required for each individual component. Furthermore, when pulling out the components from the molten zinc inevitably leads to the flow of zinc and dripping on component edges and corners. This creates zinc noses on the component. The elimination of these zinc noses in the wake, which is usually done manually, represents a significant cost factor, especially when it comes to the galvanization of large quantities and / or compliance with high tolerances requirements. In the case of a fully loaded goods carrier, it is generally not possible to reach all the components and to individually remove the zinc noses directly at the galvanizing point. Usually, the galvanized components are to be removed after galvanizing from the product carrier and must be individually examined and reworked manually, which is very expensive.

Furthermore, it is in the known piece fire galvanizing so that the dipping and Austauchbewegung of the goods carrier takes place in and out of the galvanizing at the same point. Due to the process-related occurrence of zinc ash as a reaction product of the flux and the zinc melt after immersion of the components that accumulates on the surface of the zinc bath, it is imperative to remove the zinc ash from the surface by stripping or rinsing before immersion To avoid sticking to the galvanized components when pulling out, so that as possible no contamination on the galvanized component arise. In view of the large number of components located 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 proves to be very complicated and in some cases problematic. On the one hand, removal of the zinc ash results from the surface the galvanizing bath a time delay of the process while reducing productivity and on the other hand a source of error with regard to the galvanizing quality of the individual components. Ultimately remain in the known piece of hot-dip galvanizing impurities and zinc lugs on the galvanized components, which are to be removed by manual reworking. This refinement is regularly very costly and time consuming. In this regard, it should be noted that reworking does not only mean cleaning or repair, but also includes, in particular, the visual inspection. Due to the process, all components have the risk of contaminants sticking or of zinc lumps to be removed. Accordingly, all components must be inspected individually. But this examination, without any necessary subsequent work steps, represents a very high cost, especially in the field of large-scale production with many components to be tested and very high quality requirements.

The problem on which the present invention is based is therefore to provide a system or a method for piece galvanizing 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), preferably for high-volume hot-dip galvanizing of a large number of identical or similar components (eg motor vehicle components), whereby the previously described disadvantages of the prior art should at least largely be avoided or at least mitigated.

In particular, such a plant or such a process is to be provided, which (s) enable an improved process economy and a more efficient, in particular more flexible process sequence compared to conventional hot-dip galvanizing plants or processes.

In order to solve the above problem, the present invention proposes - according to an aspect of the present invention - a hot-dip galvanizing plant according to claim 1; Further, in particular special and / or advantageous embodiments of the system according to the invention are the subject of the relevant sub-systems. Furthermore, according to one aspect of the present invention, the present invention relates to a method for hot-dip galvanizing according to the independent method claim; Further, in particular special and / or advantageous embodiments of the method according to the invention are the subject of the related sub-claims.

It goes without saying in the following explanations that embodiments, embodiments, advantages and the like, which are carried out below for purposes of avoiding repetitions only as an aspect of the invention, of course also apply accordingly with respect to the other aspects of the invention, without this being so requires a separate mention. In the case of all relative or percentage weight-related data given below, in particular relative quantities or weights, it is further to be noted that in the context of the present invention, these are to be selected by the person skilled in the art in such a way that all components or ingredients, in particular, as defined below, always add to or add to 100% or 100 wt .-%; but this is self-evident to the person skilled in the art.

In addition, the expert may deviate from the range indicated below, depending on the application or the individual case, if necessary, without departing from the scope of the present invention.

In addition, it is true that all of the values or parameter information or the like mentioned below can in principle be determined or determined using standardized or explicitly stated determination methods or otherwise with methods of determination or measurement known per se to the person skilled in the art.

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

The invention relates to a system for hot-dip galvanizing or Schmelztauchverzin- kung of components, preferably for large-scale hot-dip galvanizing a plurality of identical or similar components, especially in discontinuous operation, preferably for piece galvanizing, with a conveyor with at least one goods carrier for grouped promotion of a plurality of on the Goods components to be fastened, an optionally decentralized provided degreasing device for degreasing of the components, a surface treatment device, in particular pickling, preferably for chemical, in particular wet chemical and / or mechanical surface treatment of the components, preferably for pickling the surfaces of the components, a Flussmit- applicator device for flux application to the surface of the components and a hot-dip galvanizing device for hot-dip galvanizing the components with a molten zinc / aluminum Le galvanizing bath. According to the invention, in a system of the type mentioned above for solving the underlying object, a separating device is provided for preferably automatically feeding, immersing and emptying a component separated from the goods carrier into the galvanizing bath of the hot-dip galvanizing device.

Accordingly, according to the invention, the invention relates to a process for hot-dip galvanizing of components using a molten zinc / aluminum alloy, preferably for high-volume galvanizing of a plurality of identical or similar components, in particular in discontinuous operation, preferably for piece galvanizing. It is envisaged that the components are attached to a goods carrier for grouped promotion before hot dip galvanizing. Subsequently, the components of a surface treatment, preferably a chemical, in particular wet chemical, and / or mechanical surface treatment, in particular a pickling subjected. Subsequently, the components are flux-coated on their surface and then the components provided with the flux on their surface are subjected to hot-dip galvanizing in a galvanized zinc / aluminum alloy galvanizing bath.

According to the invention, it is provided in the aforementioned method that during hot-dip galvanizing the components are separated from the product carrier and / or fed in the singulated state, preferably automatically, to the galvanizing bath, immersed therein and subsequently emptied therefrom.

As a result, the invention differs from the prior art in that the components are separated from the originally grouped state and supplied in the singulated state to the galvanizing bath of the zinc / aluminum alloy. This, at first glance, uneconomical and process-delaying measure has surprisingly been found to be particularly preferred, especially with regard to the production of high-precision hot-dip galvanized components.

With regard to economic aspects, the solution according to the invention has initially been omitted since in the case of the piece galvanizing process known from the prior art, depending on the size and weight, in some cases several hundred components are attached to a product carrier and at the same time galvanized together. A separation of the components from the goods carrier before the kung and galvanizing in the isolated state thus initially increases the duration of the pure galvanizing process considerably.

In connection with the invention, however, it has been recognized that, in particular for certain components, such as high-strength and ultra-high-strength steels, which are temperature-sensitive, targeted and optimized handling of the components in the actual galvanizing process is necessary. In the case of individual galvanizing in connection with the system according to the invention or the method according to the invention, it can be readily ensured that the components are each subject to identical process parameters. Especially for spring steel or chassis and body components made of high and ultra high strength steels, such. As 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. This ultimately results in always the same zinc layer thickness. In addition, the characteristics of the components are influenced by the galvanizing in an identical manner, since it is ensured by the invention that the components have been exposed to identical process parameters. Another significant advantage of the invention results from the fact that in the separation according to the invention each component can be precisely manipulated and treated, for example, by special rotational and steering movements of the component when pulling out of the melt. As a result, the Nachbearbeitungsaufwand significantly reduced to the part can be completely avoided. Furthermore, the invention offers the possibility that zinc ash adhesions can be significantly reduced and sometimes even avoided. This is possible since the process according to the invention can be controlled such that a component to be galvanized in the singulated state moves away from the immersion site after immersion and is moved to a location remote from the immersion site. This is followed by dipping. While the zinc ash rises in the area of the immersion site and is located on the surface of the immersion site, there are few or no zinc ash residues at the place of immersion. Thanks to this special technique, zinc ash adhesions can be significantly reduced or avoided. In the context of the present invention, it has been found that taking into account the sometimes unnecessary reworking in the invention, the overall production time in the production of galvanized components can even be reduced compared with the prior art, ie the invention ultimately provides a higher productivity, and in particular because the manual post-processing in the prior art is very time consuming.

Another advantage of an individual galvanizing plant is that no wider and deeper, but only a narrow galvanizing boiler 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. The result of the invention with the occasional galvanizing components with higher quality and cleanliness at the surface, the components have been exposed as such in each case identical process conditions and thus have the same component characteristics. Also in economic terms, the invention offers economic advantages over the prior art, since the production time can be reduced by up to 20% taking into account the no longer necessary or sometimes very limited post-processing.

In the invention, it is possible that after the initial grouping of the components on the or on the goods carrier the separation after the surface treatment or after the flux application is made. According to the device, the separation of the components from the goods carrier via the singling device is then provided following the degreasing or following the surface treatment, in particular pickling, or following the fluxing application. In experiments carried out under cost-benefit aspects has been found that it is most appropriate that the components are separated from the goods carrier after the flux application, the singulator is thus located between the Feuerverzinkungseignchtung and the flux application device. In this embodiment of the invention, the degreasing, the surface treatment and the flux application takes place in the grouped state of the components, while only the galvanizing is performed in the isolated state. According to the invention, in a preferred embodiment of the invention, it is provided that the separating device has at least one separating means arranged between the flux-applying device and the hot-dip galvanizing device. This separating means is then preferably designed so that it picks one of the components from the group of components and then supplies it 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 parked by the product carrier. It is understood that it is also possible in principle that more than one separating means is provided, so at the same time a plurality of individual components are hot-dip galvanized in the isolated state. In this context, it is then also understood that at least the galvanizing of the separated components is carried out in an identical manner, even if components of different separating means simultaneously or staggered and independently by the hot-dip galvanizing or galvanizing bath.

In an alternative embodiment of the system according to the invention and the associated method, it is provided that the separating means is indeed designed such that it removes one of the components from the group of components, but that the removed component does not feed directly to the galvanizing. The separating means can take the component removed from the group of components, for example, to a conveyor system belonging to the separating device, for example a conveyor belt. B. a goods carrier or a monorail, handed over which the isolated component is then galvanized in the isolated state. Ultimately, in this embodiment, according to the system, it is provided that the separating device has at least two separating means, namely a first separating means, which separates the components from the group of components, and at least one second separating means, for example in the form of a conveying system, which then isolated component passes through the galvanizing bath.

In a further, preferred embodiment of the invention, the separating means is designed such that a separated component is immersed in a dip area of the bath, then moved from the immersion area to an adjacent immersion area and subsequently immersed in the replacement area. As previously stated, zinc ash is produced on the surface of the immersion area as a reaction product of the flux with the molten zinc. Due to the movement of the component immersed in the molten zinc Diving area towards the immersion area there is no or hardly any zinc ash at the surface of the immersion area. In this way, the surface of the immersed galvanized component remains free or at least substantially free of zinc ash adhesions. It is understood that the immersion area is adjacent to the immersion area, ie, it is a spatially spaced apart and, in particular, non-intersecting areas of the galvanizing bath.

In a preferred embodiment of the aforementioned concept of the invention is otherwise provided that the component remains after immersion at least as long in the immersion region of the galvanizing bath until the reaction time between the component surface and the zinc / aluminum alloy of the galvanizing completed. In this way it is ensured that the zinc ash, which moves upwards within the melt, spreads only on the surface of the immersion area. Subsequently, the component can then be moved into the immersion region, which is essentially free of zinc ash, and dipped out there.

In experiments that have been carried out in the context of the invention, it has been found that it is expedient if the component remains between 20% to 80%, preferably at least 50%, of the galvanizing time in the region of the immersion region and only then moves into the immersion region becomes. In terms of plant technology, this means that the singling device or the associated singulation means are designed and, if necessary, adapted to one another by an appropriate control, so that the aforementioned method sequence can be carried out without problems.

In particular with components made of temperature-sensitive steels and with customer-specific requirements for components with product identity as identical as possible, it is provided in accordance with the system and the method that the separating means be designed in such a way that all components separated from the product carrier are arranged identically, in particular with identical movement, in an identical arrangement and / or with identical time, are passed through the galvanizing bath. This can ultimately be realized without further ado by a corresponding control of the separating device or of the at least one associated separating means. Due to the identical handling identical components, ie components that consist of the same material and each have the same shape, each have identical product properties. This does not belong only the same zinc layer thicknesses, but also identical characteristics of the galvanized components, since these have been performed in an identical manner by the galvanizing bath. Furthermore, the invention provides system and process according to the separation advantage that zinc noses can be easily avoided. For this purpose, according to the system, a stripping device is provided following the immersion region, wherein in a preferred embodiment of this inventive concept, the separating means is designed such that all isolated from the goods carrier components are passed after emersion of the stripping device for stripping liquid zinc in an identical manner. In an alternative embodiment, which can also be realized in combination with the stripping device, it is provided that all components separated from the product carrier are moved in an identical manner after emptying in such a way that dripping noses of liquid zinc are removed, in particular drip off and / or uniformly be distributed to the component surfaces. As a result, the invention makes it possible to guide each individual component not only through the galvanizing bath, but also either in a specific positioning, for example an inclination of the component, and move past one or more scrapers and / or the component by special Rotary and / or steering movements to move after the immersion so that zinc noses are at least substantially avoided.

Moreover, the system according to the invention preferably has a plurality of flushing devices, optionally with a plurality of flushing stages. Thus, a rinsing device is preferably provided after the degreasing device and / or after the surface treatment device. The individual flushing devices ultimately ensure that the degreasing agents used in the degreasing device or the surface treatment agents used in the surface treatment device are not introduced into the next process step.

Furthermore, the system according to the invention preferably has a drying device following the flux application device, so that the flux is dried after application to the surface of the components. In this way it is prevented that a liquid entry from the flux solution takes place in the galvanizing bath. In a preferred development of the invention, a cooling device, in particular a quenching device, is provided following the hot-dip galvanizing device, at which point the component is cooled or quenched after hot-dip galvanizing.

Furthermore, an after-treatment device can be provided in particular following the cooling device. The aftertreatment device is used in particular for a passivation, sealing or coloring of the galvanized components. However, the post-treatment step can also include, for example, post-processing, in particular the removal of impurities and / or the removal of zinc noses. As has been stated above, however, the post-processing step in the invention is considerably reduced and sometimes even unnecessary in comparison with the method known in the prior art. Furthermore, the invention relates to a system and / or a method of the aforementioned type, wherein the components are 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 additionally, the galvanizing bath contains zinc and aluminum in a zinc / aluminum weight ratio in the range of 55-99.999: 0.001-45, preferably 55-99.97: 0.03-45, more preferably 60-98: 2-40, preferably 70-96: 4-30. Alternatively or additionally, the galvanizing bath has the following composition, in which the weights are based on the galvanizing bath and in the sum of all constituents of the composition results in 100% by weight:

(i) zinc, in particular in amounts ranging from 55 to 99.999% by weight, preferably 60 to 98% by weight,

(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 from 0.1 to 45% by weight .

(iii) optionally silicon, in particular in amounts ranging from 0.0001 to 5 wt .-%, preferably 0.001 to 2 wt .-%;

(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 amounts in the range of 0.0001 to 10 wt .-%, preferably 0.001 to 5 wt .-%. In connection with experiments carried out, it has been found that in the case of zinc baths with the composition given above, it is possible to achieve very thin and very homogeneous coatings on the component, which satisfy in particular the high demands on component quality in motor vehicle construction.

Alternatively or additionally, the flux has the following composition, the weight data being based on the flux and resulting in the sum of all constituents of the composition 100 wt .-%:

(i) zinc chloride (ZnCl ₂ ), especially in amounts ranging from 50 to 95% by weight, preferably from 58 to 80% by weight;

(ii) ammonium chloride (NH ₄ Cl), especially in amounts ranging from 5 to 50% by weight, preferably 7 to 42% by weight;

(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 of 1 to 30 wt .-%, preferably 2 to 20 wt .-%;

(iv) optionally at least one metal chloride, preferably heavy metal chloride, preferably selected from the group of nickel chloride (NiCl ₂ ), manganese chloride (MnCl ₂ ), lead chloride (PbCl ₂ ), cobalt chloride (CoCl ₂ ), tin chloride (SnCl ₂ ), antimony chloride (SbC ) and / or bismuth chloride (B1CI3), in particular in total amounts in the range of 0.0001 to 20 wt .-%, preferably 0.001 to 10 wt .-%;

(V) optionally at least one further additive, preferably wetting agent and / or surfactant, in particular in amounts ranging from 0.001 to 10% by weight, preferably 0.01 to 5 wt .-%.

Alternatively or additionally, it is provided that the flux application device, in particular the Flußmittelbad the flux application device containing flux in preferably aqueous solution, in particular in amounts and / or concentrations of the flux in the range of 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 of 200 to 700 g / l, in particular 350 to 550 g / l, preferably 500 to 550 g / l. In tests with a flux in the above-mentioned composition and / or concentration, in particular in conjunction with the previously described zinc / aluminum alloy, it has been found that very small layer thicknesses, in particular of less than 20 μm, result, with a low weight and reduced costs accompanied. Especially in the motor vehicle sector these are essential criteria.

Other 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 drawing itself. In this case, all described and / or illustrated features alone or in any combination form the subject of the present invention, regardless from their summary in the claims or their dependency.

a schematic process sequence of the individual stages of the process according to the invention,

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

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

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.

In Fig. 1, a sequence of the method according to the invention in a system 1 according to the invention is shown schematically. In this context, it should be pointed out that the flowchart shown is a method which is possible according to the invention, but individual method steps may also be omitted or provided in a different order than shown and described below. Also, further method steps may be provided. Moreover, it is the case that not all stages of the process basically have to be provided in a spatially combined Annex 1. The decentralized realization of individual process stages is also possible. In the flowchart shown in FIG. 1, the step A designates the delivery and depositing of components 2 to be galvanized at a connection point. The components 2 are already mechanically surface-treated in the present example, in particular sandblasted. This may or may not be foreseen.

In stage B, the components 2 are connected to a goods carrier 7 of a conveyor 3 to form a group of components 2. In part, the components 2 are also connected to each other and thus only indirectly with the goods carrier 7. It is also possible for the goods carrier 7 to have a basket, a frame or the like, in or into which the components 2 are inserted.

In stage C, the components 2 are degreased. In this case, alkaline or acid degreasing agents 11 are used to remove residues of fats and oils on the components 2.

In stage D, a rinse, in particular with water, of the degreased components 2 is provided. In this case, the residues of degreasing agent 1 1 are rinsed off from the components 2. In the process document E, a pickling of the surfaces of the components 2, so a wet-chemical surface treatment. The pickling is usually carried out in dilute hydrochloric acid.

Stage E is followed by stage F, which in turn is a rinse, 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, to be galvanized components 2 are then, still grouped together as a group on the product carrier 4, floated, namely subjected to a flux treatment. In the present case, the flux treatment in stage H is likewise carried out in an aqueous flux solution. After a sufficient residence time in the flux 23, the product carrier 7 with the components 2 in stage I is subjected to drying in order to produce a solid flux film on the surface of the components 2 and to remove adhering water. In method step J, the components 2 previously combined as a group are singulated, ie removed from the group, and subsequently further treated in the singulated state. The separation can take place in that the components 2 are removed individually from the product carrier 7 or also in that the product carrier 7 first deposits the group of components 2 and the components 2 are then removed individually from the group.

After the separation in step J, the components 2 are now hot-dip galvanized in the stage K. For this purpose, the components 2 are each immersed in a galvanizing bath 28 and dipped again after a predetermined residence time.

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

Subsequently, the galvanized component is quenched in step M.

The quenching in method step M is followed by a post-treatment in stage N, which may be, for example, a passivation, sealing or organic or inorganic coating of the galvanized component 2. However, the aftertreatment also includes a possible reworking of the component 2.

2 to 4, an embodiment of a system 1 according to the invention is shown schematically. 2 to 4, an embodiment of a system 1 according to the invention for the hot or hot dip galvanizing of components 2 is shown in a schematic representation. The plant 1 is provided for hot dip galvanizing a plurality of identical components 2 in the discontinuous operation, the so-called piece galvanizing. In particular, the plant 1 is designed and suitable for hot dip galvanizing of components 2 in large series. The large-scale galvanizing refers to galvanizing, in which successively more than 100, in particular more than 1000 and preferably more than 10,000 identical components 2 are galvanized, without in between components 2 of different shape and size are galvanized. The system 1 has a conveying device 3 for conveying or for the simultaneous transport of a plurality of components 2, which are combined into a group. In the present case, the conveyor device 3 is a crane track with a rail guide 4, on which a trolley 5 with a lifting mechanism can be moved. About a hoisting rope 6 a goods carrier 7 is connected to the trolley 5. The goods carrier 7 is used to hold and secure the components 2. The connection of the components 2 with the goods carrier 7 is usually carried out at a connection point 8 of the system, to which the components 2 are grouped for connection to the goods carrier 7.

At the junction 8, a degreasing device 9 connects. The degreasing device 9 has a degreasing basin 10 in which a degreasing agent 1 1 is located. The degreasing agent 1 1 may be acidic or basic. The degreasing device 9 is adjoined by a flushing device 12, which has a sink 13 with flushing agent 14 located therein. The rinsing agent 14 in the present case is water. Downstream of the rinsing device 12, that is to say in the process direction, is a surface treatment device designed as a pickling device 15 for wet-chemical surface treatment of the components 2. The pickling device 15 has a pickling tank 16 with a pickling means 17 located therein. The mordant 17 in the present case is dilute hydrochloric acid.

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

In the process direction downstream of the rinsing device 18 is a flux application device 21 with a fluxing basin 22 and therein flux 23. The flux contains in a preferred embodiment zinc chloride (ZnCl ₂ ) in an amount of 58 to 80 wt .-% and ammonium chloride (NH ₄ CI) in the amount of 7 to 42 wt .-% on. Furthermore, if appropriate, a small amount of alkali metal and / or alkaline earth metal salts and, if appropriate, a further heavy metal chloride are provided in a further reduced amount. Furthermore, if necessary, a wetting agent is also provided in small quantities. It is understood that the above weight data are based on the flux 23 and make up in the sum of all components of the composition 100 wt .-%. Incidentally, the flux 23 is in aqueous solution, in a concentration in the range of 500 to 550 g / l. It should be pointed out that the aforementioned devices 9, 12, 15, 18 and 21 can each basically have a plurality of cymbals. These individual basins, but also the basins described above, are arranged in cascade behind one another.

The flux applicator 21 is followed by a drying device 24 to remove adhering water from the flux film, which is located on the surface of the components 2. Furthermore, the plant 1 has a Feuerverzinkungseinnchtung 25, in which the components 2 are hot-dip galvanized. The Feuerverzinkungseinnchtung 25 has a galvanizing tank 26, optionally with a housing provided on the top 27. In galvanizing tank 26 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, if appropriate, small amounts of silicon and optionally in further reduced proportions a small amount of alkali and / or alkaline earth metals and heavy metals are provided. It is understood that the aforementioned weights are based on the galvanizing 28 and make up in the sum of all components of the composition 100 wt .-%.

In the process direction after the Feuerverzinkungseinnchtung 25 is a cooling device 29, which is provided for quenching of the components 2 after the Feuerverzin- kung. 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 Feuerverzinkungseinnchtung 25 is a separating device 31, which is provided for automated feeding, immersing and dehumidifying a separated from the goods carrier 7 component 2 in the galvanizing bath 28 of the Feuerverzinkungseinnchtung 25. In the exemplary embodiment shown, the separating device 31 has a separating means 32 which is used for handling the components 2, namely for removing a component 2 from the group of components 2 or for removing the grouped components 2 from the product carrier 7 and for feeding, immersing and Diving of the separated component 2 is provided in the galvanizing bath 28. For singling is located between the separating means 32 and the drying device 24, a transfer point 33, at which the components 2 are either stored or in particular in the hanging state of the goods carrier 7 and thus removed from the group or can be singled. For this purpose, the separating means 32 is preferably designed so 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 away from it.

Incidentally, the separating means 32 is designed in such a way that it moves a component 2 immersed in the galvanizing bath 28 occasionally from the immersion region to an adjacent immersion region and then emerges in the region of exchange. The immersion area and the immersion area are spaced apart from each other, so do not correspond to each other. In particular, the two areas do not overlap. The movement from the immersion region to the immersion region does not take place until 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, the separating device 31 has centrally and / or the separating means 32 locally via a control device, according to which the movement of the separating means 32 takes place in such a way that all components 2 separated from the goods carrier 7 move with identical movement, in identical arrangement and with identical time through the Galvanizing 28 are performed. Not shown is that above the galvanizing bath 28 and still within the housing 27, a scraper of a stripping device, not shown, which is provided for stripping liquid zinc. Moreover, the separating means 32 can also be controlled via the associated control device so that an already galvanized component 2 is still moved within the housing 27, for example by corresponding rotational movements such that excess zinc drips and / or alternatively is evenly distributed on the component surface.

FIGS. 2 to 4 show different states during operation of the system 1. FIG. 2 shows a state in which a multiplicity of components 2 to be galvanized are deposited at the connection point 8. Above the group of components 2 is the goods carrier 7. After lowering the goods carrier 7, the components 2 are attached to the goods carrier 7. In the illustrated embodiment For example, the components 2 are arranged in layers. In this case, all components 7 can each be connected to the goods carrier 7. But it is also possible that only the upper layer of components 2 is connected to the goods carrier 7, while the following position is connected to the respective overlying layer. It is also possible that the group of components 2 is arranged in a basket-like frame or the like.

In Fig. 3, the group of components 2 is above the pickling means 15. The stages C and D, namely degreasing and rinsing, have already been carried out.

In Fig. 4, the group of components 2 has been deposited at the transfer point 33. The trolley 5 is on the way back to the connection point 8, at which are already new to be galvanized components 2 as a group. From the deposited at the transfer point 33 group of components 2 has already been removed via the separating means 32, a component 2, which is just before feeding into the hot-dip galvanizing 25.

LIST OF REFERENCE NUMBERS

1 plant

2 component

3 conveyor

4 rail guide

5 trolley

6 hoist rope

7 goods carriers

8 connection point

9 degreasing device

10 degreasing tanks

1 1 degreaser

12 rinsing device

13 sinks

14 detergent

15 pickling device

16 pickling tanks

17 pickling agent

18 rinsing device

19 sinks

20 washing-up liquid

21 flux applicator

22 flux basins

23 flux

24 drying device

25 galvanizing equipment

26 galvanizing tanks

27 enclosure

28 galvanizing bath

29 Cooling device

30 aftertreatment device

31 Separation device

32 separating agents

33 transfer point

Claims

claims:

Plant (1) for the hot-dip galvanizing of components (2), preferably for large-batch hot-dip galvanizing of a plurality of identical or similar components (2), especially in discontinuous operation, preferably for piece bonding, with a conveying device (3) having at least one product carrier (7 ) for the grouped promotion of a plurality of on the product carrier (7) to be fastened components, an optionally decentralized provided degreasing device (9) for degreasing the components (2), a surface treatment device, in particular pickling device (15), preferably for chemical, especially wet-chemical , and / or mechanical surface treatment of the components (2), preferably for pickling the surfaces of the components (2), flux application means (21) for flux application to the surface of the components (2) and a hot dip galvanizing means (25) for hot dip galvanizing the components (2 ) with a molten zinc / aluminum L. zinc-plating bath (28), d a d u c h e c e n e c e n e,

in that a separating device (31) is provided for preferably automatically feeding, immersing and dehumidifying a component (2) isolated from the goods carrier (7) into the galvanizing bath (28) of the hot-dip galvanizing means (27).

Plant according to claim 1,

characterized in that the separation of the components (2) from the goods carrier (7) via the singling device (31) is provided following the degreasing or subsequent to the surface treatment, in particular pickling, or subsequent to the flux application.

Plant according to claim 1 or 2,

characterized in that the singling device (31) has at least one separating means (32) arranged in particular between the fluxing application means (21) and the hot-dip galvanizing means (25). Plant according to one of the preceding claims,

characterized,

in that the separating means (32) is designed so that a separated component (2) is immersed in an immersion region of the galvanizing bath (28), then moved from the immersion region to an adjacent immersion region and subsequently immersed in the replacement region; and or

in that the separating means (32) is designed in such a way that all the components (2) isolated from the goods carrier (7) are guided in an identical manner, in particular with identical movement, in an identical arrangement and / or with identical time, through the galvanizing bath (28).

Plant according to one of the preceding claims,

characterized,

in that a stripping device is provided following the immersion region of the galvanizing bath (28), in particular wherein the separating means (32) is designed such that all components (2) separated from the goods support (7) after stripping the stripping device for stripping in an identical manner be passed; and or

in that the separating means (32) is designed in such a way that all components separated from the goods carrier (7) are moved in an identical manner after emptying in such a way that dripping noses are removed, in particular drip off and / or distributed uniformly on the component surfaces.

Plant according to one of the preceding claims,

characterized,

in that at least one flushing device (12, 18) is provided, in particular with at least one flushing step, in particular wherein the flushing device (12, 18) is provided following the degreasing device (9) and / or following the surface treatment device, preferably a flushing device (12, 18) is provided in each case following the degreasing device (9) and subsequent to the surface treatment device; and or a drying device (24) is provided following the flux application device (21); and or

in that a cooling device (29), in particular a quenching device, is provided following the hot-dip galvanizing device (25); and / or that an after-treatment device (30) is provided after the hot-dip galvanizing device (25) and optionally at the optional cooling device (29).

Process for the hot-dip galvanizing of components (2) using a molten zinc / aluminum alloy, preferably for high-volume hot-dip galvanizing of a plurality of identical or similar components (2), in particular in discontinuous operation, preferably for piece bonding,

wherein the components (2) are fastened to a goods carrier (7) for grouped conveyance before hot-dip galvanizing, subsequently subjecting the components (2) to surface treatment, preferably chemical, in particular wet-chemical, and / or mechanical surface treatment, in particular pickling Then, the components (2) are provided on their surface with a flux (23) and then provided on their surface with the flux (23) components (2) in a molten zinc / aluminum alloy having zinc plating ( 28) are subjected to hot-dip galvanizing,

characterized ,

in the case of hot-dip galvanizing, the components (2) are separated from the product carrier (7) and / or supplied in isolated form, preferably automatically, to the galvanizing bath (28), dipped therein and subsequently emptied therefrom.

Method according to claim 7,

characterized in that the components (2) are separated from the product carrier (7) after the surface treatment, in particular pickling, or after the flux application.

9. The method according to claim 7 or 8,

characterized in that an isolated component (2) is immersed in an immersion region of the galvanizing bath (28), then moved from the immersion region to an adjacent immersion region and subsequently immersed in the immersion region, in particular wherein the separated component

(2) is moved from the immersion area to the replacement area only after completion of the reaction time of the flux (23) with the zinc / aluminum alloy. 10. Method according to one of the preceding method claims,

characterized,

that all of the goods carrier (7) isolated components (2) in an identical manner, in particular with identical movement in an identical arrangement and / or with identical time, by the galvanizing bath (28) are guided; and / or that all of the goods carrier (7) isolated components (2) are passed after immersion in a stripping device for stripping the liquid zinc / aluminum alloy in an identical manner; and or

in that all components (2) isolated from the product carrier (7) are moved in an identical manner after emptying in such a way that dripping noses of the liquid zinc / aluminum alloy are removed, in particular drip off and / or distributed uniformly on the component surface.

1 1. Method according to one of the preceding method claims,

characterized,

the components (2) are rinsed after the degreasing and / or after the surface treatment, in particular pickling, in particular in each case one or more times, preferably wherein the components (2) are rinsed after the degreasing and after the surface treatment, in particular pickling , in particular in each case one or more times rinsed; and or

that the flux (23) is dried after application to the surface of the components (2) and / or the components (2) are dried after the application of the flux (23) and / or

that the component (2) is cooled after the hot-dip galvanizing, in particular quenched and / or

that the component (2) is post-treated after the hot-dip galvanizing, in particular after the optionally provided cooling.

Installation according to one of claims 1 to 6 or method according to one of claims 7 to 1 1,

characterized,

that the components (2) are iron-based and / or iron-containing components (2), in particular steel-based and / or steel-containing components (2), preferably automotive components or components (2) for the automotive sector; and or

the galvanizing bath (28) comprises zinc and aluminum in a zinc / aluminum weight ratio in the range of 55-99.999: 0.001-45, preferably in the range of 55-99.97: 0.03-45, in particular in the range of 60-98 : 2-40, preferably in the range of 70-96: 4-30; and or

that the galvanizing bath (28) has the following composition, the weight data being based on the galvanizing bath (28) and the sum of all constituents of the composition being 100% by weight: (i) zinc, in particular in amounts ranging from 55 to 99.999 Wt .-%, preferably 60 to 98 wt .-%; (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 in the range from 0.1 to 45% by weight. -%, preferably 2 to 40 wt .-%, (iii) optionally silicon, in particular in amounts in the range of 0.0001 to 5 wt .-%, preferably 0.001 to 2 wt .-%; (iv) optionally at least one further ingredient and / or 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 amounts in the range of 0.0001 to 10% by weight, preferably 0.001 to 5% by weight; and or the flux (23) has the following composition, the weight data being based on the flux (23) and resulting in the sum of all constituents of the composition 100% by weight: (i) zinc chloride (ZnCl ₂ ), in particular in amounts in the range from 50 to 95% by weight, preferably from 58 to 80% by weight; (ii) ammonium chloride (NH ₄ Cl), especially in amounts ranging from 5 to 50% by weight, preferably 7 to 42% by weight; (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 of 1 to 30 wt .-%, preferably 2 to 20 wt .-%; (iv) optionally at least one metal chloride, preferably heavy metal chloride, preferably selected from the group of nickel chloride (NiCl ₂ ), manganese chloride (MnCl ₂ ), lead chloride (PbCl ₂ ), cobalt chloride (CoCl ₂ ), tin chloride (SnCl ₂ ), antimony chloride ( SbC) and / or bismuth chloride (B1CI3), in particular in total amounts in the range of 0.0001 to 20 wt .-%, preferably 0.001 to 10 wt .-%; (V) optionally at least one further additive, preferably wetting agent and / or surfactant, in particular in amounts ranging from 0.001 to 10% by weight, preferably 0.01 to 5 wt .-%, and / or

fluxing means (21), in particular the fluxing means (22) of the fluxing means (21), containing flux (23) in preferably aqueous solution, in particular in amounts and / or concentrations of the fluxing agent (23) in the range of 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 of 200 to 700 g / l, in particular 350 to 550 g / l, preferably 500 to 550 g / l.