EP3400318B1 - Hot-dip galvanization system, hot-dip galvanization method and their use - 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 automotive industry, by means of hot dip galvanizing (hot-dip galvanizing).

In particular, the present invention relates to a system and a method for hot dip galvanizing (hot dip galvanizing) of components (ie iron-based or iron-containing components, especially steel-based or steel-containing components (steel components)), especially for large-scale hot-dip galvanizing a plurality of identical or similar components (eg. B. automotive components), in discontinuous operation (so-called piece galvanizing).

Furthermore, the present invention relates to the use of the plant according to the invention or the process according to the invention for hot-dip galvanizing (hot dip galvanizing) in large series.

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 (semifinished product), which is further processed after galvanizing, in particular by forming, stamping, cutting, etc., whereas components to be protected by piece galvanizing are first completely manufactured and then hot-dip galvanized (whereby the components all around 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 sheets 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.

The conventional hot-dip galvanizing is based in particular on the immersion of iron or steel components in 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 particular by means of a common product carrier, designed as a crossbeam or frame, for example) 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 usually followed by a rinsing, typically by immersion in a water bath to avoid carryover of degreasers with the galvanizing in the subsequent process step of pickling, this being especially in a change from alkaline degreasing to an acidic base 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, the so-called fluxing (flux treatment) takes place, whereby 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 to carry out a last 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 re-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 galvanizing in the molten zinc this remains for a sufficient period of time in the molten zinc bath, in particular until the galvanizing has assumed its temperature and is coated with a zinc layer. 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, Anbindehähte or the like, away. Following the galvanizing process, a sometimes complicated post-processing or aftertreatment usually takes place. In this case, excess zinc residues, in particular so-called drip noses 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 microns (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 adhesion with the base material, it makes the formability of the galvanized steel more difficult. 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, there is no formation of the brittle iron / tin alloy layer, since the aluminum, so to speak, initially forms a barrier layer on the steel surface of the relevant component, onto which the actual zinc layer is 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 with 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 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 related references to this patent family (e.g. 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 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 unit fire galvanizing identical or similar components, especially in the Großserienstückfeuerverzinkung, economical and to ensure an identical process flow, it is in the prior art so that a variety of identical or similar 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 high temperature sensitive components, especially in high and ultra high strength steels such. As for spring steel, chassis and body components and press-hardened metal 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 the goods 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 WO 95/04607 A1 relates to a process for hot-dip galvanizing steel components, wherein a flux is applied to the surface of the steel components, wherein a preheating of the components takes place in a non-reducing atmosphere for drying the flux and for introducing additional heat energy.

Furthermore, the concerns US Pat. No. 6,277,443 B1 a batch process for galvanizing steel components, wherein the zinc coatings have little or no lead, wherein the components are cleaned, pickled and rinsed and dipped in a hot flux solution and then dried before being fed to the zinc alloy zinc bath.

In addition, the concerns US Pat. No. 1,935,087 a device for applying a protective layer on metallic components, such as steel pipes, wherein the components are immersed in a galvanizing bath and coated with zinc and then removed from the galvanizing bath.

Furthermore, the concerns US 2003/219543 A1 a flux and a flux bath for hot-dip galvanizing and a process and a hot-dip galvanizing bath for hot-dip galvanizing an iron or steel product, wherein the flux composition comprises 60 to 80% by weight zinc chloride, 7 to 20% by weight ammonium chloride, 2 to 20% by weight a flux modifier comprising at least one alkali or alkaline earth metal and 0.1 to 5% by weight of at least one compound of NiCl ₂ , CoCl ₂ and MnCl ₂ , and 0.1 to 1.5% by weight of at least one compound from PbCl ₂ , SnCl ₂ , BiCl ₃ and SbCl ₃ .

Finally, the concerns US Pat. No. 3,639,142 A. a hot-dip galvanizing process for elongated steel components, wherein the elongated steel components are pretreated and submerged in the galvanizing bath grouped together by means of a hook carrier.

The problem underlying the present invention 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 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), 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 should be provided, which (s) compared to conventional hot-dip galvanizing plants or processes allow an improved process economy and a more efficient, in particular more flexible process flow.

To solve the above problem, 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 embodiments of the system according to the invention are the subject of the relevant sub-systems.

Furthermore, the present invention - according to a second aspect of the present invention - a method for hot dip galvanizing according to the independent method claim before; Further, in particular special and / or advantageous embodiments of the method according to the invention are the subject of the related sub-claims.

Moreover, the present invention - according to a third aspect of the present invention - relates to the use of the installation 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 statements that embodiments, embodiments, advantages and the like, which are designed below for the purpose of avoiding repetition only as an aspect of the invention, of course also apply correspondingly with respect to the other aspects of the invention, without this being a separate one Mention needs.

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, especially as defined below, always to Add or add 100% or 100% by weight; 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 components for large-series hot-dip galvanizing a plurality of identical or similar components with a conveyor with at least one goods carrier for grouped promotion of a plurality of components to be fastened to the goods carrier, a degreasing device for degreasing the components, a surface treatment device for chemical and / or or mechanical surface treatment of the components, a flux application device for flux application to the surface of the components and a hot-dip galvanizing device for hot-dip galvanizing the components with a galvanized zinc / aluminum alloy galvanizing bath,
wherein a separating device is provided for feeding, immersing and dehumidifying a component separated from the goods carrier into the galvanizing bath of the hot-dip galvanizing device,
wherein the separating device has at least one separating means,
in the singling each component can be precisely manipulated and treated by special turning and steering movements when pulling out of the melt and
wherein the separating means is designed such that all isolated from the goods carrier components are moved in an identical manner after replacement such that dripping noses are removed.

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 hot dip galvanizing a plurality of identical or similar components, especially 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 galvanizing and galvanizing in the isolated state thus initially increases the time 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, a targeted and optimized handling of the components in the actual Galvanizing process is necessary. In the case of individual galvanizing in connection with the installation 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 flux application. In experiments carried out under cost-benefit aspects has been found that it is most appropriate that the components are separated from the product carrier after the flux application, the singulator is thus located between the hot-dip galvanizing 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, 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 so that it removes 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.

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. As a goods carrier or a monorail train passed, over which the isolated component is then galvanized in the isolated state. Ultimately, in this embodiment, according to the system is provided that the separating means comprises at least two separating means, namely a first separating means which performs the separation of the components from the group of components, and at least a second separating means, for example in the manner of a conveyor system, then the isolated component 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 from the immersion area to 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 region is adjacent to the exchange region, so it is spatially spaced apart and in particular not overlapping 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.

Particularly in the case of components made of temperature-sensitive steels and in customer-specific requirements for components with identical product properties as far as possible, the separating means is designed in such a way that all components separated from the product carrier are identically arranged, in particular with identical movement, and / or or with identical time, 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. These include not only identical zinc layer thicknesses but also identical characteristics of the galvanized components, since these have each been passed through the galvanizing bath in an identical manner.

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 idea the separating means is designed such that all isolated from the goods carrier components are passed after emptying of the stripping means 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 the component is cooled or quenched after the 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 stage may also include, for example, the 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.

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.-%,
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, 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:

1. (i) zinc, in particular in amounts ranging 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 from 0.1 to 45% by weight .
3. (iii) optionally silicon, in particular in amounts ranging from 0.0001 to 5 wt .-%, preferably 0.001 to 2 wt .-%;
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 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.

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 (SnCl₂), Antimonchlorid (SbCl₃) und/oder Wismutchlorid (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 constituents of the composition 100 wt .-%:

1. (i) zinc chloride (ZnCl ₂ ), especially in amounts ranging from 50 to 95% by weight, preferably from 58 to 80% by weight;
2. (ii) ammonium chloride (NH ₄ Cl), especially in amounts ranging 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 of 1 to 30 wt .-%, preferably 2 to 20 wt .-%;
4. (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 ), stannous chloride (SnCl ₂ ), antimony chloride (SbCl ₃ ) and / or bismuth chloride (BiCl ₃ ), in particular in total amounts in the range of 0.0001 to 20 wt .-%, preferably 0.001 to 10 wt .-%;
5. (V) optionally at least one further additive, preferably wetting agent and / or surfactant, in particular in amounts ranging from 0.001 to 10 wt .-%, 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 experiments with a flux in the aforementioned composition and / or concentration, in particular in connection with the previously described zinc / aluminum alloy, it has been found that very small layer thicknesses, in particular less than 20 microns, resulting in a low weight and reduced costs accompanied. Especially in the motor vehicle sector these are essential criteria.

Furthermore, according to a further aspect of the invention, the present invention relates to the use of a plant as defined above and / or the process as defined above for large-scale hot-dip galvanizing of a plurality of identical or similar components. It is particularly preferred if the large-scale hot-dip galvanizing in discontinuous operation, preferably in the form of a piece galvanizing, is performed.

Other features, advantages and applications of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawing and the drawing itself. In this case, all described and / or illustrated features, alone or in any combination, the subject of the present invention, regardless of their Summary in the claims or their dependency.

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

Fig. 2

a schematic representation of a system according to the invention and the sequence of the method according to the invention in a 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 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 in Fig. 1 illustrated flow diagram, the level A refers to the delivery and the placement of parts to be galvanized 2 at a junction. 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 that the goods carrier 7 has a basket, a frame or the like, in which or in 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 11 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 drip 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 post-processing of the component 2 which may be required.

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

In the Fig. 2 to 4 is a schematic representation of an embodiment of a system 1 according to the invention for hot or hot dip galvanizing of components 2 shown. 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 conveyor 3 for conveying or for the simultaneous transport of a plurality of components 2, which are combined to form 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 11 is located. The degreasing agent 11 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 rinsing agent 20 is again water.

In the process direction behind the rinsing device 18 is a flux applicator 21 with a flux pool 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 Cl ) in the amount of 7 to 42% by weight. 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 system 1 has a hot-dip galvanizing device 25, in which the components 2 are hot-dip galvanized. The hot-dip galvanizing device 25 has a galvanizing tank 26, optionally with a housing 27 provided on the upper side. In the galvanizing tank 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, 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 hot-dip galvanizing device 25 is a cooling device 29, which is provided for quenching of the components 2 after hot-dip galvanizing. Finally, after the cooling device 29 is an aftertreatment device 30 provided, in which the hot-dip galvanized components 2 can be post-treated and / or reworked.

Between the drying device 24 and the hot-dip galvanizing device 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 28 of the hot-dip galvanizing device 25. The separating device 31 has in the illustrated embodiment, a separating means 32 for handling the components 2, namely for removal of a component 2 from the group of components 2 and to remove the grouped components 2 from the goods carrier 7 and for feeding, dipping and Austauchen of isolated 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 such that it is movable in the direction of the transfer point 33 and away from it and / or is movable 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. In this case, the movement from the immersion region to the immersion region does not take place until a predetermined period of time has elapsed, namely after completion of the reaction time of the flux 23 with the surface of the respective components 2 to be galvanized.

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 bath 28 be guided.

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.

In the Fig. 2 to 4 Now different states are shown in the operation of Appendix 1. Fig. 2 shows a state in which at the junction 8 a plurality of components to be galvanized 2 are stored. 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, 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 is the group of components 2 above the pickling means 15. The stages C and D, namely the degreasing and rinsing, have already been made.

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. <B> LIST OF REFERENCES: </ b> 1 investment 18 flushing 2 component 19 Sink 3 Conveyor 20 dish soap 4 rail guide 21 Flux applicator 5 trolley 22 Flux pool 6 hoist rope 23 flux 7 goods carriers 24 drying device 8th junction 25 Feuerverzinkungseinrichtung 9 degreasing 26 Verzinkungsbecken 10 Entfettungsbecken 27 housing 11 degreasing 28 galvanizing 12 flushing 29 cooling device 13 Sink 30 treatment device 14 dish soap 31 separating device 15 pickling 32 separating device 16 pickling tank 33 Transfer point 17 mordant

Claims (15)

1. An installation (1) for the hot-dip galvanising of components (2) for large-series hot-dip galvanising of a large number of identical or similar components (2), comprising a conveyor system (3) having at least one goods carrier (7) for grouped conveying of a plurality of components to be fastened to the goods carrier (7), a degreasing device (9) for degreasing the components (2), a surface treatment device for chemical and/or mechanical surface treatment of the components (2), a flux application device (21) for flux application to the surface of the components (2) and a hot-dip galvanising device (25) for hot-dip galvanising of the components (2), having a galvanising bath (28) comprising a molten zinc/aluminium alloy,
   characterised
   in that a separating device (31) is provided for feeding, immersing, and removing a component (2) separated from the goods carrier (7) into or from the galvanising bath (28) of the hot-dip galvanising device (27),
   wherein the separating device (31) has at least one separating means (32),
   wherein, during the separation, each component (2) can be accurately manipulated and treated by special turning and steering movements when pulling out of the melt and
   wherein the separating means (32) is designed in such a way that all the components (2) separated from the goods carrier (7) are moved in an identical manner after the removal, in such a way that drip extensions are removed.
2. The installation according to claim 1,
   characterised in that the separation of the components (2) from the goods carrier (7) by means of the separating device (31) is provided following the degreasing or following the surface treatment or following the flux application.
3. The installation according to claim 1 or claim 2,
   characterised in that the separating device (31) comprises at least one separating means (32) arranged between the flux application device (21) and the hot-dip galvanising device (25).
4. The installation according to one of the preceding claims,
   characterised
   in that the separating means (32) is designed so that a separated component (2) is immersed in an immersion region of the galvanising bath (28), then moved from the immersion region to an adjacent removal region and subsequently removed in the removal 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 through the galvanising bath (28).
5. The installation according to one of the preceding claims,
   characterised in that a stripping device is provided following the removal region of the galvanising bath (28).
6. The installation according to one of the preceding claims,
   characterised
   in that at least one rinsing device (12, 18) is provided; and/or
   in that a drying device (24) is provided following the flux application device (21).
7. The installation according to one of the preceding claims,
   characterised
   in that a cooling device (29) is provided following the hot galvanising device (25); and/or in that a post-treatment device (30) is provided following the hot-dip galvanising device (25) and optionally the optional cooling device (29).
8. A method for the hot-dip galvanising of components (2) using a molten zinc/aluminium alloy for large-series hot-dip galvanising of a large number of identical or similar components (2),
   wherein the components (2) are attached to a goods carrier (7) for grouped conveying prior to hot-dip galvanising, subsequently subjecting the components (2) to a chemical and/or mechanical surface treatment, then providing the components (2) with a surface flux (23) on their surfaces, and then the components (2) that are provided on the surfaces thereof with the flux (23) are subjected to hot-dip galvanising in a galvanising bath (28) comprising a molten zinc/aluminium alloy,
   characterised
   in that during the hot-dip galvanising, the components (2) are fed from the goods carrier (7) in the separated state to the galvanising bath (28), immersed therein and subsequently removed from the latter,
   wherein during the separation, each component (2) is accurately manipulated and treated by special rotation and steering movements when pulling out of the melt, and
   wherein all the components (2) separated from the goods carrier (7) are moved in an identical manner after the removal, in such a way that drip extensions of the liquid zinc/aluminium alloy are removed.
9. The method according to claim 8,
   characterised
   in that the components (2) are separated from the goods carrier (7) after the surface treatment or after the flux application.
10. The method according to claim 8 or claim 9,
    characterised
    in that a separated component (2) is immersed in an immersion region of the galvanising bath (28), then moved from the immersion region to an adjacent removal region and subsequently removed in the removal region.
11. The method according to one of the preceding method claims,
    characterised
    in that all of the components (2) separated from the goods carrier (7) are guided in an identical manner through the galvanising bath (28); and/or
    in that, following the removal, all of the components (2) separated from the goods carrier (7) are guided in an identical manner past a stripping device for stripping off the liquid zinc/aluminium alloy.
12. The method according to one of the preceding method claims,
    characterised
    in that the components (2) are rinsed after the degreasing and/or after the surface treatment; and/or
    in that the flux (23) is dried after the application to the surface of the components (2); and/or
    in that the components (2) are dried after the application of the flux (23).
13. The method according to one of the preceding method claims,
    characterised
    in that the component (2) is cooled after the hot-dip galvanising and/or
    in that the component (2) is post-treated after the hot-dip galvanising.
14. The method according to one of the preceding method claims,
    characterised
    in 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.
15. Use of the installation (1) according to one of claims 1 to 7 and/or of the method according to one of claims 8 to 14 for large-series hot-dip galvanising of a large number of identical or similar components (2), in particular in discontinuous operation, preferably for piece galvanising.

Images