EP4116456A1 - Method and apparatus for galvanizing iron and steel workpieces - Google Patents

Abstract

A method is described for galvanizing low-silicon iron or steel workpieces in a galvanizing plant (100), in which the workpieces to be galvanized are dried in a drying oven (3) after pretreatment (2) by degreasing, pickling and treatment with flux and placed in a zinc bath (4) in order to then have excess zinc blown off and blown out in the stripping station (6) and optionally a blow-out station (8), and the exact dwell time (61) of the pipes in the zinc bath (4) using a process server (13 ) stored process model on the basis of at least one determined material parameter (51) at the incoming inspection (1) and is preferably adjusted by means of at least one measured value determined at the final inspection (12), in particular the product zinc layer thickness (55).

Description

The invention relates to a galvanizing process for iron and steel workpieces with a low silicon content, in which, for the controlled growth of a zinc layer, a predetermined process model with predetermined process parameters is adapted with correction values on the basis of continuously determined measured values, the system required for this, and products manufactured with it.

Iron and steel workpieces are usually galvanized to improve the corrosion resistance of the workpieces. The amounts of zinc and other alloy components of the coating required for this depend on the required periods of time for which these workpieces must have the required corrosion resistance.

Since modern steel alloys are becoming ever more pure and have a low silicon content, the application of durable zinc layers is proving to be increasingly problematic, since the diffusion processes during the hot-dip bath are permanently inhibited with these silicon contents. A reproducible setting in the required layer thicknesses is therefore no longer guaranteed.

Since the alloys used to produce the hot-dip coatings are a significant cost factor, monitoring the layer growth and layer composition is of primary interest. In particular, processes for minimizing the required quantities while at the same time ensuring a sufficient layer thickness and adequate corrosion protection are of particular interest.

The galvanizing of workpieces in the form of tubes has been fundamentally known in the prior art since the 1930s, but it is becoming common for tubes described an unsupervised piece process in which the workpieces are simply dipped into the molten zinc and then drained. This is not a problem for workpieces with a higher silicon content, but with the currently required material grades with very low silicon contents, this leads to thin zinc layers, since sufficient diffusion between the substrate and the zinc layer can no longer take place.

the EP0026757B1 shows a procedure in which the problems of the procedure are dealt with. In this document, however, process parameters are fixed in certain areas and are independent of measured variables. In addition, according to this document, the process for a desired coating is to be carried out as wet galvanizing—the state of the art that is widespread to this day. In particular, it is pointed out that the reaction between the zinc coating alloy and the iron substrate can be prevented in this way, i.e. it is practically frozen due to the low temperatures. In the case of steels with a low silicon content in particular, this would lead to an insufficient thickness of the corrosion layer, since the diffusion processes cannot take place sufficiently for the given residence time in the zinc bath. This document also states that the pipes should be blown out and blown off with a mixture of compressed air and steam, but this leads to uneven zinc layer thicknesses and unevenness, particularly on the inside of the pipe.

Also the CH340689 describes the blowing off and blowing out of sheet metal and pipes after hot-dip coating. In detail, the formation of a uniform zinc oxide-hydroxide layer is required here, which is formed under the influence of fluids containing water vapor when residual zinc is removed. This method also shows the need for a pressure of 15 bar, but this high pressure is extremely disruptive in terms of noise from the plant and requires extremely costly noise reduction measures. Next is this resulting zinc oxide hydroxide layer disadvantageous in the subsequent thermal treatment and leads to irregularities in the zinc layer thicknesses.

In order to implement an automated process, the DE10256750A1 the general possibility of automated and computer-controlled process management in plants in the field of sheet steel production. The use of measured values for setting process parameters is described here in very basic terms. However, the document does not provide any information on hot-dip coating of iron and steel pipes for the production of anti-corrosion coatings, since this is still conventionally done in a batch process in many cases, in which individual batches have to be manipulated.

The object of the invention is therefore to design a method of the type described above in such a way that it can be used to ensure the controlled growth of an anti-corrosion layer based on a zinc alloy on substrates with low silicon contents.

This object is achieved according to the invention by the method with the features according to independent patent claim 1, which represents the first aspect of the invention, the product with the features according to independent patent claim 14, which represents the second aspect of the invention, and by the system with the Features according to independent claim 15, which constitutes the third aspect of the invention. Further features and details of the invention result from the dependent claims, the description and the drawings. Features and details that are disclosed in connection with one of the aspects of the invention also apply in full in connection with the other two aspects of the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to the full content of the other aspects of the invention.

The invention relates to a method for galvanizing, in particular hot-dip galvanizing, of workpieces. A workpiece is, in particular, an object that still has to be processed, the processing taking place in the present case in the form of galvanizing. The invention is not limited to specific shapes, types and geometries of workpieces. The workpieces can be panels or any form of three-dimensional body, for example. In a preferred embodiment, the workpiece is a hollow profile element. A hollow profile is in particular an elongated hollow body, which is not limited to specific sizes and profile geometries. In a preferred embodiment, on the basis of which the relationships according to the invention are frequently illustrated below, without the invention being restricted to this specific exemplary embodiment, the hollow profile element is a tube.

If the dwell time of the pipes in a zinc bath is specified by means of a process model stored on a server unit and additionally with at least one silicon content measured value determined at an incoming inspection and preferably by at least one further measured product zinc layer thickness determined at a final inspection, and according to a preferred alternative, a Correction for the process parameter dwell time, fluctuations in the environment of the process plant can be compensated and the end product can be manufactured with sufficient stability in terms of corrosion resistance.

The tracking of the process parameters on the basis of measured values can thus ensure a constant quality and strength of the product zinc layer thickness. Growth curves of the zinc-containing diffusion layer are preferably stored in the process model, which are dependent on the silicon or the silicon-phosphorus proportions in the substrate material of the workpieces Measured values and the process parameters contain, whereby an exact and above all continuous process regulation and control can be made possible.

A method model within the meaning of the present invention is in particular a representation of the actual method taking place in reality. The method model, which is stored in particular on a server unit, preferably includes growth curves, in particular layer growth curves, which in a preferred embodiment, for a given substrate thickness for the respective silicon proportions or for the combination of silicon and phosphorus proportions in the substrate, the expected layer thicknesses after a specific residence time in the zinc bath and/or the raw zinc layer thicknesses required to achieve the desired final zinc layer thicknesses determine the growth time in the thermal treatment.

According to a first alternative of the method according to the invention, the residence time of the workpieces in the zinc bath is specified by the method model, for example the stored growth curves, depending on the thickness of the raw zinc layer. According to this first alternative, the dwell time of the workpieces in the zinc bath is specified by means of a process model stored on a server unit and additionally with at least one measured silicon content determined at an incoming inspection.

According to a second alternative according to the invention of the method according to the invention, this first alternative is linked to a measurement for determining the end of the treatment. According to this second alternative, the dwell time of the workpieces in the zinc bath is specified by means of a process model stored on a server unit and additionally with at least one measured silicon content determined at an incoming inspection. In addition, at least one further measurement value of the product zinc layer thickness determined during a final inspection is used to correct the process parameter residence time. In particular, the measured value of the product final zinc layer and the measured silicon content, which can only refer to the silicon content, or to the combination of the silicon and phosphorus content according to the formula [Si] + 2.5* [P], the triggering measured values for an adjustment of the process parameters and can find support by using the measured value raw zinc layer thickness. With this control circuit, the results on the product can be kept within the required values even with deviating ambient conditions and, in addition, a quasi-continuous process can also be created in systems with piece processing on the zinc bath in further processing.

Is the silicon content measured value the silicon content or a combination of the silicon and phosphorus content determined during the incoming inspection of the workpieces and in particular for silicon [Si] ≤ 0.030% or for [Si] + 2.5 * [P] ≤ 0 .90% and/or that another determined measured value substrate thickness is the material thickness of the workpieces, the selection of the relevant growth curves from the stored process model and corresponding control of the required process parameters can be carried out particularly easily and a uniform product zinc layer thickness can be guaranteed.

If the workpieces are dried and preheated in a drying oven at a surface temperature of ≤ 100 °C, preheating the pipes can bring about a rapid start to the diffusion processes between the ferrous substrate and the zinc layer. A rapid onset of diffusion can be brought about as a result and can lead to uniform, sufficient growth of the iron-zinc layer and good layer adhesion.

The workpieces are completely immersed in the zinc bath and at a temperature between 455 °C and 460 °C and a product zinc layer thickness of the measured value and the measured silicon content, varying dwell time between 20 s to 180 s or 20 s/mm wall thickness of the galvanized workpiece and using an extractor at a speed of > 0.8 m/s or between 0.5 m/min and 3 m/ min drawn out of the zinc bath, fluctuations in the temperature of the zinc bath can be compensated particularly easily. A speed > 8m/s is preferred for workpieces, in particular closed profiles, which are stripped and/or blown out in the following process step. The slower speed is preferred for all other workpieces.

If the excess zinc on the outside of the workpiece is blown off in the stripping station with a preferably ring-shaped nozzle against the direction of movement of the workpiece with preheated, steam-free compressed air, the process parameter pressure stripping compressed air can be between 0.5 bar and 4 bar, depending on at least a measured product zinc layer thickness or measured layer ratio pure zinc, can be varied and the manipulation time of the transfer from the stripping station to the blow-out station lasts less than 10 s and/or a distance between the nozzle opening and the surface of the workpiece of 5 mm to 15 mm is constantly maintained and /or if the angle of the outlet of the preferably ring-shaped nozzle in the stripping station has an inclination of between 2° and 5° to the vertical of the outer wall of the workpiece, a very even and thin zinc layer can be produced as a result. As a result, improved homogeneity of this layer can be achieved despite a very thin raw zinc layer thickness, which means that rapid and uniform layer growth can occur during the subsequent diffusion process in a later thermal treatment. The adjustment of the process parameter pressure stripping compressed air depending on the measured values for product zinc layer thickness actually achieved in the final inspection from the galvanized workpieces produced immediately before, can thus achieve a more uniform quality and deviations by temperature fluctuations from the environment or differences in the manipulation times during the handover can be compensated.

In a preferred embodiment, the workpieces are hollow profile workpieces, in particular tubes. In such a case, the workpieces are preferably blown out in a blow-out station after the zinc bath.

In the blow-out station, the inside of the galvanized hollow profile workpiece is freed from excess zinc with steam-free compressed air preheated to between 200 °C and 400 °C at a variable process parameter blow-out compressed air pressure of 0.5 to 4 bar, in particular with a blow-out lance with annular slot at its front end, whereby the lance is centered by means of a guide on the side facing away from the zinc bath in front of the end of the hollow profile workpiece and is brought to a layer thickness dependent on at least one measured product zinc layer thickness and the measured product zinc layer thickness, in a final check If the value is in the range from 20 µm to 77.5 µm, in particular 40 µm to 55 µm and has a pure zinc phase on the surface, the formation of zinc oxide hydroxide layers can be largely prevented, resulting in a more uniform surface structure on the hollow profile workpiece -Inside can arise, which improves the finished product improved corrosion properties, since fewer germs and defects on the surface can ensure improved corrosion resistance. Surprisingly, in contrast to the method of mixing compressed air and steam described in detail in the prior art, it has been shown that using preheated and, in particular, steam-free compressed air can result in a more uniform raw zinc layer thickness and less waviness on the zinc surface.

Is the tip of the blow-out lance exchangeable and in particular is there a residual gap between the nozzle opening and the inner wall of the hollow profile workpiece with a spacing of 2 mm to 5 mm remains, a particularly even and smooth surface of the zinc layer on the inside of the hollow profile workpiece can be achieved and poor quality due to wear on the lance tip can be avoided.

If, by determining the measured value of the raw zinc layer thickness before a thermal treatment, the transfer to a thermal treatment or the bypassing of a thermal treatment is triggered when the TARGET zinc layer thickness has already been reached, a particularly time-efficient process can be implemented, whereby on the one hand the growth when the layer thickness has not yet been reached take place in the thermal treatment, or the duration of the process can be significantly shortened by a direct transfer to the cooling basin and a secure layer growth can be produced. Furthermore, a diffusion of iron up to the surface of the zinc layer can be prevented in this way when the growth of the zinc layer is already advanced.

If the galvanized workpiece is subjected to thermal treatment, the temperature being between 250 °C and 500 °C, in particular between 350 °C and 500 °C, and the workpiece is then transferred to a cooling basin by means of a transfer in a manipulation time of less than 5 s this can prevent excessive diffusion of the zinc layer into the ferrous substrate and prevent the zinc layer from reacting right up to the surface, which can result in a particularly strong anti-corrosion layer on the inside and outside of the workpiece. A manipulation time of less than 5 s can thus enable a pure zinc layer on the surface of the end product. According to a preferred embodiment, the workpiece is transferred to the cooling basin by means of the transfer when the residence time of the workpiece specified by the process model, which is also used in particular as a growth time, in the thermal treatment has been reached. Alternatively or in addition to this, according to another preferred embodiment, the measured value is the final zinc layer thickness, and thus in particular the layer growth, continuously determined and, when the TARGET zinc layer thickness determined by a process model is reached, the workpiece is transferred to the cooling basin.

For example, a raw zinc layer thickness is compared after the process with the TARGET zinc layer thickness, which results, for example, from the growth curve or can be derived, and based on the layer growth curves for the thermal treatment, an adjustment of the process parameters temperature and growth time is specified in order to achieve the desired final achieve zinc layer thickness.

The dwell time of the workpiece in the thermal treatment can thus be terminated, depending on the design, after measurement and/or after the model growth time.

If the temperature of the cooling pool is less than 70 °C, in particular less than 50 °C, or has a cooling rate greater than 20 °C/s and/or the waste heat from the cooling pool is returned to the pre-treatment station and has in particular a fluid/fluid heat exchanger on, the growth of the zinc layer can be frozen in a particularly efficient manner and further diffusion can be effectively prevented. This effectively interrupts the diffusion of iron up to the surface and ensures that a pure zinc layer is achieved.

Is the setting of a process parameter pressure stripping compressed air in a stripping station and/or a process parameter pressure blow-out compressed air of a blow-out station based on the determined measured value raw zinc layer thickness and depending on TARGET values of the process model, in which the substrate data and/or process parameters, in particular residence time of the zinc bath and/or layer growth curves are defined as a function of the size of the determined measured value silicon content, in particular the silicon and phosphorus content in the substrate and/or sizes for the determined measured value layer ratio pure zinc, the process parameters dwell time, compressed air stripping pressure, compressed air blowing pressure and temperature can be continuously adjusted to the permanently changing measured values raw zinc layer thickness, product zinc layer thickness (55) and/or layer ratio pure zinc, which is defined as the ratio of the layer thickness of the iron zinc phase to the layer thickness of the remaining pure zinc phase on the surface of the zinc-containing coating. As a result, a permanent control circuit for the continuous control of the process parameters of the process plant can be established, which can only enable the layer growth of these thin layers on substrates with a low silicon content with good layer bonding at the same time. If the wiping nozzle has a nozzle opening of 3 to 5 mm, the air flow can be controlled in a particularly favorable manner.

If the product zinc layer thickness measured value deviates from the desired TARGET value specified by the process model in a final inspection, the process parameter residence time in a zinc bath is corrected and/or the process parameter temperature in a thermal treatment, any fluctuations in counteracted by the process environment and advantageous adjustments to the parameters specified from the process model are brought about, a permanently equivalent layer thickness can be generated in this way.

If the waste heat from the zinc bath is fed to the drying oven by means of a gas/gas heat exchanger, the process can be carried out more cost-effectively in an energy-efficient manner.

If the proportion of silicon [Si] is ≤ 0.030% or for [Si] + 2.5 ^* [P] ≤ 0.90% in the substrate and the measured product zinc layer thickness, in a final inspection, is in the range from 20 µm to 77 µm, 5 μm, in particular 40 μm to 55 μm and a pure zinc phase on the surface, a particularly high-quality product can be produced and a Sufficiently high corrosion resistance of the workpieces and at the same time savings on the required zinc layer can be achieved. In particular, the presence of the pure zinc layer is particularly advantageous so that an excellent anti-corrosion effect can be achieved.

If the data of a process model are on a server unit, which is made available in such a way that it is able to continuously measure values, in particular substrate thickness, silicon content, raw zinc layer thickness, final zinc layer thickness, product zinc layer thickness, layer ratio pure zinc, with the TARGET to compare the process parameters of the process model and, in the event of a deviation, to readjust at least one of the process parameters, in particular the dwell time, compressed air stripping pressure, compressed air blowing pressure, temperature, and there is a pretreatment station which, in particular, degreases, pickles and treats the workpieces with flux at a temperature of 30 °C to 80 °C and a drying oven in which the tube is dried and preheated to a surface temperature of 95 °C to 100 °C and a zinc bath, having a process parameter residence time, in particular with a temperature between 455 °C and 460 °C C and a residence time of 20 s to 180 s , an extractor, in particular with a manipulation time of less than 5 s, a stripping station, having a process parameter pressure stripping compressed air, in particular between 0.5 and 4 bar, a transfer, in particular with a manipulation time of less than 10 s, optionally a blow-out station, having a process parameter Blow-out compressed air pressure, in particular between 0.5 and 4 bar, a device for determining a measured value for the raw zinc layer thickness, a thermal treatment having a process parameter of temperature and a device for determining the measured value for the final zinc layer thickness, in particular a magnetic-inductive or eddy current measurement, a transfer, in particular with a manipulation time of less than 5s and an optional bypass of the thermal treatment, a cooling station, in particular with a temperature of the cooling medium below 70° C. or a cooling rate greater than 20° C./s and a final inspection, having at least one determination device measured value of the product zinc layer thickness and/or a measured value of the layer ratio of pure zinc, a system can thus be operated in a particularly suitable manner, which enables galvanizing of low-silicon iron and steel materials.

An inventive sequence of such a method, with reference to the figure 1 , in which a flow chart of a method according to the invention is shown, can be represented as follows. In the process shown, a workpiece in the form of a tube is galvanized.

figure 1 shows a process sequence according to the invention, in which several measured values - substrate thickness (51) and silicon content or silicon and phosphorus content (52) - are determined in the incoming inspection (1).
In the pre-treatment (2), the pipes are degreased, pickled and treated with flux at a temperature of 30 °C to 80 °C.
In the drying oven (3) the pipe is dried and preheated to a surface temperature of 95°C to 100°C before it is completely immersed in the zinc bath (4). The temperature in the zinc bath (4) is between 455 °C and 460 °C in order to achieve a sufficiently high reactivity of the low-silicon substrate and a residence time of 20 s to 180 s is required.

According to a first alternative of the method, the residence time in the zinc bath (4) is determined by the method model, for example the stored growth curves as a function of the raw zinc layer thickness (53). According to this first alternative, the dwell time (61) of the tube in the zinc bath (4) is specified by means of the process model and additionally with at least one measured silicon content (52) determined at an incoming inspection (1). According to a second alternative of the method, this first alternative is linked to a measurement to determine the end of the treatment. According to this second alternative, the dwell time of the workpieces in the zinc bath (4) is determined by means of the process model and additionally with at least one measured value determined at an incoming inspection (1). Silicon content (52) specified. In addition, at least one further measurement value of the product zinc layer thickness (55) determined in a final inspection (12) results in a correction for the process parameter residence time (61).

The recirculation of the process heat from the zinc bath (4) to the drying oven (3) enables a particularly energy-efficient procedure. The tube is pulled out by the extractor (5) at a speed > 0.8 m/s and in the stripping station (6) the excess zinc layer is stripped off with a ring nozzle, with a process parameter of compressed air stripping pressure (62). The further transfer (7) takes place in less than 10 s to the blow-out station (8) in which the process parameter blow-out compressed air pressure (63) varies and depends on at least one measured value product zinc layer thickness (55) or layer ratio pure zinc (56) can be adjusted.

The measured raw zinc layer thickness (53), which is carried out magnetically or as an eddy current measurement, is the basis for thermal treatment (9) or a diversion to the cooling basin (11).

In the thermal treatment (9), the controlled layer growth takes place at a temperature (64) between 350 °C and 550 °C and a growth time (65) between 20 s and 420 s, especially for closed profiles, or up to 35 min for all other workpieces, or until the measured final zinc layer thickness (54) is reached and the transfer (10) is triggered, which is completed within 5 s. The tubes are rapidly cooled in the cooling basin (11) and layer growth and diffusion are thus frozen.
The cooling takes place at a maximum water temperature of 70° C., but preferably below 50° C. or a secured cooling rate greater than 20° C./s.
The process waste heat from the cooling station (11) is fed to the pre-treatment (2) via a heat exchanger.

In the final inspection (12), the measured values for the zinc layer thickness (55) and the ratio of iron-zinc layer to pure zinc layer (56) are determined, which detail the process parameters (65, 64, 63, 62, 61) specified by the process model (13). vary to compensate for fluctuations.

The process model on the server unit (13) includes layer growth curves which, for a given substrate thickness for the respective silicon proportions (52) or for the combination of silicon and phosphorus proportions in the substrate, show the layer thicknesses to be expected after a specific residence time (61) in the zinc bath (4) or specify the raw zinc layer thicknesses (53) required to achieve the desired final zinc layer thicknesses (54) time in the thermal treatment (9). The raw zinc layer thickness (53) after the process is compared with the TARGET zinc layer thickness, which results from the process model or can be derived, and an adjustment of the process parameters temperature (64) and/or growth time (65 ) specified in order to achieve the desired final zinc layer thickness (54). According to a first alternative, the workpiece is transferred to the cooling basin (11) by means of the transfer (10) when the growth time (65) of the workpiece in the thermal treatment (9) specified by the process model has been reached. Alternatively or in addition to this, according to another alternative, the measured final zinc layer thickness (54) is continuously determined and, when the TARGET zinc layer thickness specified by a process model is reached, the workpiece is transferred to the cooling basin (11) by means of the transfer (10). In figure 1 both alternatives are shown, namely the growth time (65), which is either determined by the growth curve stored in the process model as a function of the raw zinc layer thickness (53), or which is additionally carried out with the measurement of the final zinc layer thickness (54) to determine the end of treatment .

Correlations between the raw zinc layer thickness (53) and the final zinc layer thickness (54) take place at a given temperature (64), since the maximum duration up to the measured Achievement of the final zinc layer thickness (54) in the thermal treatment (9) is limited.

If, in a preferred embodiment of the method, a deviation from the TARGET zinc layer thicknesses required for the products is determined for the galvanized pipes when the measured value for the product zinc layer thickness (55) is recorded after comparison with the method model, which preferably takes place automatically in the server unit. the thickness of the raw zinc layer thickness (53) can be influenced in a suitable manner by directly varying the process parameters such as dwell time (61), compressed air pressure (63), compressed air stripping pressure, so that favorable processing times in the thermal treatment can be achieved at a temperature (64) that can also be varied (9) before the TARGET value for the final zinc layer thickness measurement value (54) is reached.

Compared to conventional methods, a continuous or quasi-continuous method can be created in which temperature influences from the environment or deviations in the manipulation times can be compensated at any time and thus a consistent quality of the end products can be ensured in a suitable manner.

An embodiment of the method according to the invention can be as follows:
Steel substrate with silicon content: [Si] or [Si] + 2.5 ^* [P] = 0.056% substrate thickness: D = 3.0mm Residence time in the zinc bath: t = 90s Zinc bath temperature: Y = 455°C Raw zinc layer thickness: a = 50 µm TARGET zinc layer thickness: c = 55 µm Duration until the final zinc layer thickness is reached: T=15 mins Temperature of thermal treatment: X = 400°C Final zinc layer thickness: b = 60 µm

Claims (15)

Method for galvanizing, in particular hot-dip galvanizing, iron or steel workpieces in a galvanizing plant (100), in which the workpieces to be galvanized are immersed in a zinc bath (4) after a pretreatment (2), in particular by degreasing, pickling and treatment with flux, and excess zinc is blown off in a stripping station (6), in particular at a zinc bath temperature of between 455 °C and 460 °C and in particular a dwell time (61) of the workpieces in the zinc bath of between 20 s and 180 s, characterized in that the dwell time (61) of the workpieces in the zinc bath (4) is specified by means of a process model stored on a server unit (13) and additionally with at least one measured silicon content (52) determined at an incoming inspection (1), or that the dwell time (61) of the workpieces in the zinc bath (4) is specified by means of a process model stored on a server unit (13) and additionally with at least one measured value of silicon content (52) determined at an incoming inspection (1), and by at least one other a final check (12) determined product zinc layer thickness (55), a correction for the process parameter dwell time (61) takes place. Method according to Claim 1, characterized in that the determined measured silicon content (52) is the silicon content or a combination of the silicon and phosphorus content, which is determined during the incoming inspection (12) of the workpieces and in particular for silicon [Si] ≤ 0.030% or for [Si]+2.5*[P]≦0.90% and/or that a further determined measured value of the substrate thickness (51) is the material thickness. Method according to one of Claims 1 to 2, characterized in that the workpieces are dried and preheated in a drying oven (3) at a surface temperature ≤ 100°C. Method according to one of Claims 1 to 3, characterized in that the workpieces are completely immersed in the zinc bath (4) and at a temperature between 455 °C and 460 °C and a product zinc layer thickness (55) and the measured value Depending on the silicon content (51), varying residence times between 20 s and 180 s are galvanized and using an extractor (7) at a speed of >0.8 m/s or between 0.5 m/min and 3 m/min from the zinc bath (4) be drawn. Method according to one of Claims 1 to 4, characterized in that the workpieces are designed as hollow profile workpieces, in particular as pipes, and that the workpieces are blown out in a blow-out station (8) after the zinc bath (4). Method according to one of Claims 1 to 5, characterized in that the excess zinc on the outside of the workpiece is blown off in the stripping station (6) with a preferably ring-shaped nozzle counter to the direction of movement of the workpiece with preheated, water vapor-free compressed air and the process parameter pressure stripping - Compressed air (62), between 0.5 bar and 4 bar, is or can be varied depending on at least one measured product zinc layer thickness (55) or measured layer ratio pure zinc (56) and the manipulation time of the transfer (7). from the stripping station (6) to the blow-out station (8) takes less than 10 s and/or a constant distance of 5 mm to 15 mm between the nozzle opening and the surface of the workpiece is maintained and/or the angle of the exit of the ring-shaped nozzle in the stripping station is a Inclination to the vertical of the outer wall of the workpiece is between 2° and 5° Method according to one of Claims 5 or 6, insofar as this is dependent on Claim 5, characterized in that in the blow-out station (8) the inside of the galvanized hollow profile workpiece is blasted with steam-free compressed air preheated to between 200 °C and 400 °C at a variable Process parameters Pressure blow-out compressed air (63) of 0.5 to 4 bar is freed from excess residual zinc, in particular with a blow-out lance with a ring slot at its front end, the lance being guided by means of a guide on the side facing away from the zinc bath (4) in front of the hollow profile workpiece end is centered and brought to a layer thickness that is dependent on at least one measured product zinc layer thickness (65) and the measured product zinc layer thickness (65) has a value of in the range from 20 µm to 77.5 in a final check (12). μm, in particular 40 μm to 55 μm and has a pure zinc phase on the surface, and that the tip of the blow-out lance is preferably exchangeable and in particular a residual gap between the nozzle opening and the inner wall of the hollow profile workpiece with a distance of 2 mm to 5 mm remains. Method according to one of Claims 1 to 7, characterized in that by determining a measured value for the raw zinc layer thickness (53) before a thermal treatment (9), the transfer to a thermal treatment (9) or a bypass (9A) of the thermal treatment (9 ) is triggered when the TARGET zinc layer thickness has already been reached. Method according to one of Claims 1 to 8, characterized in that the galvanized workpiece is subjected to a thermal treatment (9) in order to achieve the final zinc layer thicknesses (54), the temperature (64) being between 250°C and 550°C , in particular between 350 °C and 500 °C and the workpiece is then transferred to a cooling basin (11) by means of a transfer (10) in a manipulation time of less than 5 s, the workpiece preferably being transferred by means of the transfer (10) to the Cooling basin (11) is passed when the predetermined by the process model growth time (65) of the workpiece in the thermal treatment (9) has been reached and/or by continuously determining the measured final zinc layer thickness (54) and, when the TARGET zinc layer thickness specified by a process model is reached, the workpiece is transferred to the cooling basin (11) by means of the transfer (10). Method according to Claim 9, characterized in that the temperature of the cooling basin (11) is less than 70 °C, in particular less than 50 °C, or has a cooling rate greater than 20 °C/s and/or the waste heat from the cooling basin (11 ) is returned to the pretreatment station (2) and in particular has a fluid/fluid heat exchanger. Method according to one of Claims 1 to 10, characterized in that the setting of a process parameter for compressed air stripping pressure (62) in a stripping station (6) and/or a process parameter for compressed air blow-out pressure (63) in a blow-out station (8) depends on the measured value determined Raw zinc layer thickness (53) and as a function of the TARGET values of the process model, in which the substrate data and/or process parameters, in particular the residence time (61) of the zinc bath (4) and/or layer growth curves, are carried out as a function of the size of the measured silicon content ( 52), in particular the proportion of silicon and phosphorus in the substrate and/or quantities for the measured value of the layer ratio pure zinc (56). Method according to Claim 9, characterized in that if the measured value for the product zinc layer thickness (55) deviates from the desired TARGET value specified by the method model in the final inspection (12), a correction of the process parameter residence time (61) in the zinc bath (4) and /or the process parameter temperature (64) and/or growth time (65) takes place in a thermal treatment (9). Method according to Claim 3 or 4, characterized in that the waste heat from the zinc bath (4) is fed to the drying oven (3) by means of a gas/gas heat exchanger. Product manufactured with a galvanizing process (100), in particular according to one of Claims 1 to 13, characterized in that the proportion for silicon [Si] ≤ 0.030% or for [Si] + 2.5 * [P] ≤ 0.90 % in the substrate and the measured product zinc layer thickness (55) in a final inspection (12) is in the range from 20 μm to 77.5 μm, in particular 40 μm to 55 μm and has a pure zinc phase on the surface. Plant for carrying out a galvanizing process (100), in particular according to one of Claims 1 to 13, characterized in that data from a process model are located on a server unit (13) which is provided in such a way that it is able to continuously receive measured values , in particular substrate thickness (51), silicon content (52), raw zinc layer thickness (53), final zinc layer thickness (54), product zinc layer thickness (55), layer ratio pure zinc (56), with target process parameters of the process model and to compare Deviation of at least one of the process parameters, in particular dwell time (61), compressed air stripping pressure (62), compressed air blowing pressure (63), temperature (64), to regulate, furthermore having a pretreatment station (2), which in particular degreasing, pickling and treatment of the workpieces with flux at a temperature of 30°C to 80°C, a drying oven (3) in which the tube is dried and heated to a temperature of 95°C b is 100°C, a zinc bath (4) having a process parameter residence time (61), in particular with a temperature between 455°C and 460°C and a residence time of 20 s to 180 s, an extractor (5), in particular with a manipulation time of less than 5 s, a stripping station (6), having a process parameter pressure of compressed air stripping (62), in particular between 0.5 and 4 bar, a transfer (7), in particular with a manipulation time of less than 10 s, optionally a blow-out station (8), having a process parameter pressure of blow-out compressed air (63), in particular between 0.5 and 4 bar, a device for determining a measured value of raw zinc layer thickness (53), a thermal treatment (9), having a process parameter temperature (64 ), a process parameter growth time (65) and a device for determining the measured value of the final zinc layer thickness (54), in particular by means of a magnetic-inductive or eddy current measurement, a transfer (10), in particular with a manipulation time of less than 5s and an optional bypass (9A) of the thermal treatment (9), a cooling station (11), in particular with a temperature of the cooling medium below 70 °C or a cooling rate greater than 20 °C/s and a final inspection (12), having a device for determining at least one measured value for the product zinc layer thickness (55) and /or a measured value of the layer ratio pure zinc (56).

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