WO2019120947A1

WO2019120947A1 - Corrosion protection and anti-corrosion monitoring

Info

Publication number: WO2019120947A1
Application number: PCT/EP2018/083200
Authority: WO
Inventors: Kristin Unthan; Alexander FESER; Dirk Mollenhauer
Original assignee: KM Innopat GmbH
Priority date: 2017-12-22
Filing date: 2018-11-30
Publication date: 2019-06-27
Also published as: DE102017131188A1

Abstract

The invention relates to a method and a system for corrosion protection and anti-corrosion monitoring of conductive object (O). The object (TO) has at least one layer arrangement (10) on a object surface (OF), said layer arrangement comprising at least one first insulation layer (11) which consists of electrically insulating material and faces the object surface (OF), a conductive layer (13, 13') which is arranged on the side of the first insulating layer (11), which side faces away from the object surface (OF), and a second insulation layer (12) which consists of an electrically insulating material which is arranged on the side of the conductive layer (13, 13') that faces away from the first insulation layer (11). A voltage (Uo, U~) is applied between the object surface (OF) and the conductive layer (13, 13 ') and a current (l1, l2, I3, I4) between the object surface (OF) and the conductor layer (13, 13') is tested. In the event of such current (l1, l2, I3, I4), a spatial position of a breach point (D) in the first protective layer (11) between the object surface (OF) and the conductor layer (13, 13 ') is determined on the basis of at least one measurement signal that represents a current (l1, l2, I3, I4) flowing along a region of the conductive layer (13, 13') and/or a voltage dropping across a region of the conductive layer (13, 13'), . Furthermore, an object arrangement (100) comprising an object (o) to be protected against corrosion and a corresponding corrosion protection and anti-corrosion monitoring system (1) and a suitable conductive layer finish and an insulating layer finish are described.

Description

Corrosion protection and corrosion protection monitoring

The invention relates to a method for corrosion protection and for corrosion protection monitoring of a conductive object, wherein at least one layer arrangement is applied to an object surface of the object to be protected, said layer arrangement at least one of the object surface facing first insulating layer of electrically insulating material, a conductor layer , which is located on the side facing away from the object surface side of the first insulating layer, and a second insulating layer of electrically insulating material, which is located on the side facing away from the first insulating layer side of the conductor layer, and wherein between the object surface or at least temporarily a voltage is applied to the object and the conductor layer, and at least temporarily an occurrence of a current between the object surface and the conductor layer is checked. Moreover, the invention relates to a corrosion protection and monitoring system for a conductive object, which has at least the aforementioned layer arrangement and a control and monitoring device to apply a corresponding voltage between the object surface and the conductor layer and an occurrence of a current between the object surface and the conductor layer. In addition, the invention relates to an object arrangement with such a corrosion protection and monitoring system. Incidentally, the invention relates to a suitable for this method or system conductor layer coating material and an insulating layer coating material.

To protect conductive, usually metallic, objects from corrosion, various methods are known. In most cases, the surface of the object to be protected is protected by means of coatings. In many cases, several layers are applied to each other, even from different materials. The coating can take place, for example, in the form of coatings, paints or the like. For certain areas, the application or spraying of thicker viscous media and / or oils comes into question, such as in the bottom protection or in cavity seals of motor vehicles. Other types of coatings can be produced by a galvanic surface treatment such as galvanizing or the like. In all these "passive" corrosion protection processes by "simple" coatings, the attacking medium, for example water or moisture and / or salt, through the coating from direct contact with the material surface, often steel or another corrosive susceptible metal, kept away. One problem with this is that even small local damage in the coating leads to the attacking medium coming into contact with the surface of the object, where it leads to corrosion and the damage to the coating thereby already spreads out relatively quickly. This often leads not only to the fact that the coating must be renewed, but in some cases to very complex restoration work on the object itself, which can be destroyed in large areas by the corrosion. In particular, if such damage spreads unnoticed over a large area, often a repair of the coating only makes sense if it is completely removed and reapplied, that is, the object of a complete restoration and re-coating is subjected.

In order to improve corrosion protection, so-called "cathodic corrosion protection" has been used on some properties for decades. In the case of an "active" cathodic corrosion protection, care is taken to ensure that, if the protective coating is damaged, a current flows locally which can counteract the corrosion. For this purpose, in addition to the actual protective coating of insulating or nonconductive material, an electrode arrangement or electrode structure of electrically conductive material is applied, for example in the form of wires, meshes or the like. With the aid of a voltage source, a potential difference is applied between the object to be protected, ie the object surface, and the electrode, whereby the negative pole (negative pole) adjoins the object and the positive pole adjoins the electrode structure. Is then located on the surface of the object an electrolyte such as moist dust, salt water, fresh water, slush or damp soil and the like, at a defective location where the electrolyte would normally cause corrosion of the object surface, from the electrode structure to the surface the electrolyte is made an electrically conductive connection, whereby a small DC current flows from the electrode structure via the electrolyte into the metal surface. This counteracts the migration of positive metal ions from the metal surface and thus prevents or at least greatly reduces the corrosion, ie the dissolution of the metal substrate. Ideally, this will cause the coating to virtually heal itself by the cathodic protection current. The loss of the passive intact coating is locally compensated by the active corrosion protection. The necessary currents are usually low, since the damage to a coating usually takes place only locally. The cathodic corrosion protection always works when the protective layer is damaged and an electrolyte moistens the damaged area. Is the object or the coated surface dry, z. B. by drying out the damaged area in war- In summer months, no electricity flows. This is also not necessary because then no corrosion processes can occur.

Such a system can be used on many objects susceptible to corrosion, in particular on large steel constructions, eg. B. on bridges or other structures, but also on vehicles, for example on a motor vehicle, as described in WO 87/00558 A1. Such systems are particularly interesting for objects in contact with salt water, such as ships, harbor structures and / or offshore platforms. Here, in a special way, the area is prone to come, for example by Tidenhub or swell only temporarily with the salt water in contact and also exposed to special mechanical stresses that could lead to damage to the surface.

Although this active corrosion protection is very helpful in delaying or preventing the spread of corrosion to damaged areas of the protective coating, this does not prevent damage to the protective layer per se. Incidentally, it can also happen without corrosion that the damage of the protective layer nevertheless spreads, since at the relevant point in principle there is a point at which the coating could be further detached from the object surface, for example, a paint can peel off etc This is especially true for the application in very aggressive environments such as the mentioned changing contact with salt water, since the mechanical stress on the enlargement of the damaged area can act. In this respect, it would also be sensible, when using "active" corrosion protection, to repair the protective layer in good time with relatively little effort in order to achieve the highest possible longevity of the objects. In some systems, such as the system mentioned in the cited WO 87/00558 A1, there is an operation indicator in the form of a warning light which indicates that a protection current is flowing. However, this only indicates that the system is working and that in principle there is damage. However, locally limited repair of the protective layer is only possible if the location of the damage is known. In most cases, this ultimately leads to the fact that damage elimination is waited until the coating of the entire object, for example the underbody coating as a whole, has to be completely renewed at some point. This is unfavorable, especially for larger objects, since a complete layer renewal is usually very complicated and expensive there. It is an object of the present invention to specify a method and a system for corrosion protection and corrosion protection monitoring, which addresses this problem and offers the possibility of faster finding of defect sites in the protective layer of passive corrosion protection.

This object is achieved by a method according to claim 1 and by a corrosion protection and monitoring system according to claim 10.

For carrying out the method according to the invention, as already described above, on the object surface to be protected, for example the metal surface, of the object, e.g. As a workpiece, vehicle, structure, etc. or part thereof, at least one layer arrangement be applied.

This has at least one first insulating layer of electrically insulating or nonconductive material facing the object surface (that is to say, for example, directly or indirectly arranged on the object surface, that is to say with further primer layers therebelow). This first insulating layer is also referred to below as the base or base layer. It forms, as it were, a first, inner protective layer for the object surface and also against the corrosive effect of the environment.

Furthermore, the layer arrangement has a conductor layer, which is located on the side of the first insulating layer facing away from the object surface. This conductor layer is therefore electrically conductive by the first insulating layer from the object surface, i. H. galvanically isolated. While the first insulating layer is generally substantially full-coverage, this conductive layer may optionally also be patterned, i. H. it may also be arranged only partially on the first insulating layer. For example, as will be explained later, one possible preferred structure may be a kind of loop-shaped conductor or the like. As will be explained later, this conductor layer can be applied to the first insulating layer by different methods.

Finally, the layer arrangement comprises at least one second insulating layer of electrically insulating or non-conductive material which is located on the side of the conductor layer facing away from the first insulating layer. This second insulating layer is preferably substantially covering the entire surface and thus forms a second, outer protective layer. This second insulating layer is therefore also referred to below as a cover layer. Like the first insulating layer or base layer, these too Cover layer be made of any insulating coating material, preferably in the form of a paint or the like.

In the context of the method according to the invention, a voltage between the object surface and the conductor layer is also at least temporarily applied. In addition, at least a second occurrence of a current between the object surface and the conductor layer is checked, i. H. For example, it is measured whether a current flow takes place, namely the cathodic protective current which is to occur in the event of a coating defect. The occurrence of a current between the object surface and the conductor layer can be z. B. also be registered on the voltage drop.

According to the invention, upon occurrence of such a current on the basis of at least one measurement signal which represents a current flowing along a region of the conductor layer and / or a voltage dropping over a region of the conductor layer, a spatial position of a breakdown point (hereinafter also referred to as a defect point or Leak referred) of the first protective layer between the object surface and the conductor layer determined. As will be explained later, a current or a voltage can be measured directly between a contact point on the conductor layer and the object surface or the object (eg, also at a contact point) in order to obtain the measurement signal, or it can be inductive , capacitive or otherwise suitable signals are obtained. As will be explained later, this measurement signal can also be a field strength and / or current density.

A determination of a spatial position of a breakthrough point (hereinafter also referred to as localization or desolation) is understood to mean that in some way a location information is obtained, in which area these breakthrough points are (with high probability), ie with a Spatial confinement of the leak or leakage area on the object surface is possible. Although it is preferred to locate the location of the breakthrough site as precisely as possible, it is also advantageous and is within the scope of the invention if a coarser spatial localization takes place with the aid of the method according to the invention, ie the location information has a specific location Part of the object, z. For example, specify a subarea relating to a coherent conductor layer in which the break-through point is located with correspondingly high probability. So z. B. a accuracy of the localization of one meter usually sufficient, so preferably at a localization at least a limitation to a range within 1 m ² takes place.

The determined location information can then be output and / or displayed in a suitable manner and / or stored for later outputs or displays and / or logging purposes.

With the aid of the method according to the invention, not only in addition to the passive corrosion protection by the active, cathodic corrosion protection with a local damage of the coating, the corrosion protection can be maintained, but it can also be signaled the location of the local damage and provided in time for a localized repair become. As a result, the corrosion protection extending the life of the object can be kept intact in a particularly efficient manner. Such needs-based maintenance not only offers significantly improved protection, but also great savings potential, from reducing paint consumption to reducing the amount of abrasive used to remove the coating and reducing material removal of the object.

The method according to the invention can be used on objects which already have a suitable multi-layer arrangement, since they are e.g. B. already be protected by a cathodic protection current. However, in the context of the method according to the invention, such a layer arrangement can likewise initially be applied to the object surface. Accordingly, a corrosion protection and monitoring system according to the invention for a conductive object comprises at least one multilayer layer arrangement to be applied or already applied to an object surface of the object to be protected. This has at least one - in the intended condition applied to the object - the object surface facing the first insulating layer or protective layer of electrically insulating material and an - optionally structured - conductor layer, which is located on the side facing away from the object surface side of the first insulating layer, and a second Insulating layer of electrically insulating material, which is located on the side facing away from the first insulating layer side of the conductor layer. In addition, the corrosion protection and monitoring system according to the invention comprises a control and monitoring device, which is designed to at least temporarily a Apply voltage between the object surface to be protected and the conductor layer and at least temporarily to check for occurrence of a current between the object surface and the conductor layer. According to the invention, this control and monitoring device is also designed so as to be able to detect such a current on the basis of at least one measuring signal, which comprises a current flowing along a region of the conductor layer and / or a voltage dropping over a region of the conductor layer represents, to determine a spatial position of a breakthrough point of the first protective layer between the object surface and the conductor layer. The control and monitoring device can also comprise several sub-devices or units, such as one or more voltage source (s), control unit (s) and optionally additional switching device (s), for example, controlled in a defined manner To let current flow through specific contact points on the object and / or the conductor layer or to interrupt a current flow. For this later examples will be given. The control and monitoring device preferably also has suitable means for outputting or displaying the location information in the aforementioned manner and / or for storing it for later output and / or display and / or logging purposes. An object arrangement according to the invention comprises at least one object to be protected against corrosion and a corrosion protection and monitoring system, wherein the layer arrangement of the corrosion protection and monitoring system is mounted on the object surface of the object to be protected and connected to the control and monitoring device is.

In principle, a plurality of objects can be assigned a corrosion protection and monitoring system in common, in which case respective layer arrangements are applied to the objects, which are coupled to a common control and monitoring device which correspondingly has outputs or connections for the purpose. has different layer arrangements of different objects. Likewise, however, different objects, on each of which a corresponding layer arrangement has been applied, could also be assigned to separate control and monitoring devices, which are then coupled, for example, to a common control center for monitoring the various control and monitoring devices. The invention further comprises a conductor layer coating material, preferably a conductor layer lacquer, which comprises at least the following components:

(i) at least one conductive component;

(ii) optionally at least one solvent;

(iii) optionally at least one binder;

(iv) optionally at least one dispersing additive.

Furthermore, the invention comprises an insulating layer coating material, preferably an insulating layer lacquer, which comprises at least the following components:

(i) a substance selected from an insulating material;

(ii) optionally at least one solvent;

(iii) optionally at least one binder;

(iv) optionally at least one colored pigment;

(v) optionally at least one dispersing additive;

(vi) optionally at least one rheology additive.

Particularly preferred embodiments of such conductor layer coating materials or insulating layer coating materials will be given later. The conductor layer coating material and / or the insulating layer coating material preferably serve for use in the said method or the corrosion protection and monitoring system according to the invention.

Further, particularly advantageous refinements and developments of the invention emerge from the dependent claims and from the following description, wherein the independent claims of a claim category can also be developed analogously to the dependent claims and exemplary embodiments or description parts of another claim category and in particular also individual features of different exemplary embodiments or variants can be combined to form new exemplary embodiments or variants.

According to the invention, localization information or location information is to be obtained via a spatial position of the breakdown point on the basis of a measurement signal which represents a current flowing along a region of the conductor layer and / or a voltage drop across a region of the conductor layer. There are various possibilities. Preferably, when a current occurs, ie when it is first determined that a current is actually occurring and thus a breakdown point is detected, it is ensured that a defined voltage is maintained between the object surface and the conductor layer. The control and monitoring device can thus control or regulate the voltage to a possibly-defined value. Thus, a sufficient cathodic protection current can be provided. Preferably, this is a relatively low DC voltage in order to avoid electrolysis or explosive gas formation, preferably by a maximum voltage of 1, 23 volts, more preferably about 1 volt. As will be explained later, it may be advantageous in certain embodiments if an AC voltage is also applied for the purpose of locating the breakdown location. In this case, this defined DC voltage form a minimum or base voltage, which can then be superimposed with a defined AC voltage. Particularly preferably, the spatial position of the opening is determined on the basis of a current and / or voltage distribution.

For this purpose, the position determination may preferably take place on the basis of the ratios of currents and / or voltages between the object surface and various, spatially spaced-apart contact points of the conductor layer. By means of the currents flowing through different, spatially separated contact points of the conductor layer to the object surface, measuring signals can be obtained particularly well (or the current measured values can be used as corresponding measuring signals), in each case a measure for the currents flowing along different regions of the conductor layer To obtain currents or falling voltages, so a current and / or voltage distribution.

The use of at least two spatially separated, separate contact points on the, optionally structured, conductor layer thus allows a particularly simple determination of a spatial position of the breakdown point, at least for example a limitation to a certain area between the two contact points on the conductor layer, as will be explained later by examples. Preferably, the conductor surface is formed so that the surface resistance over the surface is substantially constant, ie spatially not or at least only slightly different. At the contact points, it may be z. B. to contact surfaces, special contact elements or electrodes, connectors o. Ä. act on the object or at the conductor layer are arranged for such contact with the voltage source. An example of this would be contact tags, to which terminals are fastened, which are connected to the voltage source via suitable lines. It may be sufficient for the object and possibly advantageous to use only one contact point in order to provide a defined path for the location measurement or the location information acquisition. Preferably, however, the object (via a defined contact point or at a plurality of contact points) can also be at ground potential and the "negative pole" of the voltage source of the control and monitoring device is likewise formed by the ground potential. Then no additional connection of the object to the negative pole is required.

Preferably, not only a single current at a single contact point but additionally or alternatively also at least one summation current of a group of contact points (ie the sum of the individual currents at the contact points of the group) of the conductor layer can be determined and used for the evaluation, provided more than two contact points are used on the conductor layer. It is also possible to use summation currents of several different groups, wherein one contact point can also belong to several groups.

With knowledge of the currents or voltages, in particular the current and / or voltage distribution, between the object or the object surface and the various contact points or contact point groups and, where appropriate, using further information or knowledge of further system parameters, eg , As the electrical properties of the coating system or the layer arrangement, such as specific sheet resistance, capacitance, etc., so can win the desired localization information. The accuracy may depend on the specific system structure and the accuracy of the system parameters. For this purpose, as mentioned, the control and monitoring device can also have additional switching devices in order, for example, to allow current to flow in a defined manner via certain contact points on the object and / or the conductor layer or to interrupt a current flow at specific contact points. For example, in cases where, because of the better current flow for cathodic protection, the conductive object has more than one contact point or connection to the voltage source, for the purpose of localization all electrical connections except for the are interrupted to a defined contact point via switching devices, so as to perform a better localization. Similarly, switching devices can be used to connect contact points. In a particularly simple embodiment, a current is measured between a first contact point of at least two contact points on the conductor layer and the object surface and a current between a second contact point of the at least two contact points on the conductor layer and the object surface. Based on this, a detection of the spatial position of the breakthrough site then takes place. This is particularly simple if the conductor layer is structured in a suitable manner, for example, in a preferred variant, comprises at least one loop-shaped conductor track or has a meandering structure. In this case, two contact points are sufficient at the two ends or end regions of the loop-shaped conductor track in order to determine at which point along the track the break-through point must be (approximately) arranged. If the course of the conductor track on the object surface is known, for example deposited on a plan, the location of the break-through point on the object can be specified almost exactly and local repair work can be carried out accordingly. A current measurement can in each case preferably be effected by means of a current measuring resistor (shunt), wherein the voltage which is a measure of the current is usually picked off by means of a differential amplifier above the current measuring resistor. The output value can preferably be digitized (for example in a suitable analog / digital converter or via a voltage / frequency converter), so that the further processing of the measured values can be carried out with the aid of a suitable computer device. This makes it particularly easy to carry out the calculations required for determining the localization information and in particular also to determine any sum currents of any desired groups of contact points and ratios of currents and / or voltages relating to specific contact points or contact point groups and to use them in the calculations.

Depending on the design, different currents and / or voltages can be measured or recorded simultaneously and used to determine the spatial position of the breakdown point, or different currents and / or voltages are measured sequentially in time. Temporally sequential means that the currents and / or voltages can also be interrogated several times in succession, preferably cyclically. recurrent. For example, the currents from different contact points of the conductor layer could be queried one after the other in groups, wherein also summation currents of different groups can be detected one after the other. Such a measurement and possibly also further transmission and / or processing of the various measurement data in such a temporal multiplex method has the advantage that the electronic complexity is reduced because it can be measured via a switchover with only one current sensor electronics.

As already mentioned above, the accuracy of the localization of the spatial position usually depends on the respective structure of the overall system, for example, how large the object to be protected, how the object surface is formed, how many and where the contact points are mounted, in which shape the conductor layer is formed (structured or not and, if so, in which form the structure is constructed). It is desirable to have as accurate a localization as possible, however, in some applications a localization to certain areas is sufficient, for example, in the case of a very complex and large bridge structure, localization on one side of a bridge pier, etc. or a subarea on this side. The more accurate the localization must be, the greater the requirements for the uniformity of the conductor layer and the complexity of the system. In order to keep this effort low and still allow the most accurate localization in the event of the occurrence of a defect, in a preferred variant, a determination, d. H. a detection of the spatial position or desolation of the breakthrough also stepwise. In a first stage, information (localization information) can be ascertained as to whether the breakthrough point in a specific first spatial area, eg. B. on a support of a larger object is located. In a further step, a more precise sclerotherapy of the break-through point within the first spatial area can then take place. In this case, the process can be continued in more than two stages, thus limiting the defect location to an ever narrower range.

For this purpose, detection of the spatial position of the break-through point using at least one mobile or mobile attachable measuring sensor can particularly preferably take place in at least one stage. By "mobile" or "mobile attachable" measuring sensor is here to be understood as a measuring sensor, the z. B. without fixation (for example, by hand) on the cover Be guided layer or z. B. there temporarily, for example via suction cups, clamping elements, etc., can be positioned releasably stationary. These are preferably inductive and / or capacitive measuring electrodes. In principle, however, magnetic field sensors could also be used.

The use of mobile or mobile attachable measuring sensors has the advantage that the number of measuring sensors on the object can possibly be significantly reduced, since the mobile attachable or mobile measuring sensors can always be used for a more precise localization, which is only then used must be within a range finer localization is desired. In principle, these mobile or mobile measuring sensors could also be connected to the control and / or monitoring device. It can also be used here but a mobile meter, which is completely self-sufficient from a z. B. permanently installed control and control device works. However, such a mobile measuring device can in turn also be coupled to the control and monitoring device in terms of data technology, possibly also via a further higher-level control or control center.

Most preferably, a single mobile measuring sensor is sufficient, which is guided freely over the cover layer.

In order to maintain as constant a distance as possible from the conductor surface in the case of a mobile measuring sensor guided freely over the cover layer during the measurement, the mobile measuring sensor preferably has sliding elements with which the mobile measuring sensor can be placed on the cover layer and easily slid on it.

The defect localization can therefore be carried out in particular exclusively with a mobile (capacitive) field strength sensor, without (as described in more detail in the above embodiments) measuring the currents in or at the contacting points (directly). For this purpose, the minimum of the field strength (preferably an alternating field) can be measured. At the defect location, the field strength is minimal (because of the short circuit to ground generated here). Likewise, the defect localization can also be carried out exclusively with a mobile current density sensor, without measuring the currents in the contacting points. For this purpose, the defect points are searched for via local maximum current densities. For example, with a magnetometer, a hand-held device with a magnetic field sensor, simply the highest current density and thus the largest local magnetic field at the surface can be searched. It can be assumed that this occurs at the break-through point. With particular advantage, the local magnetic field can be measured with two or three Hall sensors arranged orthogonally to one another in order to detect the two or three spatial planes of the magnetic field.

In particular when mobile attachable or mobile attachable measuring sensors are used, but also with permanently mounted measuring sensors, it is advantageously possible to apply an alternating voltage signal between the object surface and the conductor layer in order to detect the spatial position of the breakdown point, preferably only temporarily.

If an alternating voltage signal is applied, a signal proportional to the current density change can be measured with a simple coil arrangement as inductive measuring sensor, preferably two or three coils arranged orthogonally to one another, for two or three spatial planes of the magnetic field, and localization can thus be effected. The current density alternating signal, for example, is significantly higher or can be significantly higher than in the simple measurement of the magnetic field of a direct current. In addition, in such a method, unlike with the use of magnetic field sensors, such as Hall sensors, no external magnetic field compensation is required.

In conjunction with an alternating voltage signal, a capacitive measurement can also be carried out. At the defect site it can be assumed that the electric field strength is lowest there. Accordingly, a minimum of the electric field strength can be detected. As a sensor, for example, a provided with one or more electrode surfaces planar sensor arrangement can be used, for. B. is arranged on an electronic board and with the conductive layer of the layer arrangement on the object as a counter electrode and the insulating layer, d. H. the insulating cover layer, and possibly an overlying layer of air forms a capacity.

Preferably, this AC voltage signal is superimposed on a DC voltage for generating the cathodic protective current.

A localization of a defect site using an AC signal or an AC current works even if only a single contact point is present on the conductor structure, via which the voltage between the conductor layer and the Object surface is created, and thus can be particularly well used on objects that already have a system for cathodic corrosion protection and where a retrofit in the inventive manner is desired without further contact points must be attached.

In addition to the localization of the defect, it is in principle also possible in the context of the method according to the invention to determine the extent of the defect, ie. H. how bad the damage is. For this purpose, the defect extent of the breakthrough parts of the first protective layer between the object surface and the conductor layer can preferably at least approximately be detected on the basis of a current and / or voltage measured between the object surface and the conductor layer. Particularly preferably, this is done by a current summation over all contact points, d. H. It is determined how much total current flows between the object surface and the conductor layer. Both the determined location information or the values required for this purpose and / or the extent of the defect or the values required therefor can also preferably be coded into a frequency signal and thus transmitted to more distant or higher-order computer units. Such a frequency signal can then be counted by the evaluation computer in a simple manner in order then to arrive at the desired information and hereby carry out the further determination of the desired values or to further process the values already transmitted.

In the conductor layer coating material according to the invention, preferably the conductor layer lacquer or the like, the conductive component preferably comprises one or a combination of the following materials:

carbonaceous materials, preferably graphite and / or graphene and / or carbon black (carbon black = carbon black, carbon black, carbon black) and / or carbon nanotubes;

metal-containing materials and / or conductive pigments, preferably silver particles, gold nanoparticles, platinum nanoparticles, silver nanoparticles, silver-coated

Glass flakes, silver chromium-coated glass flakes, titanium dioxide nanoparticles, copper nanoparticles;

Polymers, preferably organic conductive polymers and / or polymer blends, in particular PEDOT: PSS (poly (3,4-ethylenedioxythiophene) polystyrenesulfonates, polyaniline, polypyrrole. Use of carbo-nanotubes is most preferred.

The conductor layer coating material may, for. B. applied as a conductor layer paint, for example, sprayed or printed. Depending on the nature of the conductor layer coating material, it can also be applied by evaporation later, for. B. in a physical vapor deposition method or sol-gel method.

A binder of the conductor layer coating material may preferably comprise at least one polymer.

A dispersing additive of the conductive layer coating material may preferably comprise polymers having pigment affinity side chains.

In the case of the insulating-layer coating material according to the invention, preferably insulating-layer lacquer or the like, the insulating material preferably comprises a polymer, in particular of epoxy resin, polyurethane or the like.

Also, a binder of the insulating layer coating material may preferably comprise at least one polymer.

The first insulating layer may also be a foil or the like. Such a base film may, for. B. be applied by means of a pressure-sensitive adhesive layer or the like on the object surface. Likewise, the second insulating layer may be a foil or the like. In principle, it would also be possible that both the base layer and the cover layer are formed as a film.

For example, if the base layer as a base film and / or the cover layer formed as a cover sheet, so z. B. the conductor layer also be printed on one of these slides.

In principle, the base layer and cover layer could also be provided with the intervening conductor layer as a complete composite of a layer arrangement, in that e.g. B. the two films, base film and cover sheet are laminated together with intervening conductor layer or by the cover layer is also applied over the applied to the base film conductor layer, for example, printed or, conversely, the base layer is applied to the conductor layer applied to the cover film, for example printed on it. In principle, all possible combinations are conceivable here.

If, for example, films are used, they too may of course have further layers or in turn themselves be produced as laminates or the like, in particular have adhesive layers, for example, to adhesively bond the relevant film to the object surface or another film.

The invention will be explained in more detail below with reference to the accompanying figures with reference to embodiments. The same components are provided with identical reference numbers in the various figures. It shows schematically:

FIG. 1 shows a section through an object to be protected against corrosion with an undamaged layer arrangement with two insulating layers and an intervening conductor layer as well as an applied voltage for cathodic corrosion protection,

FIG. 2 shows the object as in FIG. 1, but now with a damaged layer arrangement for explaining the effect of the cathodic corrosion protection;

FIG. 3 shows an object arrangement with an object to be protected from corrosion and a corrosion protection and monitoring system according to the invention according to a first exemplary embodiment,

FIG. 4 shows a corrosion protection and monitoring system according to the invention in accordance with a second exemplary embodiment with a plan view of a structured conductor surface,

FIG. 5 shows a plan view of a modified structured conductor surface for a corrosion protection and monitoring system according to the invention, similar to FIG. 4,

FIG. 6 shows a further exemplary embodiment of a corrosion protection and monitoring system according to the invention with a plan view of a conductor surface with four contact points, FIG. 7 shows a flow diagram of an exemplary embodiment of a method according to the invention for corrosion protection and corrosion protection monitoring.

With reference to FIGS. 1 and 2, the principle of an "active" cathodic corrosion protection of an object O is first shown.

As can be seen from the figures, the object to be protected O is coated with a layer arrangement 10 which consists of several layers 11, 12, 13. First, a first insulating layer 11 made of an electrically insulating material is applied to the surface OF of the object O. This may be, for example, a paint. Directly above, d. H. on the side facing away from the object O side of the first insulating layer 11, a conductor layer 13 is applied. This conductor layer 13 is then outwardly, i. H. on the side facing away from the first insulating layer 11, covered with a second insulating layer 12 made of electrically insulating material. The conductor layer 13 is thus galvanically isolated on the one hand from the conductive object O or the object surface OF by the first insulating layer 11 and, on the other hand, also with respect to the environment through the outermost second insulating layer 12. As already mentioned at the outset, some or some of them can all of the layers also be formed as films. In particular, the layer arrangement 10 may also be a film composite of a plurality of films and / or layers applied to foils, in particular pressed-on layers.

Furthermore, the layer arrangement 10 can also have further layers, for example adhesive layers or even further protective layers or decorative layers on the outer side of the second insulating layer. By means of this layer arrangement 10, the surface OF of the object O is already passively protected very well against corrosion, as long as the layer arrangement 10 or at least one layer of the layer arrangement 10 is undamaged. Depending on the load of the object O or after a certain time, local damage to such a layer arrangement 10 will occur in many cases, as a result of which passive corrosion protection no longer lasts. , As can be seen in Figures 1 and 2 of this Grun- de created by means of a voltage source a DC voltage U ₀ between the O object and thus the object surface OF, and the conductor layer 13, so that the electric potential of the conductor layer 13 against - Is increased over the object surface OF by the voltage U ₀ . This may be a relatively low voltage, for example 1 V. The effect of this layer arrangement 10 and the applied voltage U ₀ is clear in FIG. If there is a local damage of the layer assembly 10, so that they except for the object surface OF of an outer medium M, z. As an electrolyte such as salt water, fog, road salt, etc., can be penetrated, ie that all three layers 1 1, 12, 13 are damaged, the conductor layer 13 is also locally electrically connected by the medium M with the object surface OF and, via the medium M, there is a current flow I _K from the conductor layer 13 acting as an anode (since it is connected to the positive pole of the voltage source) and the object O forming the cathode or the object surface OF. This low current flow I _K ensures that exactly at the point where the damage has occurred, ie at the defect point D, a dissolution of the (usually metallic) object surface OF is prevented or at least reduced to an uncritical degree, because the metallic substrate is cathodically polarized. Consequently, the coating with the illustrated layer arrangement 10 and the applied voltage U ₀ initially virtually heals itself and the corrosion protection is maintained, since the loss of the intact coating is compensated by the active corrosion protection. Nevertheless, it is not unlikely that gradually the damage to the layers 1 1, 12, 13 also expands, so that at some point a repair of the layer arrangement 10 is required. If, in fact, the defect point D becomes too large, the effect of the cathodic corrosion protection will no longer be sufficient at some point.

In order to be able to carry out such repairs as effectively as possible, it would be desirable to be able to locate the location of the defect site D as simply as possible, or at least to be able to limit it to a certain area, and preferably also to be able to determine the extent of the defect site D, so that only then and only there repair of the layer structure 10 is made where it is necessary, but on the other hand, it can not come to a propagation of defects, which could lead to a corrosion on the object O then.

For this purpose, FIG. 3 shows (in a similar representation as in FIGS. 1 and 2) an object O with such a layer arrangement 10 within the scope of a corrosion protection and monitoring system 1 according to the invention, which would permit this. Here, too, an insulating layer 11 of the layer arrangement 10 is applied to the object surface OF, firstly a conductor layer 13, and then again a conductor layer 13 Insulating layer 12 as outer cover layer. The conductor layer 13 is formed so that the surface resistance over the surface is substantially constant, ie spatially not or at least only slightly different. Likewise, a DC voltage U ₀ is also applied in this embodiment by means of a DC voltage source 25 between the metal object O and the conductor layer 13, wherein the plus side is again applied to the conductor layer 13 so that it acts as an anode, and the metal object O or the object surface OF as the cathode, if, in the case of a defect, a conductive connection should occur between the conductor layer 13 and the object surface OF.

In addition, the exemplary embodiment of the corrosion protection and monitoring system 1 according to the invention according to FIG. 3 also has an AC voltage source 26 connected in series with the DC voltage source 25, with which the DC voltage U _{0 is} superposed by an AC voltage LL. The advantage of such a superposition of an AC voltage LL will be explained in more detail later with reference to FIGS. 6 and 7.

In the exemplary embodiment illustrated in FIG. 3, the negative side or the ground of the DC voltage source 25 is connected directly to a contact point K ₀ on the object O. Likewise, the connection of the negative pole of the voltage source 25 with the object O can also be grounded, ie both the object O is grounded and the ground also forms the "negative pole" of the DC voltage source 25. In this respect, the contact point K ₀ at the object O is arbitrary. It is also irrelevant in which order the DC voltage source 25 and the AC voltage source 26 are connected in series.

Both the DC voltage source 25 and the AC voltage source 26 are controlled here by suitable control signals SG, SW from a control interface 23 of a control and monitoring device 20. In this case, the DC voltage source 25 is controlled so that a defined voltage is maintained, for example, from 1 to 1, 23 V, so that the cathodic protection current is also reliably maintained and not too high and not too low.

The positive voltage is applied here to two spaced apart contact points Ki, K ₂ to the conductor layer 13 and it is measured by suitable measuring devices Mi, M ₂ each of the current which extends from the positive pole of the voltage source 25 to the contact points Ki, K ₂ , This can be done, for example, by means of suitable shunt Resistors and these associated differential amplifiers made and possibly downstream analog-to-digital converters, so that first the current across the shunt resistor is tapped as a voltage value, which is then digitized again. The digital output value is then a measured value which is proportional to the current I ₂ , I ₂ , which flows from the positive pole of the voltage source 25 to the respective contact point K ₁ , K ₂ as soon as a defect point occurs.

These measured values or measurement signals Ml-i, Ml ₂ are fed to a calculation unit 21 of the control and monitoring device 20. In this calculation unit 21, it can first be detected whether any current is flowing at all. As long as the layer arrangement 10 is undamaged, this is normally not the case. If there is a defect point D, then, as explained above with reference to FIGS. 1 and 2, a current flows between the conductor layer 13 and the surface OF of the object O, ie the cathodic protective current occurs.

It depends on the location of the defect point D within the conductor layer 1 3 relative to the two contact points Ki, K ₂ from how large the current \ ^, l ₂ at the respective contact parts Ki, K ₂ is. This is because the conductor layer 1 3 has a specific resistivity which is as constant as possible in space and, the more remote the defect point D from the contact point Ki, K ₂ , the greater the resistance formed by the conductor layer 1 3. The height of the two streams h, l ₂ thus forms an indication of the location of the defect point D within the conductor layer in relation to the contact points Ki, K ₂ . The sum of the two currents h, l ₂ , ie the total current flowing between the anode formed by the conductor layer 13 and the cathode, ie the object O, is a measure of the extent of the defect D.

The information determined in the calculation unit 21 about the extent of the defect points D and location information, where this defect location D is located or at least in which area this defect location D could be located, can then be output via an output unit 22 of the control and monitoring device 20 be stored, for example, in a data storage for logging or transmitted to a central monitoring unit or maintenance personnel, etc.

Examples for this and a particularly simple exemplary embodiment for a localization of the defect location D are given below with reference to FIG. 4. 4, only two contact points Ki, K _{2 are used} , which in turn are connected to the positive pole of the DC voltage source 25 in order to generate a DC voltage U ₀ between the conductor layer 13 'shown schematically from above and the object (FIG. not shown in FIG. 4). As explained, the object as well as the negative pole of the voltage source 25 may be connected to ground. In the embodiment according to FIG. 4, no AC voltage source is additionally shown. However, it is also possible to provide an AC voltage source in this embodiment, if desired. By suitable measuring devices Mi, M ₂ are also - as in the hang in connection with Figure 3 described manner - the currents \ ^ l ₂ is measured at the contact points Ki, K _2, which occur when there is a defect D in the layer arrangement comes. Corresponding measured values or measurement signals Mh, Ml ₂ are again transferred to a calculation unit 21 of the control and monitoring device 20, which in turn can determine the defect extent from the sum of the currents ^, ℓ ₂ and based on the individual currents ^ , l ₂ can close on the location of the defect D.

In order to make the localization of the defect D as simple as possible, there is no continuous, but a meander-shaped structured conductor layer 13 'applied, which comprises a kind of loop-shaped conductor 14, which leads from the first contact Ki to the second contact K ₂ . In the illustrated exemplary embodiment according to FIG. 4, this is achieved by applying the conductor layer uniformly and over the whole surface to the surface, except for parallel running slots 15 extending from opposite sides into the surface. The slot 15 then extends between the slots 15 Printed circuit 14 with a defined strip width b. Such a structuring can be effected, for example, by masking the slits 15 on the base layer, ie the first insulating layer 11. After the uniform application of the electrical rule conductor layer 13 'then the strips can be removed with the applied thereon Leitlack again, so that the meandering structure is formed.

With this meander-shaped structured conductor surface, the position of the defect point D in the corrosion protection layer can be determined particularly advantageously with only two measuring devices Mi, M ₂ , one at the beginning and one at the end of the meander-shaped conductor track structure 13 ', as follows. The total current which occurs due to the DC voltage U ₀ and which flows off via the defect point D divides via the contact points Ki, K ₂ and flows through the meander-shaped structure 13 over the partial stretches from the respective contact point Ki, K ₂ to the defect point D '. In principle:

U ₀ = Ir ^R 1 = · ^R 2

RI and R ₂ are the resistances of the two sections from the contact points Ki, K ₂ to the defect point D. Since it can be approximately assumed that there is a constant sheet resistance over the trace, the resistors Ri, R _{2 are} proportional to the lengths ai, a _{2 of} the two sections: k · U ₀ _- I _J · E _{J -} 1 ₂ · a ₂ k is a proportionality constant which is irrelevant for the further calculation. Thus, the following applies:

The currents h, l ₂ in the two connection lines thus behave inversely proportional to the lengths ai, a _{2 of} the sections of the meander-shaped track in each case from the contact points Ki, K ₂ to the defect point D. With the total length L = na of the track between The contact points Ki, K ₂ , where n is the number of meanders and a is the strip length of the electrically conductive paths, follows for the position of the defect point D:

In this simple calculation, it is assumed that the resistances from the voltage source to the contact points Ki, K _{2 are} negligibly small, ie that there are no line resistances or that these are compensated by appropriate measures. In order to provide as simple as possible the same way and thus line resistances and to be able to contact both connections, if possible, via a plug with two contact paths, and the end of the conductor can be returned to the vicinity of the beginning. An example of this is shown in FIG. Here, the contact points Ki, K _{2 of} the meander-shaped conductor structure 13 'lie directly next to each other.

As these examples show, the location of the defect point D can be determined relatively well in a simple manner with the aid of two contact points Ki, K ₂ and a suitable structuring of the conductor surface 13 '. If, for example, a plan is known about the position of the contact points Ki, K ₂ or the structuring, the search can also be performed manually using the information obtained about the distance of the defect point D from one of the contact points Ki, K ₂ . Preferably, however, this is done purely mathematically, for example on a virtual model of the object, and it can then conveniently be a suitable output of the virtual model, for example on a screen or a print done in which the contact point is marked on the model.

The example of FIG. 4 also shows schematically how an output and / or monitoring and / or control of the control and monitoring device 20 could be carried out remotely. Thus, the control and monitoring device 20 is here provided with an interface to the Internet WEB (Internet of Things), there is also a serial interface RS232 for the direct connection of a computer, there is also for a wireless communication to a computer or smartphone, a WLAN interfaces and a BLE interface (Bluetooth Low Energy). The entire electronics, for example the control and monitoring device, can also be preferably realized as a single-board computer with a cape (a plugged-on measuring electronics board with the required analog electronics). As mentioned before, this single-board computer can take over the measurement data transmission and presentation in the Internet of Things. Furthermore, it can serve as a web server for the monitoring and parameterization of the sensor system. This can advantageously be achieved via a bidirectional connection between client and server, eg. B. Websocket Protocol. However, it would also be possible to use a conventional hypertext transfer protocol (http), in which case the client would query the server via polling so as to deliver the information from the on-site single-chip computer to a central control unit. For example, the control information of a bridge to be protected and monitored with regard to the corrosion state can thus be transmitted to a central control unit of a road maintenance or the like.

Corresponding interfaces and procedures or technical implementations, as explained above for the control and monitoring device 20 in connection with FIG. 4, can likewise be used in the other exemplary embodiments, even if they are not explicitly shown there.

With reference to FIG. 6, it will now be explained in a largely simplified manner how a corresponding localization of a defect location D on an unstructured conductor surface 13 could take place.

For this purpose, the voltage source, which here again comprises a DC voltage source 25 and a series-connected AC voltage source 26, over here z. B. four contact points Ki, K ₂ , K ₃ , K ₄ connected to the conductor surface 13. Accordingly, there are also four separate current measuring devices Mi, M ₂ , M ₃ , M ₄ to the currents h, l ₂ , l ₃ , l, each in the event of a defect on the contact points Ki, K ₂ , K _3rd , K _{4 run} from the positive pole of the DC voltage source 25 through the defect point D to the object surface OF, to be able to measure separately. These measuring devices Mi, M ₂ , M ₃ , M ₄ can again be constructed in the same way as in the previous exemplary embodiments. They deliver the measured values Ml-i, Ml ₂ , Ml ₃ , Ml ₄ back to a calculation unit 21 of the control and monitoring device 20. As in the aforementioned embodiments, this also has an output unit 22 to the determined values or the thereof The values obtained can be output and / or stored or sent via the extent and the position of the defect site D. The DC voltage source 25 and the AC voltage source 26 can in turn be controlled via a control interface 23.

In this exemplary embodiment, too, in principle, the current I ₂ , I ₂ , I ₃ , I ₄ , which flows via a contact point K ₁ , K ₂ , K ₃ , K ₄ , depends on the resistance between the contact points K ₁ , K ₂ , K ₃ , K ₄ and the respective defect site D. Analogous to the procedure according to FIG. 4, therefore, the defect location D can also be located from the ratio of the currents h, l ₂ , l ₃ , l.

For example, from the sum of the group of the two currents l ₂ , l ₃ at the two left contact points K ₂ , K ₃ on the one hand and the sum of the group of the two currents h, l On the other hand, the horizontal position of the defect point D in FIG. 6 can be delimited at the right contact points Ki, K ₄ .

With the sum of the group of currents \ ^, l ₂ at the two upper contact points Ki, K ₂ and the sum of the group of currents l ₄ , l ₃ at the two lower contact points K ₄ , K ₃ can in turn be the vertical position of Restrict defect D.

Due to inhomogeneities of the electric flow fields and possibly tolerances in the homogeneity of the electrical conductor layer, the accuracy of the determination of the defect position can be limited. In principle, however, at least initially a defect region DB can be determined in this way, in which the defect point D is most likely to be located.

In order then to allow a more precise defect localization, a more precise search can be carried out in a further stage, wherein the localization can then be limited to the defect region DB already determined in the first stage.

For this purpose, for example, a handheld device with a magnetic field sensor, for example with two or three orthogonally arranged Hall sensors, could be used to determine the magnetic field. The highest current density and thus also the largest local magnetic field should occur at the defect point D.

In a preferred variant, an alternating voltage signal U _{~ is} superimposed on the DC voltage signal U ₀ by means of the AC voltage source 26 for the search, in particular for the further search in a next stage, after a defect area DB has already been limited. In this case, it is also possible to use mobile sensors 30 in the form of inductive sensors or capacitively operating sensors which are able to determine a measurement signal for the (local) strength of the alternating current in the conductor layer 13 under the outermost cover layer 12 ,

In this case, the search can in turn be carried out with a mobile or a plurality of such mobile or mobile sensors 30, which transmit their results or the alternating current density measured values (measurement signals), eg, the sensor. B. via flexible cables, to a mobile device 31 forward. Subsequently, the mobile sensors 30 can be displaced in order to narrow the area even further, until finally the defect location D has been localized sufficiently precisely. The process steps or method steps in such a multi-stage sequence will be explained again with reference to FIG.

In a first step PA, a DC voltage is first applied. In a step PB, the current flow via the contact points is then measured and evaluated in step PC in which defect region DB the defect point D could be located.

In a further step PD, an alternating voltage is then applied by means of the alternating voltage source 26, wherein this alternating voltage is superimposed on the direct voltage, so that the cathodic protection current is still maintained. In a step PE, the alternating current is then detected with the mobile sensors 30 so as to further narrow down the defect area DB or to locate the defect location D as accurately as possible.

The advantage of using a superimposed alternating voltage signal is that a signal proportional to the current density change can then be measured with a simple coil arrangement, for example a measuring arrangement constructed from two or three orthogonal coils. In the case of a capacitive measurement, on the other hand, it is taken into account that the electric field strength is lowest at the defect location. Accordingly, a minimum of the electric field strength is detected here.

Examples of possible fields of application of the invention are, as already mentioned, the automotive or any steel structures such as bridges or the like. In particular, the destruction of protective layers z. Rockfall, for example, represents a potentially promising field of application. Automobiles and bridges, for example, are subject to constant use as well as regular inspections. Uncritical damaged areas need then not be repaired, if it is determined by means of the corrosion protection and monitoring system according to the invention (by evaluation of the total current) that the extent of the defect is not particularly large. On the other hand, if critical defects are identified, they can be repaired more easily because they are easy to localize. Such a corrosion protection and monitoring system offers particular advantages in water change zones, where on the one hand a On the other hand, there is also constant mechanical stress, for example in the area of sheet piling or offshore landing platforms. It is finally pointed out once again that the methods and systems described in detail above are merely exemplary embodiments which can be modified by the person skilled in the art in many different ways without departing from the scope of the invention. Furthermore, the use of the indefinite article "on" or "one" does not exclude that the characteristics in question may also be present multiple times. Likewise, the term "unit" does not exclude that it consists of several interacting sub-components, which may also be spatially distributed if necessary.

LIST OF REFERENCE NUMBERS

I Corrosion protection and monitoring system 10 Layer arrangement

I I first insulating layer

12 second insulating layer

13 conductor layer

13 'structured conductor layer

14 trace

15 slots

20 control and monitoring device

21 calculation unit

22 output unit

23 control interface

25 DC voltage source

26 alternating voltage source

30 mobile sensor

31 mobile device

a strip length

ai, a ₂ lengths of the sections

b strip width

D defect site

DB defect area

l _K current flow

li, l ₂ , I3, L Electricity

K ₀ contact point

K1, K ₂ , K ₃ , K ₄ contact points

M medium

Mi, M ₂ , M ₃ , M ₄ measuring equipment

MI1, Ml ₂ , Ml ₃ , Ml ₄ Measured values / measuring signals

O object

OF surface

SG control signal

Uo DC voltage

U _~ AC voltage PA, PB, PC, PD, PE Process steps WEB interface

RS232 serial interface

WLAN interface

BLE interface

Claims

claims

1. A method for corrosion protection and corrosion protection monitoring of a leitfähi gene object (O), which on an object surface (OF) at least one layer arrangement (10), at least

a first insulating layer (11) of electrically insulating material facing the object surface (OF),

an optionally structured conductor layer (13, 13 '), which is located on the side of the first insulating layer (11) facing away from the object surface (OF), and

a second insulating layer (12) of electrically insulating material, which is located on the side of the conductor layer (13, 13 ') remote from the first insulating layer (11),

includes, where

- At least temporarily, a voltage (U ₀ , U _~ ) between the object surface (OF) and the conductor layer (13, 13 ') is applied and

at least temporarily, an occurrence of a current (h, l ₂ , I ₃ , L) between the object surface (OF) and the conductor layer (13, 13 ') is checked,

and wherein upon occurrence of such a current (h, l ₂ , I3, L), on the basis of at least one measuring signal which has a current (h, l ₂ , l ₃ ) flowing along a region of the conductor layer (13, 13 ') , l ₄ ) and / or a voltage dropping over a region of the conductor layer (13, 13 ') represents a spatial position of a breakdown point (D) of the first protective layer (11) between the object surface (OF) and the conductor layer (13, 13 ') is determined.

2. The method of claim 1, wherein upon occurrence of a current (h, l ₂ , l ₃ , L) between the object surface (OF) and the conductor layer (13, 13 '), a defined voltage (U ₀ ) between the object surface (OF ) and the conductor layer (13, 13 ') is held.

3. The method of claim 1 or 2, wherein the spatial position of the breakdown point (D) on the basis of a current and / or voltage distribution, preferably based on the ratios of currents (h, l ₂ , l ₃ , l ₄ ) and / or voltages between the object surface (OF) and different contact points (K1, K ₂ , K ₃ , K ₄ ) of the conductor layer, especially of sum currents of different groups (G1, G ₂ , G ₃ , G) of contact steep (Ki, K ₂ , K ₃ , K ₄ ) of the conductor layer (13, 13 '), is determined.

4. The method according to any one of the preceding claims, wherein different currents (h, l ₂ , I ₃ , I ₄ ) and / or voltages are measured sequentially in time.

5. The method according to any one of the preceding claims, wherein a determination of the spatial position of the breakdown point (D) takes place stepwise, wherein in a first stage

Information can be determined as to whether the break-through point lies in a first spatial area, and in at least one further step, a more precise sclerosing of the break-through point in the first spatial area takes place.

6. The method according to any one of the preceding claims, wherein a determination of the spatial position of the breakdown point (D) using at least one mobile or mobile attachable measuring sensor, preferably at least one inductively and / or capacitively operating measuring electrode (Mi, M ₂ , M ₃ , M ₄ ).

7. The method according to any one of the preceding claims, wherein an alternating voltage signal (U _~ ) between the Objektoberfläche (OF) and the conductor layer (13, 13 ') is applied, preferably one for determining the spatial position of the breakdown point (D) DC voltage (U ₀ ) is superimposed.

8. The method according to any one of the preceding claims, wherein based on a / between object surface (OF) and the conductor layer (13, 13 ') measured current (h, l ₂ , l ₃ , l ₄ ), preferably by a current summation, and or a defect extent of the breakdown point (D) of the first protective layer (11) between the object surface (OF) and the conductor layer (13, 13 ') is detected.

9. The method according to any one of the preceding claims, wherein in a first step, first on the object surface (OF) a layer arrangement (10) is applied, the at least

having.

10. Corrosion protection and monitoring system (1) for a conductive object (O), which corrosion protection and monitoring system (1) comprises at least the following components:

a layer arrangement (10) to be applied or applied to an object surface (OF) of the object (O), which at least

a, optionally structured, conductor layer (13, 13 ') which is located on the side of the first insulating layer (11) remote from the surface of the object (OF), and

having,

a control and monitoring device (20), which is designed to at least temporarily apply a voltage (U ₀ , U _~ ) between the object surface (OF) and the conductor layer (13, 13 ') and at least temporarily Occurrence of a current (h, l ₂ , I3, L) to detect

wherein the control and monitoring device (20) is designed to detect, upon occurrence of such a current (h, l ₂ , I ₃ , L), on the basis of at least one measurement signal which extends along a region of the conductor layer (13 , 13 ') flowing current (h, l ₂ , l ₃ , l ₄ ) and / or a voltage drop over a region of the conductor layer (13, 13') represented voltage, a spatial position of a breakthrough point (D) of the first protective layer (1 1) between the object surface (OF) and the conductor layer (13, 13 ') to determine.

1 1. corrosion protection and monitoring system according to claim 10, wherein the conductor layer (13 ') at least one loop-shaped arranged conductor track (14).

12. object arrangement (100) comprising at least one object to be protected against corrosion (O) and a corrosion protection and monitoring system (1) according to claim 10 or 11.

13, conductor layer coating material, preferably conductor layer paint, in particular for a conductor layer (13, 13 ') for use in a method according to any one of claims 1 to 9 and / or with a corrosion protection and monitoring system (1) according to claim 10 or 11, which comprises at least the following components: (i) at least one conductive component, wherein the conductive component preferably comprises carbon nanotubes;

(ii) optionally at least one solvent;

(iii) optionally at least one binder;

(iv) optionally at least one dispersing additive.

14. Insulating layer coating material, preferably insulating layer lacquer, in particular for a first insulating layer (11) and / or second insulating layer (12) for use in a method according to one of claims 1 to 9 and / or with a corrosion protection and Monitoring system (1) according to claim 10 or 11, which comprises at least the following components:

(i) a substance selected from an insulating material, preferably a polymer;

(ii) optionally at least one solvent;

(iii) optionally at least one binder;

(iv) optionally at least one colored pigment;

(v) optionally at least one dispersing additive;

(vi) optionally at least one rheology additive.

15. Use of a conductor layer coating material according to claim 13 and / or an insulating layer coating material according to claim 14 in a method according to one of claims 1 to 9 and / or in a corrosion protection and monitoring system (1) according to claim 10 or 1 1.