Enamel coated stainless steel product, production method and flowmeter

Abstract

The invention relates to a stainless steel product (1) comprising:-a stainless steel plate (2), an adhesion promoter (4) being applied to a surface (3) of the stainless steel plate (2), the adhesion promoter (4) comprising a CoCr and / or NiCr alloy, and an enamel coating (5) being applied to the adhesion promoter (4). The invention also relates to a magnetic inductive flowmeter (6), a field device (10) and a method for producing a stainless steel product (1).

Description

Technical Field

[0001] The invention relates to a stainless steel product, a magnetic induction flow meter, a field device and a method for producing the stainless steel product. Background Art

[0002] In automation, in particular process automation, field devices for capturing and / or modifying process variables are often used. In order to detect process variables, sensors integrated into, for example, level measuring devices, flow meters, pressure and temperature measuring devices, pH-redox potentiometers, conductivity meters, etc. are used to detect the corresponding process variables, such as level, flow, pressure, temperature, pH value or conductivity. Actuators (such as, for example, valves or pumps) are used to influence process variables. Thus, the flow rate of a fluid in a pipeline section or the level in a container can be changed by means of an actuator. In principle, all devices that are process-oriented and provide or process process-related information are referred to as field devices. Therefore, in conjunction with the present invention, "field device" also refers to remote I / O, radio adapters or electronic measuring components that are usually arranged at the field level.

[0003] The field device is in particular selected from the group consisting of a flow meter, a fill level measuring device, a pressure measuring device, a temperature measuring device, a limit level measuring device and / or an analytical measuring device.

[0004] The flow meter is in particular a Coriolis, ultrasonic, vortex, thermal and / or magnetic-inductive flow meter.

[0005] The level measuring device is in particular a microwave level measuring device, an ultrasonic level measuring device, a time domain reflectometry device, a radiation level measuring device, a capacitive level measuring device, an inductive level measuring device and / or a temperature sensitive level measuring device.

[0006] The pressure measuring device is in particular an absolute pressure device, a relative pressure device or a differential pressure device.

[0007] The temperature measuring device is in particular a measuring device having a thermocouple and / or a temperature-dependent resistor.

[0008] The limit level measuring device is in particular a vibrating limit level measuring device, an ultrasonic limit level measuring device and / or a capacitive limit level measuring device.

[0009] Analytical measuring devices are in particular pH sensors, conductivity sensors, oxygen and reactive oxygen species sensors, (spectro)photometric sensors and / or ion-selective electrodes.

[0010] Magnetic induction flowmeters are used to determine the flow rate and volume flow of a flowing medium in a pipeline. Here, a magnetic induction flowmeter in the pipeline and a magnetic induction flow measuring probe inserted into the side opening of the pipeline are used. The magnetic induction flowmeter has a device for generating a magnetic field, which generates a magnetic field perpendicular to the flow direction of the flowing medium. A single coil is usually used for this purpose. In order to achieve a uniformly dominant magnetic field, the pole shoes are additionally formed and attached so that the magnetic field lines extend substantially perpendicular to the horizontal axis or parallel to the vertical axis of the measuring tube over the entire pipe cross section. In addition, the magnetic induction flowmeter has a measuring tube on which the device for generating a magnetic field is arranged. The measuring electrode pairs attached to the side of the measuring tube tap a measuring voltage or a potential difference, which is applied perpendicular to the flow direction and is applied to the magnetic field, and the measuring voltage or potential difference occurs when the conductive medium flows in the flow direction when the magnetic field is applied. Since the tapped measuring voltage depends on the velocity and flow rate of the flowing medium according to Faraday's law of induction, and considering the known pipe cross-sectional area, the volume flow rate can be determined according to the induced measuring voltage.

[0011] Unlike magnetic-inductive flowmeters, which comprise a measuring tube for conducting the medium with an attached device for generating a magnetic field penetrating the measuring tube and measuring electrodes, magnetic-inductive flow measuring probes are inserted with their usually round cylindrical housing into the side opening of the pipeline and fixed in a fluid-tight manner. A special measuring tube is no longer necessary. The measuring electrode arrangement and the coil arrangement on the side of the measuring tube mentioned in the introduction are omitted and replaced by a device for generating a magnetic field, which is arranged inside the housing and directly adjacent to the measuring electrodes and is designed so that the axis of symmetry of the magnetic field lines of the generated magnetic field intersects perpendicularly with the front face or face between the measuring electrodes. In the prior art, there are already a variety of different magnetic-inductive flow measuring probes.

[0012] Magnetic-inductive flow meters are commonly used in process and automation engineering for fluids, starting from a conductivity of approximately 5 μS / cm. Corresponding flow measuring devices are sold by the applicant in a wide variety of embodiments for various fields of application, for example under the names PROMAG or MAGPHANT.

[0013] The use of enameled pipes and pipelines in the chemical and pharmaceutical industries and in the drinking water supply is known. In the chemical and pharmaceutical industries, pipes are coated with multiple layers of enamel to provide a protective layer that is sufficiently resistant to chemical corrosion. The material of the pipes is usually carbon steel, such as P 235 G1 TH. For the drinking water supply, cast iron pipes are used, which are only coated on the inside with a layer of enamel. The adhesion between the enamel coating and the carbon steel or cast iron is generally very good. When stainless steel is used, the application of enamel is generally not necessary. On the one hand, stainless steel itself is generally sufficiently corrosion-resistant, and on the other hand, the adhesion between stainless steel and enamel is very poor and is not suitable for most applications. Summary of the invention

[0014] The present invention aims to solve this problem.

[0015] This object is achieved by a stainless steel product according to claim 1 , a magneto-inductive flow meter according to claim 10 , a field device according to claim 11 and a method according to claim 15 .

[0016] The stainless steel product according to the present invention comprises:

[0017] - Stainless steel plate,

[0018] Wherein, an adhesion promoter is applied on the surface of the stainless steel plate.

[0019] The adhesion promoter comprises a Ni alloy, in particular a NiCr alloy, and / or a Co alloy, in particular a CoCr alloy.

[0020] Therein, an enamel coating is applied over an adhesion promoter.

[0021] The term "stainless steel" is governed by EN 10020 and is the name of alloy or non-alloy steel with a specific purity. For example, one requirement is that the sulfur and phosphorus content must not exceed 0.025% by mass.

[0022] As defined in the patent application, an adhesion promoter is an intermediate layer which ensures that the adhesion of a second coating applied to the intermediate layer is improved. The adhesion promoter is usually much thinner than the second coating to be joined (in this case the enamel coating).

[0023] Enamel refers to a mass of an inorganic composition, usually composed of silicates and oxides, produced in a largely glassy solid form by melting, fusing or sintering (which means a melting process that is interrupted shortly before complete melting). The mass is applied to a support material, sometimes together with additives, usually in one or more layers, and melted at high temperature for a short firing time, usually with the purpose of coating the support material. (See Enamel: Wikipedia, April 20, 2022 [online] https: / / de.wikipedia.org / wiki / Email [May 20, 2022]).

[0024] Advantageous embodiments of the invention are subject matter of the dependent claims.

[0025] One embodiment provides that the adhesion promoter has a nominal layer thickness ,

[0026] For the layer thickness , the following conditions apply: ,in particular , and preferably .

[0027] One embodiment provides that the adhesion promoter has a Cr content of at least 10 mass %, in particular at least 15 mass % and at most 45 mass %, in particular at most 40 mass %.

[0028] One embodiment provides that the adhesion promoter has a Ni content of at least 35 mass %, in particular at least 45 mass % and at most 80 mass %, in particular at most 75 mass % Ni.

[0029] One embodiment provides that the adhesion promoter has a Co content of at least 40 mass %, in particular at least 50 mass % and at most 80 mass %, in particular at most 75 mass % Co.

[0030] One embodiment provides that the enamel coating has a nominal layer thickness ,

[0031] For the layer thickness , the following conditions apply: ,in particular , and preferably .

[0032] An embodiment provides that the enamel coating, in particular with regard to the layer thickness, meets the requirements of ISO 28721-1 (2019-09).

[0033] ISO 28721-1 specifies the quality requirements for devices, assemblies, appliances and fittings made of enameled steel (including semi-crystalline enamel coatings) and cast steel for use in process plants.

[0034] One embodiment provides that the adhesion promoter is applied by a thermal spraying process (DIN EN 657), a powder spraying process or a cold gas spraying process.

[0035] One embodiment provides that the surface has an average roughness according to DIN EN ISO 4287:2010 , for this average roughness, the following conditions apply: ,in particular , and preferably .

[0036] The mean roughness is a measure of surface roughness that describes the unevenness of the surface height. The mean roughness represents the average distance from the measuring point to the center line of the reference distance. Surface roughness is standardized in EN ISO 25178 (2020).

[0037] The magnetic-inductive flow meter according to the invention for determining a flow rate-related measured variable of a flowable medium comprises:

[0038] - a measuring tube, which is used to guide the medium,

[0039] wherein the measuring tube comprises, at least in some sections, a stainless steel product according to at least one of the preceding claims,

[0040] Among them, the enamel coating is electrically insulating.

[0041] - a magnetic field generating device for generating a magnetic field penetrating the measuring tube; and

[0042] - Device for tapping off the measuring voltage induced in a flowable medium.

[0043] When conducting measuring tubes are used, they must be protected from contact with conducting media by means of so-called bushings. Bushings are electrical insulators which cover the interior of the measuring tube and partly also the area of ​​the connecting body (e.g. flange). The use of enamel as bushing is already known from EP 60 87 93 A2 and DE 19 705 436 A1. However, the use of enamel as bushing in conjunction with measuring tubes made of or comprising stainless steel sheet is not known to date.

[0044] The use of Inconel tubes in MID applications is also known. US3750468A can be cited as an example. A disadvantage of using Inconel tubes is the magnetic properties of nickel. This can be reduced by mixing with chromium and carbon, but the reduction also depends on the operating temperature of the magnetic inductive flowmeter. According to the present invention, instead of using Inconel tubes, CoCr and / or NiCr alloys are provided as thin layers between the stainless steel plate and the enamel coating.

[0045] A field device according to the invention for determining a measured variable of a medium comprises:

[0046] - components, especially those in contact with the medium,

[0047] wherein the component comprises in some sections a stainless steel product according to the invention; and

[0048] - Devices for determining measured variables of a medium.

[0049] Advantageous embodiments of the invention are subject matter of the dependent claims.

[0050] One embodiment provides that the component comprises a vibratory unit, in particular a tuning fork or a vortex sensor marker.

[0051] An embodiment provides that the component comprises a housing and / or a measuring head.

[0052] One embodiment provides that the assembly comprises a measuring tube.

[0053] The method for producing a stainless steel product according to the present invention, in particular a stainless steel product according to the present invention, comprises the following steps:

[0054] - Apply adhesion promoter to the surface of the stainless steel plate,

[0055] wherein the adhesion promoter comprises CoCr and / or NiCr alloy; and

[0056] - Apply the enamel coating to the adhesion promoter.

[0057] Advantageous embodiments of the invention are subject matter of the dependent claims.

[0058] One embodiment provides the following additional method steps:

[0059] - Roughening the surface of stainless steel sheets so that they have an average roughness according to DIN EN ISO 4287:2010 , the following conditions apply: , , and preferably .

[0060] In this case, the surface is roughened prior to applying the adhesion promoter. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The present invention is explained in more detail with reference to the following drawings. In the drawings:

[0062] Figure 1 shows a cross section of an embodiment of a stainless steel product according to the invention,

[0063] Figure 2 An embodiment of a magnetic induction flow meter according to the present invention is shown;

[0064] Figure 3 An embodiment of a field device according to the invention is shown;

[0065] Figure 4 Another embodiment of a field device according to the invention is shown;

[0066] Figure 5 shows another embodiment of a field device according to the invention; and

[0067] Figure 6 A further embodiment of a field device according to the invention is shown. DETAILED DESCRIPTION

[0068] Figure 1 A cross section of an embodiment of a stainless steel product 1 according to the invention is shown. The stainless steel product 1 comprises a stainless steel plate 2 according to EN 10027. The stainless steel plate 2 can be flat or curved. Suitable stainless steel plates 2 have, for example, the following material numbers: 1.4003, 1.4006, 1.4016, 1.4021, 1.4104, 1.4301, 1.4305, 1.4306, 1.4307, 1.4452, 1.4462 or 1.4429. The stainless steel plate 2 has a surface 3 having an average roughness according to DIN EN ISO 4287:2010. , for this average roughness, the following conditions apply: ,in particular , and preferably By adjusting the roughness of the surface 3 of the stainless steel product, the adhesion of the enamel can be improved. The roughness is obtained by the production method of the stainless steel sheet (for example, hot rolling or cold rolling), or can be adjusted by additional roughening methods (such as grinding or sandblasting).

[0069] An adhesion promoter 4 is applied to the surface 3 of the stainless steel plate 2. This is used to improve the adhesion of the enamel coating 5 on the stainless steel plate 2. The adhesion promoter 4 includes a NiCr alloy. According to the present invention, the adhesion promoter 4 may additionally or alternatively include a CoCr alloy. The adhesion promoter 4 is applied to the surface 3 by means of a thermal spraying process. This includes plasma spraying, high-velocity fuel spraying, vacuum plasma spraying or flame spraying. Alternatively, the adhesion promoter 4 can also be applied by means of a powder coating process or a cold gas spraying process. Electroplating-based or vacuum-based coating processes, such as physical vapor deposition or chemical vapor deposition, are less suitable. The adhesion promoter 4 has a nominal layer thickness of , the following conditions apply: ,in particular , and preferably .

[0070] The enamel coating 5 is applied to the adhesion promoter 4 in such a way that a substantially continuous coating is formed, which completely covers the adhesion promoter 4 at least in some sections. One of the above-mentioned thermal spraying processes is also suitable for this purpose. Alternatively, the enamel coating 5 can also be applied by means of a powder spraying process or a cold gas spraying process. The enamel coating 5 has a nominal layer thickness of , the following conditions apply: ,in particular , and preferably .

[0071] For the use of the stainless steel product 1 in process engineering plants, the enamel coating 5 is designed such that, in particular with regard to the layer thickness, the requirements of ISO 28721-1 (2019-09) are met.

[0072] The adhesion promoter 4 has a Cr content of at least 10 mass %, in particular at least 15 mass % and at most 45 mass %, in particular at most 40 mass %.

[0073] Furthermore, the adhesion promoter 4 has a Ni content of at least 35 mass %, in particular at least 45 mass % and at most 80 mass %, in particular at most 75 mass % Ni.

[0074] Alternatively, the Cr content can be replaced by a Co content of at least 40 mass %, in particular by a Co content of at least 50 mass % and at most 80 mass %, in particular at most 75 mass % Co.

[0075] Examples of suitable NiCr alloys are Inconel 718 and Inconel 625. The term Inconel is a trademark of SpecialMetals Corporation. Inconel refers to a superalloy containing mainly nickel. Additionally, the superalloy may also contain some other metals, such as magnesium, iron and titanium.

[0076] Examples of suitable CoCr alloys are alloy 188 (eg, HAYNES 188) and alloy L 605 (eg, HAYNES 25). Additionally, the alloy may also contain some other metals, such as nickel, magnesium, iron and silicon.

[0077] The adhesion promoter 4 is preferably selected such that its thermal expansion coefficient is greater than / equal to that of the stainless steel plate and less than / equal to that of the enamel coating 5 .

[0078] Figure 2 An embodiment of a magnetic-inductive flowmeter 6 according to the invention is shown. The magnetic-inductive flowmeter 6 for determining a flow rate-related measured variable of a flowable medium comprises a measuring tube 7 for conducting a flowable and electrically conductive medium. The measuring tube 7 comprises, at least in some sections, a stainless steel product 1 according to the invention. For this purpose, an adhesion promoter (not shown) and an enamel coating 5 according to the invention are provided on the inner side surface of the stainless steel tube (support tube) (see Figure 1), the stainless steel tube (support tube) is formed by a bent stainless steel sheet at least in some sections. The enamel coating 5 forms the required bushing for the metal support tube. In addition, the enamel coating 5 is designed to be electrically insulating to prevent the separated charges in the medium from being released into the conductive support tube or the stainless steel tube. The measuring tube 7 also includes connection devices on the two end faces of the support tube. The connection device shown is a flange 17. However, a variety of alternative connection devices are also known. A magnetic field generating device 8 for generating a magnetic field penetrating the measuring tube 7 is arranged on the outer surface of the measuring tube 7. The magnetic field generating device 8 can include a single coil 18, a coil system including a plurality of coils 18, or at least one permanent magnet. In addition, the magnetic field generating device 8 can include a component for guiding the magnetic field. One or more coils can each include a coil core. If at least two coils are provided, each coil has a coil core, and the coil cores can be connected to each other via a field guide plate. In addition, a device 9 for tapping the measurement voltage induced in the medium is provided. The device 9 for tapping the measurement voltage induced in the medium includes at least one measuring electrode. The measuring electrode is arranged in an opening in the measuring tube 7 that contacts the medium. Typically, at least two radially arranged measuring electrodes are provided, which are arranged on the measuring tube in such a way that the measuring electrode axes intersecting the two measuring electrodes and the main field axis of the generated magnetic field intersect perpendicularly. The magnetic field generating device 8 is connected to an electronic unit. The latter comprises an operating circuit 19 for operating the magnetic field generating device 8 with a drive signal. In addition, the electronic unit comprises a measuring circuit 20, which is configured to determine a measuring voltage applied to the device 9. The electronic unit is configured to determine a measured variable related to the flow rate based on the measured measuring voltage.

[0079] Alternatively or additionally, a housing (not shown) made of stainless steel at least in some sections can be provided, which in a cross section through the magnetic-inductive flow meter 6 surrounds the magnetic field generating device 8 and the measuring tube 7 and which, according to the invention, has a Figure 1 Adhesion promoter and enamel coating.

[0080] The magneto-inductive flow meter 6 shown is an example of a field device according to the invention, whose components in contact with the medium correspond to a measuring tube 7 which comprises, at least in some sections, a stainless steel product 1 according to the invention.

[0081] Figure 3An embodiment of a field device 10 according to the invention is shown. The field device 10 for determining a measured variable of a medium, in particular a flowable medium, comprises a component 11, in particular a component 11 in contact with the medium, which comprises a stainless steel product according to the invention at least in some sections. The component 11 shown is a housing 15 for accommodating an electronic unit 21 and / or a device 12 for determining a measured variable of a medium. The device 12 for determining a measured variable of a medium can comprise at least one sensor, in particular a temperature sensor, a vibration sensor, a pressure sensor, a conductivity sensor, a pH sensor, a capacitive sensor and / or an antenna, in particular a microwave antenna and / or an optical detector and / or an acoustic transducer. The field device 10 can also be a thermocouple, which has a housing made of a stainless steel product according to the invention as housing.

[0082] Figure 4 Another embodiment of a field device according to the invention is shown. The field device shown is a magnetic-inductive flow measurement probe 30, which is arranged in a side opening of a pipeline in contact with the medium and is configured to determine the flow rate of the flowing medium. The magnetic-inductive flow measurement probe 30 comprises a measuring head 16 in contact with the medium and in which a magnetic field generating device 38 is arranged. The magnetic field generating device 38 comprises exactly one coil 33, a coil core 34 and a field guiding device. In the front part of the measuring head 16, an electrically insulating precursor 31 is arranged, in which / on which two measuring electrodes 32 are attached.

[0083] The measuring head 16 is formed, at least in some sections, from a stainless steel plate with an adhesion promoter and an enamel coating according to the invention. The magnetic-inductive flow measuring probe 30 is an exemplary field device which has a measuring head 16 in contact with the medium and which includes a stainless steel plate according to the invention. Other field devices are known which have a measuring head in contact with the medium and which include, at least in some sections, a stainless steel product according to the invention.

[0084] Figure 5An embodiment of a field device according to the invention is shown. The field device shown is a vortex flowmeter 40. The universal vortex flowmeter 40 is described, for example, in "Durchfluss-Handbuch", 4th edition, 2003, ISBN 3-9520220-3-9, pages 103 et seq. or in EP1556670A1. The universal vortex flowmeter 40 is based on the fact that vortices are alternately shed from both sides of a bluff body 41 around which the fluid flows in a measuring tube 42, and form a so-called Kármán vortex street, wherein the vortices cause periodic pressure fluctuations, which are detected by a vortex detector 43. For a specific measuring device, the shedding frequency of the vortex is substantially proportional to the flow and the Strouhal number (dimensionless number). Therefore, the flow rate or volume flow rate can be ascertained in a simple manner by determining the vortex frequency. The vortex detector of the vortex flowmeter 40 shown comprises a sensor mark 44, which comprises a stainless steel product according to the invention at least in some sections.

[0085] Figure 6 A further embodiment of a field device according to the invention is shown. The field device shown is a vibrating limit level gauge 50. The device is used as a fill level measuring device and usually has a tuning fork 52 as a vibrating unit 51. However, variants with a single rod or a membrane are also known. During operation, the vibrating unit 51 excites mechanical vibrations by means of an electromechanical transducer unit, which in turn can be provided by, for example, a piezoelectric drive or an electromagnetic drive. It goes without saying that in addition to the examples described above, there are other possibilities that also belong to the invention.

[0086] Various corresponding field devices are manufactured by the applicant and distributed, for example in the case of fill level measuring devices, under the names LIQUIPHANT and / or SOLIPHANT. The underlying measuring principle is known from numerous publications. The excitation of the vibrating unit 51 can be performed using analog and digital methods and is usually performed via an analog electrical oscillation circuit. The electromechanical transducer unit excites the vibrating unit 51 to mechanically oscillate by means of an electrical excitation signal and receives the oscillations and converts them into electrical receiving signals. The electromechanical transducer unit therefore comprises separate drive and receiving units or a combined drive / receiving unit. In this case, the drive / receiving unit is part of a control circuit integrated into the electronic unit, which usually adjusts the excitation signal so that there is a predeterminable phase shift between the excitation signal and the receiving signal.

[0087] Reference numerals list

[0088] Stainless steel products1

[0089] Stainless steel plate 2

[0090] Surface of stainless steel products3

[0091] Adhesion promoter 4

[0092] Enamel coating 5

[0093] Magnetic induction flow meter 6

[0094] Measuring tube 7

[0095] Magnetic field generating equipment8

[0096] Device for tapping off a measuring voltage induced in a medium 9

[0097] Field Device 10

[0098] Component 11

[0099] Device 12 for determining a measured variable of a medium

[0100] Tuning fork 13

[0101] Vortex propeller 14

[0102] Housing 15

[0103] Measuring head 16

[0104] Flange 17

[0105] Coil 18

[0106] Operation circuit 19

[0107] Measurement circuit 20

[0108] Electronics Unit 21

[0109] Magnetic induction flow measurement probe 30

[0110] Precursor 31

[0111] Measuring electrode 32

[0112] Coil 33

[0113] Coil core 34

[0114] Magnetic field generating device 38

[0115] Vortex flowmeter 40

[0116] Baffle 41

[0117] Measuring tube 42

[0118] Vortex detector 43

[0119] Sensor logo 44

[0120] Vibration limit level gauge 50

[0121] Vibrating unit 51

[0122] Tuning fork 52

Claims

1. A stainless steel product (1), comprising: - Stainless steel plates (2), wherein an adhesion promoter (4) is applied to the surface (3) of the stainless steel plate (2), The adhesion promoter (4) comprises a Ni alloy, in particular a NiCr alloy, and / or a Co alloy, in particular a CoCr alloy. Therein, an enamel coating (5) is applied on the adhesion promoter (4).

2. The stainless steel product (1) according to claim 1, in, The adhesion promoter (4) has a nominal layer thickness , Wherein, for the layer thickness , the following conditions apply: ,in particular , and preferably .

3. The stainless steel product (1) according to at least one of the preceding claims, in, The adhesion promoter (4) has a Cr content of at least 10 mass %, in particular at least 15 mass % and at most 45 mass %, in particular at most 40 mass %.

4. Stainless steel product (1) according to at least one of the preceding claims, in, The adhesion promoter (4) has a Ni content of at least 35 mass %, in particular at least 45 mass % and at most 80 mass %, in particular at most 75 mass %.

5. Stainless steel product (1) according to at least one of the preceding claims, in, The adhesion promoter (4) has a Co content of at least 40 mass %, in particular at least 50 mass % and at most 80 mass %, in particular at most 75 mass %.

6. Stainless steel product (1) according to at least one of the preceding claims, in, The enamel coating (5) has a nominal layer thickness , Wherein, for the layer thickness , the following conditions apply: ,in particular , and preferably .

7. Stainless steel product (1) according to at least one of the preceding claims, in, The enamel coating (5), in particular with regard to the layer thickness, meets the requirements of ISO 28721-1 (2019-09).

8. Stainless steel product (1) according to at least one of the preceding claims, in, The adhesion promoter (4) is applied by means of a thermal spraying process, a powder spraying process or a cold gas spraying process.

9. Stainless steel product (1) according to at least one of the preceding claims, in, The surface (3) has an average roughness according to DIN EN ISO 4287:2010 , for the average roughness, the following conditions apply: ,in particular , and preferably .

10. A magnetic induction flow meter (6) for determining a flow rate-related measurement variable of a flowable medium, comprising: - a measuring tube (7) for guiding the medium; wherein the measuring tube (7) comprises, at least in some sections, a stainless steel product (1) according to at least one of the preceding claims, wherein the enamel coating (5) is electrically insulating, - a magnetic field generating device (8) for generating a magnetic field penetrating the measuring tube (7); and - a device (9) for tapping off a measurement voltage induced in the medium.

11. A field device (10) for determining a measured variable of a medium, comprising: - components (11), in particular components in contact with the medium, wherein the component (11) comprises, at least in some sections, a stainless steel product (1) according to any one of claims 1 to 9; and - A device (12) for determining the measured variable of the medium.

12. The field device (10) according to claim 11, in, The assembly (11) comprises a vibratory unit, in particular a tuning fork (13) or a vortex sensor marker (14).

13. The field device (10) according to claim 11 or claim 12, in, The component (11) comprises a housing (15) and / or a measuring head (16).

14. The field device (10) according to at least one of claims 11 to 13, in, The assembly (11) comprises a measuring tube (7).

15. A method for producing a stainless steel product (1), in particular a stainless steel product (1) according to any one of claims 1 to 9, comprising the following method steps: - applying an adhesion promoter (4) to the surface (3) of the stainless steel plate (2), in, The adhesion promoter (4) comprises CoCr and / or NiCr alloy; as well as - Applying an enamel coating (5) to the adhesion promoter (4).

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