WO2019057547A1 - MULTILAYER IRON-BASED SHADE PRODUCTS - Google Patents

Abstract

The present invention relates to a multilayer material capable of shielding against electromagnetic radiation, to a method for the production thereof, to a method for shielding against electromagnetic radiation, static electric and/or static magnetic fields, and to the use of said material for shielding against electromagnetic radiation, static electric and/or static magnetic fields.

Description

 Multilayer iron-based shielding products

Technical area

The present invention relates to an electromagnetic radiation shielding multilayer material, a method for its production, a method for shielding electromagnetic radiation, and the use of the material for shielding electromagnetic radiation, static or dynamic electrical and / or static or dynamic magnetic fields. Technical background

 Electromagnetic interference is described as the effect of electromagnetic quantities on circuits, devices, systems and organisms. This interference can cause a reversible or irreversible impairment, which can lead to an intolerable malfunction of equipment and systems. Electromagnetic interference occurs when electromagnetic energy from a source of interference (transmitter) passes through a coupling to an interference sink (receiver), where it leads to a reduction in function or even destruction. Sources of interference, as a natural or artificially produced source, can lead to the intentional or unintentional emission of electromagnetic energy. In the modern industry, in the energy supply and in the automotive industry, the number of electronic devices, especially with increasing operating frequencies, is steadily increasing. An impairment of the electrical devices with each other can hardly be achieved today by spatial separation or design changes, since the trend is also always on the miniaturization of devices and components. To ensure electromagnetic compatibility between electrical equipment or sources of interference and the environment, electromagnetic shielding is therefore usually used as an effective countermeasure.

Typical screen materials for the treatment of static or low-frequency magnetic fields are usually iron alloys whose main characteristics are the highest possible magnetic permeability and saturation flux density with simultaneously low coercive field strength and remanent flux density. Known shielding acting materials contain a high proportion of nickel, especially in the case of high demands on the shielding properties, and are thus very cost-intensive. In addition, they usually have only low mechanical strength and without additional surface treatment only a low mechanical resistance to corrosive media.

It is therefore an object to provide shielding acting materials that provide an advantageous combination of good mechanical properties, good corrosion resistance and have good shielding properties. In particular, corresponding materials are needed for use in increasing electrification in the automobile.

This problem is solved by the inventive electromagnetic radiation shielding, multilayer material with at least one layer 1, at least containing (in each case in wt .-%) up to 0.400 C,

 up to 3.00 Mn

 up to 4.00 Si,

 up to 2.00 AI,

 up to 1, 00 Cr,

Remainder Fe and unavoidable impurities, said multilayer material having a screen factor S (v) of 25.00 to +120.00 dB in a dynamic magnetic field or a dynamic electromagnetic field having a frequency v of 0, 1 to 1000 kHz wherein the screen factor S (v) is determined from the quotient of the field strength measured at the location of the sink, with or without shielding material located between sink and source.

bestimmt wird, wobei U₂(v) die in der zweiten Spule induzierte Spannung, l^ ) der in der ersten Spule fließende Strom und li₀(v) der Strom in der ersten Spule und U₂o(v) die Spannung in der zweiten Spule, jeweils ohne eingebrachte Probe, sind. The present invention preferably relates to the material according to the invention, wherein the screening factor S (v) is induced by detecting the voltage U ₂ (v) in a second coil, which is induced by a current I 1 in a first coil, while a sample of the shielding multilayer material is located between the first and the second coil and the coils are at a distance of at most 40 mm, is determined. More preferably, the present invention relates to the material according to the invention, wherein the screen factor S (v) according to the equation of the formula (I)

where U ₂ (v) is the voltage induced in the second coil, 1) the current flowing in the first coil and li ₀ (v) is the current in the first coil and U ₂ o (v) is the voltage in the first coil second coil, each without introduced sample, are.

Furthermore, these objects are also achieved by the method according to the invention for producing a multilayer material shielding electromagnetic radiation, by the method according to the invention for shielding electromagnetic radiation and by the inventive use of the material for shielding electromagnetic radiation, static or dynamic electrical and / or static or dynamic magnetic fields.

The material according to the invention will be described in detail below.

The electromagnetic radiation shielding multi-layer material according to the invention contains at least one layer 1. According to a preferred embodiment, the material according to the invention additionally contains a layer 2, the layer 1 and the layer 2 having different compositions. The present invention therefore preferably relates to the material according to the invention, wherein it has a layer 1 and a layer 2 and the layer 1 and the layer 2 have different compositions.

In the multilayer material according to the invention, three layers 1, 2 and 3 are particularly preferred. In this case, it is possible according to the invention that at least one layer, for example 1, 2 and / or 3, has a high screen factor S (v) and the remaining layers 1, 2 and / or 3 are good mechanical characteristics and / or resistant to corrosion. Preferably, layer 1 has a high screen factor S (v) and layers 2 and 3 have good mechanical characteristics and are not susceptible to corrosion. In a further preferred embodiment, layer 2 has a high screen factor S (v) and layers 1 and 3 have good mechanical characteristics and are not susceptible to corrosion. In a further preferred embodiment, layer 3 has a high screen factor S (v) and layers 1 and 2 have good mechanical characteristics and are not susceptible to corrosion.

According to a further preferred embodiment, the material according to the invention comprises a layer 3, the layer 2 being arranged below and the layer 3 above the layer 1. The thicknesses of the layers present in the multilayer material are generally freely selectable. In a preferred embodiment, the thickness of the layer 1 comprises 40 to 90% and the thicknesses of the layers 2 and 3 a total of 10 to 60% of the total thickness of the material, and the sum of the thicknesses 1, 2 and 3 gives 100% each. The layer 1 preferably has 60 to 80% and the thicknesses of the layers 2 and 3 a total of 20 to 40% of the total thickness of the material.

Viewed in absolute terms, the total thickness of the material according to the invention can have any thickness that appears appropriate to the person skilled in the art, for example 0.5 to 10 mm. Thus, the present invention preferably relates to the material according to the invention, wherein the layer 1 has a thickness of 0, 1 to 9 mm. More preferably, the layers 2 and 3 preferably present have thicknesses of 0.2 to 4 mm. The thicknesses of the layers 2 and 3 may be the same or different according to the invention.

In a further embodiment of the material according to the invention, in addition to the layers 1, 2 and 3, there are further layers. For example, in one embodiment of the material according to the invention in addition to the layers 1, 2 and 3, a layer L4 below the layer 2 before. Preferably, the thickness of the layer 1 in this embodiment is 40 to 90% and the thicknesses of the layers 2, 3 and L4 in total 10 to 60% of the total thickness of the material, and the sum of the thicknesses 1, 2, 3 and L4 results respectively 100%. In a further embodiment, in addition to the layers 1, 2, 3, L4, there is a layer L5 above the layer 3. Preferably, the thickness of the layer 1 in this embodiment, 40 to 90% and the thicknesses of the layers 2, 3, L4 and L5 in total 10 to 60% of the total thickness of the material, and the sum of the thicknesses 1, 2, 3, L4 and L5 gives 100% each. In a further embodiment, in addition to the layers 1, 2, 3, L4 and L5, there is a layer L6 below the layer L4. Preferably, the thickness of the layer 1 in this embodiment, 40 to 90% and the thicknesses of the layers 2, 3, L4 and L5 in total 10 to 60% of the total thickness of the material, and the sum of the thicknesses 1, 2, 3, L4 , L5 and L6 each gives 100%. In a further embodiment, in addition to the layers 1, 2, 3, L4, L5 and L6, there is a layer L7 above the layer L5. Preferably, the thickness of the layer 1 in this embodiment 40 to 90% and the thicknesses of the layers 2, 3, L4, L5 and L6 in total 10 to 60% of the total thickness of the material, and the sum of the thicknesses 1, 2, 3rd , L4, L5, L6 and L7 each gives 100%. In addition to the described layers 1, 2 and 3, according to the invention further layers may be present, for example on the sides of the layers 2 or 3 which are remote from the layer 1 or between the layers 1 and 2 or 1 and 3.

Location 1

Layer 1 of the material according to the invention contains at least (in each case in% by weight) up to 0.400 C,

 up to 3.00 Mn,

 up to 4.00 Si,

 up to 2.00 AI,

 up to 1, 00 Cr,

 Residual Fe and unavoidable impurities.

In the context of this mentioned analysis, layer 1 of the material according to the invention can generally contain any steel grade known to the person skilled in the art, which offers the material according to the invention advantageous mechanical properties, good shielding properties and / or advantageous corrosion protection. In a preferred embodiment, the layer 1 additionally contains at least one alloying element selected from the group consisting of As, Cu, Nb, Ti and Sn. In a preferred embodiment, layer 1 of the material according to the invention therefore contains (in each case in% by weight) up to 0.400, more preferably up to 0.1, more preferably up to 0.05 C, up to 3.00, particularly preferably up to 0.5, more preferably up to 0.3 Mn, up to 4.00, more preferably up to 0.5, most preferably up to 0.1 Si,

 up to 2.00, more preferably up to 0.1, more preferably up to 0.01 Al, up to 1.00, more preferably up to 0.1, even more preferably up to 0.01 Cr, up to 0, 1, more preferably up to 0.05 P,

 up to 0, 1, more preferably up to 0.01 S,

 up to 0, 1, more preferably up to 0.08 Cu,

 up to 0, 1, more preferably up to 0.001 N,

 up to 0, 1, more preferably up to 0.05 Sn,

 Residual Fe and unavoidable impurities.

A possible lower limit for the alloying elements C, Mn, Si, Al, Cr, P, S, Cu, N or Sn is, for example, at least 0.0001% by weight, preferably at least 0.001% by weight.

The alloying elements Si, Al, Cr and Co are particularly preferably not present in this embodiment, ie. their amounts are below the analytical detection limit.

In a further preferred embodiment, layer 1 of the material according to the invention (in each case in% by weight) contains:

0.001 to 0.5, more preferably 0, 1 to 0.3 C,

 0, 1 to 3.00, more preferably 0.5 to 2.00 Mn,

 0.01 to 0.5, more preferably 0, 1 to 0.4 Si,

 0.01 to 0, 1, more preferably 0.01 to 0.08 Al,

 0.01 to 0.5, more preferably 0, 1 to 0.4 Cr,

 0.001 to 0.1, more preferably 0.001 to 0.05 P,

 0.001 to 0, 1, more preferably 0.002 to 0.01 S,

 0.01 to 0.5, more preferably 0.02 to 0.3, Cu

 0.001 to 0, 1, more preferably 0.001 to 0.01 N,

 0.001 to 0.1, more preferably 0.002 to 0.05 Sn,

0.001 to 0.1, more preferably 0.002 to 0.05 Nb, 0.001 to 0.3, more preferably 0.01 to 0.08,

 0.001 to 0, 1, more preferably 0.02 to 0.04, As,

 0.0001 to 0, 1, more preferably 0.0001 to 0.008 B,

 0.001 to 0, 1, more preferably 0.002 to 0.008 Mo,

 0.001 to 0.2, more preferably 0.001 to 0.15 Ni,

 0.001 to 0, 1, more preferably 0.001 to 0.02 V,

 Residual Fe and unavoidable impurities.

In the material according to the invention, preferably a ferritic microstructure is present in layer 1, which may also have fractions of retained austenite and / or bainite.

In particular, the layer 1 has a structure containing 0 to 100 wt .-%, preferably 5 to 95 wt .-%, ferrite, 0 to 95 wt .-%, preferably 0 to 60 wt .-%, bainite, 0 to 20 wt %, preferably 5 to 20% by weight perlite, 0 to 100% by weight, preferably 3 to 35% by weight, martensite or up to 100% by weight martensite, 0 to 20% by weight, preferably 2 to 15 wt .-%, retained austenite and optionally carbides, wherein the respective sum 100 wt .-% results on.

Layer 1 of the material according to the invention has, for example, a thickness of 0, 1 to 9 mm, preferably 0, 1 to 6 mm. The present invention therefore preferably relates to the material according to the invention, wherein the layer 1 has a thickness of 0, 1 to 9 mm, particularly preferably 0, 1 to 6 mm.

Layer 1 of the material according to the invention, and thus preferably also the material according to the invention itself, can be used in all dimensions which the expert considers suitable for the respective application. By way of example, the material according to the invention is present as a sheet-metal semifinished product, for example as a coil, sheet metal, sheet, plate, etc. According to the invention, the material can be brought into any shape known to those skilled in the art. The material according to the invention can be reshaped by forming processes known to those skilled in the art.

In layer 1 of the material according to the invention, layer 1 preferably has a particle size of 2 to 200 μm, preferably 2 to 100 μm, more preferably 5 to 30 μm. This preferred grain size according to the invention contributes, for example, to improve the magnetic properties.

Location 2

In a preferred embodiment of the present invention, the material contains a layer 2. Preferably, the layer 2 is below the layer 1. More preferably, layer 2 has the same values in terms of width and length as layer 1 of the material according to the invention, so that the layers 1 and 2 are preferably arranged flush with each other. Layer 2 of the material according to the invention may in general have any thickness that appears appropriate to the person skilled in the art, for example 0.2 to 4 mm. Layer 2 of the material according to the invention may in general contain any steel grade known to the person skilled in the art which gives the material according to the invention advantageous mechanical properties, good shielding properties and / or advantageous corrosion protection.

In a preferred embodiment, the layer 2 additionally contains at least one alloying element selected from the group consisting of As, Cu, Nb, Ti and Sn. In a preferred embodiment, layer 2 of the material according to the invention therefore contains (in each case in% by weight): up to 0.400, more preferably up to 0.1, more preferably up to 0.05 C, up to 3.00, particularly preferably up to to 0.5, more preferably up to 0.3 Mn,

 up to 4.00, more preferably up to 0.5, particularly preferably up to 0.1 Si,

 up to 2.00, more preferably up to 0.1, more preferably up to 0.01 Al, up to 1.00, more preferably up to 0.1, even more preferably up to 0.01 Cr, up to 0, 1, more preferably up to 0.05 P,

 up to 0, 1, more preferably up to 0.01 S,

 up to 0, 1, more preferably up to 0.08 Cu,

 up to 0, 1, more preferably up to 0.001 N,

 up to 0, 1, more preferably up to 0.05 Sn,

 Residual Fe and unavoidable impurities. A possible lower limit for the alloying elements C, Mn, Si, Al, Cr, P, S, Cu, N or Sn is, for example, at least 0.0001% by weight, preferably at least 0.001% by weight.

The alloying elements Si, Al, Cr and Co are particularly preferably not present in this embodiment, ie. their amounts are below the analytical detection limit.

In a further preferred embodiment, layer 2 of the material according to the invention contains a stainless steel, preferably a ferritic stainless steel, for example contains layer 2 (in% by weight):

0.001 to 0.8, more preferably 0.001 to 0.5, particularly preferably 0.001 to 0.4, C, 0.1 to 4.0, particularly preferably 0.2 to 2.0, particularly preferably 0.5 to 1.5 , Si,

 0.1 to 12, more preferably 0.2 to 2.0, particularly preferably 0.5 to 1.5, Mn,

0.01 to 0.05, particularly preferably 0.02 to 0.04, P, 0.001 to 0.05, more preferably 0.001 to 0.04, particularly preferably 0.01 to 0.03, S, 0.1 to 30, particularly preferably 12.0 to 24.0, particularly preferably 15.0 to 20, 0, Cr, 0, 1 to 4.00, particularly preferably 0.5 to 1.5, particularly preferably 0.8 to 1, 4, Nb,

 0.01 to 0.8, more preferably 0, 1 to 0.5, particularly preferably 0.2 to 0.4, Ti,

 Residual Fe and unavoidable impurities.

The present invention therefore preferably relates to the material according to the invention, wherein it additionally has at least one layer 2 containing (in each case in% by weight): up to 0.400, particularly preferably up to 0.1, in particular preferred up to 0.05 C, up to 3.00, more preferably up to 0.5, particularly preferably up to 0.3 Mn, up to 4.00, particularly preferably up to 0.5, particularly preferably up to 0, 1 Si,

 up to 2.00, more preferably up to 0.1, more preferably up to 0.01 Al, up to 1.00, more preferably up to 0.1, even more preferably up to 0.01 Cr, up to 0, 1, more preferably up to 0.05 P,

 up to 0, 1, more preferably up to 0.01 S,

 up to 0, 1, more preferably up to 0.08 Cu,

 up to 0, 1, more preferably up to 0.001 N,

 up to 0, 1, more preferably up to 0.05 Sn,

 Residual Fe and unavoidable impurities, or a stainless steel, preferably a ferritic stainless steel, and the layer 1 and the layer 2 have different compositions.

In the material according to the invention, preferably a ferritic microstructure is present in layer 2. Location 3

In a further preferred embodiment of the present invention, the material contains a layer 3. Preferably, the layer 3 is above the layer 1. More preferably, layer 3 has the same values in width and length as layer 1 of the material according to the invention, so that the layers 1 and 3 are preferably arranged flush with each other. The material according to the invention particularly preferably contains a layer 2 and a layer 3. The layer 2 is preferably below the layer 1 and the layer 3 above the layer 1. Further preferably, the layers 2 and 3 have the same values in terms of width and length as the layer 1 of the material according to the invention, so that the layers 1, 2 and 3 are preferably arranged flush with each other. Layer 3 of the material according to the invention may in general have any thickness that appears appropriate to the person skilled in the art, for example 0.2 to 4 mm. Layer 3 of the material according to the invention may in general contain any steel grade known to the person skilled in the art, which offers the material according to the invention advantageous mechanical properties, good shielding properties and / or advantageous corrosion protection.

In a preferred embodiment, layer 3 of the material according to the invention therefore contains (in each case in% by weight): up to 0.400, more preferably up to 0.1, more preferably up to 0.05 C, up to 3.00, particularly preferably up to to 0.5, more preferably up to 0.3 Mn,

 up to 4.00, more preferably up to 0.5, particularly preferably up to 0.1 Si,

 up to 2.00, more preferably up to 0.1, more preferably up to 0.01 Al, up to 1.00, more preferably up to 0.1, even more preferably up to 0.01 Cr, up to 0, 1, more preferably up to 0.05 P,

 up to 0, 1, more preferably up to 0.01 S,

 up to 0, 1, more preferably up to 0.08 Cu,

 up to 0, 1, more preferably up to 0.001 N,

 up to 0, 1, more preferably up to 0.05 Sn,

 Residual Fe and unavoidable impurities.

A possible lower limit for the alloying elements C, Mn, Si, Al, Cr, P, Cu, N or Sn is, for example, at least 0.0001% by weight, preferably at least 0.001% by weight.

The alloying elements Si, Al, Cr and Co are particularly preferably not present in this embodiment, ie. their amounts are below the analytical detection limit. In a further preferred embodiment, layer 3 of the material according to the invention contains a stainless steel, preferably a ferritic stainless steel, for example contains layer 3 (in% by weight):

0.001 to 0.8, more preferably 0.001 to 0.5, particularly preferably 0.001 to 0.4, C, 0.1 to 4.0, particularly preferably 0.2 to 2.0, particularly preferably 0.5 to 1.5 , Si,

 0.1 to 12, more preferably 0.2 to 2.0, particularly preferably 0.5 to 1.5, Mn,

 0.01 to 0.05, particularly preferably 0.02 to 0.04, P,

0.001 to 0.05, particularly preferably 0.001 to 0.04, particularly preferably 0.01 to 0.03, S, 0, 1 to 30, more preferably 12.0 to 24.0, particularly preferably 15.0 to 20.0, Cr,

 0, 1 to 4.00, particularly preferably 0.5 to 1.5, particularly preferably 0.8 to 1, 4, Nb,

 0.01 to 0.8, more preferably 0, 1 to 0.5, particularly preferably 0.2 to 0.4, Ti,

 Residual Fe and unavoidable impurities.

According to the invention, the layer 1 and the layer 3 preferably have different compositions. In the material according to the invention, preferably a ferritic microstructure is present in layer 3.

In a preferred embodiment of the material according to the invention, layer 3 has the same composition as layer 2. In a further preferred embodiment of the material according to the invention, layer 3 has a different composition than layer 2.

In addition to the layers 1, 2 and 3, the material according to the invention may optionally contain further layers, in particular layers 4, 5, 6 and 7. The layer 4 and optionally the layer 6 below the layer 2 and the layer 5 and optionally the layer 7 above the layer 3 are arranged. The layers which may be present may correspond to layers 1, 2 and / or 3 in terms of thickness, compositions, structural compositions, etc.

The multilayer material according to the invention is distinguished by particularly good shielding properties.

The material according to the invention has a screen factor S (v) of 25.00 to +120.00 dB, preferably 30.00 to 120.00 dB in a dynamic, magnetic field or a dynamic electromagnetic field with at a frequency v of 0, 1 to 1000 kHz, preferably 0, 1 to 400 kHz, particularly preferably 0, 1 to 200 kHz, on.

The screen factor S (v) is preferably determined by measuring the voltage U ₂ (v) in a second coil induced by a current li (v) in a first coil while interposing a sample of the shielding multilayer material the first and the second coil is located and the coils are at a distance of at most 40 mm.

The screen factor S (v) is particularly preferably calculated according to the equation of the formula (I)

(I)

bestimmt, wobei U₂(v) die in der zweiten Spule induzierte Spannung, l^ ) der in der ersten Spule fließende Strom und l₁₀(v) der Strom in der ersten Spule und U₂o(v) die Spannung in der zweiten Spule, jeweils ohne eingebrachte Probe, sind.

where U ₂ (v) is the voltage induced in the second coil, 1) the current flowing in the first coil, and ₁₀ (v) the current in the first coil and U ₂ o (v) the voltage in the second coil Coil, each without introduced sample, are.

More preferably, the screen attenuation S (v) of the material according to the invention is determined by a method, comprising at least the following steps:

(A) providing a first coil Sl having a first inductance 1, which is connected to a first signal generator SGI and a device for current measurement li (v) to a first circuit,

(B) providing a second coil S2 with a second inductance 2, which is connected to a device for measuring voltage U ₂ (v) to a second circuit, wherein the coils Sl and S2 are spatially arranged to each other so that they are on the same axis of rotation lie and a free space is formed between them,

 (C) introducing a sample of the material according to the invention into the free space,

 (D) generation of a sinusoidal voltage with a frequency v of 0, 1 to 1000 kHz by the first signal generator SG 1 in the first coil Sl,

 (E) measuring the current value li (v) in the first circuit,

(F) measuring the voltage U ₂ (v) in the second circuit,

wobei lio(v) der Strom im ersten Stromkreis und U₂₀(v) die Spannung im zweiten Stromkreis, jeweils ohne eingebrachte Probe, sind . (G) Determining the screen factor S (v) via the equation of the formula (I)

where lio (v) is the current in the first circuit and U ₂₀ (v) is the voltage in the second circuit, each without a sample inserted.

Step (A):

 Step (A) comprises providing a first coil Sl having a first inductance 1, which is connected to a first signal generator SGI and a device for measuring current to a first circuit.

First, a coil Sl with an inductance 1 is provided. Preferably coils corresponding to coils S1 having 1 to 100, preferably 15 to 30 windings are used. More preferably, these windings are on a ring of an electrically insulating material, such as plastic, in particular polyamide, before. The diameter of the coil Sl is preferably 60 to 80 mm. The winding of the coil Sl is preferably made of an electrically conductive wire, in particular a stranded wire made of copper. More preferably, the electrically conductive wire is electrically insulated on the outside, for example by an electrically insulating plastic coating. The length of the Wire, from which the winding of the first coil Sl is constructed, according to the invention is preferably 3 to 7 m. The coil has an inductance Sl 1 of example 4 ^■ 10 ^-2 to 1.5 10 ³ μΗ, preferably 30 to 60 μΗ on. The coil S1 can generally be arranged in any possible way. Preferably, the coil Sl is arranged so that the winding plane is aligned parallel to the ground or a table top on which the device is constructed.

Furthermore, according to the invention, a first signal generator SGI is used. This signal generator SGI is used according to the invention to generate a magnetic field with a frequency v (measuring frequency) in the first coil S1. According to the invention, it is possible to use any signal generator known to the person skilled in the art which is suitable for generating a corresponding frequency, for example a National Instruments "Virtual Bench." The signal generator SGI preferably uses a frequency v of 0, 1 to 200 kHz. for example, 0, 1 kHz, 0.2 kHz, 0.5 kHz, 1, 0 kHz, 2.0 kHz, 5.0 kHz, 10.0 kHz, 20.0 kHz, 50.0 kHz, 100.0 kHz or 200 kHz generated.

Furthermore, there is a device for measuring current in the first circuit. Suitable devices for current measurement are known per se to those skilled in the art, for example a Chauvin Arnoux Ma 200 current clamp. Particularly preferably, an oscilloscope is used.

In the first circuit, further devices known to the person skilled in the art may be present, for example amplifiers or capacitors for reactive power compensation.

The elements present in the first circuit, i. at least first coil Sl, first signal generator SGI, means for measuring current and optionally further elements are preferably connected in series to a first circuit. The electrical connections in the first circuit can generally be carried out in any manner known to those skilled in the art. The electrical connections are preferably carried out by cable connections, in particular shielded BNC connections.

Step (B):

Step (B) of the method comprises providing a second coil S2 with a second inductance 2 connected to a voltage measuring device, the coils S1 and S2 being arranged spatially relative to each other so that they lie on the same axis of rotation and between them on Freiraum is formed. In general, all coils which appear suitable to the person skilled in the art can be used. Coils with 1 to 400, preferably 100 to 200, windings are preferably used as the coil S2. More preferably, these windings are on a ring made of an electrically insulating material, such as plastic from polyamide. The diameter of the coil S2 is preferably 20 to 40 mm. In a preferred embodiment, a coil is used in which windings are wound around a fixed core, for example a ferrite core. The winding of the coil S2 is preferably made of an electrically conductive wire, in particular a copper wire. More preferably, the electrically conductive wire is electrically insulated on the outside, for example by an electrically insulating plastic coating. The length of the wire from which the winding of the first coil S2 is constructed is preferably 1 to 2 m.

The coil S2 has an inductance 2 of, for example, 0.2 to 9.0 ^■ 10 ³ μΗ, preferably 200 to 800 μΗ, on. The inductance 2 of the coil S2 is preferably selected such that there are no resonances in the frequency range to be measured due to the intrinsic capacitance of the preferably used BNC cables.

According to the invention, the coil S2 is arranged such that the coils S1 and S2 are spatially arranged relative to each other such that they lie on the same axis of rotation and a free space is formed between them. In this context, "on the same axis of rotation" means that the two coils are spatially positioned relative to one another so that a common axis passes through the centers of the annular coils It is further preferred for the coil S1 to be located above the coil S2, wherein a clearance is formed between the two coils, which is created such that a sample of the potentially shielding material can be introduced into it Distance, that is the free space, between the coils Sl and S2 40 to 60%, preferably 45 to 55%, for example 50%, of the diameter of the coil 1. More preferably, the free space has a width or height of 10 to 60 mm up.

Furthermore, there is a device for voltage measurement in the second circuit, for example devices known per se to the person skilled in the art, for example by a HAMEG HM022 digital oscilloscope.

In the second circuit, further elements may be present, for example high-impedance terminating resistors. The elements present in the second circuit, ie at least second coil S2, high-resistance terminating resistor and possibly further elements are preferably connected in series with a second circuit. To the coil S2, the device for voltage measurement is preferably connected in parallel. The electrical connections for voltage measurement on coil 2 can generally be made in any manner known to those skilled in the art. The electrical connections are preferably carried out by cable connections, in particular shielded BNC connections.

The first circuit and the voltage measurement at coil S2 are each formed by means of shielded electrical connections, preferably cable connections, in particular shielded BNC connections.

Step (C):

 Step (C) of the method comprises introducing a sample of the multilayer material into the clearance.

This step (C) can generally be carried out in any manner known to those skilled in the art. The introduction can be done manually or automatically. The method is preferably performed to measure the shielding properties of flat materials, i. H . the materials to be tested have a much greater extension in length and width compared to their thickness. The sample to be examined preferably has a square base area. More preferably, the edge length of this square at least five times the diameter of the coil 1.

Preferably, the sample has a thickness of 0.01 to 6 mm. More preferably, the potentially shielding product is a flat steel product, for example a hot or cold strip or boards obtained therefrom.

It is preferred that the sample to be measured is fixed between the two coils for the measurement by methods known to those skilled in the art, for example by means of a corresponding permanently installed guide in the free space between the two coils S 1 and S 2.

The distance between the sample and the coils S 1 and S 2 is preferably up to 40 mm in each case. It is inventively preferred that the sample to be examined is grounded during the measurement. Step (D):

 Step (D) of the method comprises the generation of a sinusoidal voltage with a frequency v of 0, 1 to 1000 kHz, preferably 0, 1 to 400 kHz, more preferably 0, 1 to 200 kHz, by the first signal generator SG 1 in the first Coil Sl.

Step (D) of the method is preferably carried out after the sample to be measured has been introduced into the free space between the two coils.

The sinusoidal voltage generated in the coil S1 is an alternating voltage with a frequency v of preferably 0.1 to 200 kHz, see also step (A) of the method. Devices and methods for generating a corresponding sinusoidal voltage of corresponding frequency are known per se to the person skilled in the art, for example the "Virtual Bench" from National Instruments The frequency v generated in step (D) is a so-called measuring frequency is generated in coil S1 at a certain current value \\ {v} In the second coil S2 it is then measured which voltage U ₂ (v) is generated by the resulting magnetic field by a mathematical comparison of these values in the presence of the to be measured Sample with the values in the absence of the sample can be deduced on the screen factor of the sample.

Steps):

Step (E) of the method involves measuring the current \ \ {v} in the first circuit.

Devices and methods for measuring the current strength {V} in the first circuit are known per se to the person skilled in the art, for example a Chauvin Arnoux Ma 200 current clamp. It should be noted that the current li (v) is measured in the first circuit while the sample to be measured is between the coils Sl and S2. The obtained measured values can be noted manually. Preferably, the device for measuring the current intensity li () in the first circuit is connected to a data processing system, so that the storage and processing of the data obtained is carried out electronically. Step (F):

Step (F) of the method comprises measuring the voltage U ₂ (v) on coil 2.

Devices and methods for measuring the voltage U ₂ (v) on coil 2 are known per se to those skilled in the art, for example a HAMEG HMO2022 digital oscilloscope. It is essential to the invention that the voltage U ₂ (v) at coil 2 is measured, while the sample to be measured is located between the coils S 1 and S 2. The obtained measured values can be noted manually. Is preferred the device for measuring the voltage U ₂ (v) connected to coil 2 with a data processing system, so that the storage and processing of the data obtained is carried out electronically.

Step (G):

Step (G) of the method comprises determining the screen attenuation S (v) via the equation of

wobei lio( ) der Strom im ersten Stromkreis und U₂o(v) die Spannung an Spule 2, jeweils ohne eingebrachte Probe, sind. Formula (I)

where lio () is the current in the first circuit and U ₂ o (v) is the voltage across coil 2, each without a sample inserted.

Step (G) of the method is preferably carried out with the aid of a data processing system. Methods and devices for this purpose are known per se to the person skilled in the art. The determination of \ Q {V), d. H . Current in the first circuit, and U ₂ o (v), d. H. Voltage at the second coil S2, takes place in each case as described in steps (E) and (F), in contrast, no sample between the coils Sl and S2 is present.

During the measurement, the material according to the invention is preferably used in a thickness of 0.01 to 6 mm, preferably 0.03 to 4 mm.

The present invention therefore preferably relates to the material according to the invention, wherein it has a thickness of 0.01 to 6 mm, preferably 0.03 to 4 mm, during the measurement. The present invention further relates to the method for producing the material according to the invention, wherein the individual layers are combined to form a sandwich material and subsequently rolled into the multilayer material. Such a method is generally disclosed in DE 10 2005 006 606 B3. For this purpose, preferably as a starting material for the inventive method for producing the multilayer material cuboidal plates with the compositions according to position 1, layer 2, etc. used, which have been prepared for example by pre-blocking or by rough rolling of slabs. It is also conceivable to use slabs of greater thickness directly as plate material, if this is permitted by the available rolling machinery. The stacked plates each have different material properties according to the layers described above, wherein the sequence of plates in a plate pack can preferably be organized so that in a plate package two or more plates of the same kind can be present. This is the case, for example, when a three-ply tape is to be produced, in which the layers 2 and 3 applied to the ply 1 each consist of the same material. After the plates are as close to each other as possible dense and with as full contact as possible, the relative position of the plates is fixed by welding. An exclusion of trapped air between the plates can thereby be supported by the fact that the superimposed plates of the plate pack are pressed against each other before and during welding. The welding is preferably carried out so that the plates of the plate package are gas-tight welded together. This has the advantage that even with hindsight, for example, as a result of a delay of the plates during their transport, no air or other interfering gases can get between the plates of the plate package. After welding, the plate pack obtained in accordance with the invention is heated to a hot rolling start temperature which is preferably in the range of 1100 to 1300 ° C. conventional for steels. Depending on the types of steel being processed, the range of heating may preferably be 1200 to 1300 ° C. The heated plate stacks are then hot rolled. The plate packs are rolled to a hot strip of desired thickness. The present invention therefore relates in particular to the process according to the invention, wherein the rolling is carried out as hot rolling.

The multilayer shielding material according to the invention can be used uncoated. The material according to the invention is used coated in a preferred embodiment. Corresponding coatings, which protect against corrosion in particular, are known per se to the person skilled in the art and are preferably based on zinc or aluminum or zinc alloys or aluminum alloys, and may additionally contain magnesium and / or silicon. The present invention therefore preferably relates to the material according to the invention, wherein it has a surface coating. The coating can be applied to the material according to the invention, in particular to at least one of the outer layers, in general by all methods known to the person skilled in the art, for example by electrolytic coating, vapor deposition or hot dip method. The coating can be present on one or both sides. If the shielding material of the invention provided with a corresponding surface coating and used, it is advantageously better protected against corrosion. Another advantage of the shielding material of the present invention is that it has improved electrical conductivity compared to materials known in the art so that high frequency fields can be more effectively shielded. The present invention also relates to a method for shielding electromagnetic radiation, dynamic or static electrical and / or dynamic or static magnetic fields, wherein the source and / or sink are at least partially surrounded by a material according to the invention. In this method according to the invention, the source and / or sink of the electromagnetic radiation, of the dynamic or static electrical and / or dynamic or static magnetic fields is at least partially surrounded by the shielding material according to the invention at least partially. A partial surrounding is useful or necessary, for example, if the source and / or sink must be accessible during operation, for example, by supply and / or discharge and / or operation. According to the invention it is also possible that the source and / or sink is completely surrounded by the shielding material according to the invention. Details and preferred embodiments, which have been mentioned to the material according to the invention, should also be applied here accordingly. The present invention also relates to the use of the material according to the invention for shielding electromagnetic radiation, dynamic or static electrical and / or dynamic or static magnetic fields.

Electromagnetic, dynamic or static electrical and / or dynamic or static magnetic fields are intentionally or unwillingly generated by the use and operation of certain magnetic, electrical or electronic devices.

The present invention relates in a particular embodiment, the inventive use, in addition, a high mechanical strength of the material is given. A particular advantage of the present invention is therefore that it is possible to provide a material which according to the invention preferably has good mechanical properties and / or good corrosion protection in addition to a high shielding effect.

The present invention further preferably relates to the use according to the invention, wherein buildings, in particular safety-relevant buildings, rooms, laboratories, production facilities, server cabinets, control cabinets, plug connections, holders and housings, for example for power electronics, computers, communication electronics, alarm systems, safety technology, fire and gas detectors, Protective covers, charging stations, kitchen appliances, medical devices, electronic devices, preferably in automobiles, electronic components, radios, magnetic applications, for example permanent magnets, electronic components and / or batteries, such as non-rechargeable batteries or accumulators, shielded or the shielding material as ceilings - And / or wall panels, as floor coverings, as cable channels, is used in metrology.

Examples

 The following embodiments serve to illustrate the invention. example 1

A sandwich material is produced from the following layers 1, 2 and 3: Layer 1: steel A, thickness 80 mm (62%), width 150 mm, length 150 mm Table 1: Analysis of steel A, data in% by weight, balance Fe

Layer 2 and 3: Material B, thickness 25 mm (19% each), width 150 mm, length 150 mm Table 2: Analysis of material B, data in% by weight, balance Fe

The sandwich material is rolled at a temperature of 850 to 950 ° C. The thickness of the multilayer material after rolling is 1.0 mm. Tensile strength, yield strength, shield factor S (v) and corrosion resistance are determined on the material, see Table 4 and Table 5.

Example 2

 From the following layers 1, 2 and 3 a sandwich material is produced:

Layer 1: Material B, thickness 120 mm (80%), width 150 mm, length 150 mm, for analysis see example 1

Layer 2 and 3: Stainless steel, thickness 15 mm (10% each), width 150 mm, length 150 mm Table 3: Analysis of stainless steel, data in% by weight, remainder Fe

The sandwich material is rolled at a temperature of 850 to 950 ° C. The thickness of the multilayer material after rolling is 1.0 mm. Tensile strength, yield strength, shield factor S (v) and corrosion resistance are determined on the material, see Table 4 and Table 5.

Example 3

 Layer 1: steel A, thickness 90 mm (69%), width 150 mm, length 150 mm, analysis see example 1, layer 2: stainless steel, thickness 15 mm (12 %), Width 150 mm, length 150 mm, analysis see example 2, position 3: material B, thickness 25 mm (19%), width 150 mm, length 150 mm, for analysis see example 1

The sandwich material is rolled at a temperature of 850 to 950 ° C. The thickness of the multilayer material after rolling is 1, 0 mm. The tensile strength, yield strength and corrosion resistance are determined on the material, see Table 4. Tensile strength and yield strength are determined by methods known to those skilled in the art. The corrosion resistance is assessed visually. The screen factor S (v) is determined by the method mentioned in the description.

Table 4: Tensile strength, yield strength and corrosion resistance of the materials of Examples 1, 2 and 3

 Tensile strength Tensile strength

 No corrosion resistance

[N / mm ² ] [N / mm ² ]

 Example 1 450 300 no

 Example 2 300 126 yes

Example 3 530 350 yes, one-sided Table 5: Screening factors S (v) of the materials of Examples 1 and 2

 n .b. not determined

Industrial Applicability

 The shielding material according to the invention can advantageously be used for shielding electromagnetic radiation, static or dynamic electrical and / or static or dynamic magnetic fields.

Claims

claims Electromagnetic radiation shielding, multilayer material with at least one layer 1, at least containing (in each case in% by weight) up to 0.400 C, up to 3.00 Mn, up to 4.00 Si, up to 2.00 AI, up to 1.00 Cr, Remainder Fe and unavoidable impurities, said multilayer material having a screen factor S (v) of 25.00 to +120.00 dB in a dynamic magnetic field or a dynamic electromagnetic field having a frequency v of 0, 1 to 1000 kHz wherein the screen factor S (v) is determined from the quotient of the field strength measured at the location of the sink, with or without shielding material located between sink and source. Material according to claim 1, characterized in that it additionally comprises at least one layer 2 containing (in each case in% by weight): up to 0.400, particularly preferably up to 0, 1, in particular preferred up to 0.05 C, up to 3.00, more preferably up to 0.5, especially preferably up to 0.3 Mn, up to 4.00, more preferably up to 0.5, particularly preferably up to 0.1 Si, up to 2.00, more preferably up to 0, 1, especially preferably up to 0.01 Al, up to 1.00, more preferably up to 0, 1, especially preferably up to 0.01 Cr, up to 0, 1, more preferably up to 0.05 P, up to 0, 1, more preferably up to 0.01 S, up to 0, 1, more preferably up to 0.08 Cu, up to 0, 1, more preferably up to 0.001 N, up to 0, 1, more preferably up to 0.05 Sn, Residual Fe and unavoidable impurities, or a stainless steel, preferably a ferritic stainless steel, and the layer 1 and the layer 2 have different compositions. Material according to claim 2, characterized in that it additionally contains a layer 3, wherein the layer 2 below and the layer 3 above the layer 1 are arranged. Material according to claim 3, characterized in that the thickness of the layer 1 40 to 90% and the thicknesses of the layers 2 and 3 in total 10 to 60% of the total thickness of the material and the sum of the thicknesses 1, 2 and 3 each 100% results. Material according to claim 3 or 4, characterized in that the layer 3 has the same composition as the layer 2. Material according to one of claims 1 to 5, characterized in that the screening factor S (v) according to the equation of the formula (I)

where U ₂ (v) is the voltage induced in the second coil, 1) the current flowing in the first coil and li ₀ (v) is the current in the first coil and U ₂ o (v) is the voltage in the first coil second coil, each without introduced sample, are. Material according to one of claims 1 to 6, characterized in that the layer 1 has a thickness of 0, 1 to 9 mm. Material according to one of claims 1 to 7, characterized in that layer 1 contains a microstructure containing 0 to 100 wt .-%, preferably 5 to 95 wt .-%, ferrite, 0 to 95 wt .-%, preferably 0 to 60 wt Wt .-%, bainite, 0 to 20 wt .-%, preferably 5 to 20 wt .-% pearlite, 0 to 100 wt .-%, preferably 3 to 35 wt .-%, martensite or up to 100 wt .-% Martensite, 0 to 20 wt .-%, preferably 2 to 15 wt .-%, retained austenite and optionally carbides, wherein the respective sum 100 wt .-% results. Material according to one of claims 1 to 8, characterized in that in layer 1, a particle size of 2 to 200 μιη, preferably 2 to 100 μιη, more preferably 5 to 30 μιη, is present. A method for producing an electromagnetic radiation shielding, multilayer material according to any one of claims 1 to 9, characterized in that the individual layers are combined into a sandwich material and then rolled into the multilayer material. 11. The method according to claim 10, characterized in that the rolling is carried out as hot rolling. 12. A method for shielding electromagnetic radiation, dynamic or static electrical and / or dynamic or static magnetic fields, wherein the source and / or sink are at least partially surrounded by a material according to any one of claims 1 to 9. 13. Use of the material according to one of claims 1 to 9 for the shielding of electromagnetic radiation, dynamic or static electrical and / or dynamic or static magnetic fields. 14. Use according to claim 13, characterized in that buildings, in particular safety-relevant buildings, rooms, laboratories, production facilities, server cabinets, control cabinets, plug connections, holders and housings, for example for power electronics, computers, communication electronics, alarm systems, security technology, fire and gas detectors, Protective covers, charging stations, kitchen appliances, medical devices, electronic devices, preferably in automobiles, electronic components, radios, magnetic applications, for example permanent magnets, electronic components and / or batteries, such as non-rechargeable batteries or accumulators, shielded or the shielding material as ceilings - And / or wall panels, as floor coverings, as cable channels, is used in metrology.