EP3714072A1 - Grain-oriented electrical steel strip and method for producing such an electrical steel strip - Google Patents
Grain-oriented electrical steel strip and method for producing such an electrical steel stripInfo
- Publication number
- EP3714072A1 EP3714072A1 EP18807895.0A EP18807895A EP3714072A1 EP 3714072 A1 EP3714072 A1 EP 3714072A1 EP 18807895 A EP18807895 A EP 18807895A EP 3714072 A1 EP3714072 A1 EP 3714072A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- strip
- ppm
- peak
- melt
- alsl
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
- C21D8/1277—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular surface treatment
- C21D8/1283—Application of a separating or insulating coating
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
- C21D1/76—Adjusting the composition of the atmosphere
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
- C21D8/1244—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest
- C21D8/1255—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest with diffusion of elements, e.g. decarburising, nitriding
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
- C21D8/1244—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest
- C21D8/1272—Final recrystallisation annealing
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
- C21D8/1277—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular surface treatment
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
- C21D8/1277—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular surface treatment
- C21D8/1288—Application of a tension-inducing coating
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/54—Furnaces for treating strips or wire
- C21D9/56—Continuous furnaces for strip or wire
- C21D9/561—Continuous furnaces for strip or wire with a controlled atmosphere or vacuum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
- H01F1/16—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of sheets
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2201/00—Treatment for obtaining particular effects
- C21D2201/05—Grain orientation
Definitions
- the present invention relates to a grain-oriented electrical steel strip having a magnesium silicate layer on at least one surface, wherein in a DRIFT spectrum of the magnesium silicate layer at least one peak in the range 960 to 975 cm-1 (A) and at least one peak in the range of 976 to 990 cm-1 (B), wherein the peak height of the at least one peak in the region (A) is higher than the peak height of the at least one peak in the region (B), a process for its production under certain
- Atmospheric conditions in the annealing step and the use of such an electrical strip are atmospheric conditions in the annealing step and the use of such an electrical strip.
- an optimization of the nitrogen level is achieved during a hood annealing carried out in the course of the method according to the invention.
- EP 1 025 268 B1 discloses a process for the production of grain-oriented electrolytic material, which after a hot rolling step and a
- WO 2017/037019 A1 likewise discloses a method for the production of grain-oriented electrical steel strip. This method comprises an annealing step after the cold rolling of the electrical strip, in which an oxide layer is formed on the surface. This oxide layer is examined by FTIR spectroscopy. From the FTIR investigation, it is then determined how the area ratio between Fe 2 SiO 4 and a SiO 2 in the layer is. In the annealing step disclosed in this document, a certain ratio of the maximum temperature attained in the annealing step and the dew point of the atmosphere in the annealing step is to be maintained.
- EP 1752548 A1 and EP 1752549 A1 disclose processes for the production of grain-oriented electrical steel. These methods also each comprise an annealing step in which the cold-rolled electrical steel is annealed recrystallizing and decarburizing, and which preferably takes place in an ammonia atmosphere.
- the control of the nitridic phase during the annealing is important because it already at temperatures below the secondary crystallization temperature with the
- Annealing atmosphere can interact. Too low a set nitridic phase manifests itself in too low an inhibition effect and, consequently, in higher core losses, while an over-adjusted nitridic phase can both shift the secondary crystallization temperature above the inhibitor dissolution temperature and produce an inhomogeneous forsterite layer, resulting in insufficient
- the object of the present invention is therefore to a
- the peak height of the at least one Peaks in the range (A) is higher than the peak height of the at least one peak in the range (B).
- a method for producing a grain-oriented electrical tape comprising at least the following steps:
- step (G) annealing the cold strip from step (F) at a temperature of 700 to 900
- step (K) optional finish annealing the cold strip wherein step (G) is performed in an atmosphere in which a dew point DP is given by the following equation (1)
- N mean nitrogen content in the material after step (G) in ppm.
- electrical steel is understood to mean an electrical steel produced by rolling suitably composed steel and blanks divided therefrom and intended for the production of parts for electrotechnical applications.
- Grain-oriented electrical tapes of the type in question are particularly suitable for applications in which a particularly low loss of magnetization is in the foreground and high demands are placed on the permeability or polarization.
- Such requirements exist in particular for parts for power transformers, distribution transformers, higher value small transformers or in rotating electrical machines.
- the method according to the invention may comprise, in addition to the further steps explicitly described herein, which are carried out in the conventional production of electrical tapes in order to achieve optimized magnetic properties or properties which are important for practical use. These include, for example, reheating the precursor obtained after the casting of the steel, descaling the hot strip prior to cold rolling, or in the case of multi-stage cold rolling, performing each in a conventional manner between the cold rolling stages
- Step (A) of the process according to the invention comprises the melting of a molten steel containing (in each case in% by weight) 2.0 to 4.0 Si,
- step (A) of the process according to the invention preference is given to
- Melted molten steel containing (in wt .-%) 2 to 4 Si, 0.01 to 0.1 C, 0.01 to 0.065 Al and 0.002 to 0.02 N, and in each case optionally 0.005 to 0.5 Cu, 0.005 to 0.060 S and also optionally each 0 to 0.3 Cr, Mn, Ni, Mo, P, As, Sn, Sb, Se, Te, B or Bi, the remainder contains iron and unavoidable impurities.
- Step (A) of the process according to the invention can be carried out by all methods known to the person skilled in the art.
- a molten steel of known composition is preferably melted.
- This melt is then treated by secondary metallurgy.
- This treatment is first preferably carried out in a vacuum plant to adjust the chemical composition of the steel to the required narrow analytical margins and preferably to achieve low hydrogen contents of at most 10 ppm in order to minimize the risk of strand breakage during casting of molten steel.
- step (A) the use of a ladle furnace for slag conditioning would also be possible, followed by treatment in a vacuum system for adjusting the chemical composition of the molten steel within narrow analytical limits.
- this combination is associated with the disadvantage that in the case of casting delays the
- step (A) it is also possible in step (A) to use only the ladle furnace.
- this has the disadvantage that the analysis accuracy is not as good as in the treatment in a vacuum system and also high
- Hydrogen contents in the casting melt can occur with the risk of strand breakthroughs.
- step (A) it is further preferred in step (A) to use only the vacuum system.
- this involves the risk that, in the case of casting delays, the temperature of the melt drops to such an extent that the molten steel can no longer be cast.
- step (B) of the process according to the invention the molten steel produced in step (A) is then cast into a starting material.
- This starting material may according to the invention be for example a slab, a thin slab or a cast strip.
- a strand is first produced from the melt by casting.
- a strand is preferably poured for this purpose, which has a thickness of, for example, 25 mm to 150 mm.
- the aim is to avoid the formation of nitridic precipitates prior to hot rolling and during hot rolling as much as possible in order to make extensive use of the possibility of a controlled production of such precipitates during the cooling of the hot strip.
- LCR Liquid Core Reduction
- SR Soft Reduction
- Thickness reduction of a cast strand can be used alone or in combination.
- the strand thickness is reduced at the core liquid inside the strand just below the mold.
- LCR is used in the prior art in thin slab continuous casters primarily to achieve lower hot strip thicknesses, especially for higher strength steels.
- LCR can reduce the reduction in the number of passes or the rolling forces in the rolling mills of the hot strip mill with the result that the work roll wear of the rolling mills and the scale porosity of the rolling mills
- Hot bands can be reduced and the tape can be improved.
- the thickness reduction achieved by LCR according to the invention is preferably in the range of 5 mm to 30 mm.
- Under SR is meant the targeted reduction in thickness of the strand in the swamp tip near Enderstarrung.
- the SR aims to reduce mitigation and core porosity.
- the achievable by the SR reduction, in particular the silicon Mitsenigerung in the subsequently hot-rolled precursors allows a homogenization of the chemical Composition over the tape thickness, which is beneficial for the magnetic values.
- Good results of the SR are obtained when the at the
- SR achieved thickness reduction, for example 0.5 to 5 mm.
- the following specification can be used: beginning of the SR zone at a solidification rate fs of 0.2 and end of the SR zone at fs equal to 0.7 to 0.8.
- thin slabs are preferably produced in step (B) of the process according to the invention.
- the usually emerging from the casting mold strand is bent at lower points and guided in a horizontal direction.
- the strand cast from the melt at a temperature of 700 to 1000 ° C, preferably 850 to 950 ° C, bent and directed, cracks can be avoided on the surface of the separated from the strand thin slabs which may otherwise be due, in particular, to edge cracks in the strand.
- the steel used according to the invention has a good ductility at the strand surface or in the edge region, so that it can follow well the deformations occurring during bending and straightening. Of the thus cast strand thin slabs are divided in a conventional manner.
- Step (C) of the process according to the invention comprises hot rolling of the starting material from step (B), in particular of the produced thin slabs, into a hot strip.
- the starting material obtained in step (B), in particular a thin slab is preferably heated in an oven to the appropriate hot rolling start temperature and then fed to hot rolling.
- the temperature at which the starting material, in particular a thin slab, enter the furnace is preferably above 650 ° C.
- the residence time in the oven should be less than 60 minutes in order to avoid adhesive scale.
- the hot rolling is preferably carried out in step (C) following the first forming pass in the two-phase region (a / g). Also, this measure has the goal of reducing the formation of nitridic precipitates in the course of hot rolling as far as possible in order to control these excretions via the cooling conditions on the outlet roller table behind the last
- the AIN is kept in solution at these temperatures.
- Another positive aspect of hot rolling in the two-phase mixed area is the grain refining effect.
- End product affects. Furthermore, the avoidance of nitridic precipitations during hot rolling is further supported, for example, in that a degree of deformation of at least 40% is achieved in the first forming pass, in order to have only relatively small stitch reductions in the last stands for achieving the desired end strip thickness. In this respect, therefore, preferred is the scored over the first two Umformstiche
- the reduction in stitching in the last stand should preferably be limited to a maximum of 30%, more preferably less than 20%, and it is also favorable for an optimum warm rolling result in view of the desired properties if the reduction in the penultimate stand of the finishing train is less than 25 % is.
- Hot strip precipitations which would adversely affect the magnetic properties of the final product, benefit from early cooling of the hot strip behind the last mill stand of the finishing train. According to a practical embodiment of the invention, it is therefore preferable to start with the water cooling within a maximum of five seconds after leaving the last mill stand.
- the aim is to have the shortest possible break times, for example, of one second and less.
- the cooling of the hot strip can be known to the expert
- Step (D) of the process of the invention comprises coiling the hot strip obtained in step (C) into a coil.
- Corresponding methods for coiling a hot strip are known per se to those skilled in the art.
- the reel temperature should preferably be in the temperature range of 500 to 780 ° C. Overlying temperatures would on the one hand lead to undesirably coarse precipitates and on the other hand the Beizbarkeit
- a so-called short-distance reel is preferably used, which is arranged directly after the compact cooling zone.
- inventive method in the production of the hot strip is preferably carried out so that the hot strip obtained sulfide and / or nitridic precipitates having an average particle diameter less than 150 nm and an average density of at least 0.05 pm-2 is achieved.
- Such a hot strip has optimal conditions for the effective control of grain growth during the subsequent process steps.
- the thickness of the hot strip obtained according to the invention is preferably 1.5 to 3.5 mm, more preferably 2 to 2.7 mm.
- the hot strip thus produced can optionally be annealed after reeling or before cold rolling.
- step (F) the hot strip is rolled in one or more cold rolling steps to a cold strip.
- step (F) the hot strip is rolled in one or more cold rolling steps to a cold strip.
- multi-stage cold rolling between the cold rolling steps
- the thickness of the cold strip obtained according to the invention is preferably 0.10 to 0.35 mm, more preferably 0.15 to 0.23 mm.
- Step (G) of the process of the invention comprises annealing the cold strip at a temperature of 700 to 950 ° C, preferably 800 to 900 ° C.
- Step (G) of the process according to the invention can in principle be carried out in all devices known to the person skilled in the art.
- step (G) is carried out such that a dew point DP corresponds to the following
- Equation (1) Alsl / N (melt) * 10 ⁇ DP ⁇ Alsl / N (melt) * 30 (1), and thus the nitrogen concentration N in the material after step (G) is adjusted so that the following equation (2)
- N mean nitrogen content in the material after step (G) in ppm.
- the annealing in step (G) should be carried out in an atmosphere in which the dew point DP indicated in ° C, the above equation (1).
- Als means the content of aluminum in the melt which has been used in step (A) of the process according to the invention.
- the unit of Alsl is ppm.
- Alsl is according to the invention preferably 100 to 650 ppm, more preferably 150 to 550 ppm, most preferably 200 to 400 ppm
- N (melt) means the nitrogen content in the melt which has been used in step (A) of the process according to the invention.
- the unit of N (melt) is ppm.
- N (melt) according to the invention is preferably 20 to 200 ppm, more preferably 40 to 150 ppm, most preferably 60 to 120 ppm.
- the present invention relates to the process according to the invention, wherein the dew point DP is 20 to 90 ° C, particularly preferably 30 to 70 ° C.
- the dew point DP set in step results in the
- N means the nitrogen content in the material after step (G) in ppm.
- the unit of N is ppm.
- the nitrogen content in the material after step (G) N is 70 to 180 ppm, more preferably 90 to 160 ppm.
- Step (G) of the process according to the invention is preferably carried out in a nitrogen-containing atmosphere. It is known to the person skilled in the art that step (G) is preferably carried out in the presence of ammonia, nitrogen and / or
- the ammonia-containing atmosphere can be present in the entire oven part, or preferably only in the last oven part.
- a grain-oriented electrical steel which has a magnesium silicate layer on at least one surface which, in a DRIFT spectrum, has at least one peak in the range of 960 to 975 cm -1 (A) and at least one peak in the range of 976 to 990 cm 1 shows.
- the ratio of the peaks to one another is influenced by the stripping and sticking processes during step (I), wherein in the embodiment according to the invention the peak height of the at least one peak in the region (A) is higher than the peak height of the at least one Peaks in the region (B).
- an annealing separator layer may be applied to at least one surface of the cold strip of step (G), preferably such an annealing separator layer is applied to both surfaces of the cold strip of step (G).
- the annealing separator is typically MgO.
- Annealing separator prevents the turns of a coil wound from the cold strip to weld together during a subsequent high-temperature annealing.
- Step (I) of the method according to the invention comprises
- Step (I) of the process according to the invention is typically carried out in a hood furnace under protective gas, preferably in a
- the nitrogen content of the material after step (G) is set to 200 ppm, for example.
- this nitrogen value is only an auxiliary quantity, but it is preferred according to the invention that the nitrogen value in the temperature range of 700 to 900 ° C in step (I) is controlled, and adjusted so that it is below 14/27 * Alsl.
- the optional step (J) of the method according to the invention comprises applying an insulating layer to the surface of the cold strip having the forsterite layer.
- Suitable materials which can act as an insulating layer are, for example, phosphates, silicates or mixtures thereof. Corresponding processes are known per se to the person skilled in the art.
- step (J) of the method according to the invention can be thermally directed. Corresponding methods for this purpose are likewise known to the person skilled in the art.
- the optional step (K) of the process according to the invention comprises a final annealing of the cold strip according to the invention. In the so-called “stress relief annealing", the cold strip is stress relieved. This final annealing can be carried out before or after the assembly of the steel flat product produced in the manner described above into the blanks required for further processing.
- Final annealing which is carried out after the blanks have been cut, may be supplemented by the additional costs incurred during the division process
- the grain-oriented electrical strip produced according to the invention is characterized by the fact that it has low core losses and, due to a high degree of toothing of the forsterite layer with the surface of the electrical strip, good adhesion of the forsterite layer.
- the present invention therefore also relates to a grain-oriented electrical steel, producible by the method according to the invention.
- the present invention also relates to grain oriented electrical steel with a magnesium silicate layer on at least one surface, wherein in a DRIFT spectrum of the magnesium silicate layer at least one peak in the range 960 to 975 cm-1 (A) and at least one peak in the range of 976 to 990 cm -1 (B), the peak height of the at least one peak in the region (A) being higher than the peak height of the at least one peak in the region (B).
- the electrical strip according to the invention is preferably obtained by the method according to the invention.
- DRIFT Diffuse Reflection Fourier Transform Infrared Spectroscopy
- an IR light beam is directed onto the sample surface by means of concave mirrors and the reflected light is also detected by means of concave mirrors, see, for example, Beasley et al., "Comparison of Transmission FTIR, ATR and DRIFT sprecta ", Journal of Archeological Science, Vol. 46, June 2014, pages 16 to 2).
- This allows the evaluation of deeper oxide layers and thus a deeper analysis of the molecular components in the oxide layer.
- the electrical steel according to the invention is characterized in that it comprises a magnesium silicate layer, i. a so-called forsterite layer, which has at least two peaks in a DRIFT spectrum of this layer, at least one peak in a wavenumber range of 960 to 975 cm-1 (area (A)), and at least one peak in one
- the ratio of the peak height of the at least one peak in the region (A) to the peak height of the at least one peak in region (B) is greater than 1.0, preferably greater than or equal to 1.05, particularly preferably greater than or equal to 1.3.
- the present invention relates to the electrical strip according to the invention, wherein an annealing separator layer is present on at least one surface, preferably such an annealing separator layer lies on both
- the forsterite layer of the electrical tape according to the invention which has at least the two mentioned characteristic peaks, shows an advantageous particularly strong toothing with the surface of the electrical tape.
- the electrical steel according to the invention shows particularly low core losses
- the electrical strip according to the invention is particularly suitable in
- Power transformers are Power transformers, distribution transformers, small transformers or to be used in rotating electrical machines.
- the present invention therefore further relates to the use of the electrical strip according to the invention in power transformers,
- Grain-oriented electrical tapes 1 to 14 were obtained by the steps of melting a molten steel containing the alloying elements shown in Table 1, casting the molten steel into a thin slab, hot rolling the thin slab at a temperature of 1050 ° C. into a hot strip, and tumbling the hot strip at a temperature from 700 ° C to a coil, cold rolling the hot strip in 5 steps to a thickness between 0.23 and 0.3mm, annealing the cold strip at a temperature of 700 to 900 ° C according to the process parameters given in Table 2.
- the electrical strip according to the invention can be used in power transformers, distribution transformers, small transformers or in rotating electrical machines.
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102017220714.0A DE102017220714B3 (en) | 2017-11-20 | 2017-11-20 | Optimization of the nitrogen level during the hood annealing |
PCT/EP2018/080928 WO2019096736A1 (en) | 2017-11-20 | 2018-11-12 | Grain-oriented electrical steel strip and method for producing such an electrical steel strip |
Publications (1)
Publication Number | Publication Date |
---|---|
EP3714072A1 true EP3714072A1 (en) | 2020-09-30 |
Family
ID=64456940
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP18807895.0A Pending EP3714072A1 (en) | 2017-11-20 | 2018-11-12 | Grain-oriented electrical steel strip and method for producing such an electrical steel strip |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP3714072A1 (en) |
DE (1) | DE102017220714B3 (en) |
WO (1) | WO2019096736A1 (en) |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5472521A (en) * | 1933-10-19 | 1995-12-05 | Nippon Steel Corporation | Production method of grain oriented electrical steel sheet having excellent magnetic characteristics |
US5685920A (en) * | 1994-05-13 | 1997-11-11 | Nippon Steel Corporation | Annealing separator having excellent reactivity for grain-oriented electrical steel sheet and method of use the same |
JP3390102B2 (en) * | 1995-03-02 | 2003-03-24 | 新日本製鐵株式会社 | Method for producing grain-oriented electrical steel sheet with good glass coating |
DE19745445C1 (en) | 1997-10-15 | 1999-07-08 | Thyssenkrupp Stahl Ag | Process for the production of grain-oriented electrical sheet with low magnetic loss and high polarization |
EP0947597B2 (en) * | 1998-03-30 | 2015-06-10 | Nippon Steel & Sumitomo Metal Corporation | Method of producing a grain-oriented electrical steel sheet excellent in magnetic characteristics |
SI1752548T1 (en) | 2005-08-03 | 2016-09-30 | Thyssenkrupp Steel Europe Ag | Method for producing a magnetic grain oriented steel strip |
SI1752549T1 (en) | 2005-08-03 | 2016-09-30 | Thyssenkrupp Steel Europe Ag | Process for manufacturing grain-oriented magnetic steel spring |
CN101768697B (en) * | 2008-12-31 | 2012-09-19 | 宝山钢铁股份有限公司 | Method for manufacturing oriented silicon steel with one-step cold rolling method |
CN102758127B (en) * | 2011-04-28 | 2014-10-01 | 宝山钢铁股份有限公司 | Method for producing high magnetic induction orientation silicon steel with excellent magnetic performance and good bottom layer |
CN103695619B (en) * | 2012-09-27 | 2016-02-24 | 宝山钢铁股份有限公司 | A kind of manufacture method of high magnetic strength common orientation silicon steel |
DE102015114358B4 (en) | 2015-08-28 | 2017-04-13 | Thyssenkrupp Electrical Steel Gmbh | Method for producing a grain-oriented electrical strip and grain-oriented electrical strip |
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2017
- 2017-11-20 DE DE102017220714.0A patent/DE102017220714B3/en active Active
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2018
- 2018-11-12 EP EP18807895.0A patent/EP3714072A1/en active Pending
- 2018-11-12 WO PCT/EP2018/080928 patent/WO2019096736A1/en unknown
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DE102017220714B3 (en) | 2019-01-24 |
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