EP0753588A1 - Herstellungsverfahren eines kornorientiertes Elektrostahlbleches mit einer Spiegeloberfläche und mit geringen Eisenverlusten - Google Patents
Herstellungsverfahren eines kornorientiertes Elektrostahlbleches mit einer Spiegeloberfläche und mit geringen Eisenverlusten Download PDFInfo
- Publication number
- EP0753588A1 EP0753588A1 EP95111069A EP95111069A EP0753588A1 EP 0753588 A1 EP0753588 A1 EP 0753588A1 EP 95111069 A EP95111069 A EP 95111069A EP 95111069 A EP95111069 A EP 95111069A EP 0753588 A1 EP0753588 A1 EP 0753588A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- annealing
- steel sheet
- final
- grain
- oriented electrical
- 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.)
- Granted
Links
Images
Classifications
-
- 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
- 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
Definitions
- the present invention relates to a method for the production of a grain-oriented electrical steel sheet used as an iron core of a transformer or other electric appliances. More particularly, the present invention relates to a method for the production of a grain-oriented electrical steel sheet in which core loss is reduced by imparting it with a mirror surface and keeping it free of precipitates at the surface region.
- Grain-oriented electrical steel sheet material for use in various types of electric equipment mainly transformers, contains 0.8 - 4.8% Si and has a crystal texture preferentially aligned in the ⁇ 110 ⁇ 001 ⁇ orientation.
- the required characteristics of a grain-oriented electrical steel sheet are a high magnetic flux density and a low core loss, which are represented by B 8 and W 17/50 , respectively.
- Core loss can be subdivided into eddy current loss and hysterisis loss.
- the former decreases in proportion to reductions in the width of the magnetic domains of the steel sheet, and the later can be reduced by eliminating hindrances to the movement of magnetic domain walls.
- Primary causes of this hindrance are uneven or rough surfaces of the steel sheet and the presence of precipitates near the steel surface.
- An inner oxide layer mainly composed of SiO 2 and a glass film mainly composed of forsterite (Mg 2 SiO 4 ) are present on the surface of a grain-oriented electrical steel sheet produced by the current production process.
- the inner oxide layer is formed on the steel surface by decarburization annealing.
- the glass film is formed on the above inner oxide layer during the final annealing, which reacts SiO 2 with MgO, to avoid having windings of the coil stick to each other.
- this glass film is formed based on the above inner oxide layer, the interface between the glass film and the steel sheet is not smooth because of the presence of precipitates. As a result, these precipitates become a hindrance to movement of the magnetic domains.
- This phenomenon is well known from the various reports, for example, by S. D. Washko, T. H. Shen and W. G. Morris, Journal of Applied Physics., vol. 53, pp 8296 - 8298. Since then, there have been proposed various methods for dealing with this phenomenon. For example, one of the methods is to prevent glass film formation during the final annealing, and another is to obtain an even and smooth steel surface by chemical or mechanical polishing after removal of the glass film.
- a primary object of the present invention is to provide a grain-oriented electrical steel sheet having a mirror surface and reduced core loss, free of precipitates directly below the surface.
- a further object of the present invention is to provide a simplified process that lowers production cost by elimination of the acid pickling step.
- the present inventors conducted numerous experiments aimed at overcoming the defects of the conventional techniques and attaining the foregoing object, to develop a more effective production process for obtaining a miller steel surface free of precipitates directly below the surface of the grain-oriented electrical steel sheet products.
- the present inventors found that if the amount of impurities contained in the oxide used as an annealing separator, especially the concentration of alkali metals, is controlled in accordance with the amount of oxygen which is contained in the steel sheet during the decarburization annealing, the formation of precipitates, which increases core loss, can be prevented from the start and furthermore, formation of a mirror surface can be promoted in the final annealing step.
- a grain-oriented electrical steel sheet having a mirror surface with low core loss by means of using an annealing separator mainly composed of non-hydrating oxides and controlling the concentration of alkali metal impurities in the annealing separator and the oxygen amount in the steel sheet just prior to the final annealing, for achieving a decreased core loss.
- a mirror surface is obtained by satisfying the relationship: [A] > 0.2 ⁇ [O],
- the present invention provides a non-hydrating oxide contained in an annealing separator mainly composed of alumina for obtaining a mirror steel surface and reduced core loss.
- the above mentioned alkali metal impurities consist of at least one of Li, Na and K.
- the annealing separator further contains at least one of hydroxide, nitrate, sulfate, chloride or acetate of Li, Na or K.
- a mirror steel surface free of precipitates directly below the surface can be easily obtained by a simplified process for decreasing core loss, especially hysterisis loss.
- Figure 1 shows the results of X-ray diffraction (CuK ⁇ ) microscopy of a grain-oriented electrical steel sheet, coated with alumina as an annealing separator, and then given a final annealing.
- CuK ⁇ X-ray diffraction
- (a) shows an example of the results of X-ray diffraction analysis (CuK ⁇ ) in the case of using high purity alumina.
- (b) shows an example of the results of X-ray diffraction analysis (CuK ⁇ ) of in the case of using alumina containing 0.2 weight % of Na as impurity.
- Figure 2 is a diagram illustrating the relationship between the amount of Na in alumina as an annealing separator and the oxygen content of the steel sheet during the decarburization annealing, and the formation of precipitates directly below the steel surface. "o” indicates absence of precipitates and “ ⁇ ” indicates presence of precipitates.
- Figure 3 is a micrograph showing a cross sectional view of a grain-oriented electrical steel sheet which was coated by alumina as an annealing separator, and then final annealed.
- (a) shows an example of the case of using high purity alumina.
- (b) shows an example of the case of using alumina containing 0.2 weight % of Na as impurity.
- the present inventors used various kinds of alumina, the oxide which is commonly used as an annealing separator, and found that Na as an impurity contained in alumina influenced the formation of precipitates and the mirror condition of the steel surface. This is because when a large amount of Na is present, the mirror surface can be obtained even if an oxide film exists. In addition, no precipitates are observed directly below the steel surface when the steel surface exhibits the mirror condition. The present inventors have not ascertained the reason for this. It is thought that reduction of SiO 2 formed during the decarburization annealing may be accelerated in the final annealing step because of the existence of Na. If the reduction of SiO 2 easily occurs in the final annealing step, the precipitates directly below the steel surface, once formed, decrease and disappear. Otherwise they are not formed from the start. As a result, a mirror steel surface can be easily obtained.
- carbon is an essential element for obtaining the required crystal texture in the intermediate product so as to preferentially promote ⁇ 110 ⁇ 001 ⁇ crystal orientation in the final product. Though this carbon must be included in the required amount in the early production stage, the carbon remaining in the final product increases the core loss. Accordingly, a primary recrystallization annealing is carried out in a wet hydrogen/nitrogen mixed atmosphere for decaburization. This primary recrystallization annealing is ordinarily called decaburization annealing. The concentration of the remaining carbon in the final product must be limited to less than 30 ppm.
- the speed of the decarburizing reaction depends upon the reaction potential of the oxygen in the decarburization atmosphere.
- the reaction potential of the oxygen becomes low, the decarburizing reaction slows down.
- the reaction oxygen potential can be increased to form an inner oxide layer, mainly composed of SiO 2 , on the surface of the electrical steel sheet.
- decarburized annealed steel sheets treated under normal conditions have inevitably included an inner oxide layer mainly composed of SiO 2 .
- an inner oxide layer mainly composed of SiO 2 .
- a coat of coarse and high purity alumina is applied to the decarburized steel sheet having the inner oxide layer, and given a final annealing, a grain-oriented electrical steel sheet having no oxide film on the surface can be obtained.
- the thus obtained steel sheet not only exhibits a mirror steel surface but also has precipitates present directly below the steel surface. These precipitates are clearly observed in the microscopic sectional view of the steel surface as shown in Fig. 3(a).
- the origin of the SiO 2 contained among these precipitates is thought to be the inner oxide layer containing SiO 2 formed during the decarburization annealing.
- the origin of the Al 2 O 3 contained among the precipitates is assumed to be the sol Al contained in the steel sheet for controlling the secondary recrystallization, and to be the alumina used as an annealing separator. This is because the precipitates are not exposed on the steel surface.
- the SiO 2 inner oxide layer formed during the decarburization annealing remains directly below the steel surface, so that this SiO 2 is not reduced by the reducing atmosphere during the final annealing.
- sol Al when sol Al is contained in the steel sheet, this sol Al reacts with the SiO 2 and forms mullite directly below the steel surface. Since these precipitates are present inside the steel sheet, they are not reduced under the condition of the reducing atmosphere at a high temperature in the latter half of the final annealing. If these precipitates are not present at the steel surface, atomic diffusion is vigorously promoted so that the formation of a mirror finish is accelerated. On the other hand, if these precipitates are present directly below the steel surface, the promotion of atomic diffusion is prevented so that the formation of a mirror finish is also prevented during the final annealing.
- the present invention can be basically applied to the production of all kinds of grain-oriented electrical steel sheet on the premise of the above mentioned conditions (1) - (3).
- the present inventors used various kinds of alumina, the oxide which is commonly used as an annealing separator, containing different amounts of impurities such as Na, K or Li and/or their compounds, and found that when Na is contained in alumina as an impurity, it influences the formation of precipitates and the condition of the mirror brightness, even if an oxide film is present. In addition, this phenomenon depends upon the amount of Na. Accordingly, when alumina containing a large amount of Na was used as an annealing separator, no precipitates were found directly below the steel surface, and a mirror surface was obtained. This phenomenon is clearly observed in the microscopic views of Fig. 3(a) and Fig. 1(b). The present inventors have not yet clarified the reason for this.
- Carbon is an element required for ⁇ phase formation, and is necessary for controlling the primary recrystallization texture prior to the final annealing for ensuring an appropriate secondary recrystallization. Therefore, carbon must be contained in the cold rolled steel sheet in the range of 0.02 - 0.1%. If the carbon content is more than 0.1%, the primary recrystallized texture deteriorates and a long period of time is required for decarburization.
- Silicon is an important element for increasing electric resistance and decreasing core loss. If the silicon content is less than 0.8%, ⁇ to ⁇ transformation occurs during final annealing and the crystal structure and the orientation are impaired, while if the silicon content is more than 4.8%, cold rolling becomes difficult because of cracking.
- the preferred silicon content is from 0.8% to 4.8%.
- Manganese and sulfur form an inhibitor which suppresses primary grain growth.
- the manganese and sulfur contents must each be limited to the range of 0.005 - 0.04%.
- Acid soluble aluminum is a basic element which combines with nitrogen to form AlN or (Al, Si)N as an inhibitor for obtaining a high magnetic flux density.
- the preferred acid soluble alumina content is from 0.012 to 0.05%.
- Nitrogen is also a basic element which combines with the acid soluble aluminum to form an inhibitor. If the nitrogen content is more than 0.01%, blisters are undesirably formed in the final product. The preferred nitrogen content is not more than 0.01%.
- inhibitors such as B, Bi, Pb, S, Se, Sn or Ti, in addition to the acid soluble aluminum.
- a hot rolled steel strip adjusted to the composition range mentioned above by a known process is cold rolled directly or with hot rolled band annealing in a short period of time.
- This hot rolled band annealing is effective for improving the magnetic properties of the final product, and is carried out at a temperature between 750°C and 1200°C for 30 seconds to 30 minutes.
- the annealing conditions are determined based on the desired product quality or cost.
- the cold rolling is carried out at a reduction rate of more than 80% to the final thickness by a known cold rolling process as described in Japanese Patent Publication (Kokoku) No. Sho 40-15644.
- the condition of the cold rolling is of course variable depending upon the inhibitors used.
- the decarburization annealing is carried out on the cold rolled steel strip in a wet atmosphere at a temperature between 750°C and 900°C for primary recrystallization and the removal of carbon from the cold rolled steel strip.
- the nitriding treatment is carried out following the decarburization annealing in the case of using (Al, Si)N as the main inhibitor.
- the nitriding treatment is carried out in an atmospheric gas containing NH 3 having nitriding capability.
- the nitriding amount is more than 0.005% to the total amount of nitrogen contained in the steel sheet, preferably more than the aluminum equivalent of the steel sheet.
- an annealing separator is coated on the decarburized or nitrided steel strip to form a glass film during the final annealing and prevent sticking.
- the annealing separator can be used in the present invention is an oxide which is hard to hydrate. If an oxide which is easy to hydrate, like MgO, is used, peroxidation occurs at the steel surface during the final annealing or an oxide layer forms on the steel surface by reaction with the oxide film formed by decarburizing, so that a mirror surface cannot be obtained.
- the annealing separator is a stable oxide having a non-hydrating characteristic, it is not limited to a specific oxide.
- An oxide like ZrO 2 or Y 2 O 3 can be used.
- Alumina is a suitable oxide for the present invention because of its non-hydrating characteristic and low cost. It is advisable to use inexpensive alumina because it contains a large amount of sodium.
- This annealing separator is applied as a slurry in the conventional way or by electrostatic coating. When the annealing separator is suspended in water, it is desirable to add an anti-corrosion agent to the suspension, to prevent rusting of the steel surface during the coating. In the case of using relatively coarse oxide particles suspended in water, a caking agent such as methylcellulose is added to improve the coating ability and adhesibility.
- the specific requirement for obtaining a mirror surface according to the present invention is that the condition defined as follows must be satisfied during the decarburization annealing and the coating with the annealing separator.
- the condition is the relationship; [A] > 0.2 ⁇ [O] , where [O] is the amount of oxygen (g/m 2 ) contained in the steel sheet just prior to the final annealing and [A] is the total concentration of alkali metal impurities (weight %) in the annealing separator.
- the oxygen content in the steel sheet can be reduced by a light acid pickling treatment after the decarburization annealing.
- this method is not recommendable from the point of view of production cost because it requires an additional step.
- the non-hydrating oxide containing the alkali metal impurity as the annealing separator can be used in accordance with the amount of generated oxygen contained in the steel sheet when the decarburization is almost completed, and selecting an appropriate atmosphere and annealing period which prevent the oxidation of the steel sheet.
- the following means can be used for securing the necessary concentration of the alkali metal impurity of the non-hydrating oxide as the annealing separator.
- the commercial low priced alumina generally used naturally contains Na as an impurity, approximately in an amount of 0.2%, due to its production process. Therefore, this inexpensive commercial alumina is very useful as the annealing separator for achieving the object of the present invention.
- an alkali metal chloride (or salt) is added to the oxide powder or an alkali metal chloride (or salt) is dissolved in the necessary amount in the slurry for making the annealing separator.
- a water soluble salt selected from the group consisting of hydroxide, nitrate, sulfate, chloride or acetate of Na, K, or Li etc.
- the final annealing is carried out for secondary recrystallization and purification after the annealing separator is coated.
- a specific heating cycle which maintains a constant temperature for promoting the secondary recrystallization during the heating step is effective for increasing the magnetic flux density as described in Japanese Unexamined Patent Publication (Kokai) No. 2-258929.
- the heated steel strip is kept at a temperature higher than 1100°C in a 100% hydrogen atmosphere for the purification of nitride and a mirror conditioning the steel surface.
- An insulation coating is applied to the steel strip for imparting a tensioning effect and reducing core loss.
- magnetic domain refining treatment by the laser irradiation may be applied for further reducing core loss.
- the present invention will now be described in detail with reference to the following examples, that by no means limit the scope of the invention.
- the present invention will be applicable to other steel compositions or other production process as already described as far as satisfying the following conditions independently or altogether; (1) the steel contains Si, (2) decarburization annealing is necessary, and (3) a mirror surface is formed without glass film containing forsterite during the final annealing in the production of a grain-oriented electrical steel sheet.
- the nitriding treatment was carried out in an NH 3 atmosphere gas bringing the nitrogen content in the steel sheet to 0.025% for strengthening inhibitors.
- an annealing separator was coated onto the nitrided steel sheet.
- Conventional MgO was applied to several steel sheets, and alumina containing different kinds of alkali metal as impurities and different concentrations in the slurry state were applied to the remaining steel sheets.
- final annealing was carried out by heating the steel sheets to 1200°C at a constant heating rate of 10 °C/hr in an atmosphere of 100% nitrogen gas, and by maintaining them at a temperature of 1200°C for 20 hours in an atmosphere of 100% hydrogen gas.
- the atmosphere gas was switched from nitrogen to hydrogen at 1200°C.
- insulation coating and the magnetic domain refinement treatment by laser irradiation were applied to the finally annealed sheets.
- the resultant products had the magnetic properties as shown in Table 1.
- an annealing separator was applied to the decarburized steel strip.
- Conventional MgO was applied to several steel sheets, and alumina containing different kinds of alkali metal as impurities and different concentrations in the slurry is applied to the remaining steel sheets.
- final annealing was carried out by heating the steel sheets to 1200°C at a constant heating rate of 15° C/hr in a mixed atmosphere comprising 15% nitrogen and 85% hydrogen gas, and further maintaining the steel at a temperature of 1200°C for 20 hours in an atmosphere of 100% hydrogen gas. The atmosphere gas was switched from nitrogen to hydrogen at 1200°C.
- insulation coating and the magnetic domain refining treatment by laser irradiation were applied to the final annealed strip.
- the resultant products had the magnetic properties as shown in Table 2.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Manufacturing & Machinery (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Manufacturing Of Steel Electrode Plates (AREA)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP95111069A EP0753588B2 (de) | 1995-07-14 | 1995-07-14 | Verfahren zum herstellen eines kornorientierten elektrostahlblechs mit einer spiegeloberflache und mit geringem kernverlust |
DE1995613811 DE69513811T3 (de) | 1995-07-14 | 1995-07-14 | Verfahren zum herstellen eines kornorientierten elektrostahlblechs mit einer spiegeloberflache und mit geringem kernverlust |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP95111069A EP0753588B2 (de) | 1995-07-14 | 1995-07-14 | Verfahren zum herstellen eines kornorientierten elektrostahlblechs mit einer spiegeloberflache und mit geringem kernverlust |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0753588A1 true EP0753588A1 (de) | 1997-01-15 |
EP0753588B1 EP0753588B1 (de) | 1999-12-08 |
EP0753588B2 EP0753588B2 (de) | 2005-04-27 |
Family
ID=8219435
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP95111069A Expired - Lifetime EP0753588B2 (de) | 1995-07-14 | 1995-07-14 | Verfahren zum herstellen eines kornorientierten elektrostahlblechs mit einer spiegeloberflache und mit geringem kernverlust |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0753588B2 (de) |
DE (1) | DE69513811T3 (de) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1006207A1 (de) * | 1998-03-11 | 2000-06-07 | Nippon Steel Corporation | Unidirektional magnetisches stahlblech |
EP1464712A1 (de) * | 2002-01-08 | 2004-10-06 | Nippon Steel Corporation | Verfahren zur herstellung von kornorientierten siliciumstahlplatten mit spiegeloberfläche |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3785882A (en) * | 1970-12-21 | 1974-01-15 | Armco Steel Corp | Cube-on-edge oriented silicon-iron having improved magnetic properties and method for making same |
EP0305966A1 (de) * | 1987-08-31 | 1989-03-08 | Nippon Steel Corporation | Verfahren zur Herstellung von kornorientierten Stahlblechen mit Metallglanz und ausgezeichneter Stanzbarkeit |
JPH0617132A (ja) * | 1992-07-02 | 1994-01-25 | Nippon Steel Corp | 磁束密度の極めて高い超低鉄損方向性電磁鋼板及びその製造方法 |
JPH0639123A (ja) * | 1993-04-30 | 1994-02-15 | Daiichi Shokai Co Ltd | パチンコ機の管理装置 |
EP0607440A1 (de) * | 1992-05-08 | 1994-07-27 | Nippon Steel Corporation | Verfahren zur herstellung elektrisch gerichteter spiegelnder bleche |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT1127263B (it) † | 1978-11-28 | 1986-05-21 | Nippon Steel Corp | Sostanza di separazione da utilizzare nella fase di ricottura di strisce di acciaio al silicio a grani orientati |
JPH0756048B2 (ja) † | 1990-11-30 | 1995-06-14 | 川崎製鉄株式会社 | 被膜特性と磁気特性に優れた薄型方向性けい素鋼板の製造方法 |
-
1995
- 1995-07-14 DE DE1995613811 patent/DE69513811T3/de not_active Expired - Lifetime
- 1995-07-14 EP EP95111069A patent/EP0753588B2/de not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3785882A (en) * | 1970-12-21 | 1974-01-15 | Armco Steel Corp | Cube-on-edge oriented silicon-iron having improved magnetic properties and method for making same |
EP0305966A1 (de) * | 1987-08-31 | 1989-03-08 | Nippon Steel Corporation | Verfahren zur Herstellung von kornorientierten Stahlblechen mit Metallglanz und ausgezeichneter Stanzbarkeit |
EP0607440A1 (de) * | 1992-05-08 | 1994-07-27 | Nippon Steel Corporation | Verfahren zur herstellung elektrisch gerichteter spiegelnder bleche |
JPH0617132A (ja) * | 1992-07-02 | 1994-01-25 | Nippon Steel Corp | 磁束密度の極めて高い超低鉄損方向性電磁鋼板及びその製造方法 |
JPH0639123A (ja) * | 1993-04-30 | 1994-02-15 | Daiichi Shokai Co Ltd | パチンコ機の管理装置 |
Non-Patent Citations (2)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 18, no. 226 (C - 1194) 25 April 1994 (1994-04-25) * |
PATENT ABSTRACTS OF JAPAN vol. 9, no. 166 (C - 290) 11 July 1985 (1985-07-11) * |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1006207A1 (de) * | 1998-03-11 | 2000-06-07 | Nippon Steel Corporation | Unidirektional magnetisches stahlblech |
EP1006207A4 (de) * | 1998-03-11 | 2005-01-05 | Nippon Steel Corp | Unidirektional magnetisches stahlblech |
EP1728885A1 (de) * | 1998-03-11 | 2006-12-06 | Nippon Steel Corporation | Kornorientiertes Elektrostahlblech und dessen Herstellungsverfahren |
EP1464712A1 (de) * | 2002-01-08 | 2004-10-06 | Nippon Steel Corporation | Verfahren zur herstellung von kornorientierten siliciumstahlplatten mit spiegeloberfläche |
EP1464712A4 (de) * | 2002-01-08 | 2006-08-09 | Nippon Steel Corp | Verfahren zur herstellung von kornorientierten siliciumstahlplatten mit spiegeloberfläche |
US7364629B2 (en) | 2002-01-08 | 2008-04-29 | Nippon Steel Corporation | Method for manufacturing grain-oriented silicon steel sheets with mirror-like surface |
EP2319944A1 (de) * | 2002-01-08 | 2011-05-11 | Nippon Steel Corporation | Methode zur Herstellung von Stahlblechen mit spiegelähnlicher Oberfläche und orientierten Körnern |
Also Published As
Publication number | Publication date |
---|---|
EP0753588B1 (de) | 1999-12-08 |
DE69513811T3 (de) | 2005-09-22 |
DE69513811D1 (de) | 2000-01-13 |
EP0753588B2 (de) | 2005-04-27 |
DE69513811T2 (de) | 2000-04-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JPH0774388B2 (ja) | 磁束密度の高い一方向性珪素鋼板の製造方法 | |
KR950005793B1 (ko) | 자속밀도가 높은 일방향성 전기 강스트립의 제조방법 | |
US6280534B1 (en) | Grain oriented electromagnetic steel sheet and manufacturing thereof | |
JPH0756048B2 (ja) | 被膜特性と磁気特性に優れた薄型方向性けい素鋼板の製造方法 | |
EP0076109B2 (de) | Methode zur Erzeugung von kornorientierten Siliziumstahlblechen mit ausgezeichneten magnetischen Eigenschaften | |
US5509976A (en) | Method for producing a grain-oriented electrical steel sheet having a mirror surface and improved core loss | |
EP0753588B1 (de) | Verfahren zum herstellen eines kornorientierten elektrostahlblechs mit einer spiegeloberflache und mit geringem kernverlust | |
JP3412959B2 (ja) | 鉄損の低い鏡面方向性珪素鋼板の製造方法 | |
EP0036726B1 (de) | Verfahren zum Herstellen siliziumhaltiger Eisenbleche mit Behandlungsatmosphären aus Stickstoff und Wasserstoff | |
CN1054885C (zh) | 生产一种具有镜面和改进了铁损的晶粒取向电工钢板的方法 | |
JP2674917B2 (ja) | フォルステライト被膜のない高磁束密度方向性珪素鋼板の製造方法 | |
EP0535651B1 (de) | Verfahren zur Herstellung von kornorientierten Siliziumstahlblechen | |
US4416707A (en) | Secondary recrystallized oriented low-alloy iron | |
CA2154143C (en) | Method for producing a grain-oriented electrical steel sheet having a mirror surface and improved core loss | |
JP2000034521A (ja) | 磁気特性に優れる方向性電磁鋼板の製造方法 | |
JP3061491B2 (ja) | 磁気特性の優れた厚い板厚のグラス被膜の少ない一方向性電磁鋼板の製造方法 | |
JPH08143975A (ja) | 優れたグラス被膜と磁気特性を得るための方向性電磁鋼板用焼鈍分離剤及びスラリー | |
KR0155981B1 (ko) | 철손이 향상된 거울 같은 표면을 가진 방향성전기강판의 제조방법 | |
JPS6253572B2 (de) | ||
JP2706020B2 (ja) | 方向性珪素鋼板の製造方法 | |
JPH09256068A (ja) | 優れたグラス被膜を得るための方向性電磁鋼板の製造方法 | |
JP2706039B2 (ja) | 鏡面方向性珪素鋼板の製造方法 | |
JPH07312308A (ja) | 磁気特性の優れたグラス被膜の少ない一方向性電磁鋼板の製造方法 | |
JP2716916B2 (ja) | 方向性珪素鋼板の製造方法 | |
JPH06136448A (ja) | 方向性珪素鋼板の製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 19950814 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE FR GB IT |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
17Q | First examination report despatched |
Effective date: 19981104 |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): DE FR GB IT |
|
REF | Corresponds to: |
Ref document number: 69513811 Country of ref document: DE Date of ref document: 20000113 |
|
ITF | It: translation for a ep patent filed |
Owner name: STUDIO TORTA S.R.L. |
|
ET | Fr: translation filed | ||
PLBQ | Unpublished change to opponent data |
Free format text: ORIGINAL CODE: EPIDOS OPPO |
|
PLBI | Opposition filed |
Free format text: ORIGINAL CODE: 0009260 |
|
PLBF | Reply of patent proprietor to notice(s) of opposition |
Free format text: ORIGINAL CODE: EPIDOS OBSO |
|
26 | Opposition filed |
Opponent name: EBG GESELLSCHAFT FUER ELEKTROMAGNETISCHE WERKSTOFF Effective date: 20000908 |
|
PLBF | Reply of patent proprietor to notice(s) of opposition |
Free format text: ORIGINAL CODE: EPIDOS OBSO |
|
PLBF | Reply of patent proprietor to notice(s) of opposition |
Free format text: ORIGINAL CODE: EPIDOS OBSO |
|
PLAW | Interlocutory decision in opposition |
Free format text: ORIGINAL CODE: EPIDOS IDOP |
|
PLBO | Opposition rejected |
Free format text: ORIGINAL CODE: EPIDOS REJO |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: IF02 |
|
APAC | Appeal dossier modified |
Free format text: ORIGINAL CODE: EPIDOS NOAPO |
|
APAE | Appeal reference modified |
Free format text: ORIGINAL CODE: EPIDOS REFNO |
|
APAC | Appeal dossier modified |
Free format text: ORIGINAL CODE: EPIDOS NOAPO |
|
APBU | Appeal procedure closed |
Free format text: ORIGINAL CODE: EPIDOSNNOA9O |
|
PUAH | Patent maintained in amended form |
Free format text: ORIGINAL CODE: 0009272 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: PATENT MAINTAINED AS AMENDED |
|
27A | Patent maintained in amended form |
Effective date: 20050427 |
|
AK | Designated contracting states |
Kind code of ref document: B2 Designated state(s): DE FR GB IT |
|
APAH | Appeal reference modified |
Free format text: ORIGINAL CODE: EPIDOSCREFNO |
|
ET3 | Fr: translation filed ** decision concerning opposition | ||
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: IT Payment date: 20080728 Year of fee payment: 14 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20090714 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R082 Ref document number: 69513811 Country of ref document: DE Representative=s name: VOSSIUS & PARTNER PATENTANWAELTE RECHTSANWAELT, DE Effective date: 20130227 Ref country code: DE Ref legal event code: R082 Ref document number: 69513811 Country of ref document: DE Representative=s name: VOSSIUS & PARTNER, DE Effective date: 20130227 Ref country code: DE Ref legal event code: R081 Ref document number: 69513811 Country of ref document: DE Owner name: NIPPON STEEL & SUMITOMO METAL CORPORATION, JP Free format text: FORMER OWNER: NIPPON STEEL CORP., TOKIO/TOKYO, JP Effective date: 20130227 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: CD Owner name: NIPPON STEEL & SUMITOMO METAL CORPORATION, JP Effective date: 20130913 Ref country code: FR Ref legal event code: CA Effective date: 20130913 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20140709 Year of fee payment: 20 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20140709 Year of fee payment: 20 Ref country code: FR Payment date: 20140708 Year of fee payment: 20 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R071 Ref document number: 69513811 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: PE20 Expiry date: 20150713 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION Effective date: 20150713 |