WO2013121924A1 - 無方向性電磁鋼板 - Google Patents
無方向性電磁鋼板 Download PDFInfo
- Publication number
- WO2013121924A1 WO2013121924A1 PCT/JP2013/052555 JP2013052555W WO2013121924A1 WO 2013121924 A1 WO2013121924 A1 WO 2013121924A1 JP 2013052555 W JP2013052555 W JP 2013052555W WO 2013121924 A1 WO2013121924 A1 WO 2013121924A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- mass
- less
- content
- steel sheet
- inclusions
- Prior art date
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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/008—Heat treatment of ferrous alloys containing Si
-
- 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
-
- 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
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- 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
- C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
-
- 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
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- 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
- C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
-
- 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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- 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
-
- 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
- C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
-
- 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
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- 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
- C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
-
- 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
- C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/004—Dispersions; Precipitations
Definitions
- the present invention is a high-grade non-oriented electrical steel sheet used for high-frequency applications such as iron cores of motors, particularly for reducing energy loss and improving the efficiency of electrical equipment and contributing to energy saving.
- the present invention relates to a non-oriented electrical steel sheet having excellent iron loss after annealing.
- Patent Document 1 As a measure for improving the iron loss in the high frequency range of the non-oriented electrical steel sheet, for example, as described in Patent Document 1, generally increasing the electrical resistance by increasing the content of Si or Al. Has been done. Recently, in order to reduce costs, an alloy material of Si or Al having a high Ti content may be used as an inexpensive alloy material.
- Ti having high affinity with these elements is inevitably contained in the alloy raw material, so Ti is inevitably mixed into the steel sheet.
- Ti in the steel sheet is 0.001% by mass or more, a large number of fine Ti inclusions having a diameter of about several tens of nanometers such as TiN, TiS, and TiC are generated in the steel sheet.
- the fine Ti inclusions in the steel sheet inhibit the growth of crystal grains when the steel sheet is annealed, and deteriorate the magnetic properties.
- One of the measures is to use an alloy raw material having a small content of Ti as an impurity.
- this measure is used, there is a problem that the cost of the alloy raw material is increased.
- reducing N, S, and C in the steel sheet is one of the measures for reducing Ti inclusions, and it is possible to sufficiently reduce S and C by vacuum degassing or the like with the current technology.
- a long process is required, and productivity is lowered.
- the cost is increased due to the strengthening of the seal, and even if such measures are taken, N is mixed into the molten steel. There is a problem that is inevitable.
- the present invention is a non-oriented electrical steel sheet that can be manufactured with excellent cost and productivity by a conventional manufacturing process, is excellent in grain growth during annealing, and has high-frequency iron loss.
- the purpose is to provide.
- the gist of the present invention for solving the above problems is as follows. (1) C: 0.01% by mass or less, Si: 1.0 mass% or more and 3.5 mass% or less, Al: 0.1% by mass or more and 3.0% by mass or less, Mn: 0.1% by mass or more and 2.0% by mass or less, P: 0.1% by mass or less, S: 0.005 mass% or less, Ti: 0.001% by mass or more and 0.01% by mass or less, N: 0.005 mass% or less, and Y: more than 0.05 mass% to 0.2 mass% or less, A non-oriented electrical steel sheet characterized by containing iron and the balance being iron and inevitable impurities.
- the non-oriented electrical steel sheet according to the present invention has few fine Ti inclusions in the steel sheet, the grain growth property during annealing is good, and the iron loss in the high frequency range is excellent. Furthermore, it is possible to manufacture with excellent cost and productivity, and it is possible to improve motor characteristics and contribute to energy saving.
- FIG. 1 is a diagram showing the relationship between the Y content in a steel sheet, the Ti inclusion content of the product sample after strain relief annealing, and the crystal grain size.
- Y is yttrium, an element having an atomic number of 39, and a kind of rare earth element.
- the method for investigating inclusions will be explained.
- the sample was polished from the surface to an appropriate thickness, and the surface of the sample was mirror-finished.
- the inclusion was investigated using the field emission type
- the inclusion composition was analyzed for inclusions having a diameter of 10 nm to 500 nm, and the number of inclusions in the unit observation area was counted.
- ASTM E127 Annual Book of ASTM Standards Vol. It was converted into the number density of inclusions per unit volume of the sample by the DeHoff equation shown in 03.03 (1995).
- the above method is merely an example, and a replica or thin film may be created from the sample and investigated, or a transmission electron microscope may be used.
- the etching method for example, the method described in Kurosawa et al. (Fumio Kurosawa, Isamu Taguchi, Ryutaro Matsumoto: Journal of the Japan Institute of Metals, 43 (1979), p. 1068) was used.
- the sample was electrolytically corroded in a non-aqueous solvent solution, and the inclusion was extracted by dissolving only the steel while leaving the inclusion.
- the cross section of the sample was mirror-polished and subjected to nital etching to reveal the crystal grains, and the average crystal grain size was measured.
- FIG. 1 is a diagram showing the relationship between the Y content, the amount of Ti inclusions, and the crystal grain size in a product sample according to the above-described experiment.
- the relationship between the Y content and the Ti inclusion amount is indicated by a broken line
- the relationship between the Y content and the crystal grain size is indicated by a solid line.
- the types of Ti inclusions observed were TiN, TiS and TiC. These Ti inclusions are generated at different temperatures, TiN is generated at 1000 ° C. or higher, TiS is generated at 900 ° C. or higher and lower than 1000 ° C., and TiC is generated at 700 ° C. or higher and 800 ° C. or lower. Many of these Ti inclusions are usually generated as fine inclusions having a diameter of about several tens of nanometers with crystal grain boundaries, dislocations, and the like as precipitation sites, and the growth of steel crystal grains is pinned and inhibited.
- the required range of the Y content in the steel sheet was more than 0.05% by mass in order to significantly reduce the Ti inclusions.
- the Y content in the product sample exceeds 0.2% by mass, the segregation of Y at the crystal grain boundary becomes remarkable, the crystal grain boundary becomes brittle, and lashes are generated on the surface of the product sample.
- the effect of Y described above brings about suppression of Ti inclusions in the steel sheet, that is, TiN, TiS, etc. are suppressed by hot rolling plate annealing or cold rolling plate finish annealing, or during strain relief annealing. This contributes to suppressing TiC.
- C not only deteriorates the magnetic properties by forming TiC in the steel sheet, but also the precipitation of C makes the magnetic aging remarkable, so the upper limit of the C content was set to 0.01% by mass. Since the lower limit of the C content is preferably as low as possible, it is not particularly limited, and may contain 0% by mass.
- [Si] Si is an element that reduces iron loss. If the Si content is less than the lower limit of 1.0% by mass, the iron loss cannot be reduced sufficiently. From the viewpoint of further reducing the iron loss, the preferable lower limit of the Si content is 1.5% by mass, more preferably 2.0% by mass. Further, if the Si content exceeds the upper limit of 3.5% by mass, the workability becomes extremely poor, so the upper limit was made 3.5% by mass. A more preferable value as the upper limit of the Si content is 3.3% by mass with better workability by cold rolling, a further preferable value is 3.1% by mass, and a more preferable value is 3.0%. % By mass.
- [Al] Al is an element that reduces iron loss. If the Al content is less than the lower limit of 0.1% by mass, the iron loss cannot be reduced sufficiently. Further, when the Al content exceeds the upper limit of 3.0% by mass, the cost is remarkably increased.
- the lower limit of the Al content is preferably 0.2% by mass, more preferably 0.3% by mass, and still more preferably 0.4% by mass from the viewpoint of iron loss.
- the upper limit of the Al content is preferably 2.5% by mass, more preferably 2.0% by mass, and still more preferably 1.8% by mass from the viewpoint of cost.
- [Mn] Mn is added in an amount of 0.1% by mass or more in order to increase the hardness of the steel sheet and improve the punchability.
- the reason why the upper limit of the Mn content is set to 2.0% by mass is due to economic reasons.
- [P] P contains P in order to increase the strength of the material and improve workability. However, if P is contained excessively, the workability in cold rolling deteriorates, so the P content is 0.1% by mass or less. In addition, since P is inevitably mixed in the production process of the steel sheet, a lower limit of the P content is not provided, but it is usually preferable not to make it less than 0.0001% by mass from the viewpoint of steelmaking cost.
- [Y] Y acts on Ti in the steel sheet in a solid solution state to suppress the formation of Ti inclusions.
- the effect is acquired when Y content exceeds 0.05 mass%.
- Y content if it is 0.055 mass% or more, it is preferable and it is more preferable if it is 0.06 mass% or more.
- the Y content is excessive, Y segregates at the grain boundaries in the steel sheet, the crystal grain boundaries become brittle, and the product quality is deteriorated due to the occurrence of whipping. Therefore, there is an upper limit to the Y content, and if it is 0.2% by mass or less, the segregation of Y at the grain boundaries is suppressed.
- the upper limit of the Y content is preferably 0.15% by mass or less, more preferably 0.12% by mass or less.
- [S] S becomes a sulfide such as TiS or MnS, which deteriorates crystal grain growth and iron loss.
- the upper limit of S content for preventing these is 0.005 mass%, a more preferable upper limit is 0.003 mass%. Since the lower limit of the S content is preferably as small as possible, it is not particularly limited and may contain 0% by mass.
- the upper limit of the allowable N content is set to 0.005% by mass.
- the upper limit of the N content is preferably 0.003% by mass, more preferably 0.0025% by mass, and still more preferably 0.002% by mass. Further, from the viewpoint of suppressing nitrides, N is preferably as small as possible.
- the lower limit of the N content is not particularly limited, but it is preferable to make the lower limit of the N content more than 0% by mass because industrial restrictions are large in order to make it as close as possible to 0% by mass. .
- the minimum of N content has set 0.001 mass% as a standard. In the case of further denitrification, it is more preferable to reduce the N content to 0.0005% by mass because the nitride is further suppressed.
- Ti produces fine inclusions such as TiN, TiS, and TiC, thereby worsening crystal grain growth and iron loss.
- the upper limit of the allowable Ti content is set to 0.01% by mass.
- the upper limit is preferably 0.005% by mass. If the Ti content is less than 0.001% by mass, the amount of Ti precipitates becomes excessive, and the effect of inhibiting the crystal grain growth is substantially eliminated.
- the alloy raw material whose Ti content is less than 0.001% by mass is expensive, the cost increases. For this reason, the lower limit which needs suppression of the Ti inclusion by this invention is accept
- Ti may be contained in the alloy raw material in an amount of 0.002% by mass or more. In this case, the present technology is particularly effective.
- [Cu] Cu improves corrosion resistance and increases specific resistance to improve iron loss. However, when the Cu content is excessive, whipping or the like is generated on the surface of the product plate and the surface quality is impaired, so the Cu content is preferably 0.5% by mass or less.
- [Cr] Cr improves the corrosion resistance and increases the specific resistance to improve the iron loss.
- excessive addition of Cr increases the cost, so the upper limit of the Cr content is preferably 20% by mass.
- Sn and Sb are segregation elements, which inhibit the texture of the (111) plane that deteriorates the magnetic properties and improve the magnetic properties. Even if these elements are used alone or in combination of the two, the above-described effects are exhibited. However, if the total of Sn and Sb exceeds 0.3% by mass, the workability by cold rolling deteriorates, so the upper limit of the total of Sn and Sb is preferably 0.3% by mass.
- Ni develops a texture favorable to magnetic properties and improves iron loss.
- the upper limit of the Ni content is preferably 1.0% by mass.
- Ca is a desulfurization element, fixes S in the steel sheet, and prevents or suppresses the formation of sulfide inclusions such as TiS and MnS.
- the upper limit of the Ca content is preferably 0.01% by mass.
- [Zr] Zr inhibits crystal grain growth even in a small amount and worsens iron loss after strain relief annealing. When it is reduced as much as possible, the Zr content is usually 0.01% by mass or less. However, if the Zr content is within this range, no harmful effects occur and there is no problem.
- V forms nitrides or carbides and inhibits domain wall movement and crystal grain growth. When it is reduced as much as possible, the V content is usually 0.01% by mass or less. However, if the V content is within this range, no harmful effects occur and there is no problem.
- Nb forms nitrides or carbides and inhibits domain wall movement and crystal grain growth. When it is reduced as much as possible, the Nb content is usually 0.01% by mass or less. However, when the Nb content is within this range, no harmful effects occur and there is no problem.
- [Mg] Mg is a desulfurization element, reacts with S in the steel sheet to form sulfide, and fixes S. If the content is increased, the desulfurization effect is enhanced, but if the Mg content exceeds 0.05 mass%, crystal grain growth is hindered by excessive Mg sulfide. Usually, the Mg content is 0.05% by mass or less, but if the Mg content is within this range, no harmful effects occur and there is no problem.
- [O] Oxides in the steel sheet form oxides.
- Al is contained by 0.1% by mass or more and is sufficiently deoxidized, so the O content in the steel sheet is 0.005% by mass or less.
- the O content is in this range, no harmful effects such as domain wall movement or inhibition of crystal grain growth due to oxides occur, and there is no problem.
- [B] B is a grain boundary segregation element and forms a nitride. Grain boundary movement is hindered by this nitride, and iron loss deteriorates. When it is reduced as much as possible, the B content is usually 0.005% by mass or less. However, when the B content is within this range, no harmful effects occur and there is no problem.
- the steel is refined by a conventional method such as a converter or a secondary refining furnace, and melted within a desired composition range. Thereafter, a slab or other slab is cast by continuous casting or ingot casting. Thereafter, the obtained slab is hot-rolled, and if necessary, hot-rolled sheet annealing is performed on the hot-rolled sheet within a range of 1100 ° C to 1300 ° C. Next, the product is finished to a thickness by one cold rolling or two or more cold rollings with intermediate annealing at 850 ° C. to 1000 ° C. Next, finish annealing is performed within a range of 800 ° C. to 1100 ° C., and an insulating film is applied to obtain a product. In some cases, strain relief annealing is performed in the range of 700 ° C. to 800 ° C.
- the number density of Ti inclusions in the steel sheet is 0.3 ⁇ 10 10 pieces / mm 3 or less, preferably 0.2 ⁇ 10 10 without changing the manufacturing process.
- C 0.0015 mass%, Si: 2.9 mass%, Mn: 0.5 mass%, P: 0.09 mass%, S: 0.002 mass%, Al: 0.43 mass%, And N: 0.0022% by mass and various elements as shown in Table 1, with the balance being iron and inevitable impurities.
- steel of these components was refined by a converter and a vacuum degassing apparatus and received in a ladle, passed through a tundish, supplied molten steel into a mold by an immersion nozzle, and continuously cast to obtain a slab.
- metal Y was added in a vacuum degassing tank. Thereafter, the slab was hot-rolled, and the obtained hot-rolled sheet was hot-rolled at 1150 ° C.
- the precipitate and crystal grain size of the product plate were investigated by the above method, and the iron loss of the product plate was examined by the Epstein method shown in JIS-C-2550 after cutting the product plate into 25 cm length. The survey results are also shown in Table 1.
- No. 1 as an example of the present invention. 6-No. In No. 21, the number of Ti inclusions (number density) such as TiN, TiS and TiC in the product plate was 0.3 ⁇ 10 10 pieces / mm 3 or less. Moreover, the crystal grain size of these samples is 100 ⁇ m or more, and the crystal grain growth property is good. It was favorable with respect to the comparative examples except for 22.
- the comparative example No. 1-No. No. 5 has a Y content below the lower limit of the range of more than 0.05% by mass and not more than 0.2% by mass.
- the Ti content exceeds the upper limit of the range of 0.001% by mass to 0.01% by mass.
- No. of the comparative example. 24 and 25 use rare earth elements other than Y instead of Y.
- many Ti inclusions such as TiN, TiS and TiC were generated in the product plate, and the grain growth property and iron loss value were inferior to those of the present invention.
- No. of the comparative example. No. 22 has a Y content exceeding the upper limit of 0.05% by mass to 0.2% by mass, but segregation of Y is observed at the crystal grain boundaries of the product plate, and the surface of the product plate is Wrinkles occurred and the surface quality was inferior.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Power Engineering (AREA)
- Dispersion Chemistry (AREA)
- Electromagnetism (AREA)
- Manufacturing & Machinery (AREA)
- Soft Magnetic Materials (AREA)
- Manufacturing Of Steel Electrode Plates (AREA)
Abstract
Description
(1)C:0.01質量%以下、
Si:1.0質量%以上3.5質量%以下、
Al:0.1質量%以上3.0質量%以下、
Mn:0.1質量%以上2.0質量%以下、
P:0.1質量%以下、
S:0.005質量%以下、
Ti:0.001質量%以上0.01質量%以下、
N:0.005質量%以下、及び
Y:0.05質量%超0.2質量%以下、
を含有し、残部が鉄および不可避的不純物であることを特徴とする無方向性電磁鋼板。
(2)さらに、
Cu:0.5質量%以下、及びCr:20質量%以下からなる群から選ばれる1種または2種の第1の群、
Sn及びSbからなる群から選ばれる1種または2種を合計で0.3質量%以下とする第2の群、
Ni:1.0質量%以下とする第3の群、及び
Ca:0.01質量%以下とする第4の群、
から選ばれる1種または2種以上の群の元素を有することを特徴とする(1)に記載の無方向性電磁鋼板。
真空溶解を用いたラボ実験を以下の手順により行った。まず、C:0.0019質量%~0.0032質量%、Si:2.7質量%~3.1質量%、Al:0.2質量%~0.46質量%、Mn:0.3質量%~0.5質量%、P:0.03質量%~0.05質量%、S:0.0022質量%~0.0035質量%、Ti:0.002質量%~0.005質量%、及びN:0.0018質量%~0.0033質量%を含む基本成分とし、Y:0質量%~0.25質量%の範囲内で成分を変化させた種々の溶鋼を溶解した。そして、インゴットに凝固させた後、ラボ実験として、熱間圧延、熱間圧延板焼鈍、冷間圧延、仕上げ焼鈍、歪取り焼鈍の順で実験を行って厚さ0.35mmの製品サンプルを製造した。次に、以下の方法により介在物ならびに結晶粒の調査を行った。
[C]
Cは、鋼板中でTiCを形成して磁気特性を劣化させるだけでなく、Cが析出することによって磁気時効が著しくなるので、C含有量の上限を0.01質量%とした。C含有量の下限は少ないほど好ましいため、特に限定されるものではなく、0質量%を含んでも良い。
Siは鉄損を減少させる元素である。Si含有量が下限の1.0質量%より少ないと充分に鉄損を減少させることができない。なお、鉄損をさらに減少させる観点から、Si含有量の好ましい下限は1.5質量%、より好ましくは2.0質量%である。また、Si含有量が上限の3.5質量%を超えると加工性が著しく不良となるため、上限を3.5質量%とした。なお、Si含有量の上限としてより好ましい値は、冷間圧延による加工性がより良好な3.3質量%であり、さらに好ましい値は3.1質量%であり、一層好ましい値は3.0質量%である。
AlはSiと同様に鉄損を減少させる元素である。Al含有量が下限の0.1質量%より少ないと充分に鉄損を減少させることができない。また、Al含有量が上限の3.0質量%を超えると、コストの増加が著しい。Al含有量の下限は、鉄損の観点から、好ましくは0.2質量%、より好ましくは0.3質量%、さらに好ましくは0.4質量%とする。また、Al含有量の上限は、コストの観点から、好ましくは2.5質量%、より好ましくは2.0質量%、さらに好ましくは1.8質量%とする。
Mnは鋼板の硬度を増加させ、打抜性を改善するために、Mnを0.1質量%以上添加する。なお、Mn含有量の上限を2.0質量%とした理由は経済的理由によるものである。
Pは材料の強度を高め、加工性を改善させるために、Pを含有させる。但し過剰にPが含有されていると、冷間圧延における加工性が低下するため、P含有量は0.1質量%以下とする。なお、Pは鋼板の製造過程で不可避的に混入するためP含有量の下限を設けないが、通常は、製鋼コストの点から0.0001質量%未満にはしないことが好ましい。
Yは固溶状態で鋼板中のTiに作用してTi介在物の生成を抑制する。Y含有量が0.05質量%を超えるとその効果が得られる。また、Y含有量が多いほど、その効果が明確となるため、0.055質量%以上であれば好ましく、0.06質量%以上であればさらに好ましい。但し、Y含有量が過剰となると、鋼板中でYが結晶粒界に偏析し、結晶粒界が脆化し、ヘゲ疵の発生などにより製品品質の劣化を引き起こす。よってY含有量には上限が存在し、0.2質量%以下であれば結晶粒界におけるYの偏析が抑制される。Y含有量の上限値は、好ましくは0.15質量%以下、より好ましくは0.12質量%以下である。
SはTiSやMnS等の硫化物となり、結晶粒成長性を悪化させ、鉄損を悪化させる。これらを防止するためのS含有量の上限は0.005質量%であるが、より好ましい上限は0.003質量%である。S含有量の下限は少ないほど好ましいため、特に限定されるものではなく、0質量%を含んでも良い。
NはTiNなどの窒化物となり鉄損を悪化させるので、許容できるN含有量の上限として0.005質量%とした。なお、N含有量の上限として好ましくは0.003質量%、より好ましくは0.0025質量%、さらに好ましくは0.002質量%である。また、窒化物を抑制する観点からNはできる限り少ないほうが好ましい。このため、N含有量の下限は特に限定されるものではないが、0質量%に限りなく近づけるには工業的な制約が大きいため、N含有量の下限を0質量%超とすることが好ましい。なお、工業製造プロセスで脱窒素を行うことが可能な範囲において、N含有量の下限は0.001質量%を目安としている。さらに極限的に脱窒素した場合、N含有量を0.0005質量%まで下げると窒化物がさらに抑制されてより好ましい。
TiはTiN、TiS、TiCなどの微細介在物を生成し、結晶粒成長性を悪化させ、鉄損を悪化させる。本発明によりTi介在物が抑制されるものの、許容できるTi含有量の上限を0.01質量%とした。また、上記の理由により、上限として好ましくは0.005質量%である。なお、Ti含有量が0.001質量%を下回るとTi析出物が過少となり、結晶粒成長の阻害効果が実質的に問題なくなる。一方、Ti含有量が0.001質量%未満となる合金原料は高価であることから、コストアップとなってしまう。このため、本発明によるTi介在物の抑制が必要な下限は、不純物として不可避的に混入する0.001質量%までは許容できる。なお、特に安価な合金原料を用いた場合には合金原料にTiが0.002質量%以上含有される場合があり、その場合には特に本技術が有効である。
Cuは耐食性を向上させ、また固有抵抗を高めて鉄損を改善する。但し、Cu含有量が過剰な場合は製品板の表面にヘゲ疵などが発生して表面品位を損ねるため、Cu含有量は0.5質量%以下が好ましい。
Crは耐食性を向上させ、また固有抵抗を高めて鉄損を改善する。但し、Crを過剰に添加すると、コストが高くなるため、Cr含有量の上限を20質量%とすることが好ましい。
Niは磁気特性に有利な集合組織を発達させ、鉄損を改善する。但し、Niを過剰に添加するとコストが高くなるため、Ni含有量の上限を1.0質量%とすることが好ましい。
Caは脱硫元素であり、鋼板中でSを固定し、TiSやMnSなどの硫化物介在物の生成を防止または抑制する。但し、Ca含有量が0.01質量%を超えると耐火物の溶損などの問題が発生して好ましくないため、Ca含有量の上限を0.01質量%とすることが好ましい。
Zrは微量でも結晶粒成長を阻害し、歪取り焼鈍後の鉄損を悪化させる。できる限り低減した場合、通常、Zr含有量は0.01質量%以下となるが、Zr含有量がこの範囲では有害作用が起こらず問題ない。
Vは窒化物あるいは炭化物を形成し、磁壁移動や結晶粒成長を阻害する。できる限り低減した場合、通常、V含有量は0.01質量%以下となるが、V含有量がこの範囲では有害作用が起こらず問題ない。
Nbは窒化物あるいは炭化物を形成し、磁壁移動や結晶粒成長を阻害する。できる限り低減した場合、通常、Nb含有量は0.01質量%以下となるが、Nb含有量がこの範囲では有害作用が起こらず問題ない。
Mgは脱硫元素であり、鋼板中のSと反応してサルファイドを形成し、Sを固定する。含有量が多くなると脱硫効果が強化されるものの、Mg含有量が0.05質量%を超えると、過剰なMg硫化物により結晶粒成長が妨げられる。通常、Mg含有量は0.05質量%以下となるが、Mg含有量がこの範囲では有害作用が起こらず問題ない。
鋼板中のOにより酸化物が形成される。但し、本発明ではAlが0.1質量%以上含有され、充分に脱酸されているため、鋼板中のO含有量は0.005質量%以下となっている。O含有量がこの範囲では、酸化物による磁壁移動や結晶粒成長の阻害などの有害作用が起こらず問題ない。
Bは粒界偏析元素であり、また窒化物を形成する。この窒化物によって粒界移動が妨げられ、鉄損が悪化する。できる限り低減した場合、通常、B含有量は0.005質量%以下となるが、B含有量がこの範囲では有害作用が起こらず問題ない。
Claims (2)
- C:0.01質量%以下、
Si:1.0質量%以上3.5質量%以下、
Al:0.1質量%以上3.0質量%以下、
Mn:0.1質量%以上2.0質量%以下、
P:0.1質量%以下、
S:0.005質量%以下、
Ti:0.001質量%以上0.01質量%以下、
N:0.005質量%以下、及び
Y:0.05質量%超0.2質量%以下、
を含有し、残部が鉄および不可避的不純物であることを特徴とする無方向性電磁鋼板。 - さらに、
Cu:0.5質量%以下、及びCr:20質量%以下からなる群から選ばれる1種または2種の第1の群、
Sn及びSbからなる群から選ばれる1種または2種を合計で0.3質量%以下とする第2の群、
Ni:1.0質量%以下とする第3の群、及び
Ca:0.01質量%以下とする第4の群、
から選ばれる1種または2種以上の群の元素を有することを特徴とする請求項1に記載の無方向性電磁鋼板。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP13749234.4A EP2708615B1 (en) | 2012-02-14 | 2013-02-05 | Non-oriented electrical steel sheet |
JP2013527814A JP5360336B1 (ja) | 2012-02-14 | 2013-02-05 | 無方向性電磁鋼板 |
US14/115,758 US8840734B2 (en) | 2012-02-14 | 2013-02-05 | Non-oriented electrical steel sheet |
CN201380001525.0A CN103582716B (zh) | 2012-02-14 | 2013-02-05 | 无方向性电磁钢板 |
KR1020137030747A KR101457839B1 (ko) | 2012-02-14 | 2013-02-05 | 무방향성 전자 강판 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012029884 | 2012-02-14 | ||
JP2012-029884 | 2012-02-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013121924A1 true WO2013121924A1 (ja) | 2013-08-22 |
Family
ID=48984038
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2013/052555 WO2013121924A1 (ja) | 2012-02-14 | 2013-02-05 | 無方向性電磁鋼板 |
Country Status (6)
Country | Link |
---|---|
US (1) | US8840734B2 (ja) |
EP (1) | EP2708615B1 (ja) |
JP (1) | JP5360336B1 (ja) |
KR (1) | KR101457839B1 (ja) |
CN (1) | CN103582716B (ja) |
WO (1) | WO2013121924A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2021508781A (ja) * | 2017-12-26 | 2021-03-11 | ポスコPosco | 無方向性電磁鋼板およびその製造方法 |
US11230745B2 (en) | 2015-12-23 | 2022-01-25 | Posco | Non-oriented electrical steel sheet and manufacturing method therefor |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106460122B (zh) * | 2014-06-26 | 2018-06-05 | 新日铁住金株式会社 | 电磁钢板 |
JP5975076B2 (ja) * | 2014-08-27 | 2016-08-23 | Jfeスチール株式会社 | 無方向性電磁鋼板およびその製造方法 |
KR101647655B1 (ko) * | 2014-12-15 | 2016-08-11 | 주식회사 포스코 | 방향성 전기강판 및 그 제조방법 |
WO2016148010A1 (ja) * | 2015-03-17 | 2016-09-22 | 新日鐵住金株式会社 | 無方向性電磁鋼板およびその製造方法 |
KR101919521B1 (ko) * | 2016-12-22 | 2018-11-16 | 주식회사 포스코 | 방향성 전기강판 및 이의 제조방법 |
JP6828816B2 (ja) | 2017-06-02 | 2021-02-10 | 日本製鉄株式会社 | 無方向性電磁鋼板 |
TWI688658B (zh) * | 2019-03-20 | 2020-03-21 | 日商新日鐵住金股份有限公司 | 無方向性電磁鋼板 |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5436966B2 (ja) | 1974-11-29 | 1979-11-12 | ||
JP2005264280A (ja) * | 2004-03-22 | 2005-09-29 | Jfe Steel Kk | 打ち抜き性及び耐被膜剥離性に優れた方向性電磁鋼板及びその製造方法 |
JP2005336503A (ja) | 2003-05-06 | 2005-12-08 | Nippon Steel Corp | 鉄損に優れた無方向性電磁鋼板およびその製造方法 |
JP2006131943A (ja) * | 2004-11-04 | 2006-05-25 | Nippon Steel Corp | 鉄損に優れた無方向性電磁鋼板 |
JP2006219692A (ja) | 2005-02-08 | 2006-08-24 | Nippon Steel Corp | 無方向性電磁鋼板およびその製造方法 |
JP2007016278A (ja) | 2005-07-07 | 2007-01-25 | Sumitomo Metal Ind Ltd | 回転子用無方向性電磁鋼板およびその製造方法 |
JP2010280936A (ja) * | 2009-06-03 | 2010-12-16 | Nippon Steel Corp | 無方向性電磁鋼板およびその製造方法 |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5436966A (en) | 1977-08-29 | 1979-03-19 | Sanyo Electric Co Ltd | Thickness measuring device |
US7470333B2 (en) | 2003-05-06 | 2008-12-30 | Nippon Steel Corp. | Non-oriented electrical steel sheet excellent in core loss and manufacturing method thereof |
CN100476004C (zh) * | 2003-05-06 | 2009-04-08 | 新日本制铁株式会社 | 铁损优良的无方向性电磁钢板及其制造方法 |
US7662242B2 (en) | 2004-11-04 | 2010-02-16 | Nippon Steel Corporation | Non-oriented electrical steel superior in core loss |
CN100549206C (zh) * | 2005-02-23 | 2009-10-14 | 新日本制铁株式会社 | 轧制方向的磁特性优良的无取向电磁钢板及其制造方法 |
KR100973627B1 (ko) | 2005-07-07 | 2010-08-02 | 수미도모 메탈 인더스트리즈, 리미티드 | 무방향성 전자 강판 및 그 제조 방법 |
-
2013
- 2013-02-05 KR KR1020137030747A patent/KR101457839B1/ko active IP Right Grant
- 2013-02-05 WO PCT/JP2013/052555 patent/WO2013121924A1/ja active Application Filing
- 2013-02-05 EP EP13749234.4A patent/EP2708615B1/en active Active
- 2013-02-05 CN CN201380001525.0A patent/CN103582716B/zh active Active
- 2013-02-05 US US14/115,758 patent/US8840734B2/en active Active
- 2013-02-05 JP JP2013527814A patent/JP5360336B1/ja active Active
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5436966B2 (ja) | 1974-11-29 | 1979-11-12 | ||
JP2005336503A (ja) | 2003-05-06 | 2005-12-08 | Nippon Steel Corp | 鉄損に優れた無方向性電磁鋼板およびその製造方法 |
JP2005264280A (ja) * | 2004-03-22 | 2005-09-29 | Jfe Steel Kk | 打ち抜き性及び耐被膜剥離性に優れた方向性電磁鋼板及びその製造方法 |
JP2006131943A (ja) * | 2004-11-04 | 2006-05-25 | Nippon Steel Corp | 鉄損に優れた無方向性電磁鋼板 |
JP2006219692A (ja) | 2005-02-08 | 2006-08-24 | Nippon Steel Corp | 無方向性電磁鋼板およびその製造方法 |
JP2007016278A (ja) | 2005-07-07 | 2007-01-25 | Sumitomo Metal Ind Ltd | 回転子用無方向性電磁鋼板およびその製造方法 |
JP2010280936A (ja) * | 2009-06-03 | 2010-12-16 | Nippon Steel Corp | 無方向性電磁鋼板およびその製造方法 |
Non-Patent Citations (5)
Title |
---|
"ASTM E127: Annual Book of ASTM standards", vol. 03.03, 1995 |
CHUN-KAN HOU ET AL.: "Effect of Cerium Content on the Magnetic Properties of Non- oriented Electrical Steels", ISIJ INTERNATIONAL, vol. 48, no. 4, 2008, pages 531 - 539, XP055100002 * |
FUMIO KUROSAWA; ISAO TAGUCHI; RYUTARO MATSUMOTO, THE JOURNAL OF THE JAPAN INSTITUTE OF METALS, vol. 43, 1979, pages 1068 |
MASAAKI KONO ET AL.: "Effect of REM Addition on Grain Growh Behavior of Non-oriented Electrical Steel Sheets", CURRENT ADVANCES IN MATERIALS AND PROCESSES, vol. 15, no. 6, 1 September 2002 (2002-09-01), pages 1207, XP008171911 * |
See also references of EP2708615A4 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11230745B2 (en) | 2015-12-23 | 2022-01-25 | Posco | Non-oriented electrical steel sheet and manufacturing method therefor |
JP2021508781A (ja) * | 2017-12-26 | 2021-03-11 | ポスコPosco | 無方向性電磁鋼板およびその製造方法 |
US11773463B2 (en) | 2017-12-26 | 2023-10-03 | Posco Co., Ltd | Non-oriented electrical steel sheet and method for preparing same |
Also Published As
Publication number | Publication date |
---|---|
CN103582716B (zh) | 2015-05-13 |
KR20130140208A (ko) | 2013-12-23 |
EP2708615A1 (en) | 2014-03-19 |
JP5360336B1 (ja) | 2013-12-04 |
US8840734B2 (en) | 2014-09-23 |
JPWO2013121924A1 (ja) | 2015-05-11 |
KR101457839B1 (ko) | 2014-11-04 |
CN103582716A (zh) | 2014-02-12 |
EP2708615B1 (en) | 2016-05-04 |
US20140072471A1 (en) | 2014-03-13 |
EP2708615A4 (en) | 2015-02-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5360336B1 (ja) | 無方向性電磁鋼板 | |
KR102095142B1 (ko) | 무방향성 전기강판과 그 제조 방법 | |
JP4510911B2 (ja) | 高周波用無方向性電磁鋼鋳片の製造方法 | |
JP4681689B2 (ja) | 無方向性電磁鋼板及びその製造方法 | |
US9947446B2 (en) | Hot-rolled steel sheet for production of non-oriented electrical steel sheet and method of manufacturing same | |
KR102244171B1 (ko) | 무방향성 전기 강판 및 그 제조 방법 | |
KR20130125830A (ko) | 고강도 무방향성 전자기 강판 | |
JPWO2013179438A1 (ja) | 無方向性電磁鋼板 | |
CN115087757A (zh) | 无取向电工钢板及其制造方法 | |
JP5263012B2 (ja) | 無方向性電磁鋼板およびその製造方法 | |
TWI550104B (zh) | 高頻率鐵損特性優良的無方向性電磁鋼板 | |
KR101353462B1 (ko) | 무방향성 전기강판 및 제조 방법 | |
KR100872607B1 (ko) | 펀칭 가공성과 왜곡 제거 소둔 후의 자기 특성이 우수한무방향성 전자 강판과 그 제조 방법 | |
TWI484048B (zh) | Non - directional electromagnetic steel plate | |
JP3843955B2 (ja) | 無方向性電磁鋼板 | |
WO2022219742A1 (ja) | 無方向性電磁鋼板用熱延鋼板及びその製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref document number: 2013527814 Country of ref document: JP Kind code of ref document: A |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 13749234 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14115758 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2013749234 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 20137030747 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |