US20160273064A1 - Non-oriented electrical steel sheet and method of manufacturing the same - Google Patents
Non-oriented electrical steel sheet and method of manufacturing the same Download PDFInfo
- Publication number
- US20160273064A1 US20160273064A1 US14/778,459 US201414778459A US2016273064A1 US 20160273064 A1 US20160273064 A1 US 20160273064A1 US 201414778459 A US201414778459 A US 201414778459A US 2016273064 A1 US2016273064 A1 US 2016273064A1
- Authority
- US
- United States
- Prior art keywords
- steel sheet
- rolled steel
- oriented electrical
- sulfide
- hot
- 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.)
- Abandoned
Links
Images
Classifications
-
- 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
-
- 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
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
-
- 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
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- 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
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
-
- 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
-
- 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
- C22C38/02—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
- C22C38/16—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
- C22C38/60—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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Definitions
- the present invention relates to a non-oriented electrical steel sheet which is used as a core material of an electrical device and a method of manufacturing the same, and more particularly, to a non-oriented electrical steel sheet having excellent core loss and a method of manufacturing the same.
- a non-oriented electrical steel sheet is used as a core material of various types of motors for heavy electrical apparatuses, home appliances, and the like.
- the non-oriented electrical steel sheet is commercially graded according to core loss, and is classified according to the design features of motors or transformers. Recently, from the viewpoint of energy saving, a further reduction in core loss and an increase in magnetic flux density have been strongly demanded of the non-oriented electrical steel sheet.
- Patent Document 1 a method of controlling the dispersion state of Cu sulfide to a preferable state for magnetic properties of a non-oriented electrical steel sheet, that is, core loss and magnetic flux density by holding a slab containing 0.2% or less of Cu in a range of 900° C. to 1100° C. for 30 minutes or longer, thereafter holding the slab at a higher temperature of 1150° C. and subsequently starting rolling, and limiting a cooling rate during finish hot rolling to be 50° C./sec or lower is disclosed.
- this method there are problems in productivity, such as an increase in rolling load due to a reduction in slab heating temperature and a difficulty in strict control of the cooling rate.
- Patent Document 2 a method of avoiding the generation of fine precipitates by adding CaSi to molten steel until the completion of casting to control the S content to be 0.005% or less, heating a slab to a temperature of 1000° C. or higher and then hot-rolling the slab, and coiling a coil at a specific temperature range is disclosed.
- high purity steel is essential.
- the formation of fine Cu sulfide due to Cu which is incorporated at an unavoidable level cannot be avoided. Therefore, there is a problem in that magnetic properties are rather deteriorated by the incorporation of Cu.
- Patent Document 3 a technique of suppressing the precipitation of Cu sulfide by performing rapid cooling from a temperature range of 500° C. to 600° C. to 300° C. at a cooling rate of 10° C./sec to 50° C./sec after final annealing is disclosed.
- the fact that Cu sulfide is precipitated even during cooling at a cooling rate of 50° C./sec or higher is known in Non-Patent Documents 1 and 2, and the like. That is, in the technique of Patent Document 3 in which cooling is performed at a cooling rate of 10° C./sec to 50° C./sec, it is difficult to completely eliminate the precipitation of Cu sulfide.
- Patent Documents 4 to 6 a technique in which an enhancement in magnetic properties is expected by suppressing the cooling rate after final annealing is disclosed. However, in this method, it may not be possible to make Cu sulfide harmless.
- the present invention has been made taking the foregoing circumstances into consideration, and an object thereof is to provide a non-oriented electrical steel sheet having excellent core loss and a method of manufacturing the same without causing an increase in cost or a reduction in productivity by making Cu sulfide harmless and increasing the grain size.
- the inventors conducted more detailed examination on the morphology or structure of sulfide, and found a possibility that a difference in core loss might be caused by a difference in atomic structure of Cu sulfide, and specifically, a possibility that the consistency between the crystal lattice of Fe as a primary phase and Cu sulfide might affect magnetic domain wall motion.
- the present invention has been made based on the above-described findings, and is summarized in the following (1) to (8).
- a method of manufacturing a non-oriented electrical steel sheet is a method of manufacturing the non-oriented electrical steel sheet described in any one of (1) to (3), and includes: performing a hot rolling on a slab to obtain a hot-rolled steel sheet; annealing the hot-rolled steel sheet; pickling the hot-rolled steel sheet; performing a cold rolling on the hot-rolled steel sheet to obtain a cold-rolled steel sheet; and annealing the cold-rolled steel sheet, in which, in the annealing of the cold-rolled steel sheet, after the cold-rolled steel sheet is held at T1° C., which is represented in the following Expression 2, to 1530° C. for 30 seconds to 3600 seconds, when an average cooling rate from the T1° C.
- T2° C. which is shown in Expression 3
- CR1 in the unit of ° C./sec
- CR2 in the unit of ° C./sec
- the cold-rolled steel sheet is cooled to a temperature range of the T3° C. or lower so that the CR1 and the CR2 satisfy Expressions 5, 6 and 7:
- [% Cu] is a Cu content in terms of mass % and [% S] is an S content in terms of mass %.
- the CR1 may further satisfy the following Expression 8.
- the CR2 may further satisfy the following Expression 9.
- the method of manufacturing a non-oriented electrical steel sheet described in any one of (4) to (6) may further include: subsequent to the annealing of the cold-rolled steel sheet, holding the cold-rolled steel sheet in a temperature range of the T2° C. or lower to the T3° C. or higher for 30 seconds or longer as an additional annealing.
- the hot-rolled steel sheet in the annealing of the hot-rolled steel sheet, may be cooled so that CR3 which is an average cooling rate from the T1° C. to room temperature is 15° C./sec or higher.
- properties (magnetic flux density, workability, and the like) other than core loss, required of a grain-oriented electrical steel sheet can be ensured to be the same or a higher level than a material in the related art.
- FIG. 2 is a flowchart showing an example of a process of manufacturing a non-oriented electrical steel sheet according to an embodiment.
- non-oriented electrical steel sheet according to an embodiment of the present invention may also be referred to as a non-oriented electrical steel sheet according to this embodiment
- a method of manufacturing the same will be described in detail. All of % of contents are mass %.
- the upper limit of the C content is 0.01%. From the viewpoint of the improvement in core loss, the C content is preferably 0.0020% or less. On the other hand, when the C content is less than 0.0001%, the magnetic flux density is deteriorated. Therefore, in order to ensure a sufficient magnetic flux density, the lower limit of the C content is 0.0001%.
- the C content is preferably 0.0005 to 0.0015%, and more preferably 0.0007 to 0.0010%.
- the Si content is 0.05% to 7.0% for a balance between ensuring core loss and a sheet travelling property.
- the Si content is preferably 2.3% to 3.5%, more preferably 2.9% to 3.3%, and still more preferably 3.0% to 3.2%.
- Mn reacts with S and forms sulfide, and is thus an important element in the present invention.
- MnS is precipitated and thus the transition temperature of the crystal structure of Cu sulfide is reduced.
- Cu sulfide having a cubic structure is less likely to be generated. Therefore, the upper limit of the Mn content is 3.0%.
- the Mn content is less than 0.01%, the steel sheet becomes embrittled during hot rolling. Therefore, the lower limit of the Mn content is 0.01%.
- the Mn content is preferably 0.05% to 2.0%, and more preferably 0.1% to 1.0%.
- Al is solutionized in steel, resulting in the electric resistance of steel is increased and core loss is reduced. Therefore, in order to improve core loss (reduce core loss), increasing the Al content in steel is advantageous.
- molten steel having a high Al content causes deterioration in operability during casting and thus causes embrittlement of the steel sheet. Therefore, the upper limit of the Al content is 3.0%.
- the Al content is low, AlN which accelerates grain growth in the steel sheet is not sufficiently generated, and fine TiN that impedes the grain growth is generated instead of AlN, resulting in significant deterioration in the magnetic flux density. Therefore, the lower limit of the Al content is 0.0020%.
- the Al content is preferably 0.1% to 2.0%, and more preferably 1.0% to 1.5%.
- the S content is directly associated with the amount of sulfide.
- S content is excessive, S is present in steel in a solid solution state, and steel becomes embrittled during hot rolling. Therefore, the upper limit of the S content is 0.1%.
- the precipitation temperature range a temperature range of T2° C. to T3° C., which will be described later
- the lower limit of the S content is 0.0001%.
- the S content is preferably 0.01% to 0.05%, and more preferably 0.02% to 0.03%.
- P has an effect of increasing the hardness of the steel sheet and enhancing a blanking property.
- a small amount of P has an effect of improving the magnetic flux density.
- the lower limit of the P content is 0.0010%.
- the upper limit of the P content is 0.15%.
- the P content is preferably 0.005% to 0.1%, and more preferably 0.01% to 0.07%.
- N is an element which forms nitride with Ti and the like.
- the N content is excessive, the precipitation amount of nitride such as TiN is increased, and this nitride impedes the grain growth. Therefore, the upper limit of the N content is 0.01%.
- a small amount of N contained suppresses precipitation of fine TiC, and thus an effect of accelerating the grain growth of the steel sheet is obtained. Therefore, for the purpose of ensuring a sufficient magnetic flux density, the lower limit of the N content is 0.0010%.
- the N content is preferably 0.0030% to 0.0080%, more preferably 0.0040% to 0.0080%, and still more preferably 0.0050% to 0.0070%.
- Cu is an element which forms sulfide like Mn, and is a particularly important element.
- the upper limit of the Cu content is 5.0%.
- the generation temperature of Cu sulfide needs to be a high temperature, and the lower limit of the Cu content needs to be 0.01%.
- the Cu content is preferably 0.1% to 1.5%, and more preferably 0.8% to 1.2%.
- the non-oriented electrical steel sheet according to this embodiment basically contains the above-described chemical components, and the remainder including Fe and impurities.
- a small amount of elements such as Mo, W, In, Sn, Bi, Sb, Ag, Te, Ce, V, Cr, Co, Ni, Se, Re, Os, Nb, Zr, Hf, and Ta may be contained in a range of 0.5% or less in total.
- Elements which generate sulfides such as Mg, Ca, Zn, and Ti affect the solid solution temperature of Cu sulfide, and thus the sum of the amounts thereof is preferably 0.2% or less.
- One is a cubic structure, and the other is a hexagonal structure (hexagonal close-packed structure).
- the cubic structure has a stable phase
- the hexagonal structure has a metastable phase.
- Cu sulfide (hexagonal) indicates Cu sulfide having the hexagonal structure
- Cu sulfide (cubic) indicates Cu sulfide having the cubic structure.
- the identification of diffraction peaks may be collated by using JCPDS-CARD which is a database of crystal lattices.
- JCPDS-CARD is a database of crystal lattices.
- Cu sulfide (hexagonal) can be identified by using JCPDS-CARD: 00-023-0958 or the like
- Cu sulfide (cubic) can be identified by using JCPDS-CARD: 00-024-0061 or the like.
- an XRD diffraction intensity is a height from the background to the peak of a spectrum.
- the XRD diffraction intensity (peak intensity) in this embodiment is also obtained by removing the background using the software described in Non-Patent Documents 3 and 4.
- Cu sulfide is allowed to be actively precipitated by sufficiently increasing the Cu content with respect to the S content.
- the Cu content and the Mn content are controlled to satisfy [% Cu]/[% S] ⁇ 2.5. 120 ⁇ [% Cu]/[% S]>40 is more preferable, and 70>[% Cu]/[% S]>50 is still more preferable.
- the non-oriented electrical steel sheet according to this embodiment in order to further improve core loss, it is preferable that sulfide which contains Cu and has a diameter of 5 nm to 500 nm is present in the steel sheet at a number density per unit area of 0.5 pieces/ ⁇ m 3 to 50 pieces/ ⁇ m 3 .
- the number density of sulfide is preferably 0.5 pieces/ ⁇ m 3 or higher.
- the number density is higher than 50 pieces/ ⁇ m 3 , grain growth properties are deteriorated, and thus there is concern of the deterioration in magnetic flux density.
- the upper limit of the number density is preferably 50 pieces/ ⁇ m 3 .
- the number density of sulfide is preferably in a range of 0.5 pieces/ ⁇ m 3 to 1.0 pieces/ ⁇ m 3 , and is more preferably in a rage of 0.5 pieces/ ⁇ m 3 to 0.7 pieces/ ⁇ m 3 .
- the observation of precipitates containing sulfide described above may be performed on the steel sheet having a corroded surface with an SEM (scanning electron microscope) or a TEM (transmission electron microscope) according to an extraction replica method or a thin film method.
- SEM scanning electron microscope
- TEM transmission electron microscope
- Cu sulfide is extremely fine (for example, smaller than 5 nm).
- the crystal structure of Cu sulfide is mainly cubic, and thus sulfide becomes coarse. Accordingly, the diameter of Cu sulfide can be controlled to be in a range of 5 nm to 500 nm. Regarding core loss, a preferable Cu sulfide diameter is 50 nm to 300 nm, and a more preferable Cu sulfide diameter is 100 nm to 200 nm.
- the volume fraction of Cu sulfide having the cubic structure is 50% or more of the total of Cu sulfide.
- the volume fraction of Cu sulfide having the cubic structure is more preferably 66.7%, and still more preferably 80%.
- Cu sulfide includes not only the precipitates of Cu sulfide alone, but also the precipitates which are compositely precipitated with other sulfides, oxides or carbides such as MnS and TiS. Furthermore, precipitates in which metal atoms such as Mn or Fe are solutionized in Cu sulfide, such as Cu(Mn)S or Cu(Fe)S, are also included.
- the non-oriented electrical steel sheet according to this embodiment can be manufactured by performing hot rolling, hot-rolled sheet annealing, cold rolling, final annealing, and the like on a slab which is melted in a converter and is subjected to continuous casting, in the same manner as a typical electrical steel sheet.
- the effect of improving core loss can be obtained.
- a hot rolling method such as hot direct rolling or continuous hot rolling and a slab heating temperature
- the effect of improving core loss can be obtained.
- a cold rolling method such as cold rolling performed two or more times or warm rolling and a cold rolling reduction
- the effect of improving core loss can be obtained.
- a process of forming an insulating film, a decarburization process, and the like may also be performed.
- T1° C. is a solid solution temperature of Cu sulfide obtained by calculation
- T2° C. is a precipitation start temperature of Cu sulfide having the cubic structure obtained by calculation
- T3° C. is a lower limit temperature, at which Cu sulfide having the cubic structure is precipitated, obtained by calculation.
- [% Cu] is the Cu content in terms of mass %
- [% S] is the S content in terms of mass %
- the total amount of Cu sulfide can be solutionized by holding the steel sheet at T1° C. or higher which is the calculated solid solution temperature of Cu sulfide for 30 seconds or longer.
- T1° C. or higher which is the calculated solid solution temperature of Cu sulfide for 30 seconds or longer.
- the holding temperature is lower than T1° C.
- Cu sulfide cannot be sufficiently solutionized, Cu sulfide having the hexagonal structure or having a crystal lattice damaged by cold rolling remains and has an adverse influence on core loss, which is not preferable.
- sulfides such as TiS are solutionized and are finely precipitated during cooling such that grain growth in the steel sheet is suppressed and the magnetic flux density and core loss thereof are deteriorated.
- the holding temperature at which Cu sulfide is reliably solutionized and solutionizing of other sulfides is avoided as much as possible is preferably T1+30° C. or higher and T1+200° C. or lower, and more preferably T1+50° C. or higher and T1+100° C. or lower.
- T1+30° C. or higher and T1+200° C. or lower is preferably T1+50° C. or higher and T1+100° C. or lower.
- the upper limit of T1 is 1530° C.
- the holding time when the holding time is less than 30 seconds, solutionizing does not sufficiently progress. In order to allow Cu sulfide to be more reliably solutionized, it is preferable that the holding time is 35 seconds or longer.
- the holding temperature when heating is performed for a long period of time, there is a possibility that other sulfides such as TiS having a low precipitation rate may be generated and the amount of generated Cu sulfide (cubic) which is effective in improving core loss may be reduced. Therefore, the holding temperature (a stay time at T1° C. or higher) is preferably 3600 seconds or shorter, and more preferably 300 seconds or shorter.
- the effect of improving core loss is obtained by allowing a large amount of Cu sulfide to have the cubic structure which is a stable structure at a low temperature and thus increasing the ratio of Cu sulfide having the cubic structure [Cu sulfide (cubic)] to the total amount of sulfide.
- the cause of deterioration in core loss is the precipitation of fine FeS, fine MnS, and fine Cu sulfide having the hexagonal structure [fine Cu sulfide (hexagonal)]. These precipitates are precipitated in a temperature range between the solid solution temperature T1° C. and the precipitation start temperature T2° C. of Cu sulfide (cubic). Therefore, the average cooling rate CR1 from T1° C. to T2° C. is set to 5° C./sec or more. When CR1 is lower than 5° C./sec, precipitation of fine FeS, fine MnS, and fine Cu sulfide (hexagonal) cannot be sufficiently avoided. In order to further increase core loss, CR1 is preferably higher than 20° C./sec, more preferably higher than 50° C./sec, and still more preferably higher than 100° C./sec.
- CR1 it is difficult to set CR1 to be higher than 500° C./sec due to the facilities, and thus the upper limit thereof may be 500° C./sec.
- a preferable upper limit of CR1 is 300° C./sec.
- CR2 When CR2 is higher than 50° C./sec, the amount of time for staying in the precipitation temperature range is not sufficient, and the amount of precipitated Cu sulfide (cubic) is not sufficient. In order to ensure a sufficient precipitation amount, CR2 is preferably 20° C./sec or lower, more preferably 10° C./sec or lower, and still more preferably 5° C./sec or less.
- the lower limit of CR2 is 0.5° C./sec.
- the lower limit of CR2 is preferably 1° C./sec.
- the precipitates mainly contain fine Cu sulfide (hexagonal), fine FeS, and fine MnS having an adverse influence on core loss, which is not preferable.
- final annealing may be performed two times or more.
- the steel sheet may also be subjected to first final annealing at T1° C. or higher, be temporarily cooled to T3° C. or lower, and thereafter be held in the temperature range between T2° C. to T3° C. for 30 seconds as second final annealing (additional annealing).
- additional annealing By performing the additional annealing, the amount of time that the steel sheet stays at T2° C. or lower to T3° C. or higher can be increased, and thus good core loss can be obtained.
- a more preferable temperature range of the additional annealing is T2 ⁇ 30° C. to T3+30° C.
- an still more preferable temperature range is T2 ⁇ 50° C. to T3+50° C.
- the soaking time (holding time) in the temperature range of T2° C. or lower and T3° C. or higher is preferably 35 seconds or longer and 3600 seconds or shorter, and is preferably 35 seconds or longer and 300° C. or lower.
- the non-oriented electrical steel sheet according to this embodiment as described above, it is effective to temporarily dissolve the total amount of Cu precipitates during the final annealing process.
- a large amount of Cu sulfide is precipitated during cooling in the hot rolling process.
- Cu sulfide is fine Cu sulfide (hexagonal) in a metastable phase, the total amount of Cu sulfide is rapidly solutionized during the final annealing, which is preferable.
- the total amount of Cu sulfide is solutionized by heating the steel sheet to T1° C. or higher in the hot-rolled sheet annealing process after the hot rolling process and the steel sheet is cooled at a CR3 of 15° C./sec or higher when the cooling rate from T1° C. to room temperature is denoted as CR3.
- CR3 is more preferably 30° C./sec or higher, and still more preferably 60° C./sec or higher.
- the steel sheet is subjected to slow heating at an average temperature rising rate of 100° C./sec or lower during the final annealing, and thus Cu sulfide is more easily solutionized, which is preferable.
- room temperature indicates 23 ⁇ 5° C. specified in JIS C 2556.
- FIG. 2 is a flowchart showing an example of a process of manufacturing the non-oriented electrical steel sheet according to this embodiment.
- the non-oriented electrical steel sheet according to this embodiment Cu sulfide is transformed so as to have the cubic structure which is a stable crystal system by holding the steel sheet in a predetermined temperature range between T2° C. to T3° C. described above.
- the Cu sulfide (cubic) has good consistency with the interface of steel, has a high growth rate, and is thus easily coarsened.
- W15/50 W/kg
- W15/50 is a core loss at a frequency of 50 Hz and at a maximum magnetic flux density of 1.5 T.
- the magnetic flux density was evaluated by using B50.
- B50 indicates a magnetic flux density at a magnetic field strength of 5000 A/m.
- the minimum target value of B50 was set to 1.65 T as in the related art.
- the core loss evaluation criteria of the samples are as follows.
- An ingot having the chemical components shown in Table 4 was melted in vacuum, and the ingot was heated to 1150° C. and was hot rolled at a hot rolling finish temperature of 850° C., thereby producing a hot-rolled steel sheet having a sheet thickness of 2.3 mm.
- the hot-rolled steel sheet was subjected to hot-rolled sheet annealing, was subjected to pickling, and was cold-rolled at a rolling reduction of 85%, thereby producing a cold-rolled steel sheet having a sheet thickness of 0.5 mm. Thereafter, final annealing was performed at a holding temperature of T1+50° C. for a holding time of 45 seconds. Thereafter, furnace cooling was performed so that the average cooling rates between T1° C. and T2° C.
- T2° C. and T3° C. were respectively 35° C./sec and 15° C./sec.
- X-ray diffraction results, the precipitation states of precipitates, magnetic properties (magnetic flux density and core loss), brittleness, and overall evaluation results are shown in Table 5.
- Example 2 Regarding X-ray diffraction, measurement of the magnetic properties, and measurement of the precipitates, the same evaluations as in Example 1 were performed. Furthermore, in this example, a repeat bending test was performed on the basis of JIS C 2550:2000 to evaluate workability. In a case where breaking occurs with one time of bending, working properties were insufficient and were evaluated as fail, and a level at which breaking had not occurred after two times of bending was evaluated as pass (PASS).
- PASS pass
- An ingot having the same components as Steel type No. H23 shown in Table 4 was heated to 1100° C. and was hot-rolled at a finish temperature of 850° C. and a coiling temperature of 630° C., thereby producing a hot-rolled sheet having a sheet thickness of 2.0 mm.
- the hot-rolled sheet was subjected to final annealing under the conditions shown in Table 5, and was subjected to hot-rolled sheet annealing at 1000° C. for 120 seconds in some examples.
- Other manufacturing conditions, X-ray diffraction results, the precipitation states of precipitates, and the evaluation results of magnetic properties (magnetic flux density and core loss) are shown in Table 6.
- X-ray diffraction measurement of the magnetic properties, and measurement of the precipitates, the same evaluations as in Example 1 were performed.
- the present invention even when high purification, a reduction in slab heating temperature, optimization of hot rolling conditions, and the like are not performed on the non-oriented electrical steel sheet, it is possible to make fine Cu sulfide harmless. Accordingly, a non-oriented electrical steel sheet having excellent core loss can be provided.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Organic Chemistry (AREA)
- Metallurgy (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Crystallography & Structural Chemistry (AREA)
- Thermal Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Electromagnetism (AREA)
- Dispersion Chemistry (AREA)
- Power Engineering (AREA)
- Manufacturing Of Steel Electrode Plates (AREA)
- Soft Magnetic Materials (AREA)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013081078 | 2013-04-09 | ||
JP2013-081078 | 2013-04-09 | ||
PCT/JP2014/060164 WO2014168136A1 (ja) | 2013-04-09 | 2014-04-08 | 無方向性電磁鋼板およびその製造方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20160273064A1 true US20160273064A1 (en) | 2016-09-22 |
Family
ID=51689543
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/778,459 Abandoned US20160273064A1 (en) | 2013-04-09 | 2014-04-08 | Non-oriented electrical steel sheet and method of manufacturing the same |
Country Status (9)
Country | Link |
---|---|
US (1) | US20160273064A1 (ja) |
EP (1) | EP2985360B1 (ja) |
JP (1) | JP5930120B2 (ja) |
KR (1) | KR101719445B1 (ja) |
CN (1) | CN105121683B (ja) |
BR (1) | BR112015023929B1 (ja) |
PL (1) | PL2985360T3 (ja) |
TW (1) | TWI531663B (ja) |
WO (1) | WO2014168136A1 (ja) |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150357101A1 (en) * | 2013-02-21 | 2015-12-10 | Jfe Steel Corporation | Method for producing semi-processed non-oriented electrical steel sheet having excellent magnetic properties |
US9920393B2 (en) | 2012-03-15 | 2018-03-20 | Jfe Steel Corporation | Method of producing non-oriented electrical steel sheet |
US10316382B2 (en) | 2015-02-24 | 2019-06-11 | Jfe Steel Corporation | Method for producing non-oriented electrical steel sheets |
US10941458B2 (en) * | 2015-02-18 | 2021-03-09 | Jfe Steel Corporation | Non-oriented electrical steel sheet, production method therefor, and motor core |
US10975451B2 (en) | 2015-08-04 | 2021-04-13 | Jfe Steel Corporation | Method for producing non-oriented electrical steel sheet having excellent magnetic properties |
US11111557B2 (en) * | 2016-12-19 | 2021-09-07 | Posco | Non-oriented electrical steel sheet and manufacturing method therefor |
US20220018004A1 (en) * | 2018-11-30 | 2022-01-20 | Posco | Non-oriented electrical steel sheet and method for manufacturing same |
US11421297B2 (en) | 2018-03-23 | 2022-08-23 | Nippon Steel Corporation | Non-oriented electrical steel sheet |
US11566303B2 (en) | 2018-02-16 | 2023-01-31 | Nippon Steel Corporation | Non-oriented electrical steel sheet and method for manufacturing non-oriented electrical steel sheet |
US11680302B2 (en) | 2015-09-28 | 2023-06-20 | Nippon Steel Corporation | Grain-oriented electrical steel sheet and hot-rolled steel sheet for grain-oriented electrical steel sheet |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6627226B2 (ja) * | 2015-02-24 | 2020-01-08 | 日本製鉄株式会社 | 無方向性電磁鋼板の製造方法 |
JP6586815B2 (ja) * | 2015-08-14 | 2019-10-09 | 日本製鉄株式会社 | 鉄損に優れた無方向性電磁鋼板およびその製造方法 |
KR102175064B1 (ko) * | 2015-12-23 | 2020-11-05 | 주식회사 포스코 | 무방향성 전기강판 및 그 제조방법 |
BR112019009507B1 (pt) * | 2017-01-16 | 2023-04-11 | Nippon Steel Corporation | Chapa de aço elétrico não orientado e método para fabricar chapa de aço elétrico não orientado |
JP6891673B2 (ja) * | 2017-07-04 | 2021-06-18 | 日本製鉄株式会社 | 無方向性電磁鋼板およびその製造方法 |
CN107460409B (zh) * | 2017-07-05 | 2019-10-18 | 邢台钢铁有限责任公司 | 一种汽车发电机极爪用高Al电工钢方坯及其生产方法 |
KR102120276B1 (ko) * | 2018-09-27 | 2020-06-08 | 주식회사 포스코 | 무방향성 전기강판 및 그 제조방법 |
KR102178341B1 (ko) * | 2018-11-30 | 2020-11-12 | 주식회사 포스코 | 자성이 우수한 무방향성 전기강판 및 그 제조방법 |
KR102241985B1 (ko) * | 2018-12-19 | 2021-04-19 | 주식회사 포스코 | 무방향성 전기강판 및 그 제조방법 |
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 |
WO2024070489A1 (ja) * | 2022-09-30 | 2024-04-04 | 日本製鉄株式会社 | 無方向性電磁鋼板および無方向性電磁鋼板の製造方法 |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63179050A (ja) * | 1987-01-19 | 1988-07-23 | Sumitomo Metal Ind Ltd | 析出分散型強磁性厚鋼板 |
JPH09302414A (ja) | 1996-05-15 | 1997-11-25 | Nkk Corp | 低磁場特性に優れた無方向性電磁鋼板の製造方法 |
JP3430830B2 (ja) | 1996-12-20 | 2003-07-28 | Jfeスチール株式会社 | 磁気特性の優れた無方向性電磁鋼板の製造方法 |
JP3719183B2 (ja) | 2001-10-05 | 2005-11-24 | Jfeスチール株式会社 | 電動パワーステアリングモータ用の無方向性電磁鋼板およびその製造方法 |
JP4542306B2 (ja) | 2002-04-05 | 2010-09-15 | 新日本製鐵株式会社 | 無方向性電磁鋼板の製造方法 |
JP5375678B2 (ja) | 2002-04-05 | 2013-12-25 | 新日鐵住金株式会社 | 鉄損および磁束密度が極めて優れた無方向性電磁鋼板 |
JP4276459B2 (ja) * | 2003-03-31 | 2009-06-10 | 新日本製鐵株式会社 | 小型トランス用無方向性電磁鋼板 |
JP4383181B2 (ja) * | 2004-01-16 | 2009-12-16 | 新日本製鐵株式会社 | コイル内の磁気特性の均一性に優れ製造歩留まりが高い無方向性電磁鋼板およびその製造方法 |
JP4341476B2 (ja) * | 2004-06-04 | 2009-10-07 | 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 |
JP4358707B2 (ja) * | 2004-08-24 | 2009-11-04 | 新日本製鐵株式会社 | 溶接性および靱性に優れた引張り強さ550MPa級以上の高張力鋼材およびその製造方法 |
JP4568190B2 (ja) * | 2004-09-22 | 2010-10-27 | 新日本製鐵株式会社 | 無方向性電磁鋼板 |
JP4600003B2 (ja) | 2004-11-16 | 2010-12-15 | Jfeスチール株式会社 | モジュラー型モータ用無方向性電磁鋼板およびその製造方法 |
KR100733345B1 (ko) * | 2005-12-27 | 2007-06-29 | 주식회사 포스코 | 자성이 우수한 무방향성 전기강판 및 그 제조방법 |
JP5423175B2 (ja) | 2009-06-23 | 2014-02-19 | 新日鐵住金株式会社 | 無方向性電磁鋼板及びその製造方法 |
US9260764B2 (en) * | 2010-12-23 | 2016-02-16 | Posco | Low iron loss high strength non-oriented electromagnetic steel sheet and method for manufacturing same |
CN102127702A (zh) * | 2011-01-16 | 2011-07-20 | 首钢总公司 | 一种低s高牌号无取向电工钢的制备方法 |
CN102127708A (zh) * | 2011-01-16 | 2011-07-20 | 首钢总公司 | 一种低温板坯加热生产取向电工钢的方法 |
WO2012141206A1 (ja) * | 2011-04-13 | 2012-10-18 | 新日本製鐵株式会社 | 高強度無方向性電磁鋼板 |
-
2014
- 2014-04-08 CN CN201480019653.2A patent/CN105121683B/zh active Active
- 2014-04-08 BR BR112015023929-3A patent/BR112015023929B1/pt active IP Right Grant
- 2014-04-08 JP JP2015511261A patent/JP5930120B2/ja active Active
- 2014-04-08 US US14/778,459 patent/US20160273064A1/en not_active Abandoned
- 2014-04-08 EP EP14783448.5A patent/EP2985360B1/en active Active
- 2014-04-08 KR KR1020157025979A patent/KR101719445B1/ko active IP Right Grant
- 2014-04-08 PL PL14783448T patent/PL2985360T3/pl unknown
- 2014-04-08 WO PCT/JP2014/060164 patent/WO2014168136A1/ja active Application Filing
- 2014-04-08 TW TW103112830A patent/TWI531663B/zh active
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9920393B2 (en) | 2012-03-15 | 2018-03-20 | Jfe Steel Corporation | Method of producing non-oriented electrical steel sheet |
US20150357101A1 (en) * | 2013-02-21 | 2015-12-10 | Jfe Steel Corporation | Method for producing semi-processed non-oriented electrical steel sheet having excellent magnetic properties |
US9978488B2 (en) * | 2013-02-21 | 2018-05-22 | Jfe Steel Corporation | Method for producing semi-processed non-oriented electrical steel sheet having excellent magnetic properties |
US10941458B2 (en) * | 2015-02-18 | 2021-03-09 | Jfe Steel Corporation | Non-oriented electrical steel sheet, production method therefor, and motor core |
US10316382B2 (en) | 2015-02-24 | 2019-06-11 | Jfe Steel Corporation | Method for producing non-oriented electrical steel sheets |
US10975451B2 (en) | 2015-08-04 | 2021-04-13 | Jfe Steel Corporation | Method for producing non-oriented electrical steel sheet having excellent magnetic properties |
US11680302B2 (en) | 2015-09-28 | 2023-06-20 | Nippon Steel Corporation | Grain-oriented electrical steel sheet and hot-rolled steel sheet for grain-oriented electrical steel sheet |
US11111557B2 (en) * | 2016-12-19 | 2021-09-07 | Posco | Non-oriented electrical steel sheet and manufacturing method therefor |
US11566303B2 (en) | 2018-02-16 | 2023-01-31 | Nippon Steel Corporation | Non-oriented electrical steel sheet and method for manufacturing non-oriented electrical steel sheet |
US11421297B2 (en) | 2018-03-23 | 2022-08-23 | Nippon Steel Corporation | Non-oriented electrical steel sheet |
US20220018004A1 (en) * | 2018-11-30 | 2022-01-20 | Posco | Non-oriented electrical steel sheet and method for manufacturing same |
Also Published As
Publication number | Publication date |
---|---|
EP2985360A1 (en) | 2016-02-17 |
BR112015023929A2 (pt) | 2017-07-18 |
TWI531663B (zh) | 2016-05-01 |
JPWO2014168136A1 (ja) | 2017-02-16 |
TW201446977A (zh) | 2014-12-16 |
EP2985360A4 (en) | 2016-12-28 |
CN105121683B (zh) | 2016-12-28 |
KR20150119433A (ko) | 2015-10-23 |
WO2014168136A1 (ja) | 2014-10-16 |
EP2985360B1 (en) | 2018-07-11 |
PL2985360T3 (pl) | 2018-12-31 |
KR101719445B1 (ko) | 2017-03-23 |
BR112015023929B1 (pt) | 2020-03-31 |
JP5930120B2 (ja) | 2016-06-08 |
CN105121683A (zh) | 2015-12-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20160273064A1 (en) | Non-oriented electrical steel sheet and method of manufacturing the same | |
JP6627226B2 (ja) | 無方向性電磁鋼板の製造方法 | |
US10214791B2 (en) | Non-oriented electrical steel sheet | |
JP5995002B2 (ja) | 高磁束密度無方向性電磁鋼板およびモータ | |
US10096414B2 (en) | Non-oriented electrical steel sheet and method of manufacturing the same | |
US11421297B2 (en) | Non-oriented electrical steel sheet | |
US20120009436A1 (en) | Non-oriented magnetic steel sheet and method for producing the same | |
JP4383181B2 (ja) | コイル内の磁気特性の均一性に優れ製造歩留まりが高い無方向性電磁鋼板およびその製造方法 | |
KR102062222B1 (ko) | 방향성 전자 강판 및 방향성 전자 강판용의 열연 강판 | |
JP6586815B2 (ja) | 鉄損に優れた無方向性電磁鋼板およびその製造方法 | |
JP6891673B2 (ja) | 無方向性電磁鋼板およびその製造方法 | |
JP6801464B2 (ja) | 無方向性電磁鋼板 | |
JP6816516B2 (ja) | 無方向性電磁鋼板 | |
JP4331969B2 (ja) | 無方向性電磁鋼板の製造方法 | |
JP6638359B2 (ja) | 無方向性電磁鋼板およびその製造方法 | |
JP6468001B2 (ja) | 鋼板および鋼板の製造方法 | |
JP7541638B1 (ja) | 無方向性電磁鋼板とその製造方法 | |
TWI829403B (zh) | 無方向性電磁鋼板及其製造方法 | |
WO2024095595A1 (ja) | 無方向性電磁鋼板とその製造方法 | |
JP2017128759A (ja) | 無方向性電磁鋼板及びその製造方法 | |
KR20220107038A (ko) | 무방향성 전자 강판용 열연 강판 | |
KR20230136755A (ko) | 무방향성 전자 강판용 열연 강판 및 그 제조 방법 | |
KR20240021880A (ko) | 무방향성 전자 강판과 그의 제조 방법 | |
JP2019035115A (ja) | 無方向性電磁鋼板 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NIPPON STEEL & SUMITOMO METAL CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KATAOKA, TAKASHI;ARITA, YOSHIHIRO;TAKAHASHI, FUMIAKI;AND OTHERS;REEL/FRAME:036603/0742 Effective date: 20150807 |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: FINAL REJECTION MAILED |
|
AS | Assignment |
Owner name: NIPPON STEEL CORPORATION, JAPAN Free format text: CHANGE OF NAME;ASSIGNOR:NIPPON STEEL & SUMITOMO METAL CORPORATION;REEL/FRAME:049257/0828 Effective date: 20190401 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |