JP5904151B2 - Method for producing grain-oriented electrical steel sheet - Google Patents
Method for producing grain-oriented electrical steel sheet Download PDFInfo
- Publication number
- JP5904151B2 JP5904151B2 JP2013070401A JP2013070401A JP5904151B2 JP 5904151 B2 JP5904151 B2 JP 5904151B2 JP 2013070401 A JP2013070401 A JP 2013070401A JP 2013070401 A JP2013070401 A JP 2013070401A JP 5904151 B2 JP5904151 B2 JP 5904151B2
- Authority
- JP
- Japan
- Prior art keywords
- less
- temperature
- ppm
- annealing
- grain
- 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.)
- Active
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 26
- 229910001224 Grain-oriented electrical steel Inorganic materials 0.000 title claims description 23
- 238000000137 annealing Methods 0.000 claims description 72
- 238000001953 recrystallisation Methods 0.000 claims description 63
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 44
- 229910000831 Steel Inorganic materials 0.000 claims description 44
- 239000010959 steel Substances 0.000 claims description 44
- 238000005121 nitriding Methods 0.000 claims description 42
- 238000000034 method Methods 0.000 claims description 27
- 229910052757 nitrogen Inorganic materials 0.000 claims description 24
- 229910052710 silicon Inorganic materials 0.000 claims description 13
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 238000005096 rolling process Methods 0.000 claims description 7
- 238000005098 hot rolling Methods 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- 229910052717 sulfur Inorganic materials 0.000 claims description 6
- 238000003303 reheating Methods 0.000 claims description 5
- 229910052711 selenium Inorganic materials 0.000 claims description 5
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 3
- 229910052748 manganese Inorganic materials 0.000 claims description 3
- 230000000717 retained effect Effects 0.000 claims description 3
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 38
- 229910052581 Si3N4 Inorganic materials 0.000 description 37
- 239000003112 inhibitor Substances 0.000 description 20
- 238000010438 heat treatment Methods 0.000 description 18
- 238000001556 precipitation Methods 0.000 description 17
- 229910052782 aluminium Inorganic materials 0.000 description 13
- 238000005097 cold rolling Methods 0.000 description 12
- 238000005261 decarburization Methods 0.000 description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 239000002244 precipitate Substances 0.000 description 10
- 239000007789 gas Substances 0.000 description 9
- 150000004767 nitrides Chemical class 0.000 description 8
- 239000013078 crystal Substances 0.000 description 7
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 6
- 239000012298 atmosphere Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 230000004907 flux Effects 0.000 description 5
- 239000010410 layer Substances 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 230000006866 deterioration Effects 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 230000001376 precipitating effect Effects 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910000976 Electrical steel Inorganic materials 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 229910052839 forsterite Inorganic materials 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- 229910010413 TiO 2 Inorganic materials 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 239000000395 magnesium oxide Substances 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000005204 segregation Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 238000009628 steelmaking Methods 0.000 description 2
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000012300 argon atmosphere Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000008119 colloidal silica Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000011162 core material Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- XLJMAIOERFSOGZ-UHFFFAOYSA-M cyanate Chemical compound [O-]C#N XLJMAIOERFSOGZ-UHFFFAOYSA-M 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000000724 energy-dispersive X-ray spectrum Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000005324 grain boundary diffusion Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 239000005365 phosphate glass Substances 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Description
本発明は、優れた磁気特性を有する方向性電磁鋼板を安価に得ることが出来る方向性電磁鋼板の製造方法に関するものである。 The present invention relates to a method for producing a grain-oriented electrical steel sheet capable of obtaining a grain-oriented electrical steel sheet having excellent magnetic properties at low cost.
方向性電磁鋼板は、変圧器や発電機の鉄心材料として用いられる軟磁性材料で、鉄の磁化容易軸である＜001＞方位が鋼板の圧延方向に高度に揃った結晶組織を有するものである。このような集合組織は、方向性電磁鋼板の製造工程中、二次再結晶焼鈍の際にいわゆるゴス（Goss）方位と称される{110}<001>方位の結晶粒を優先的に巨大成長させる、二次再結晶を通じて形成される。 A grain-oriented electrical steel sheet is a soft magnetic material used as a core material for transformers and generators, and has a crystal structure in which the <001> orientation, which is the easy axis of iron, is highly aligned in the rolling direction of the steel sheet. . Such a texture preferentially grows grains of the {110} <001> orientation called the Goss orientation during secondary recrystallization annealing during the production process of grain-oriented electrical steel sheets. Formed through secondary recrystallization.
従来、このような方向性電磁鋼板は、4.5mass％以下程度のSiと、MnS，MnSeおよびAlNなどのインヒビター成分を含有するスラブを、1300℃以上に加熱し、インヒビター成分を一旦固溶させたのち、熱間圧延し、必要に応じて熱延板焼鈍を施して、１回または中間焼鈍を挟む２回以上の冷間圧延によって最終板厚とし、ついで湿潤水素雰囲気中で一次再結晶焼純を施して、一次再結晶および脱炭を行い、ついでマグネシア（MgO）を主剤とする焼鈍分離剤を塗布してから、二次再結晶およびインヒビター成分の純化のために、1200℃で５ｈ程度の最終仕上焼鈍を行うことによって製造されてきた（例えば、特許文献１、特許文献２および特許文献３）。 Conventionally, such a grain-oriented electrical steel sheet is heated to 1300 ° C or higher by heating a slab containing about 4.5 mass% or less of Si and an inhibitor component such as MnS, MnSe, and AlN to once dissolve the inhibitor component. After that, it is hot-rolled and subjected to hot-rolled sheet annealing as necessary, to obtain the final sheet thickness by one or more cold rollings sandwiching intermediate annealing, followed by primary recrystallization annealing in a wet hydrogen atmosphere After performing primary recrystallization and decarburization, and then applying an annealing separator mainly composed of magnesia (MgO), the secondary recrystallization and the inhibitor component are purified at 1200 ° C. for about 5 hours. It has been manufactured by performing final finish annealing (for example, Patent Document 1, Patent Document 2, and Patent Document 3).
上述したとおり、従来の方向性電磁鋼板の製造に際しては、MnS，MnSe，AlNなどの析出物（インヒビター成分）をスラブ段階で含有させて、1300℃を超える高温のスラブ加熱をすることにより、これらのインヒビター成分を一旦固溶させ、後工程で微細析出させることによって二次再結晶を発現させるという工程が採用されてきた。 As described above, when manufacturing conventional grain-oriented electrical steel sheets, precipitates (inhibitor components) such as MnS, MnSe, and AlN are included in the slab stage, and these are heated at a high temperature exceeding 1300 ° C. The step of causing secondary recrystallization by once dissolving the inhibitor component of this compound and then precipitating it finely in a subsequent step has been adopted.
このように、従来の方向性電磁鋼板の製造工程では、1300℃を超える高温でのスラブ加熱が必要であったため、その製造コストは極めて高いものとならざるを得ず、近年の製造コスト低減の要求に応えることができないというところに問題を残していた。 As described above, in the manufacturing process of conventional grain-oriented electrical steel sheets, slab heating at a high temperature exceeding 1300 ° C. is necessary, so the manufacturing cost has to be extremely high, and in recent years the manufacturing cost has been reduced. He left a problem where he was unable to meet the demand.
こうした問題を解決するために、例えば、特許文献４では、酸可溶性Al（sol.Al）を0.010〜0.060％含有させ、スラブ加熱を低温に抑えて脱炭焼鈍工程で適正な窒化雰囲気を用いて窒化を行なうことにより、また、特許文献５では、二次再結晶焼鈍の昇温過程において700〜800℃の温度域で少なくとも４時間以上滞在させ、窒化処理によって生成した窒化物を溶体化・再析出させることにより、それぞれ、二次再結晶時に（Al，Si）Nを析出させインヒビターとして用いる方法が提案されている。
（Al，Si）Nは鋼中に微細分散することで有効なインヒビターとして機能するが、Alの含有量によってインヒビター強度が決まるために、製鋼でのAl的中精度が不十分な場合は、十分な粒成長抑制力が得られない場合があった。このような途中工程で窒化処理を行ない、（Al，Si）NあるいはAlNをインヒビターとして利用する方法が数多く提案されているが、最近では、スラブ加熱温度が1300℃を超える製造方法等も開示されている。
In order to solve such a problem, for example, in Patent Document 4, 0.010 to 0.060% of acid-soluble Al (sol. Al) is contained, slab heating is suppressed to a low temperature, and an appropriate nitriding atmosphere is used in the decarburization annealing process. By performing nitriding, and in Patent Document 5, in the temperature increase process of secondary recrystallization annealing, the nitride formed by nitriding is solutionized and recrystallized by staying in a temperature range of 700 to 800 ° C. for at least 4 hours. A method has been proposed in which (Al, Si) N is precipitated and used as an inhibitor during secondary recrystallization.
(Al, Si) N functions as an effective inhibitor by being finely dispersed in the steel, but since the inhibitor strength is determined by the Al content, it is sufficient if the accuracy of Al in steelmaking is insufficient. In some cases, it was not possible to obtain a sufficient grain growth inhibiting force. Many methods have been proposed in which nitriding treatment is performed in the middle of the process and (Al, Si) N or AlN is used as an inhibitor. Recently, however, a manufacturing method in which the slab heating temperature exceeds 1300 ° C has been disclosed. ing.
一方、そもそもスラブにインヒビター成分を含有させずに二次再結晶を発現させる技術については、特許文献６に、インヒビター成分を含有させなくとも二次再結晶が出来る技術（インヒビターレス法）が開示されている。
ここに、インヒビターレス法は、より高純度化した鋼を利用し、テクスチャー（集合組織の制御）によって二次再結晶を発現させる技術である。しかしながら、インヒビターレス法では、高温のスラブ加熱が不要であって、低コストでの方向性電磁鋼板の製造が可能であるものの、インヒビターを有しないが故に、製造工程中での温度ばらつきなどの影響を受けて、製品での磁気特性にバラつきが生じやすいといった不利があった。
On the other hand, regarding a technique for causing secondary recrystallization without including an inhibitor component in the slab, Patent Document 6 discloses a technique (inhibitorless method) capable of performing secondary recrystallization without including an inhibitor component. ing.
Here, the inhibitorless method is a technique in which secondary recrystallization is manifested by texture (control of texture) using higher-purity steel. However, the inhibitorless method does not require high-temperature slab heating and enables production of grain-oriented electrical steel sheets at a low cost. As a result, there is a disadvantage that the magnetic characteristics of the product are likely to vary.
また、集合組織の制御は、磁気特性に対して重要な要素であるため、集合組織制御を行う温間圧延などには、多くの条件が提案されている。こうした集合組織制御が十分に行なえない場合は、インヒビターを用いる技術に比べると、二次再結晶後のゴス方位（{110}<001>）への集積度が低く、磁束密度も低くなる。 In addition, since texture control is an important factor for magnetic properties, many conditions have been proposed for warm rolling and the like in which texture control is performed. When this texture control cannot be performed sufficiently, the degree of integration in the Goth orientation ({110} <001>) after secondary recrystallization is low and the magnetic flux density is low as compared with the technique using an inhibitor.
上述したとおり、これまで提案されてきた方向性電磁鋼板の製造方法では、良好な磁気特性を安定的に実現することが難しい場合が多かった。
これに対し、発明者らは、スラブ加熱温度を抑えつつ、磁気特性のバラつきを低減した方向性電磁鋼板を製造するために、インヒビター成分を含有させない方向性電磁鋼板の製造方法を用いて一次再結晶集合組織の作り込みを行ない、これに途中工程で窒化を利用して窒化珪素（Si3N4）を析出させ、この窒化珪素をインヒビターとして利用することを検討した。
すなわち、方向性電磁鋼板で一般に数％程度含有される珪素を窒化珪素として析出させ、インヒビターとして利用することが可能であれば、窒化処理時の窒化量を制御することによって、窒化物形成元素（Al、Ti、Cr、Ｖ等）の多寡によらず同等の粒成長抑制力が得られるのではないかと考えた。
As described above, it has often been difficult to stably achieve good magnetic properties in the method of manufacturing grain-oriented electrical steel sheets that has been proposed so far.
In contrast, in order to manufacture a grain-oriented electrical steel sheet with reduced variation in magnetic properties while suppressing the slab heating temperature, the inventors have used a method for producing a grain-oriented electrical steel sheet that does not contain an inhibitor component to perform primary regeneration. A crystal texture was formed, and silicon nitride (Si 3 N 4 ) was deposited using nitridation in the middle of the process, and the use of this silicon nitride as an inhibitor was investigated.
That is, if silicon that is generally contained in the grain-oriented electrical steel sheet by about several percent is deposited as silicon nitride and can be used as an inhibitor, the nitride forming element ( We thought that the same grain growth inhibitory power could be obtained regardless of the amount of Al, Ti, Cr, V, etc.).
ここで、純粋な窒化珪素は、AlN中にSiが固溶した（Al,Si）Nとは異なり、鋼との結晶格子のmisfitが大きく、また共有結合特有の複雑な結晶構造を有するため、粒内に微細に析出させることは極めて困難であることが知られている。従って、単純に従来法に従って窒化処理を行った場合は、粒内に窒化珪素を微細析出させることが困難であると考えられる。 Here, pure silicon nitride is different from (Al, Si) N in which Si is dissolved in AlN, and has a large misfit of the crystal lattice with steel, and has a complex crystal structure unique to covalent bonds. It is known that it is extremely difficult to precipitate finely in grains. Therefore, when the nitriding treatment is simply performed according to the conventional method, it is considered difficult to finely precipitate silicon nitride in the grains.
しかしながら、発明者らは、これを逆に利用することによって、選択的に粒界に析出させることが出来る可能性があると考え、種々検討を行なったところ、Si3N4を粒界に選択的に析出させることが可能であること、および適切な仕上げ焼鈍条件を選択することによって、粗大な析出物をインヒビターとして利用し、効果的な二次再結晶粒を得ることが出来ることを見出した。 However, the inventors considered that it may be possible to selectively precipitate at the grain boundary by using this in reverse, and after various studies, Si 3 N 4 was selected as the grain boundary. It was found that effective secondary recrystallized grains can be obtained by using coarse precipitates as an inhibitor by selecting appropriate finish annealing conditions. .
すなわち、表層窒素濃化層からの窒素の粒界拡散の挙動と、窒化珪素の析出挙動の詳細な検討により、Alを100ppm未満に抑制したインヒビターレス成分に準じた成分を用いて、高温スラブ加熱を回避しつつ、窒化処理による窒素増量を適用することで、AlNではなく窒化珪素を析出させ、この窒化珪素を正常粒成長の抑制力として機能させることで、磁気特性のバラつきを大幅に低減し、工業的に安定して良好な特性を有する方向性電磁鋼板の製造方法に想到したのである。 That is, high-temperature slab heating using a component in accordance with an inhibitorless component in which Al is suppressed to less than 100 ppm by detailed examination of the grain boundary diffusion behavior of nitrogen from the surface nitrogen enriched layer and the precipitation behavior of silicon nitride By applying an increase in nitrogen by nitriding treatment, silicon nitride is deposited instead of AlN, and this silicon nitride functions as a suppressive force for normal grain growth, greatly reducing the variation in magnetic properties. The inventors have come up with a method for producing grain-oriented electrical steel sheets having industrially stable and good characteristics.
本発明は、上記の知見に基づき開発されたもので、窒化珪素を形成する目的で二次再結晶前の鋼板に窒素を加えた方向性電磁鋼板に対し、窒素を鋼中へ効率的に拡散させ、窒化珪素を粒界に析出させることで、良好な磁気特性を有する方向性電磁鋼板が得られる方向性電磁鋼板の製造方法を提供することを目的とする。 The present invention was developed on the basis of the above knowledge. Nitrogen is efficiently diffused into steel in a directional electrical steel sheet in which nitrogen is added to a steel sheet before secondary recrystallization for the purpose of forming silicon nitride. It is an object of the present invention to provide a method for producing a grain-oriented electrical steel sheet in which a grain-oriented electrical steel sheet having good magnetic properties is obtained by precipitating silicon nitride at grain boundaries.
本発明の要旨構成は次のとおりである。
１．質量％で、Ｃ：0.08％以下、Si：2.0〜4.5％およびMn：0.5％以下を含有すると共に、Ｓ、SeおよびＯをそれぞれ50質量ppm未満、sol.Alを100質量ppm未満、Ｎを80質量ppm以下に抑制し、さらに、［ppm sol.Al］-［ppmＮ］×(26.98/14.00)≦30質量ppm（但し、［ppmＸ］はＸ元素の鋼中含有率（質量ppm））の範囲に制御し、残部はFeおよび不可避的不純物の組成になる鋼スラブを、再加熱することなくあるいは再加熱後、熱間圧延を施して熱延板としたのち、焼鈍および圧延によって最終板厚の冷間圧延板とし、二次再結晶焼鈍前までに窒素増量（ΔＮ）が50質量ppm以上1000質量ppm以下となる窒化処理を、800℃以下の温度で、または800℃超の温度で30秒以下施した後、焼鈍分離剤を塗布し、二次再結晶焼鈍を施す一連の方向性電磁鋼板の製造工程において、
上記二次再結晶焼鈍の昇温過程で、一旦、400〜600℃の温度域（Ｔ１）に昇温した後、300℃以上600℃未満の温度域（Ｔ２）に20時間以上滞留させ、さらに、15℃／ｈ以上の速度で少なくとも800℃まで昇温する方向性電磁鋼板の製造方法。
The gist of the present invention is as follows.
1. In mass%, C: 0.08% or less, Si: 2.0 to 4.5% and Mn: 0.5% or less, S, Se and O are each less than 50 mass ppm, sol.Al is less than 100 mass ppm, N is It is suppressed to 80 mass ppm or less, and [ppm sol.Al]-[ppmN] × (26.98 / 14.00) ≦ 30 mass ppm (where [ppmX] is the content of element X in steel (mass ppm)) The steel slab whose composition is the composition of Fe and unavoidable impurities in the balance, without reheating or after reheating, is subjected to hot rolling to form a hot rolled sheet, and then the final thickness is obtained by annealing and rolling. And a nitriding treatment in which the nitrogen increase (ΔN) is 50 mass ppm or more and 1000 mass ppm or less before the secondary recrystallization annealing is performed at a temperature of 800 ° C. or less or a temperature of more than 800 ° C. In the manufacturing process of a series of grain-oriented electrical steel sheets, after applying for 2 seconds or less, applying an annealing separator, and performing secondary recrystallization annealing,
In the temperature raising process of the secondary recrystallization annealing, the temperature is once raised to a temperature range (T1) of 400 to 600 ° C., and then retained in a temperature range (T2) of 300 ° C. or higher and lower than 600 ° C. for 20 hours or more. A method for producing a grain-oriented electrical steel sheet that is heated to at least 800 ° C. at a rate of 15 ° C./h or more.
２．さらに、前記鋼スラブが、質量％で、
Ni：0.005〜1.50％、
Sn：0.01〜0.50％、
Sb：0.005〜0.50％、
Cu：0.01〜0.50％、
Cr：0.01〜1.50％
Ｐ：0.0050〜0.50％
Mo：0.01〜0.50％および
Nb：0.0005〜0.0100％
のうちから選んだ１種または２種以上を含有することを特徴とする前記１に記載の方向性電磁鋼板の製造方法。
2. Furthermore, the said steel slab is mass%,
Ni: 0.005-1.50%,
Sn: 0.01 to 0.50%,
Sb: 0.005-0.50%,
Cu: 0.01 to 0.50%,
Cr: 0.01 to 1.50%
P: 0.0050-0.50%
Mo: 0.01-0.50% and
Nb: 0.0005-0.0100%
The method for producing a grain-oriented electrical steel sheet according to 1 above, comprising one or more selected from among the above.
本発明によれば、高温スラブ加熱を施さずとも、磁気特性のバラつきが大幅に低減され、工業的に安定して良好な特性を有する方向性電磁鋼板を得ることが出来る。 According to the present invention, it is possible to obtain a grain-oriented electrical steel sheet having greatly reduced variations in magnetic properties and having industrially stable and good properties without performing high-temperature slab heating.
以下、本発明を具体的に説明する。
まず、本発明において、鋼スラブの成分組成の限定理由について説明する。なお、以下に記載する「％」および「ppm」表示は特に断らない限り、それぞれ質量％および質量ppmを意味するものとする。
Ｃ:0.08％以下
Ｃは、一次再結晶集合組織を改善する上で有用な元素であるが、含有量が0.08％を超えると、かえって一次再結晶集合組織の劣化を招くので、本発明では0.08％以下に限定した。磁気特性の観点から望ましい添加量は、0.01〜0.06％の範囲である。なお、要求される磁気特性のレベルがさほど高くない場合には、一次再結晶焼鈍における脱炭を省略あるいは簡略化するために、Ｃを0.01％以下としてもよい。
Hereinafter, the present invention will be specifically described.
First, the reason for limiting the component composition of the steel slab in the present invention will be described. Unless otherwise specified, “%” and “ppm” described below mean mass% and mass ppm, respectively.
C: 0.08% or less C is an element useful for improving the primary recrystallization texture. However, if the content exceeds 0.08%, the primary recrystallization texture is deteriorated. % Or less. A desirable addition amount from the viewpoint of magnetic properties is in the range of 0.01 to 0.06%. If the required magnetic property level is not so high, C may be set to 0.01% or less in order to omit or simplify the decarburization in the primary recrystallization annealing.
Si:2.0〜4.5％
Siは、電気抵抗を高めることによって鉄損を改善する有用元素であるが、含有量が4.5％を超えると、冷間圧延性が著しく劣化するので、Siは4.5％以下に限定した。また本発明では、Siを窒化物形成元素として機能させる必要があるため、2.0％以上含有させることが重要である。なお、鉄損の観点からの望ましい添加量は、2.0〜4.5％の範囲である。
Si: 2.0-4.5%
Si is a useful element that improves iron loss by increasing electric resistance. However, if the content exceeds 4.5%, the cold rolling property deteriorates remarkably, so Si is limited to 4.5% or less. In the present invention, Si needs to function as a nitride-forming element, so it is important to contain 2.0% or more. In addition, the desirable addition amount from the viewpoint of iron loss is in the range of 2.0 to 4.5%.
Mn:0.5％以下
Mnは、製造時における熱間加工性を向上させる効果があるので、0.005％以上含有させることが好ましいが、含有量が0.5％を超えた場合には、一次再結晶集合組織が悪化して磁気特性の劣化を招くので、Mnは0.5％以下に限定した。
Mn: 0.5% or less
Since Mn has the effect of improving hot workability during production, it is preferable to contain 0.005% or more. However, if the content exceeds 0.5%, the primary recrystallization texture deteriorates and magnetic properties are increased. Since the characteristics are deteriorated, Mn is limited to 0.5% or less.
Ｓ，SeおよびＯ:それぞれ50ppm未満
Ｓ，SeおよびＯ量がそれぞれ50ppm以上になると、所望の二次再結晶を得ることが困難となる。この理由は、粗大な酸化物や、スラブ加熱によって粗大化したMnS，MnSeが一次再結晶組織を不均一にするためである。従って、Ｓ，SeおよびＯはいずれも、50ppm未満に抑制するものとした。
S, Se, and O: less than 50 ppm each When the amount of S, Se, and O is 50 ppm or more, it becomes difficult to obtain a desired secondary recrystallization. This is because coarse oxides and MnS and MnSe coarsened by slab heating make the primary recrystallized structure non-uniform. Accordingly, S, Se, and O are all suppressed to less than 50 ppm.
sol.Al:100ppm未満
Alは、表面に緻密な酸化膜を形成し、窒化の際にその窒化量の制御を困難にしたり、脱炭を阻害したりすることがあるため、Alはsol.Al量で100ppm未満に抑制した。但し、酸素親和力の高いAlは、製鋼で微量添加することによって鋼中の溶存酸素量を低減し、鋼板の特性劣化につながる酸化物系介在物の低減などを見込めるため、100ppm未満の範囲で添加することにより磁性劣化を抑制することが出来る。
sol.Al: less than 100ppm
Al forms a dense oxide film on the surface, which may make it difficult to control the amount of nitridation during nitridation or inhibit decarburization. Therefore, Al is suppressed to less than 100 ppm in terms of sol.Al. did. However, Al with high oxygen affinity can be added in a range of less than 100ppm because it can be added in a small amount in steelmaking to reduce the amount of dissolved oxygen in the steel and reduce oxide inclusions that lead to deterioration of the steel sheet properties. By doing so, magnetic deterioration can be suppressed.
Ｎ:80ppm以下
本発明は、インヒビターレスの製造方法を適用し集合組織の作り込みまでを行なうため、Ｎは80ppm以下に抑制する必要がある。80ppmを超えると粒界偏析の影響や微量窒化物の形成により、集合組織が劣化するといった弊害が生じるからである。また、スラブ加熱時の「フクレ」などの欠陥の原因となることもあるため、80ppm以下に抑制する必要がある。なお、望ましくは60ppm以下である。
N: 80 ppm or less In the present invention, an inhibitorless manufacturing method is applied to complete the formation of a texture. Therefore, N must be suppressed to 80 ppm or less. This is because if it exceeds 80 ppm, the effect of grain boundary segregation and the formation of a trace amount of nitrides will cause the adverse effect of deterioration of the texture. Moreover, since it may cause defects such as “fluff” at the time of slab heating, it is necessary to suppress it to 80 ppm or less. Desirably, it is 60 ppm or less.
［ppm sol.Al］-［ppmＮ］×(26.98/14.00)≦30ppm（但し、［ppmＸ］はＸ元素の鋼中含有率（ppm））
窒化処理後、窒化珪素を析出させることが本発明の特徴であるところ、窒化処理後、過剰なAlが残存した状況では、より熱力学的に安定な析出状態である、AlNにSiが固溶した（Al,Si）Nが析出してしまう。このため、純粋にAlと結合する以上に、窒化により供給したＮが析出してしまい、純粋な窒化珪素を安定的に析出させることが困難になる。
そこで、本発明では、［ppm sol.Al］-［ppmＮ］×(26.98/14.00)を30ppm以下に制御する。かかる制御によって、AlNとして析出するために必要なＮ量以上のＮを事前に含有させておくことが出来るため、窒化処理以前に、AlをAlNとして析出させておくことが可能となり、窒化処理によって追加した△Ｎが窒化珪素の形成に効果的に利用することが出来るようになる。
さらに、窒化珪素を制御する上で、［ppm sol.Al］-［ppmＮ］×(26.98/14.00)を０ppm以下に制御することが好ましい。［ppm sol.Al］-［ppmＮ］×(26.98/14.00)が０ppm以下の範囲では、概ね50ppm以上の窒化により窒化珪素を形成させることが出来るからである。なお、［ppm sol.Al］-［ppmＮ］×(26.98/14.00)の下限値は、特に限定しないが、工業的には-30ppm程度である。
また、［ppm sol.Al］-［ppmＮ］×(26.98/14.00)が０ppm超、30ppm以下の範囲では、純粋な窒化珪素を形成するために、０ppm以下の範囲より多くの窒素増加分（△Ｎ）が必要となるものの、析出に寄与する残留Al量が微量であるため、純粋な窒化珪素を析出させることが出来る。なお、この時の窒素増加分（△Ｎ）は、65ppm以上が好ましい。
他方、［ppm sol.Al］-［ppmＮ］×(26.98/14.00)が30ppmを超える条件では、追加で微細析出するAlNあるいは（Al,Si）Nの影響が大きくなって、析出する窒化珪素量が安定的に得られなかったり、より熱力学的に安定なAlNや（Al,Si）Nの析出によって二次再結晶温度が過剰に高くなったりするため、二次再結晶不良を招来しやすくなる。
従って、本発明では、少なくとも［ppm sol.Al］-［ppmＮ］×(26.98/14.00)を30ppm以下に抑制する必要がある。
[Ppm sol.Al]-[ppmN] × (26.98 / 14.00) ≦ 30ppm (where [ppmX] is the content of element X in steel (ppm))
It is a feature of the present invention that silicon nitride is precipitated after nitriding, and in the situation where excess Al remains after nitriding, Si is a solid solution in AlN, which is a more thermodynamically stable precipitation state. (Al, Si) N is deposited. For this reason, more than purely bonding with Al, N supplied by nitriding is precipitated, and it becomes difficult to stably deposit pure silicon nitride.
Therefore, in the present invention, [ppm sol.Al]-[ppmN] × (26.98 / 14.00) is controlled to 30 ppm or less. By such control, it is possible to preliminarily contain N more than the N amount necessary for precipitation as AlN, so Al can be precipitated as AlN before the nitriding treatment. The added ΔN can be effectively used for forming silicon nitride.
Furthermore, in controlling silicon nitride, it is preferable to control [ppm sol.Al]-[ppmN] × (26.98 / 14.00) to 0 ppm or less. This is because, when [ppm sol.Al]-[ppmN] × (26.98 / 14.00) is in the range of 0 ppm or less, silicon nitride can be formed by nitridation of approximately 50 ppm or more. The lower limit of [ppm sol.Al]-[ppmN] × (26.98 / 14.00) is not particularly limited, but is about −30 ppm industrially.
Further, when [ppm sol.Al]-[ppmN] × (26.98 / 14.00) is more than 0 ppm and less than 30 ppm, in order to form pure silicon nitride, more nitrogen increase (△△ Although N) is required, pure silicon nitride can be deposited because the amount of residual Al that contributes to precipitation is very small. The nitrogen increase (ΔN) at this time is preferably 65 ppm or more.
On the other hand, under the condition that [ppm sol.Al]-[ppmN] × (26.98 / 14.00) exceeds 30 ppm, the influence of additional AlN or (Al, Si) N that is finely precipitated increases, and the amount of silicon nitride that precipitates Can not be obtained stably, or secondary recrystallization temperature becomes excessively high due to precipitation of more thermodynamically stable AlN or (Al, Si) N, which tends to cause secondary recrystallization failure. Become.
Therefore, in the present invention, it is necessary to suppress at least [ppm sol.Al]-[ppmN] × (26.98 / 14.00) to 30 ppm or less.
以上、必須成分について説明したが、本発明では、工業的により安定して磁気特性を改善する成分として、以下の元素を適宜含有させることが出来る。なお、残部は、Feおよび不可避的不純物である。
Ni:0.005〜1.50％
Niは、熱延板組織の均一性を高めることにより、磁気特性を改善する働きがあって、そのためには0.005％以上含有させることが好ましいが、含有量が1.50％を超えると所望の二次再結晶を得ることが困難となり、磁気特性が劣化するので、Niは0.005〜1.50％の範囲で含有させることが望ましい。
The essential components have been described above. In the present invention, the following elements can be appropriately contained as components that improve the magnetic properties more stably industrially. The balance is Fe and inevitable impurities.
Ni: 0.005-1.50%
Ni works to improve the magnetic properties by increasing the uniformity of the hot-rolled sheet structure, and for that purpose, it is preferable to contain 0.005% or more, but if the content exceeds 1.50%, the desired secondary Since it becomes difficult to obtain recrystallization and the magnetic properties deteriorate, it is desirable to contain Ni in the range of 0.005 to 1.50%.
Sn:0.01〜0.50％
Snは、二次再結晶焼鈍中の鋼板の窒化や酸化を抑制し、良好な結晶方位を有する結晶粒の二次再結晶を促進して磁気特性を向上させる有用元素であり、そのためには0.01％以上含有させることが好ましいが、0.50％を超えて含有されると冷間圧延性が劣化するので、Snは0.01〜0.50％の範囲で含有させることが望ましい。
Sn: 0.01-0.50%
Sn is a useful element that suppresses nitriding and oxidation of steel sheets during secondary recrystallization annealing and promotes secondary recrystallization of grains having good crystal orientation to improve magnetic properties. However, if it exceeds 0.50%, the cold rolling property deteriorates, so it is desirable to contain Sn in the range of 0.01 to 0.50%.
Sb:0.005〜0.50％
Sbは、二次再結晶焼鈍中の鋼板の窒化や酸化を抑制し、良好な結晶方位を有する結晶粒の二次再結晶を促進して磁気特性を効果的に向上させる有用元素であり、その目的のためには0.005％以上含有させることが好ましいが、0.50％を超えて含有されると冷間圧延性が劣化するので、Sbは0.005〜0.50％の範囲で含有させることが望ましい。
Sb: 0.005-0.50%
Sb is a useful element that effectively suppresses nitridation and oxidation of steel sheets during secondary recrystallization annealing, promotes secondary recrystallization of grains with good crystal orientation, and effectively improves magnetic properties. For the purpose, it is preferable to contain 0.005% or more, but if it exceeds 0.50%, the cold rolling property deteriorates, so Sb is preferably contained in the range of 0.005 to 0.50%.
Cu:0.01〜0.50％
Cuは、二次再結晶焼鈍中の鋼板の酸化を抑制し、良好な結晶方位を有する結晶粒の二次再結晶を促進して磁気特性を効果的に向上させる働きがあり、そのためには0.01％以上含有させることが好ましいが、0.50％を超えて含有されると熱間圧延性の劣化を招くので、Cuは0.01〜0.50％の範囲で含有させることが望ましい。
Cu: 0.01-0.50%
Cu suppresses oxidation of the steel sheet during secondary recrystallization annealing, promotes secondary recrystallization of grains having a good crystal orientation, and effectively improves magnetic properties. However, if it exceeds 0.50%, the hot rolling property is deteriorated, so it is desirable to contain Cu in the range of 0.01 to 0.50%.
Cr:0.01〜1.50％
Crは、フォルステライト被膜の形成を安定化させる働きがあり、そのためには0.01％以上含有させることが好ましいが、一方でその含有量が1.50％を超えると所望の二次再結晶を得ることが困難となり、磁気特性が劣化するので、Crは0.01〜1.50％の範囲で含有させることが望ましい。
Cr: 0.01 to 1.50%
Cr has a function of stabilizing the formation of the forsterite film, and for that purpose, it is preferable to contain 0.01% or more, but when the content exceeds 1.50%, a desired secondary recrystallization can be obtained. Since it becomes difficult and the magnetic properties deteriorate, it is desirable to contain Cr in the range of 0.01 to 1.50%.
Ｐ:0.0050〜0.50％
Ｐは、フォルステライト被膜の形成を安定化させる働きがあり、そのためには0.0050％以上含有させることが好ましいが、含有量が0.50％を超えると冷間圧延性が劣化するので、Ｐは0.0050〜0.50％の範囲で含有させることが望ましい。
P: 0.0050 ~ 0.50%
P has a function of stabilizing the formation of the forsterite film. For that purpose, P is preferably contained in an amount of 0.0050% or more. However, if the content exceeds 0.50%, the cold rolling property deteriorates, so P is 0.0050 to It is desirable to make it contain in 0.50% of range.
Nb:0.0005〜0.0100％、Mo:0.01〜0.50％
NbおよびMoは、スラブ加熱時の温度変化による割れの抑制等を介して、熱延後のヘゲを抑制する効果を有している。これらの元素は、少なくともどちらか一方を、上記下限値以上含有させなければヘゲ抑制の効果は小さく、一方、どちらかが上記上限を超えると、炭化物や窒化物を形成するなどして最終製品まで残留した際、鉄損劣化を引き起こすため、上述した範囲とすることが望ましい。
Nb: 0.0005-0.0100%, Mo: 0.01-0.50%
Nb and Mo have an effect of suppressing sag after hot rolling through suppression of cracking due to temperature change during slab heating. If these elements do not contain at least one of the above lower limit value or more, the effect of suppressing heges is small. On the other hand, if either of these elements exceeds the above upper limit, carbide or nitride is formed, and the final product. In order to cause deterioration of the iron loss when remaining up to, it is desirable to be in the above range.
次に、本発明の製造方法について説明する。
上記の好適成分組成範囲に調整した鋼スラブを、再加熱することなくあるいは再加熱したのち、熱間圧延に供する。なお、スラブを再加熱する場合には、再加熱温度は、1000℃以上1300℃以下程度とすることが望ましい。というのは、1300℃を超えるスラブ加熱は、スラブの段階で鋼中にインヒビターをほとんど含まない本発明にとって無意味であり、コストアップの要因となるだけである。一方、1000℃未満のスラブ加熱では、熱間圧延時の圧延荷重が高くなって、圧延することが困難になるからである。
Next, the manufacturing method of this invention is demonstrated.
The steel slab adjusted to the above preferable component composition range is subjected to hot rolling without being reheated or after being reheated. When the slab is reheated, the reheating temperature is preferably about 1000 ° C. or higher and 1300 ° C. or lower. This is because slab heating above 1300 ° C is meaningless for the present invention, which contains almost no inhibitor in the steel at the slab stage, and only increases costs. On the other hand, when the slab is heated at a temperature lower than 1000 ° C., the rolling load at the time of hot rolling becomes high and it becomes difficult to perform rolling.
ついで、熱延板に、焼鈍および圧延を施すことによって最終板厚の冷間圧延板とする。具体的には、必要に応じて熱延板焼鈍を施したのち、１回の冷間圧延あるいは中間焼鈍を挟む２回以上の冷間圧延を施して、最終冷延板とする。この冷間圧延は、常温で行ってもよいし、常温より高い温度たとえば250℃程度に鋼板温度を上げて圧延する温間圧延としてもよい。 Next, the hot-rolled sheet is annealed and rolled to obtain a cold-rolled sheet having a final thickness. Specifically, after performing hot-rolled sheet annealing as necessary, it is subjected to one or more cold rollings or two or more cold rollings sandwiching intermediate annealing to obtain a final cold-rolled sheet. This cold rolling may be performed at normal temperature, or may be warm rolling in which the steel sheet temperature is raised to a temperature higher than normal temperature, for example, about 250 ° C.
引続き、最終冷間圧延板に一次再結晶焼鈍を施す。この一次再結晶焼鈍の目的は、圧延組織を有する冷間圧延板を一次再結晶させて、二次再結晶に最適な一次再結晶粒径に調整することである。そのためには、一次再結晶焼鈍の焼鈍温度を800℃以上950℃未満程度とすることが望ましい。なお、この時の焼鈍雰囲気を、湿水素窒素あるいは湿水素アルゴン雰囲気とし、脱炭焼鈍を兼ねても良い。 Subsequently, primary recrystallization annealing is applied to the final cold rolled sheet. The purpose of this primary recrystallization annealing is to adjust the primary recrystallization grain size optimal for secondary recrystallization by primary recrystallization of a cold rolled sheet having a rolled structure. For that purpose, it is desirable to set the annealing temperature of the primary recrystallization annealing to about 800 ° C. or more and less than 950 ° C. Note that the annealing atmosphere at this time may be wet hydrogen nitrogen or wet hydrogen argon atmosphere, and may also serve as decarburization annealing.
本発明における窒素増量のための窒化処理は、冷間圧延後から一次再結晶焼鈍後に焼鈍分離剤を塗布する前、の間で施す。窒化の手法は、増量する窒化量を制御できれば、特に限定しないが、過去実施されている、例えば、コイル形態のままNH3雰囲気ガスを用いてガス窒化を行う手法や、走行するストリップに対して連続的に窒化を行う手法を採ることが出来る。また、ガス窒化に比べて窒化能の高い塩浴窒化を利用することも好ましい。 The nitriding treatment for increasing the amount of nitrogen in the present invention is performed after the cold rolling and before the application of the annealing separator after the primary recrystallization annealing. The method of nitriding is not particularly limited as long as the amount of nitriding to be increased can be controlled. However, for example, a method of performing gas nitriding using an NH 3 atmosphere gas in a coil form or a running strip has been implemented in the past. A method of continuously nitriding can be employed. It is also preferable to use salt bath nitriding, which has a higher nitriding ability than gas nitriding.
上記窒化処理の際、重要な点は表層に窒化物層を得ることである。特に鋼中への拡散を抑制するために800℃以下の温度で窒化を行なうことが望ましいが、時間を短時間（例えば30秒程度）とすることで高温であっても表面へ窒化物層を形成させることが可能となる。
また、窒化による窒素増量（△Ｎ）が概ね50ppmを超える条件で、本発明に適した窒化珪素を確認することが出来るものの、０ppm＜［ppm sol.Al］-［ppmＮ］×(26.98/14.00)≦30ppmの範囲では、窒化処理により増加したＮが、窒化珪素に比べ熱力学的に安定なAlN、あるいはSiを固溶した（Al,Si）Nとして析出するため、窒化珪素を析出させるためには、より多くの窒素が必要となるため、50ppm程度の窒素増量では、窒化珪素の析出が不安定になるおそれがある。そこで、65ppm以上の窒素量を窒化によって鋼板に与えることにより、窒化珪素の析出が効果的に達成される。一方、1000ppmを超えると窒化珪素の析出量が過多となり二次再結晶が生じないといった問題が生じる。
従って、窒化による窒素増量は50ppm以上1000ppm以下とするのが肝要であって、65ppm以上1000ppm以下とするのが好ましく、80ppm以上1000ppm以下とするのが更に好ましい。なお、当該窒素濃度は、たとえ鋼板の一部に濃化していたとしても、鋼板の厚み方向の平均に均した値である。
In the nitriding process, an important point is to obtain a nitride layer as a surface layer. In order to suppress diffusion into steel, it is desirable to perform nitriding at a temperature of 800 ° C. or less. However, the nitride layer is formed on the surface even at high temperatures by shortening the time (for example, about 30 seconds). It can be formed.
Further, although the silicon nitride suitable for the present invention can be confirmed under the condition that the nitrogen increase (ΔN) by nitriding exceeds approximately 50 ppm, 0 ppm <[ppm sol.Al] − [ppmN] × (26.98 / 14.00 In the range of ≦ 30 ppm, N increased by nitriding is precipitated as AlN that is thermodynamically stable compared to silicon nitride or (Al, Si) N in which Si is dissolved, so that silicon nitride is deposited. Therefore, more nitrogen is required, and therefore, when the nitrogen amount is increased by about 50 ppm, the precipitation of silicon nitride may become unstable. Therefore, precipitation of silicon nitride is effectively achieved by giving a nitrogen amount of 65 ppm or more to the steel sheet by nitriding. On the other hand, if it exceeds 1000 ppm, the amount of silicon nitride deposited becomes excessive and secondary recrystallization does not occur.
Therefore, it is important that the nitrogen increase by nitriding is 50 ppm or more and 1000 ppm or less, preferably 65 ppm or more and 1000 ppm or less, and more preferably 80 ppm or more and 1000 ppm or less. Note that the nitrogen concentration is a value averaged to the average in the thickness direction of the steel plate even if it is concentrated in a part of the steel plate.
窒化（窒素増量）工程は一次再結晶焼鈍前、焼鈍中、焼鈍後のいずれのタイミングでも適用可能であるが、最終冷間圧延前の焼鈍で一部のAlNが固溶し、sol.Alが存在した状態で冷却されることがあるため、一次再結晶焼鈍前に適用した場合、残留するsol.Alの影響で析出状態が理想状態とは異なるおそれがある。従って、再び固溶AlがAlNとして析出する一次再結晶焼鈍昇熱後のタイミング、すなわち一次再結晶焼鈍中あるいは焼鈍後で窒化処理を行なうことが、窒化珪素の析出を安定的に制御出来るので好ましい。 The nitriding (nitrogen increasing) process can be applied at any timing before, during, or after primary recrystallization annealing, but some AlN is dissolved in the annealing before the final cold rolling, and sol. Since it may be cooled in the existing state, when applied before the primary recrystallization annealing, the precipitation state may be different from the ideal state due to the influence of the remaining sol.Al. Therefore, it is preferable to perform nitriding during the primary recrystallization annealing or after annealing after the primary recrystallization annealing where solute Al is precipitated as AlN again, because the precipitation of silicon nitride can be stably controlled. .
上記一次再結晶焼鈍および窒化処理を行った後、鋼板表面に焼鈍分離剤を塗布する。二次再結晶焼鈍後の鋼板表面にフォルステライト被膜を形成するためには、焼鈍分離剤の主剤をマグネシア（MgO）とする必要があるが、フォルステライト被膜の形成が必要ない場合には、焼鈍分離剤主剤として、アルミナ（Al203）やカルシア（CaO）など、二次再結晶焼鈍温度より高い融点を有する適当な酸化物を用いることが出来る。 After performing the primary recrystallization annealing and nitriding treatment, an annealing separator is applied to the steel sheet surface. In order to form a forsterite film on the steel sheet surface after secondary recrystallization annealing, it is necessary to use magnesia (MgO) as the main component of the annealing separator. As the separating agent main component, an appropriate oxide having a melting point higher than the secondary recrystallization annealing temperature, such as alumina (Al 2 0 3 ) or calcia (CaO), can be used.
焼鈍分離剤塗布に引続き二次再結晶焼鈍を行なう。雰囲気は、Ｎ２、Ar、Ｈ２あるいはこれらの混合ガスのいずれもが適合する。二次再結晶焼鈍の昇温過程において表層の窒化物層は分解し、Ｎが鋼中へ拡散する。粒界偏析元素であるＮは、粒界を拡散経路として、鋼中へ拡散する。窒化珪素は、鋼とのmisfit率が大きいために、その析出速度は極めて遅い。ここで、窒化珪素の析出は、正常粒成長の抑制が目的であるため、正常粒成長が進行する800℃の段階では十分な量が粒界上に選択的に析出している必要がある。 Following the application of the annealing separator, secondary recrystallization annealing is performed. The atmosphere is suitable for any of N 2 , Ar, H 2 or a mixed gas thereof. In the temperature raising process of the secondary recrystallization annealing, the surface nitride layer is decomposed and N diffuses into the steel. N which is a grain boundary segregation element diffuses into steel using the grain boundary as a diffusion path. Since silicon nitride has a high misfit rate with steel, its precipitation rate is extremely slow. Here, since precipitation of silicon nitride is intended to suppress normal grain growth, a sufficient amount needs to be selectively deposited on the grain boundary at the stage of 800 ° C. where normal grain growth proceeds.
そのためには、800℃までの昇温過程を５ｈ以上とする焼鈍を行うことで析出させることが出来るが、焼鈍条件によっては析出物が大きくなりすぎて、二次再結晶に必要なオストワルド成長や固溶などに必要な時間が長くなる場合や、板厚方向に均一な濃度で析出させることができない場合がある。これを、板厚方向に均一に粒径：１μｍ以下の窒化珪素、さらに言えば、鋼板全体の70％以上が粒径：0.5μｍ以下の窒化珪素を析出させることによって、一段と製造上の安定性を高めることが出来る。 For this purpose, precipitation can be performed by annealing at a temperature rising process up to 800 ° C. for 5 hours or more. However, depending on the annealing conditions, the precipitate becomes too large, and the Ostwald growth necessary for secondary recrystallization In some cases, the time required for solid solution or the like becomes long, or in some cases, it is impossible to deposit in a uniform concentration in the plate thickness direction. This is even more stable in production by precipitating silicon nitride with a grain size of 1 μm or less uniformly in the thickness direction, more specifically 70% or more of the entire steel sheet with silicon nitride having a grain size of 0.5 μm or less. Can be increased.
このため、一度Ｔ１℃（400≦Ｔ１≦600）まで昇温することで、表層に得られた窒化物層を分解し、Ｔ２℃（300≦Ｔ２＜600）の範囲で20時間以上滞留させることで、分解した窒素が鋼板中に均一に拡散する。滞留時間の上限については必ずしも設ける必要はないが、150時間を超える焼鈍を行なっても焼鈍に要するエネルギーばかりが必要になるだけであるため、150時間以下の時間で行なうことが望ましい。また、上記Ｔ２の好ましい温度域は300〜500℃である。
そして、上記滞留後は15℃／ｈ以上の速度で少なくとも800℃まで到達させることによって、板厚方向に均一に窒化珪素を析出させることが出来る。
Therefore, once the temperature is raised to T1 ° C. (400 ≦ T1 ≦ 600), the nitride layer obtained on the surface layer is decomposed and allowed to stay for 20 hours or longer in the range of T2 ° C. (300 ≦ T2 <600). Thus, the decomposed nitrogen diffuses uniformly in the steel sheet. The upper limit of the residence time is not necessarily provided, but even if annealing exceeding 150 hours is performed, only the energy required for annealing is required. Moreover, the preferable temperature range of said T2 is 300-500 degreeC.
Then, after the residence, the silicon nitride can be uniformly deposited in the plate thickness direction by reaching at least 800 ° C. at a rate of 15 ° C./h or more.
このように、Al量を抑制し、窒化処理によるAlNや（Al,Si）Nの析出を抑え、さらに他のMnS、MnSe等に代表されるインヒビター成分をほとんど含有しないスラブに対し、上述した本発明に従う工程を適用すると、二次再結晶焼鈍昇温過程および二次再結晶開始までの段階において、従来のインヒビターに比べて粗大なサイズ（100nm以上）の窒化珪素を粒界に選択的に形成することが出来る。 In this way, the above-described book is applied to a slab that suppresses Al content, suppresses precipitation of AlN and (Al, Si) N due to nitriding treatment, and further contains almost no inhibitor component typified by MnS, MnSe, etc. When the process according to the invention is applied, silicon nitride having a coarser size (100 nm or more) than the conventional inhibitor is selectively formed at the grain boundaries in the secondary recrystallization annealing temperature raising process and the stage until the start of secondary recrystallization. I can do it.
図１(a)および(b)は、脱炭焼鈍を行なった後、500ppmの窒化増量が得られるよう窒化処理を行ない400℃まで昇温した後、そこから滞留時間が25時間となる昇温速度で500℃まで昇温し、さらに、昇温速度：20℃／ｈで800℃まで昇温してその後直ちに水冷し、その板厚中央部および板表層部を電子顕微鏡により観察したものである。同図から明らかなように、従来利用されてきた微細析出物（＜100nm）とは異なり、最小のものであっても100nm〜１μｍ程度の粗大でかつAl成分を含まない窒化珪素が板厚方向に均一に粒界析出している様子が確認される。また、図２は、上記析出物を同定したＥＤＳスペクトルである。 1 (a) and 1 (b) show that after decarburization annealing, nitriding treatment is performed so as to obtain a nitriding increase of 500 ppm, the temperature is raised to 400 ° C., and then the residence time is 25 hours. The temperature was raised to 500 ° C. at a rate, and further, the temperature was raised to 800 ° C. at a rate of temperature rise of 20 ° C./h, and then immediately cooled with water. . As is clear from the figure, unlike the fine precipitates (<100 nm) that have been used in the past, silicon nitride that is coarse and does not contain an Al component is 100 nm to 1 μm, even if it is the smallest. It is confirmed that the grain boundaries are uniformly precipitated. FIG. 2 is an EDS spectrum in which the precipitate is identified.
製造上、窒化珪素の析出には、二次再結晶昇温過程を利用するのがエネルギー効率の観点から、最も有効であることは明白であるが、同様のヒートサイクルを利用すれば窒化珪素の粒界選択析出は可能であるため、長時間の二次再結晶焼鈍の前に、窒化珪素分散焼鈍として、別途の熱処理を実施することも可能である。 From the viewpoint of energy efficiency, it is clear that the secondary recrystallization heating process is most effective for precipitation of silicon nitride in terms of production. However, if a similar heat cycle is used, Since grain boundary selective precipitation is possible, a separate heat treatment can be performed as silicon nitride dispersion annealing before the long-time secondary recrystallization annealing.
さらに、実際に二次再結晶が生じる820℃〜1050℃間の温度域においては、昇温速度を15℃/ｈ以下として保定均熱処理を10時間以上行なうことが好ましい。本発明で利用する窒化珪素は、従来利用されているインヒビター（析出物粒径＜100nm）とは異なり粗大（析出粒径≧100nm）であるため、析出物が、熱力学的に固溶あるいはオストワルド成長するために必要な時間は長くなる。すなわち、スラブ中にAlを100ppm以上含ませてAlNあるいは（Al,Si）Nを微細析出させる技術とは異なり、一次再結晶組織の正常粒成長の抑制力が小さくなるのに、より長い時間を要する。 Furthermore, in the temperature range between 820 ° C. and 1050 ° C. in which secondary recrystallization actually occurs, it is preferable to perform the holding and soaking heat treatment for 10 hours or more at a heating rate of 15 ° C./h or less. The silicon nitride used in the present invention is coarse (precipitation particle size ≧ 100 nm), unlike the conventionally used inhibitor (precipitation particle size <100 nm), so that the precipitate is thermodynamically dissolved or Ostwald. The time required to grow increases. That is, unlike the technique of finely precipitating AlN or (Al, Si) N by containing Al in the slab at 100 ppm or more, a longer time is required to reduce the ability to suppress normal grain growth in the primary recrystallized structure. Cost.
なお、二次再結晶温度近傍で等温保持する技術は、一般に、二次再結晶の核生成や、粒成長に時間を要する場合に適用するものであるが、本発明では、目的が大きく異なり、窒化珪素が熱力学的に形態を変化させるのに必要な時間を確保するためのものである。従って、二次再結晶近傍温度で昇温速度が15℃／ｈを超える場合、またその時間が10時間未満となる場合は、窒化珪素による正常粒成長の抑制効果が高温まで継続してしまい、安定した磁気特性を得られないおそれがある。 The technique of isothermal holding near the secondary recrystallization temperature is generally applied when secondary recrystallization nucleation and grain growth require time. This is to ensure the time required for the silicon nitride to change its shape thermodynamically. Therefore, if the rate of temperature rise exceeds 15 ° C./h at the temperature near secondary recrystallization, and if the time is less than 10 hours, the effect of suppressing normal grain growth by silicon nitride continues to a high temperature, There is a risk that stable magnetic properties cannot be obtained.
また、上記の二次再結晶焼鈍後、鋼板表面に、さらに絶縁被膜を塗布、焼き付けることも出来る。かかる絶縁膜の種類については、特に限定されず、従来公知のあらゆる絶縁被膜が適合する。たとえば、特開昭50−79442号公報や特開昭48−39338号公報に記載されているリン酸塩−クロム酸塩−コロイダルシリカを含有する塗布液を鋼板に塗布し、800℃程度で焼き付ける方法が好適である。 In addition, after the secondary recrystallization annealing, an insulating film can be further applied and baked on the surface of the steel sheet. The type of the insulating film is not particularly limited, and any conventionally known insulating film is suitable. For example, a coating solution containing phosphate-chromate-colloidal silica described in JP-A-50-79442 and JP-A-48-39338 is applied to a steel plate and baked at about 800 ° C. The method is preferred.
さらに、本発明では、平坦化焼鈍により、鋼板の形状を整えることが可能であり、この平坦化焼鈍を、絶縁被膜の焼付け処理と兼ねることも出来る。 Furthermore, in the present invention, the shape of the steel sheet can be adjusted by flattening annealing, and this flattening annealing can be combined with the baking treatment of the insulating film.
〔実施例１〕
Si：3.0％、Ｃ：0.04％、Mn：0.05％、Ｓ：0.001％、Cu：0.04％およびSb：0.01％を含有し、AlとＮを表１に示す割合で含有する珪素鋼板スラブを、1100℃、30分加熱後、熱間圧延して2.2mmの板厚の熱延板とし、1050℃、１分間の焼鈍を施した後、冷間圧延により0.26mmの最終板厚とし、得られた冷間圧延コイルの中央部から、100mm×400mmサイズの試料を採取し、ラボにて一次再結晶焼鈍と脱炭を兼ねた焼鈍を行った。また、一部試料については一次再結晶焼鈍と脱炭と連続窒化（ガス：NH3とN2の混合ガスを利用した窒化処理）を兼ねた焼鈍を行った。その後、窒化を施していない試料に対しては、バッチ処理の窒化（塩浴：シアン酸塩を主成分とする塩を利用した窒化処理、ガス：NH3とN2の混合ガスを利用した窒化処理）を行い、鋼中窒素量を増加させた。窒素は全厚を対象としたものを化学分析によって定量した。同一条件の鋼板を一条件につき21枚作製した。
引続き、TiO2を５質量部混合したMgOを主体とする焼鈍分離剤を水スラリ状にしてから塗布、乾燥し鋼板上に焼き付けた。この鋼板のうち20枚に対して、表１に示したＴ１温度まで昇温し、その後、Ｔ２温度の範囲で滞留させ、それから800℃まで表１に示した昇温速度で昇温した。その後1050℃まで、昇温速度を一律20℃／ｈとし、1050℃を超えた後は1200℃までを10℃／ｈで昇温する最終仕上げ焼鈍を行った。
続いてリン酸塩系のガラスコーティングを塗布して焼付け、磁化力800A/mでの磁束密度（Ｂ８，Ｔ）を測定し、評価した。
磁気特性は、各条件20枚の平均値で評価した。また残る１枚については、最終仕上げ焼鈍と同じヒートパターンで800℃まで昇温した後、試料を取り出し、そのまま水焼入れした後、鋼板組織中の窒化珪素を電子顕微鏡により観察し、板表層と板厚中心のそれぞれ圧延方向：0.15mm×板厚方向：0.06mmの領域における析出物数を測定するとともに、鋼板全体での平均粒径を解析した。
測定および解析結果を表１に併記する。
[Example 1]
A silicon steel sheet slab containing Si: 3.0%, C: 0.04%, Mn: 0.05%, S: 0.001%, Cu: 0.04% and Sb: 0.01%, and containing Al and N in the ratios shown in Table 1, After heating at 1100 ° C for 30 minutes, hot rolled to a hot-rolled sheet with a thickness of 2.2 mm. After annealing at 1050 ° C for 1 minute, the final sheet thickness is 0.26 mm by cold rolling. A sample with a size of 100 mm × 400 mm was taken from the center of the cold rolled coil and annealed for both primary recrystallization annealing and decarburization in a laboratory. In addition, some samples were subjected to primary recrystallization annealing, decarburization, and continuous nitriding (gas: nitriding using a mixed gas of NH 3 and N 2 ). After that, for samples that have not been nitrided, batch treatment nitriding (salt bath: nitriding using a salt containing cyanate as a main component, gas: nitriding using a mixed gas of NH 3 and N 2 ) Treatment) to increase the amount of nitrogen in the steel. Nitrogen was quantified by chemical analysis for the entire thickness. 21 steel sheets with the same conditions were produced per condition.
Subsequently, an annealing separator mainly composed of MgO mixed with 5 parts by mass of TiO 2 was formed into a water slurry, applied, dried and baked on the steel plate. Twenty of the steel plates were heated to the T1 temperature shown in Table 1, then retained in the T2 temperature range, and then heated to 800 ° C. at the rate of temperature shown in Table 1. Thereafter, the temperature raising rate was uniformly 20 ° C./h up to 1050 ° C., and after exceeding 1050 ° C., final finish annealing was performed to raise the temperature up to 1200 ° C. at 10 ° C./h.
Subsequently, a phosphate glass coating was applied and baked, and the magnetic flux density (B 8 , T) at a magnetizing force of 800 A / m was measured and evaluated.
The magnetic characteristics were evaluated by the average value of 20 sheets for each condition. In addition, for the remaining one sheet, the temperature was raised to 800 ° C. in the same heat pattern as in the final finish annealing, the sample was taken out and water-quenched as it was, and the silicon nitride in the steel sheet structure was observed with an electron microscope, The number of precipitates in the rolling center: 0.15 mm × sheet thickness direction: 0.06 mm region was measured, and the average grain size of the entire steel sheet was analyzed.
The measurement and analysis results are also shown in Table 1.
同表に示したとおり、本発明に従う発明例では、インヒビターレスの製造工程で製造されたものに比べ、磁気特性が改善しており、磁束密度のばらつき（最大Ｂ8〜最小Ｂ8）も少ないことが分かる。 As shown in the table, the inventive example according to the present invention has improved magnetic properties and less magnetic flux density variation (maximum B 8 to minimum B 8 ) compared to those manufactured in the inhibitorless manufacturing process. I understand that.
〔実施例２〕
表２に示す成分を含有する珪素鋼板スラブを、1100℃、30分加熱後、熱間圧延して2.Ommの板厚の熱延板とし、1050℃、１分間の焼鈍を施した後、冷間圧延により 0.27mmの最終板厚としてから、PH20／PH2＝0.3の雰囲気下で、焼鈍温度を820℃として２分間保持し脱炭焼鈍を行なった。その後、一部コイルに対してバッチ処理でガス窒化処理（NH3、N2雰囲気下）を行ない、鋼中Ｎ量を増量させた。その後、MgOを主成分とし、TiO2を10質量部添加した焼鈍分離剤を水と混ぜてスラリ状としたものを塗布した後、コイルに巻き取って、Ｔ１：400℃、Ｔ２：400〜500℃で30時間滞留し、20℃/hの昇温速度で800℃へ昇温した。次いで、最終仕上げ焼鈍を行ない、さらに、リン酸塩系の絶縁張力コーティングの塗布焼付けと鋼帯の平坦化を目的とする平坦化焼鈍を施して製品とした。
このようにして得られた製品コイルからエプスタイン試験片を採取し、磁束密度（Ｂ8）を測定した結果を表２に示す。
[Example 2]
A silicon steel sheet slab containing the components shown in Table 2 was heated at 1100 ° C. for 30 minutes, and then hot rolled to form a hot rolled sheet with a thickness of 2.Omm, and after annealing at 1050 ° C. for 1 minute, After a final sheet thickness of 0.27 mm was obtained by cold rolling, decarburization annealing was performed by holding the annealing temperature at 820 ° C. for 2 minutes in an atmosphere of PH 2 0 / PH 2 = 0.3. After that, gas nitriding treatment (under NH 3 and N 2 atmospheres) was performed on some coils by batch treatment to increase the amount of N in the steel. Thereafter, an annealing separator containing MgO as a main component and adding 10 parts by mass of TiO 2 was mixed with water to form a slurry, which was wound around a coil, T1: 400 ° C., T2: 400 to 500 It stayed at 30 ° C. for 30 hours, and the temperature was raised to 800 ° C. at a rate of temperature increase of 20 ° C./h. Subsequently, final finish annealing was performed, and further, flattening annealing for the purpose of applying and baking a phosphate-based insulating tension coating and flattening the steel strip was performed to obtain a product.
Table 2 shows the results of collecting Epstein test pieces from the product coil thus obtained and measuring the magnetic flux density (B 8 ).
同表に示したとおり、本発明に従う発明例では、いずれも高磁束密度が得られていることが分かる。 As shown in the table, it can be seen that all the inventive examples according to the present invention have a high magnetic flux density.
Claims (2)
上記二次再結晶焼鈍の昇温過程で、一旦、400〜600℃の温度域（Ｔ１）に昇温した後、300℃以上600℃未満の温度域（Ｔ２）に20時間以上滞留させ、さらに、15℃／ｈ以上の速度で少なくとも800℃まで昇温する方向性電磁鋼板の製造方法。 In mass%, C: 0.08% or less, Si: 2.0 to 4.5% and Mn: 0.5% or less, S, Se and O are each less than 50 mass ppm, sol.Al is less than 100 mass ppm, N is It is suppressed to 80 mass ppm or less, and [ppm sol.Al]-[ppmN] × (26.98 / 14.00) ≦ 30 mass ppm (where [ppmX] is the content of element X in steel (mass ppm)) The steel slab whose composition is the composition of Fe and unavoidable impurities in the balance, without reheating or after reheating, is subjected to hot rolling to form a hot rolled sheet, and then the final thickness is obtained by annealing and rolling. And a nitriding treatment in which the nitrogen increase (ΔN) is 50 mass ppm or more and 1000 mass ppm or less before the secondary recrystallization annealing is performed at a temperature of 800 ° C. or less or a temperature of more than 800 ° C. In the manufacturing process of a series of grain-oriented electrical steel sheets, after applying for 2 seconds or less, applying an annealing separator, and performing secondary recrystallization annealing,
In the temperature raising process of the secondary recrystallization annealing, the temperature is once raised to a temperature range (T1) of 400 to 600 ° C., and then retained in a temperature range (T2) of 300 ° C. or higher and lower than 600 ° C. for 20 hours or more. A method for producing a grain-oriented electrical steel sheet that is heated to at least 800 ° C. at a rate of 15 ° C./h or more.
Ni：0.005〜1.50％、
Sn：0.01〜0.50％、
Sb：0.005〜0.50％、
Cu：0.01〜0.50％、
Cr：0.01〜1.50％
Ｐ：0.0050〜0.50％
Mo：0.01〜0.50％および
Nb：0.0005〜0.0100％
のうちから選んだ１種または２種以上を含有する請求項１に記載の方向性電磁鋼板の製造方法。 Furthermore, the said steel slab is mass%,
Ni: 0.005-1.50%,
Sn: 0.01 to 0.50%,
Sb: 0.005-0.50%,
Cu: 0.01 to 0.50%,
Cr: 0.01 to 1.50%
P: 0.0050-0.50%
Mo: 0.01-0.50% and
Nb: 0.0005-0.0100%
The manufacturing method of the grain-oriented electrical steel sheet according to claim 1, comprising one or more selected from among the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013070401A JP5904151B2 (en) | 2013-03-28 | 2013-03-28 | Method for producing grain-oriented electrical steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013070401A JP5904151B2 (en) | 2013-03-28 | 2013-03-28 | Method for producing grain-oriented electrical steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2014194050A JP2014194050A (en) | 2014-10-09 |
| JP5904151B2 true JP5904151B2 (en) | 2016-04-13 |
Family
ID=51839478
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2013070401A Active JP5904151B2 (en) | 2013-03-28 | 2013-03-28 | Method for producing grain-oriented electrical steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5904151B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6260513B2 (en) * | 2014-10-30 | 2018-01-17 | Ｊｆｅスチール株式会社 | Method for producing grain-oriented electrical steel sheet |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3456415B2 (en) * | 1998-05-26 | 2003-10-14 | Ｊｆｅスチール株式会社 | Manufacturing method of high magnetic flux density grain-oriented electrical steel sheet with extremely low iron loss |
| JP3357603B2 (en) * | 1998-05-21 | 2002-12-16 | 川崎製鉄株式会社 | Manufacturing method of high magnetic flux density grain-oriented electrical steel sheet with extremely low iron loss |
| JP4123653B2 (en) * | 1999-10-12 | 2008-07-23 | Ｊｆｅスチール株式会社 | Method for producing grain-oriented electrical steel sheet |
| JP2002212639A (en) * | 2001-01-12 | 2002-07-31 | Nippon Steel Corp | Method for producing grain oriented silicon steel sheet having excellent magnetic property |
| JP2003213335A (en) * | 2002-01-28 | 2003-07-30 | Jfe Steel Kk | Method of producing grain oriented silicon steel sheet having excellent magnetic property in longitudinal direction and cross direction |
| ITRM20070218A1 (en) * | 2007-04-18 | 2008-10-19 | Ct Sviluppo Materiali Spa | PROCEDURE FOR THE PRODUCTION OF MAGNETIC SHEET WITH ORIENTED GRAIN |
-
2013
- 2013-03-28 JP JP2013070401A patent/JP5904151B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2014194050A (en) | 2014-10-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5983777B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP5692479B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP5983776B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP6436316B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| WO2011102455A1 (en) | Manufacturing method for grain-oriented electromagnetic steel sheet | |
| JP5428188B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP5920387B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP5907202B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP5857983B2 (en) | Manufacturing method of grain-oriented electrical steel sheet and MgO for annealing separator | |
| JP5928362B2 (en) | Method for producing grain-oriented electrical steel sheet and primary recrystallized steel sheet for producing grain-oriented electrical steel sheet | |
| JP6209999B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP6191564B2 (en) | Method for producing grain-oriented electrical steel sheet and nitriding equipment | |
| JP5939156B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP5904151B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP5853968B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP6056675B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP6011586B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP5999040B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP6209998B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP6036587B2 (en) | Method for producing grain-oriented electrical steel sheet and primary recrystallized steel sheet for producing grain-oriented electrical steel sheet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20141027 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20150925 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20150929 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20151127 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20160216 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20160229 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5904151 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |