JP5263363B2 - Method for producing non-oriented electrical steel sheet - Google Patents

Method for producing non-oriented electrical steel sheet Download PDF

Info

Publication number
JP5263363B2
JP5263363B2 JP2011224006A JP2011224006A JP5263363B2 JP 5263363 B2 JP5263363 B2 JP 5263363B2 JP 2011224006 A JP2011224006 A JP 2011224006A JP 2011224006 A JP2011224006 A JP 2011224006A JP 5263363 B2 JP5263363 B2 JP 5263363B2
Authority
JP
Japan
Prior art keywords
less
temperature
hot
rolling
annealing
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
Application number
JP2011224006A
Other languages
Japanese (ja)
Other versions
JP2013082973A (en
Inventor
広朗 戸田
匡 中西
善彦 尾田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Original Assignee
JFE Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by JFE Steel Corp filed Critical JFE Steel Corp
Priority to JP2011224006A priority Critical patent/JP5263363B2/en
Priority to PCT/JP2012/006496 priority patent/WO2013054514A1/en
Priority to TW101137494A priority patent/TWI503417B/en
Publication of JP2013082973A publication Critical patent/JP2013082973A/en
Application granted granted Critical
Publication of JP5263363B2 publication Critical patent/JP5263363B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • 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
    • C21D8/1216—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the working step(s) being of interest
    • C21D8/1222—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
    • 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
    • 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
    • C21D8/1261—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 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
    • 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
    • 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
    • C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/60—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
    • C21D2201/00—Treatment for obtaining particular effects
    • 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

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Organic Chemistry (AREA)
  • Metallurgy (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • Dispersion Chemistry (AREA)
  • Manufacturing Of Steel Electrode Plates (AREA)
  • Soft Magnetic Materials (AREA)

Abstract

In order to provide a non-oriented magnetic steel sheet that has no surface defects and exhibits high flux density, low iron loss and excellent recycling characteristics, a slab with a composition consisting of 0.005 mass% or less of C, 1.5-4.5 mass% of Si, 0.005 mass% or less of Al, 0.01-0.10 mass% of Mn, 0.0010-0.0050 mass% of Ca, 0.0030 mass% or less of S and 0.0030 mass% or less of N, with Ca/S >= 0.80 and the remainder being Fe and unavoidable impurities, is heated at a temperature of 1050-1150°C, is subjected to hot rolling so that the temperature after the completion of the finish rolling is 800-900°C, is rolled up at a temperature of 500-650°C, is subjected to hot-plate annealing at a temperature between 950°C and the temperature at which the slab was heated, and after being subjected to hot or cold rolling, is further subjected to finish annealing at a temperature of 950°C or higher in an atmosphere containing at least 10 vol% hydrogen and having a dew point of -20°C or lower.

Description

本発明は、主に電気機器の鉄心材料として用いられる無方向性電磁鋼板の製造方法に関し、特に鉄損や磁束密度等の磁気特性の改善は勿論、さらに、リサイクル性の向上や鋼板の表面欠陥の抑制を有利に図ろうとするものである。   The present invention relates to a method for producing a non-oriented electrical steel sheet mainly used as an iron core material for electrical equipment, in particular, improvement of magnetic properties such as iron loss and magnetic flux density, as well as improvement of recyclability and surface defects of the steel sheet. It is intended to advantageously suppress this.

近年、電力をはじめとするエネルギーの節減という世界的な動きの中で、電気機器についてもその高効率化が強く要望されている。また、電気機器を小型化する観点から、特に鉄心材料の小型化に対する要望も高まってきている。さらに、最近では環境への配慮から電気機器における鉄心材料のリサイクル化への対応も急務となっている。   In recent years, there has been a strong demand for higher efficiency of electrical equipment in the global movement of energy saving including electric power. In addition, from the viewpoint of downsizing electrical equipment, there is a growing demand for downsizing of iron core materials. Furthermore, recently, due to environmental considerations, it has become an urgent task to respond to recycling of iron core materials in electrical equipment.

上記した電気機器の高効率化や鉄心材料の小型化には、鉄心の素材となる電磁鋼板の磁気特性を改善することが有効である。ここに従来の無方向性電磁鋼板の分野では、磁気特性のうち、特に鉄損を低減する手段として、電気抵抗を増大させて渦電流損を低下させるために、SiやAl, Mn等の含有量を高める手法が一般に用いられてきた。しかしながら、この手法では磁束密度の低下を免れることができないという本質的な問題を抱えていた。   In order to increase the efficiency of the electrical equipment described above and to reduce the size of the iron core material, it is effective to improve the magnetic properties of the electromagnetic steel sheet used as the iron core material. Here, in the field of conventional non-oriented electrical steel sheets, the inclusion of Si, Al, Mn, etc. in order to increase electrical resistance and lower eddy current loss as a means of reducing iron loss, among other magnetic properties. Techniques for increasing the amount have been commonly used. However, this method has an essential problem that it cannot escape the decrease in magnetic flux density.

一方、単にSiやAl等の含有量を高めるだけでなく、併せてＣやＳを低減すること、あるいは特許文献１に記載されているようにＢを添加したり、特許文献２に記載されているようにNiを添加したりするなど、合金成分を増加させることも、一般に知られている方法である。   On the other hand, not only simply increasing the content of Si, Al, etc., but also reducing C and S, or adding B as described in Patent Document 1, or as described in Patent Document 2 It is also a generally known method to increase alloy components such as adding Ni as described above.

これら合金成分を添加する方法では、鉄損は改善されるものの、磁束密度の改善効果は小さく、満足できるものではなかった。また、合金添加に伴って鋼板の硬さが上昇して加工性が劣化するため、かような無方向性電磁鋼板を加工して電気機器に使用する場合の汎用性に乏しく、その用途は極めて限定されたものとなっていた。   Although the iron loss is improved by the method of adding these alloy components, the effect of improving the magnetic flux density is small and not satisfactory. In addition, since the hardness of the steel sheet increases due to the alloy addition and the workability deteriorates, the versatility when processing such a non-oriented electrical steel sheet for use in electrical equipment is poor, and its use is extremely It was limited.

さらに、製造プロセスを変更し、製品板における結晶方位の集積度、すなわち集合組織を改善して磁気特性を向上させる方法がいくつか提案されている。例えば、特許文献３には、Si： 2.8〜4.0 mass％（質量％）およびAl： 0.3〜2.0 mass％を含有する鋼に 200〜500 ℃の温度範囲で温間圧延を施し、{100}＜OVW＞組織を発達させる方法が開示されている。そして、特許文献４には、Si：1.5 〜4.0 mass％およびAl：0.1 〜2.0 mass％を含有する鋼を熱間圧延したのち、1000℃以上、1200℃以下の熱延板焼鈍と圧下率：80〜90％の冷間圧延を組み合わせることによって｛100｝組織を発達させる方法が開示されている。   Furthermore, several methods have been proposed for improving the magnetic properties by changing the manufacturing process to improve the degree of integration of crystal orientations in the product plate, that is, the texture. For example, Patent Document 3 discloses that steel containing Si: 2.8 to 4.0 mass% (mass%) and Al: 0.3 to 2.0 mass% is warm-rolled in a temperature range of 200 to 500 ° C., and {100} < OVW> A method for developing tissue is disclosed. And in patent document 4, after hot-rolling steel containing Si: 1.5-4.0 mass% and Al: 0.1-2.0 mass%, 1000 degreeC or more and 1200 degreeC or less hot-rolled sheet annealing and reduction ratio: A method for developing a {100} structure by combining 80-90% cold rolling is disclosed.

特開昭５８−１５１４３号公報JP 58-15143 A 特開平３−２８１７５８号公報JP-A-3-281758 特開昭５８−１８１８２２号公報Japanese Patent Laid-Open No. 58-181822 特開平３−２９４４２２号公報JP-A-3-294422 特許第３８８８０３３号公報Japanese Patent No. 3888033 特許第４１２６４７９号公報Japanese Patent No. 4126479 特許第４２５８９５１号公報Japanese Patent No. 4258951 特許第４２５８９５２号公報Japanese Patent No. 4258952

しかし、これらの方法による磁気特性の改善効果は、未だ満足できるものではなく、さらには加工性およびリサイクル性にも問題を残していた。すなわち、鋼中にある程度以上のAlが含まれていると、まず鋼板の硬さが上昇して加工性が阻害され、また鉄心材料をリサイクルしたり、需要家でスクラップ処理したりする場合に電気炉の電極を傷めるという問題があった。   However, the effect of improving the magnetic properties by these methods is not yet satisfactory, and there are still problems in processability and recyclability. In other words, if a certain amount of Al is contained in the steel, the hardness of the steel plate will rise first and workability will be hindered, and when steel core materials are recycled or scrapped by customers, There was a problem of damaging the furnace electrodes.

さらに、鉄心のリサイクル材を用いてモータのシャフトなどを鋳造する場合、0.1 mass％以上のAlが含まれていると、鋳込み時に溶鋼の表面酸化が進行して粘性が増大し、溶鋼の鋳型内充填性が悪化するために、健全な鋳込みが阻害されるところにも問題を残していた。   In addition, when casting motor shafts using recycled iron cores, if 0.1 mass% or more of Al is included, the surface oxidation of the molten steel proceeds during casting and the viscosity increases, and the molten steel is cast into the mold. Since the filling property is deteriorated, there is still a problem where the sound casting is hindered.

この問題を解決するために、特許文献５ではAlを0.02％以下、特許文献６ではAlを0.017％以下、特許文献７ではAlを0.010％以下、特許文献８ではAlを0.030％以下にし、S, Nなどの不純物量低減や熱延板焼鈍後の平均粒径、冷間圧延条件などを制御することにより、磁束密度が高く鉄損が低い無方向性電磁鋼板を製造する技術が、それぞれ開示されている。しかしながら、上述した技術に従ってAl量を低減すると、磁気特性の安定性に劣るということが、新たに問題点として浮上した。   In order to solve this problem, in Patent Document 5, Al is 0.02% or less, in Patent Document 6, Al is 0.017% or less, in Patent Document 7, Al is 0.010% or less, and in Patent Document 8, Al is 0.030% or less. , N and other technologies to manufacture non-oriented electrical steel sheets with high magnetic flux density and low iron loss by controlling the average grain size after hot-rolled sheet annealing, cold rolling conditions, etc. Has been. However, a new problem has emerged that when the Al content is reduced according to the technique described above, the stability of the magnetic properties is inferior.

一方、Alと同様にMnの含有量を低減することも磁気特性の向上に寄与すると考え、発明者らは、Mn量も低減することを試みた。その結果、特にAl≦0.005％、かつMn≦0.10％の成分では、非常に良好な磁性が得られる場合があるものの、やはりその良好な磁性を安定して得ることが難しかった。さらに、その上、Mnの低減に伴って鋼板に表面欠陥が生じやすかった。そこで、本発明の目的は、Al量及びMn量の低減による磁気特性の向上を、表面欠陥の発生を招くことなしに、安定して達成するための方途を与えるところにある。   On the other hand, reducing the content of Mn as in the case of Al is considered to contribute to the improvement of magnetic properties, and the inventors have attempted to reduce the amount of Mn. As a result, in particular, a component with Al ≦ 0.005% and Mn ≦ 0.10% sometimes obtained very good magnetism, but it was still difficult to stably obtain the good magnetism. Furthermore, surface defects were likely to occur in the steel sheet as Mn was reduced. Therefore, an object of the present invention is to provide a way to stably achieve the improvement of magnetic characteristics by reducing the Al content and the Mn content without causing the occurrence of surface defects.

さて、発明者らは、上記の課題を解決するために、Si以外のAl及びMnという合金元素を極力低減して、高磁束密度かつ低鉄損の鋼材を製造する際に、磁気特性の安定性に劣り、表面欠陥が発生しやすい原因の究明に努めた。   In order to solve the above problems, the inventors reduced the alloying elements of Al and Mn other than Si as much as possible to produce a steel material with high magnetic flux density and low iron loss. We tried to find out the cause of surface defects.

その結果、Al量が少なくなると、仕上焼鈍後の酸化物量が多くなる傾向が確認された。これはAlが多く含有された場合は、Al酸化物が生成するためにそのバリア効果でSi酸化物の生成が抑えられるが、Alが少ない場合はその効果が小さいので、Siの酸化が進行しやすくなり、却って、試料表面に生じる酸化物が多くなるためと考えられた。ここに、表層酸化物の生成は鉄損の劣化原因になるために、その抑制が必要となる。   As a result, it was confirmed that when the amount of Al decreases, the amount of oxide after finish annealing increases. This is because when Al is contained in a large amount, the generation of Si oxide is suppressed by the barrier effect because Al oxide is generated, but when the amount of Al is small, the effect is small, so the oxidation of Si proceeds. This was thought to be because the amount of oxide generated on the surface of the sample increased. Here, the generation of the surface layer oxide causes deterioration of the iron loss, so that suppression is required.

また、Mn量が少ないと、スラブ加熱中に液相のFeSが析出しやすくなり、それに伴ってSが部分的に濃化・偏析することによって、その部分が割れやすくなり、結果として表面欠陥が生じやすくなることがわかった。したがって、表面欠陥の改善には、液相のFeSを析出しにくくさせる必要がある。   In addition, when the amount of Mn is small, liquid-phase FeS is likely to precipitate during slab heating, and as a result, S partly concentrates and segregates, so that the part easily breaks, resulting in surface defects. It turns out that it becomes easy to occur. Therefore, in order to improve surface defects, it is necessary to make liquid phase FeS difficult to precipitate.

本発明は、上記の知見に立脚するものである。
すなわち、本発明の要旨構成は次のとおりである。
（１） 質量％で、C：0.005％以下、Si：1.5％以上4.5％以下、Al：0.005％以下、Mn：0.01％以上0.10％以下、Ca：0.0010％以上0.0050％以下、S：0.0030％以下およびN：0.0030％以下を、Ca/S≧0.80の下に含有し、残部Feおよび不可避的不純物の成分組成からなるスラブを、加熱後に熱間圧延を施して巻取り、ついで熱延板焼鈍を経て、冷間または温間にて圧延を施したのち、仕上焼鈍を施す一連の工程からなる無方向性電磁鋼板の製造方法において、
前記スラブ加熱温度を1050℃以上1150℃以下、前記熱間圧延の仕上げ圧延終了後の温度を800℃以上900℃以下、前記巻取り温度を500℃以上650℃以下、前記熱延板焼鈍温度を950℃以上前記スラブ加熱温度以下とし、更に仕上焼鈍を、水素を10vol％以上含有し、かつ露点が−20℃以下の雰囲気下にて950℃以上の温度で行うことを特徴とする無方向性電磁鋼板の製造方法。 The present invention is based on the above findings.
That is, the gist configuration of the present invention is as follows.
(1) By mass%, C: 0.005% or less, Si: 1.5% to 4.5%, Al: 0.005% or less, Mn: 0.01% to 0.10%, Ca: 0.0010% to 0.0050%, S: 0.0030% And N: 0.0030% or less under Ca / S ≧ 0.80, the slab consisting of the remaining Fe and the inevitable impurities component composition is rolled up by heating and then hot-rolled sheet annealed In the method for producing a non-oriented electrical steel sheet comprising a series of steps for performing finish annealing after performing cold or warm rolling,
The slab heating temperature is 1050 ° C. or higher and 1150 ° C. or lower, the temperature after finish rolling of the hot rolling is 800 ° C. or higher and 900 ° C. or lower, the winding temperature is 500 ° C. or higher and 650 ° C. or lower, and the hot rolled sheet annealing temperature is Non-directional, characterized in that it is 950 ° C or higher and not higher than the slab heating temperature, and finish annealing is performed at a temperature of 950 ° C or higher in an atmosphere containing 10 vol% or more of hydrogen and a dew point of -20 ° C or lower. A method for producing electrical steel sheets.

（２）前記成分組成は、さらに、質量％で、Sb：0.005％以上0.2％以下、Sn：0.005％以上0.2％以下、P：0.03％以上0.2％以下、Mo：0.005％以上0.10％以下、B：0.0002％以上0.002％以下、およびCr：0.05％以上0.5％以下の１種または２種以上を含有することを特徴とする請求項１に記載の無方向性電磁鋼板の製造方法。   (2) The component composition is further in mass%, Sb: 0.005% to 0.2%, Sn: 0.005% to 0.2%, P: 0.03% to 0.2%, Mo: 0.005% to 0.10%, The method for producing a non-oriented electrical steel sheet according to claim 1, comprising B: 0.0002% or more and 0.002% or less and Cr: 0.05% or more and 0.5% or less.

本発明に従って、低Alかつ低Mnにして所定の製造条件で無方向性電磁鋼板を製造することで、鋼板表面に欠陥のない高磁束密度かつ低鉄損の無方向性電磁鋼板を提供することができる。そして、本発明による無方向性電磁鋼板に含まれるAl成分は所定値よりも少ないため、鋼板の硬さが上昇して加工性が阻害されることが無く、リサイクル性を向上させることができる。   Providing a non-oriented electrical steel sheet having a low magnetic loss and a high magnetic flux density free from defects on the steel sheet surface by producing a non-oriented electrical steel sheet under predetermined production conditions with low Al and low Mn according to the present invention. Can do. And since the Al component contained in the non-oriented electrical steel sheet according to the present invention is less than a predetermined value, the hardness of the steel sheet is not increased, the workability is not hindered, and the recyclability can be improved.

AlおよびMn含有量と磁気特性および表面欠陥との関係を示す図である。It is a figure which shows the relationship between Al and Mn content, a magnetic characteristic, and a surface defect. 表面欠陥の発生程度に及ぼす仕上げ圧延終了後温度と巻取り温度の影響を示す図である。It is a figure which shows the influence of the temperature after completion | finish of finish-rolling and the coiling temperature which has on the generation | occurrence | production degree of a surface defect. 磁性に及ぼす仕上げ焼鈍条件の影響を示す図である。It is a figure which shows the influence of the finish annealing conditions which acts on magnetism. CaおよびS含有量と磁気特性および表面欠陥との関係を示す図である。It is a figure which shows the relationship between Ca and S content, a magnetic characteristic, and a surface defect. 磁気特性と表面欠陥の発生有無に及ぼすスラブ加熱温度と熱延板焼鈍温度の影響を示す図である。It is a figure which shows the influence of the slab heating temperature and hot-rolled sheet annealing temperature which have on magnetic characteristics and the presence or absence of a surface defect.

以下、本発明を具体的に説明する。なお、以下に示す鋼板成分に関する「％」表示は、特に断らない限り「質量％」を意味する。   Hereinafter, the present invention will be specifically described. In addition, unless otherwise indicated, the "%" display regarding the steel plate component shown below means "mass%".

前述したように、通常の無方向性電磁鋼板では、鉄損低減のために、Siに加えてAlやMn等の元素を添加することが多い。特にAlはSi同様、固有抵抗増大効果が大きいため、積極的に添加されている。また、Mnも固有抵抗を高める効果があり、かつ、熱間脆性の改善に有効なため、通常0.15％から0.20％の範囲以上は添加されている。   As described above, ordinary non-oriented electrical steel sheets often add elements such as Al and Mn in addition to Si in order to reduce iron loss. In particular, Al, like Si, has a large effect of increasing specific resistance, and is therefore actively added. Mn also has an effect of increasing the specific resistance and is effective in improving hot brittleness. Therefore, it is usually added in the range of 0.15% to 0.20% or more.

しかしながら、発明者らは、高磁束密度低鉄損材を得るにはAlを極力低減すると共に、Mn量も通常添加されているよりも低い範囲の成分系の方が有利と考え、それに関する検討を行った。以下に、その検討結果について詳述する。   However, the inventors considered that it is advantageous to reduce the Al content as much as possible to obtain a high magnetic flux density and low iron loss material, and that the component system with a lower range of Mn content is more advantageous than the normal addition amount. Went. Below, the examination result is explained in full detail.

すなわち、Si：3.3％で、S：0.0030％以下およびN：0.0030％以下を含み、Al量を0.0001〜0.01％、およびMn量を0.01〜0.2％の範囲にて変化させた成分組成の鋼スラブを用意した。   That is, a steel slab having a composition of Si: 3.3%, S: 0.0030% or less and N: 0.0030% or less, with the Al content varied in the range of 0.0001 to 0.01% and the Mn content in the range of 0.01 to 0.2% Prepared.

鋼スラブは1100℃で加熱した後、2.0mm厚まで熱間圧延し、得られた熱延板に1050℃の温度で熱延板焼鈍を施した。ついで、酸洗後、板厚0.35mm厚に冷間圧延したのち、1025℃の温度で仕上げ焼鈍を行った。   The steel slab was heated at 1100 ° C. and hot-rolled to a thickness of 2.0 mm, and the obtained hot-rolled sheet was subjected to hot-rolled sheet annealing at a temperature of 1050 ° C. Subsequently, after pickling, the sheet was cold-rolled to a thickness of 0.35 mm and then annealed at a temperature of 1025 ° C.

かくして得られた鋼板から、圧延方向(L)および圧延直角方向(C)にエプスタイン試験片を切り出し、磁気特性を測定した。なお、磁気特性はL＋C特性（L方向とC方向の磁気特性の平均値）で評価した。また、鋼板表面の線状欠陥発生状況（鋼板の単位面積当たりに存在する線状欠陥の長さ）を評価した。そして、0.001[m/m2]未満を欠陥無（○）、0.001[m/m2]以上〜0.01[m/m2]以下を欠陥少し有（△）、0.01[m/m2]超えを欠陥多（×）とした。得られた結果を図１に示す。図１は、AlおよびMn含有量と磁気特性および表面欠陥との関係を示す図である。図１において、横軸はAl含有量、縦軸はMn含有量であり、図中に磁束密度(B50)と鉄損(W15/50)、および表面欠陥の程度を記した。なお、各プロットにおいて、上段：B50、中段：W15/50、下段：表面欠陥の評価結果である。 From the steel plate thus obtained, Epstein specimens were cut in the rolling direction (L) and the perpendicular direction (C), and the magnetic properties were measured. The magnetic characteristics were evaluated by L + C characteristics (average value of magnetic characteristics in L direction and C direction). Further, the occurrence of linear defects on the surface of the steel sheet (the length of linear defects existing per unit area of the steel sheet) was evaluated. And less than 0.001 [m / m 2 ] no defect (○), 0.001 [m / m 2 ] or more to 0.01 [m / m 2 ] or less slightly defect (△), more than 0.01 [m / m 2 ] Was defined as having many defects (×). The obtained results are shown in FIG. FIG. 1 is a diagram showing the relationship between Al and Mn content, magnetic properties, and surface defects. In FIG. 1, the horizontal axis represents the Al content, the vertical axis represents the Mn content, and the magnetic flux density (B 50 ), iron loss (W 15/50 ), and the degree of surface defects are shown in the figure. In each plot, the upper row: B 50 , the middle row: W 15/50 , the lower row: evaluation results of surface defects.

図１よりAl≦0.005％、かつMn≦0.10％の成分組成の場合に、非常に良好な磁性(B50≧1.705TかつW15/50≦2.10W/kg)が得られる場合が多いが、同時に表面欠陥が発生しやすい傾向にあることがわかる。 From FIG. 1, in the case of a component composition of Al ≦ 0.005% and Mn ≦ 0.10%, very good magnetism (B 50 ≧ 1.705T and W 15/50 ≦ 2.10 W / kg) is often obtained. It can be seen that surface defects tend to occur at the same time.

そこで、発明者らは、Al≦0.005％、かつMn≦0.10％の成分組成を有する、磁性が良好なものの表面欠陥の発生が顕著だった試験片を、詳細に調査・検討した。その結果、それらの試験片ではSが部分的に偏析・濃化している箇所が多く見られ、特に表面欠陥が発生した位置近傍では上記Sの偏析・濃化が顕著であった。   Therefore, the inventors investigated and examined in detail a test piece having a component composition of Al ≦ 0.005% and Mn ≦ 0.10%, which had good magnetic properties but had significant surface defects. As a result, in these test pieces, there were many places where S was partially segregated and concentrated, and the segregation and concentration of S was remarkable particularly in the vicinity of the position where the surface defect occurred.

発明者らは、その原因として上記のMn，S量の場合、鋳込み後に析出していたMnSは1100℃のスラブ加熱中に固溶して、熱間圧延中に再析出するが、Mn量が少ないと液相のFeSが析出しやすくなり、その結果、Sが部分的に濃化・偏析し、その部分が割れやすくなり、結果的に表面欠陥が発生しやすくなると考えた。   In the case of the above Mn and S amounts as the cause, the MnS precipitated after casting is dissolved during the slab heating at 1100 ° C. and reprecipitated during hot rolling. If the amount of FeS is small, liquid phase FeS is likely to precipitate. As a result, S is partially concentrated and segregated, and the portion is liable to be cracked. As a result, surface defects are likely to occur.

また、Al≦0.005％、かつMn≦0.10％の成分にて、磁性が非常に良好だった試験片とあまり良好な磁性が得られなかった試験片とについても詳細に調査・検討したところ、後者では試験片表層部の酸化物量が多かった。   In addition, when the components with Al ≦ 0.005% and Mn ≦ 0.10% were used, the specimens with very good magnetism and the specimens with very poor magnetism were investigated and examined in detail. Then, the amount of oxide in the surface layer of the test piece was large.

その原因について調査したところ、同一仕上げ焼鈍条件 (温度、雰囲気、時間)では、Al量が少なくなるにつれて、仕上げ焼鈍後の試験片表面に生じる酸化物量が多くなる傾向が見られた。これは、Alが含有される場合はAl酸化物が生成するためにそのバリア効果でSi酸化物の生成が抑えられるが、Alが少ない場合、そのバリア効果がほとんどないため、Siの酸化が進行しやすくなるためと考えられた。ここに、表層酸化物の生成は、鉄損の劣化原因になるため、その抑制が必要となる。   When the cause was investigated, under the same finish annealing conditions (temperature, atmosphere, time), there was a tendency that the amount of oxide generated on the surface of the test piece after finish annealing increased as the Al amount decreased. This is because when Al is contained, Al oxide is generated, so the formation of Si oxide is suppressed by its barrier effect. However, when Al is small, the barrier effect is hardly present, so oxidation of Si proceeds. It was thought to be easy to do. Here, the generation of the surface layer oxide causes deterioration of the iron loss, so that suppression thereof is necessary.

以上より、発明者らは、鋳込み後に析出しているMnS量を少なくすべく、Caを少量添加し、MnSを硫化カルシウム(CaS)の形態にすることにより、上記・現象の発生を抑制し、表面欠陥の発生を無くすことができるのではないか、と考えた。また、同時に介在物の形態制御には熱延条件の影響もあると考え、さらに、鋼板表層酸化の観点から仕上げ焼鈍条件の影響も重要と考え、以下の実験を行った。   From the above, the inventors added a small amount of Ca to reduce the amount of MnS precipitated after casting, and by suppressing the occurrence of the above phenomenon by making MnS into the form of calcium sulfide (CaS), We thought that the occurrence of surface defects could be eliminated. At the same time, the shape control of inclusions was considered to be affected by hot rolling conditions, and the influence of finish annealing conditions was also important from the viewpoint of steel plate surface oxidation, and the following experiments were conducted.

表１に示す成分組成からなる鋼スラブを用意し、1100℃で加熱した後、仕上げ圧延終了後の温度と圧延終了後の巻取り温度を変化させて2.0mm厚まで熱間圧延した。次に1025℃の温度で熱延板焼鈍を施し、酸洗後、板厚0.35mm厚に冷間圧延した。その後、水素濃度と露点を変化させて、1050℃の温度で仕上げ焼鈍を行った。得られた鋼板から、圧延方向および圧延直角方向にエプスタイン試験片を切り出し、磁気特性を測定した。磁気特性はL+C特性で評価した。また、表面欠陥の発生程度も調査した。   Steel slabs having the composition shown in Table 1 were prepared, heated at 1100 ° C., and hot rolled to 2.0 mm thickness by changing the temperature after finishing rolling and the coiling temperature after finishing rolling. Next, hot-rolled sheet annealing was performed at a temperature of 1025 ° C., pickled, and cold-rolled to a sheet thickness of 0.35 mm. Then, finish annealing was performed at a temperature of 1050 ° C. while changing the hydrogen concentration and the dew point. From the obtained steel plate, an Epstein test piece was cut out in the rolling direction and the direction perpendicular to the rolling direction, and the magnetic properties were measured. Magnetic properties were evaluated by L + C characteristics. The extent of surface defects was also investigated.

Figure 0005263363
Figure 0005263363

表面欠陥の発生程度に及ぼす仕上げ圧延終了後温度と圧延終了後巻取り温度の影響を図２に示す。仕上げ圧延終了後温度が800℃以上900℃以下、圧延終了後巻取り温度が500℃以上650℃以下の場合に表面欠陥の発生がみられないことがわかる。   FIG. 2 shows the influence of the temperature after finishing rolling and the coiling temperature after finishing rolling on the degree of occurrence of surface defects. It can be seen that no surface defects are observed when the temperature after finish rolling is 800 ° C. or higher and 900 ° C. or lower and the winding temperature after rolling is 500 ° C. or higher and 650 ° C. or lower.

鋼板表面に欠陥の発生がみられなかった条件、すなわち仕上げ圧延終了後温度が800℃以上900℃以下、圧延終了後巻取り温度が500℃以上650℃以下の条件下で、磁性に及ぼす仕上げ焼鈍条件の影響を図３に示す。水素濃度10vol％以上かつ露点-20℃以下の条件で、高磁束密度(B50≧1.705T)かつ低鉄損(W15/50≦2.10W/kg)が得られていることがわかる。 Finish annealing on magnetism under the condition that no defects were found on the steel sheet surface, that is, the temperature after finish rolling was 800 ° C or higher and 900 ° C or lower and the winding temperature after rolling was 500 ° C or higher and 650 ° C or lower The influence of the conditions is shown in FIG. It can be seen that high magnetic flux density (B 50 ≧ 1.705T) and low iron loss (W 15/50 ≦ 2.10 W / kg) were obtained under the conditions of hydrogen concentration of 10 vol% or more and dew point of −20 ° C. or less.

上記結果を受けて、発明者らはCa, S量の影響を調べる実験を行った。
Si：3.8％、Al：0.0003％、Mn：0.07％およびN：0.0030％以下を基本成分とし、Ca量を0.0005％以上0.0060％以下および、S量を0.0004％以上0.0060％以下の範囲で変化した成分の鋼スラブを用意した。 Based on the above results, the inventors conducted an experiment to examine the effects of Ca and S content.
Si: 3.8%, Al: 0.0003%, Mn: 0.07% and N: 0.0030% or less as basic components, Ca content varied from 0.0005% to 0.0060% and S content in the range from 0.0004% to 0.0060%. Component steel slabs were prepared.

鋼スラブは1120℃で加熱した後、仕上げ圧延終了後の温度が800℃以上900℃以下、圧延終了後の巻取り温度が500℃以上650℃以下の条件下に1.8mm厚まで熱間圧延した。次に1000℃の温度で熱延板焼鈍を施し、酸洗後、板厚0.35mm厚に冷間圧延した。その後、水素濃度30vol％かつ露点-40℃の条件にて、1050℃の温度で仕上げ焼鈍を行った。   The steel slab was heated at 1120 ° C and then hot-rolled to a thickness of 1.8mm under conditions where the temperature after finish rolling was 800 ° C or higher and 900 ° C or lower and the winding temperature after rolling was 500 ° C or higher and 650 ° C or lower . Next, hot-rolled sheet annealing was performed at a temperature of 1000 ° C., pickled, and cold-rolled to a sheet thickness of 0.35 mm. Thereafter, finish annealing was performed at a temperature of 1050 ° C. under conditions of a hydrogen concentration of 30 vol% and a dew point of −40 ° C.

得られた鋼板から、磁気特性は圧延方向および圧延直角方向にエプスタイン試験片を切り出し、磁気特性を測定した。磁気特性はＬ＋Ｃ特性で評価した。また、表面欠陥の発生程度も調査した。   From the obtained steel sheet, Epstein test pieces were cut out in the rolling direction and the direction perpendicular to the rolling direction, and the magnetic properties were measured. Magnetic characteristics were evaluated by L + C characteristics. The extent of surface defects was also investigated.

得られた結果を図４に示す。図４は、CaおよびS含有量と磁気特性および表面欠陥との関係を示す図である。図４において、横軸はCa量、縦軸はS量であり、図中に磁束密度(B50)と鉄損(W15/50)、および表面欠陥の程度を記した。なお、各プロットにおいて、上段：B50、中段：W15/50、下段：表面欠陥の評価結果である。表面欠陥は、鋼板の単位面積当たり線状欠陥長さで評価し、0.001[m/m2]未満を欠陥無（○）、0.001[m/m2]以上を欠陥有（×）として評価した（以下は、すべて同じ評価基準とした）。 The obtained results are shown in FIG. FIG. 4 is a diagram showing the relationship between Ca and S content, magnetic properties, and surface defects. In FIG. 4, the horizontal axis is the Ca content, and the vertical axis is the S content. In the figure, the magnetic flux density (B 50 ), the iron loss (W 15/50 ), and the degree of surface defects are shown. In each plot, the upper row: B 50 , the middle row: W 15/50 , the lower row: evaluation results of surface defects. Surface defects were evaluated by linear defect length per unit area of the steel sheet, and less than 0.001 [m / m 2 ] was evaluated as having no defects (○), and 0.001 [m / m 2 ] or more was evaluated as having defects (×). (The following are all the same evaluation criteria.)

図４より、試験片がCa：0.0010％以上0.0050％以下およびS：0.0030％以下をCa/S≧0.80の下に含有する場合に、良好な外観と磁気特性(W15/50≦2.0W/kg, B50≧1.70T)が得られていることがわかる。 FIG. 4 shows that when the specimen contains Ca: 0.0010% or more and 0.0050% or less and S: 0.0030% or less under Ca / S ≧ 0.80, good appearance and magnetic properties (W 15/50 ≦ 2.0 W / kg, B 50 ≧ 1.70T).

なお、Ca添加については、特開2001-271147号公報にて、Ｃ：0.005 ％以下、（Si＋Al）≧1.0 ％でかつAl≧0.2 ％またはAl≦0.01％、Mn：0.1 〜1.5 ％、Ｐ：0.1 ％以下を含み、さらにＳ：0.004 ％以下、(Sb＋Sn＋Cu)：0.005 〜0.1 ％を含有する組成で、Caを10〜100ppm添加することにより、介在物や析出物が多くても鉄損を低減することができる技術が開示されているが、この従来技術における主旨は、仕上げ焼鈍時の粒成長を抑制するMn系硫化物の量を減らして、CaSの形態にすることで、製品板の粒径を大きくして鉄損を改善することにあり、本発明のMn量が少ない場合に液相のFeSの析出を防いでSの偏析・濃化を抑制することで表面欠陥の発生を抑制するのとは目的・効果が異なる。また上記・公報での明細書および実施例中で、Mn量の最も少ない例は0.15％であり、本発明のMn量0.01％以上0.1％以下に該当するものはない。   Regarding Ca addition, in JP-A-2001-271147, C: 0.005% or less, (Si + Al) ≧ 1.0% and Al ≧ 0.2% or Al ≦ 0.01%, Mn: 0.1 to 1.5%, P: Including 0.1% or less, S: 0.004% or less, and (Sb + Sn + Cu): 0.005 to 0.1%. By adding 10 to 100ppm of Ca, iron loss is reduced even if there are many inclusions and precipitates. Although the technology that can be used is disclosed, the gist of this prior art is that the amount of Mn sulfide that suppresses the grain growth during finish annealing is reduced to form CaS, thereby reducing the grain size of the product plate. The purpose is to improve iron loss by increasing the diameter, and when the Mn content of the present invention is small, the precipitation of liquid phase FeS is prevented and the occurrence of surface defects is suppressed by suppressing the segregation and concentration of S. It has different purposes and effects. In the specification and examples in the above publications, the example with the smallest amount of Mn is 0.15%, and there is nothing corresponding to the Mn amount of 0.01% or more and 0.1% or less of the present invention.

また、特開平11-293426号公報では、Ｃ：0.005％以下、Si：4.0％以下、Mn：0.05〜1.5％、Ｐ：0.2％以下、Ｎ：0.005％以下（０を含む）、Al：0.1〜1.0％、Ｓ：0.0009％以下(０を含む)を含有する組成で、Caを0.0005〜0.005％を添加することで、疲労特性に優れた無方向性電磁鋼板を製造する技術が開示されているが、この従来技術における主旨は、S 9ppm以下の材料ではCa添加により分散した球状のCa-Al酸化物を生成させることで、疲労強度を向上させることにある。したがって、Alが0.1〜1.0％含有されることが重要と考えられ、本発明のAl：0.005％以下の成分とはCa添加の目的・効果が異なる。また上記・公報での明細書および実施例中で、Mn量の最も少ない例は0.17％であり、本発明のMn量0.01％以上0.1％以下に該当するものはない。   In JP-A-11-293426, C: 0.005% or less, Si: 4.0% or less, Mn: 0.05 to 1.5%, P: 0.2% or less, N: 0.005% or less (including 0), Al: 0.1 A technique for producing a non-oriented electrical steel sheet having excellent fatigue characteristics by adding 0.0005 to 0.005% of Ca with a composition containing ˜1.0% and S: 0.0009% or less (including 0) is disclosed. However, the gist of this prior art is to improve fatigue strength by generating spherical Ca—Al oxide dispersed by the addition of Ca for materials with S 9 ppm or less. Therefore, it is considered important that Al is contained in an amount of 0.1 to 1.0%, and the purpose and effect of adding Ca is different from the component of Al of the present invention of 0.005% or less. In the specification and examples in the above publications, the example with the smallest amount of Mn is 0.17%, and none of the Mn content of the present invention falls within the range of 0.01% to 0.1%.

更に発明者らは、他の製造条件の影響を調べるために以下の実験を行った。
表２に示す成分組成になる鋼スラブをいくつか用意し、スラブ加熱温度を変化させて加熱した後、仕上げ圧延終了後の温度が860℃〜890℃、圧延終了後の巻取り温度：610℃〜640℃の下に1.6mm厚まで圧延した。次に焼鈍温度を変化させて熱延板焼鈍を施し、酸洗後、板厚0.25mm厚に冷間圧延した。その後、水素濃度20vol％かつ露点-40℃の条件で、1000℃の温度で仕上げ焼鈍を行った。 Furthermore, the inventors conducted the following experiment in order to investigate the influence of other manufacturing conditions.
Several steel slabs having the composition shown in Table 2 were prepared and heated by changing the slab heating temperature. The temperature after finishing rolling was 860 to 890 ° C, and the coiling temperature after rolling was 610 ° C. Rolled to 1.6mm thickness under ~ 640 ° C. Next, hot-rolled sheet annealing was performed while changing the annealing temperature, and after pickling, the sheet was cold-rolled to a thickness of 0.25 mm. Then, finish annealing was performed at a temperature of 1000 ° C. under conditions of a hydrogen concentration of 20 vol% and a dew point of −40 ° C.

Figure 0005263363
Figure 0005263363

得られた鋼板から、圧延方向および圧延直角方向にエプスタイン試験片を切り出し、磁気特性を測定した。磁気特性はＬ＋Ｃ特性で評価した。また、表面欠陥の発生程度も調査した。   From the obtained steel plate, an Epstein test piece was cut out in the rolling direction and the direction perpendicular to the rolling direction, and the magnetic properties were measured. Magnetic characteristics were evaluated by L + C characteristics. The extent of surface defects was also investigated.

磁気特性と表面欠陥の発生有無に及ぼすスラブ加熱温度と熱延板焼鈍温度の影響を図５に示す。スラブ加熱温度を1050℃以上1150℃以下、熱延板焼鈍を950℃以上スラブ加熱温度以下とした条件にて、良好な外観と磁気特性(W15/50≦1.9W/kg, B50≧1.70T)が得られていることがわかる。 FIG. 5 shows the influence of the slab heating temperature and the hot-rolled sheet annealing temperature on the magnetic properties and the presence or absence of surface defects. Good appearance and magnetic properties (W 15/50 ≦ 1.9 W / kg, B 50 ≧ 1.70) under the conditions of slab heating temperature of 1050 ° C to 1150 ° C and hot-rolled sheet annealing of 950 ° C to slab heating temperature It can be seen that T) is obtained.

上記した範囲のスラブ加熱温度で良好な特性が得られる理由については、鋳込み時にCaSとしてではなく。MnSとして析出していたものが、一旦、固溶した後、CaSとして析出するためと考えられる。スラブ加熱温度が低いと再固溶が生じず、一方、加熱温度が高いと、鋳込み時にCaSとして析出していたものまでが固溶してしまうため逆効果になると考えられる。   The reason why good characteristics can be obtained at the slab heating temperature in the above range is not as CaS during casting. This is presumably because what was precipitated as MnS once solid-dissolves and then precipitates as CaS. If the slab heating temperature is low, re-dissolution does not occur. On the other hand, if the heating temperature is high, the material that has been precipitated as CaS at the time of casting is solid-dissolved.

また、上記した範囲の熱延板焼鈍温度で良好な特性が得られる理由について、下限温度は、一定以上の大きさの熱延板粒径にすること、上限温度は、スラブ加熱および熱間圧延時に得られたCaSの析出および分布状態を大きく変化させないこと、が重要と考えられる。   In addition, for the reason that good characteristics can be obtained at the above-mentioned range of hot-rolled sheet annealing temperature, the lower limit temperature is a hot-rolled sheet size of a certain size or more, the upper limit temperature is slab heating and hot rolling It is thought that it is important not to change the precipitation and distribution state of CaS obtained sometimes.

以下、上記のようにして定めた本発明の成分組成範囲の限定理由について説明する。
Ｃ：0.005％以下
Ｃは、磁気時効劣化を抑制するために、0.005％以下に限定する。好ましくは0.0035％以下、より好ましくは0.0030％以下である。 Hereinafter, the reason for limiting the component composition range of the present invention determined as described above will be described.
C: 0.005% or less C is limited to 0.005% or less in order to suppress magnetic aging deterioration. Preferably it is 0.0035% or less, More preferably, it is 0.0030% or less.

Si：1.5％以上 4.5％以下
本発明の電磁鋼板において、Siは電気抵抗を増大させ、鉄損を改善する有用元素である。この鉄損改善のためには、1.5％以上のSiが必要である。一方、4.5％を超えると鋼板の加工性が劣化し、かつ磁束密度の低下も顕著になるため、Si含有量は1.5〜4.5％の範囲に限定する。 Si: 1.5% or more and 4.5% or less In the electrical steel sheet of the present invention, Si is a useful element that increases electrical resistance and improves iron loss. In order to improve this iron loss, 1.5% or more of Si is necessary. On the other hand, if it exceeds 4.5%, the workability of the steel sheet deteriorates and the decrease in magnetic flux density becomes significant, so the Si content is limited to a range of 1.5 to 4.5%.

Al：0.005％以下
Alは、Siと同様、鋼の脱酸剤として一般的に用いられており、電気抵抗を増加して鉄損を低減する効果が大きいため、通常、無方向性電磁鋼板の主要構成元素の一つである。しかしながら、本発明で目的とする高磁束密度かつ低鉄損の電磁鋼板を得るには、Al量を0.005％以下に低減することが必須であり、本発明において重要な点である。 Al: 0.005% or less
Al, like Si, is generally used as a deoxidizer for steel, and since it has a large effect of increasing electrical resistance and reducing iron loss, it is usually one of the main constituent elements of non-oriented electrical steel sheets. One. However, in order to obtain an electrical steel sheet having a high magnetic flux density and a low iron loss, which is an object of the present invention, it is essential to reduce the Al content to 0.005% or less, which is an important point in the present invention.

Mn：0.01％以上0.10％以下
Siと同様に、Mnは電気抵抗を高めて鉄損を低減する効果があるだけでなく、鋼を固溶強化する作用も有し、また熱間脆性を改善する上でも有効な元素であるため、通常、無方向性電磁鋼板においては、0.2％以上程度添加されている。しかしながら、本発明で目的とする高磁束密度かつ低鉄損の電磁鋼板を得るには、Mn量を0.1％以下と少なくすることが必須であり、本発明において重要な点である。すなわち、Mn量が0.1％を超えると飽和磁束密度が低下する。一方、熱間加工性を確保する点から、下限は0.01％とする。 Mn: 0.01% or more and 0.10% or less
Like Si, Mn not only has the effect of increasing electrical resistance and reducing iron loss, but also has the effect of strengthening steel in solid solution, and is also an effective element for improving hot brittleness. Usually, about 0.2% or more is added in the non-oriented electrical steel sheet. However, in order to obtain an electrical steel sheet having a high magnetic flux density and low iron loss, which is an object of the present invention, it is essential to reduce the Mn content to 0.1% or less, which is an important point in the present invention. That is, when the Mn content exceeds 0.1%, the saturation magnetic flux density decreases. On the other hand, the lower limit is set to 0.01% from the viewpoint of ensuring hot workability.

Ca：0.0010％以上0.0050％以下
本発明において、CaはMn量を少なくして良好な特性を得るために必須の元素であるが、0.0010％未満ではその効果は充分ではない。一方、0.0050％を超えると、その効果は飽和するため、上記範囲に限定した。 Ca: 0.0010% or more and 0.0050% or less In the present invention, Ca is an essential element for obtaining good characteristics by reducing the amount of Mn, but if it is less than 0.0010%, the effect is not sufficient. On the other hand, if it exceeds 0.0050%, the effect is saturated, so the content is limited to the above range.

S：0.0030％以下
Sは不可避的に混入してくる不純物であり、その含有量が多くなると硫化物系介在物が多量に形成されて鉄損が増加する原因となる。よって、本発明では0.0030％以下とする。 S: 0.0030% or less
S is an impurity that is inevitably mixed in. If the content of S increases, a large amount of sulfide inclusions are formed, which causes an increase in iron loss. Therefore, in the present invention, it is 0.0030% or less.

N：0.0030％以下
NもSと同様、不可避的に混入してくる不純物であり、その含有量が多いと窒化物が多量に形成されて鉄損が増加する原因となる。よって、本発明では0.0030％以下とする。 N: 0.0030% or less
N, like S, is an inevitably mixed impurity, and if its content is large, a large amount of nitride is formed, which causes an increase in iron loss. Therefore, in the present invention, it is 0.0030% or less.

Ca/S≧0.80
Ca/S＜0.80の場合、Sを固定するためのCa量が不足する。特に本発明のようにMn量が0.10％以下と少ない場合、スラブ加熱時などに液相のFeSが析出して、Sが偏析・濃化しやすくなり、それが鋼板表面欠陥の発生原因になるため、上記範囲にすることが必要である。 Ca / S ≧ 0.80
When Ca / S <0.80, the amount of Ca for fixing S is insufficient. In particular, when the amount of Mn is as small as 0.10% or less as in the present invention, liquid phase FeS precipitates during slab heating, etc., and S tends to segregate and concentrate, which causes the occurrence of steel plate surface defects. It is necessary to make the above range.

本発明では、その他、無方向性電磁鋼板の磁気特性向上や高強度化、表面性状の改善のために以下に述べる元素を適宜含有させることができる。   In the present invention, other elements described below can be appropriately contained in order to improve the magnetic properties, increase the strength, and improve the surface properties of the non-oriented electrical steel sheet.

SnおよびSb：0.005％以上 0.2％以下
SnおよびSbはいずれも、無方向性電磁鋼板の集合組織を改善し磁気特性を高める効果を有するが、その効果を得るには、Sb，Snを単独添加または複合添加するいずれの場合も0.005％以上添加する必要がある。一方、過剰に添加すると鋼が脆化し、鋼板製造中の板破断やヘゲが増加するため、Sn，Sbは単独添加または複合添加いずれの場合も0.2％以下とする。 Sn and Sb: 0.005% to 0.2%
Both Sn and Sb have the effect of improving the texture of the non-oriented electrical steel sheet and enhancing the magnetic properties. To obtain this effect, 0.005% in any case where Sb and Sn are added alone or in combination. It is necessary to add more. On the other hand, if excessively added, the steel becomes brittle and increases the number of plate breaks and lashes during the production of the steel sheet. Therefore, Sn and Sb should be 0.2% or less in either case of single addition or composite addition.

P：0.03％以上0.20％以下
Pも集合組織改善に有効な元素であるが、過剰な添加は偏析による脆化により粒界割れや圧延性の低下をもたらすので、Ｐ量は0.20％以下に制限する。なお、明確な効果を発現させるには0.03％以上の添加が必要なため、上記範囲に限定した。 P: 0.03% to 0.20%
P is also an effective element for improving the texture. However, excessive addition leads to intergranular cracking and deterioration of rolling properties due to embrittlement due to segregation, so the P content is limited to 0.20% or less. In addition, in order to express a clear effect, since addition of 0.03% or more is required, it limited to the said range.

Mo：0.005％以上0.10％以下
Moは耐酸化性を向上させることにより表面性状を改善する効果がある。しかしながら、含有量が0.005％未満では充分な効果が得られず、一方、0.10％を超えて添加してもその効果は飽和し、コスト高ともなるので、上限は0.10％とする。 Mo: 0.005% to 0.10%
Mo has the effect of improving the surface properties by improving the oxidation resistance. However, if the content is less than 0.005%, a sufficient effect cannot be obtained. On the other hand, if the content exceeds 0.10%, the effect is saturated and the cost becomes high, so the upper limit is made 0.10%.

B：0.0002％以上0.002％以下
Bは粒界偏析することにより粒界強度を向上させる元素であり、特にPの粒界偏析による脆化を抑制する効果が顕著である。その効果を得るには、0.0002％以上の添加が必要であり、また0.002％を超えて添加してもその効果は飽和するので、上記範囲に限定する。 B: 0.0002% to 0.002%
B is an element that improves the grain boundary strength by segregating at the grain boundary, and is particularly effective in suppressing embrittlement due to the grain boundary segregation of P. In order to obtain the effect, addition of 0.0002% or more is necessary, and even if added over 0.002%, the effect is saturated, so it is limited to the above range.

Cr：0.05％以上0.5％以下
本発明におけるSi主体成分では、表面性状改善に有効であり、0.05％以上の添加でその効果が明確になるが、0.5％を超えるとその効果は飽和するので、上記範囲に限定する。 Cr: 0.05% or more and 0.5% or less In the Si main component in the present invention, it is effective for improving the surface properties, and its effect becomes clear when 0.05% or more is added, but when it exceeds 0.5%, the effect is saturated. Limited to the above range.

次に、本発明に従う製造方法の限定理由について述べる。
本発明の無方向性電磁鋼板の製造は、一般の無方向性電磁鋼板に適用されている工程および設備を用いて実施することができ、各工程における条件を本発明に従って規制することが肝要である。例えば、転炉あるいは電気炉などで所定の成分組成に溶製された鋼を、脱ガス設備で二次精錬し、連続鋳造または造塊後の分塊圧延により鋼スラブとしたのち、熱間圧延、熱延板焼鈍、酸洗、冷間または温間圧延、仕上焼鈍および絶縁被膜塗布焼き付けといった工程である。また、直接鋳造法を用いて、100mm以下の厚さの薄鋳片を直接製造してもよい。 Next, the reasons for limiting the manufacturing method according to the present invention will be described.
The production of the non-oriented electrical steel sheet of the present invention can be carried out using processes and facilities applied to general non-oriented electrical steel sheets, and it is important to regulate the conditions in each process according to the present invention. is there. For example, steel that has been melted to a specified component composition in a converter or electric furnace is secondarily refined with a degassing facility, and then steel slab is obtained by continuous casting or ingot lump rolling, followed by hot rolling , Hot-rolled sheet annealing, pickling, cold or warm rolling, finish annealing and insulating coating application baking. Further, a thin cast piece having a thickness of 100 mm or less may be directly manufactured by using a direct casting method.

ここで、製造条件を以下に述べるように制御することが必要である。
すなわち、まず、熱間圧延に際してスラブ加熱温度を1050℃以上1150℃以下とし、鋳込時にCaSとしてではなく、MnSとして析出していたものを適切な固溶状態とすることが必要である。スラブ加熱温度が1050℃未満では、MnSを固溶させることができず、1150℃を超えると、鋳込時にCaSとして析出していたものまで再固溶し始めるため、上記範囲にする必要がある。 Here, it is necessary to control the manufacturing conditions as described below.
That is, first, it is necessary to set the slab heating temperature to 1050 ° C. or higher and 1150 ° C. or lower during hot rolling so that the material precipitated as MnS, not as CaS at the time of casting, is in an appropriate solid solution state. If the slab heating temperature is less than 1050 ° C, MnS cannot be dissolved, and if it exceeds 1150 ° C, it will start to re-dissolve up to what was precipitated as CaS at the time of casting. .

続いて、熱間圧延は、仕上げ圧延終了後の温度が800℃以上900℃以下、圧延終了後の巻取り温度が500℃以上650℃以下になるように実施することが必要である。この条件にすることにより、スラブ加熱時に固溶したMnSがFeSの液相になることなく、CaSの形態に変化するものと考えられる。   Subsequently, the hot rolling needs to be performed so that the temperature after finish rolling is 800 ° C. or more and 900 ° C. or less and the winding temperature after completion of rolling is 500 ° C. or more and 650 ° C. or less. By using this condition, it is considered that MnS dissolved during heating of the slab changes to a CaS form without becoming a liquid phase of FeS.

ついで熱延板焼鈍を行うが、その際、熱延板焼鈍温度を950℃以上スラブ加熱温度以下にすることが必要である。この範囲の熱延板焼鈍温度にすることにより、熱延板粒径が適度な大きさになり、かつ、スラブ加熱および熱間圧延時に得られたCaSの析出・分布状態を大きく変化させないことが重要と考えられる。   Subsequently, hot-rolled sheet annealing is performed. At that time, it is necessary to set the hot-rolled sheet annealing temperature to 950 ° C. or more and slab heating temperature or less. By setting the hot-rolled sheet annealing temperature in this range, the hot-rolled sheet grain size becomes an appropriate size, and the precipitation / distribution state of CaS obtained during slab heating and hot rolling is not greatly changed. Considered important.

次に、冷間または温間圧延を施して最終板厚にし、ついで、仕上焼鈍を施すが、その際、強還元性雰囲気である、水素：10vol％以上、露点：−20℃以下の雰囲気下にすることが必要である。   Next, cold or warm rolling is performed to obtain a final thickness, followed by finish annealing. At that time, a strong reducing atmosphere, hydrogen: 10 vol% or more, dew point: −20 ° C. or less It is necessary to make it.

上記のような強還元性雰囲気にすることで、本発明のようにAl量が非常に少ない成分においても、顕著な鉄損劣化を招かない程度に、鋼板・表層酸化物等の生成を抑制できるためと考えられる。   By using a strong reducing atmosphere as described above, even in a component with a very small amount of Al as in the present invention, it is possible to suppress the formation of steel sheets, surface oxides, etc. to the extent that significant iron loss deterioration is not caused. This is probably because of this.

また、仕上げ焼鈍温度は950℃以上にする必要がある。焼鈍温度が950℃より低いと、結晶粒径が小さいために、ヒステリシス損が高くなって、低鉄損が得られなくなる。なお、仕上げ焼鈍温度の上限はないが、1100℃を超える温度で焼鈍しても、結晶粒径をさらに大きくすることは難しく、結晶粒径の増大によるヒステリシス損低減の効果が飽和するため、仕上げ焼鈍は1100℃以下で行うことがコスト的に有利である。   Also, the finish annealing temperature needs to be 950 ° C. or higher. When the annealing temperature is lower than 950 ° C., the crystal grain size is small, so that the hysteresis loss becomes high and low iron loss cannot be obtained. Although there is no upper limit for the finish annealing temperature, it is difficult to increase the crystal grain size even if annealing is performed at a temperature exceeding 1100 ° C, and the effect of reducing hysteresis loss due to the increase in crystal grain size is saturated. It is advantageous in terms of cost to perform the annealing at 1100 ° C. or less.

なお、上記した仕上焼鈍に引き続いて、既知のコーティング処理を行っても良いのはいうまでもない。この際、良好な打抜き性を確保するためには、樹脂を含有する有機コーティングが望ましく、一方溶接性を重視する場合には半有機や無機コーティングを適用することが望ましい。   Needless to say, a known coating treatment may be performed following the above-described finish annealing. In this case, in order to ensure good punchability, an organic coating containing a resin is desirable. On the other hand, when emphasis is placed on weldability, it is desirable to apply a semi-organic or inorganic coating.

表３に示す成分組成になる鋼スラブを、表４に示す条件に従って、スラブ加熱後に、熱間圧延して巻取り、熱延板焼鈍を施し、酸洗後、板厚：0.35mmまで冷間圧延を施したのち、仕上焼鈍・コーティング処理を行った。   In accordance with the conditions shown in Table 4, the steel slab having the composition shown in Table 3 is hot-rolled and wound up after slab heating, hot-rolled sheet annealing is performed, and after pickling, the sheet thickness is cold to 0.35 mm. After rolling, finish annealing and coating were performed.

Figure 0005263363
Figure 0005263363

得られた無方向性電磁鋼板から、圧延方向および圧延直角方向にエプスタイン試験片を切り出し、磁気特性を測定した。磁気特性はL+C特性で評価した。また、表面欠陥の発生程度も調査した。表面欠陥は、鋼板の単位面積当たり線状欠陥長さで評価し、0.001[m/m2]未満を欠陥無（○）、0.001[m/m2]以上を欠陥有（×）として評価した。得られた結果を表４に併記する。 From the obtained non-oriented electrical steel sheet, an Epstein specimen was cut in the rolling direction and the direction perpendicular to the rolling direction, and the magnetic properties were measured. Magnetic properties were evaluated by L + C characteristics. The extent of surface defects was also investigated. Surface defects were evaluated by linear defect length per unit area of the steel sheet, and less than 0.001 [m / m 2 ] was evaluated as having no defects (○) and 0.001 [m / m 2 ] or more was evaluated as having defects (×). . The obtained results are also shown in Table 4.

Figure 0005263363
Figure 0005263363

記号１−１〜１−３に示す比較例（比較例１−１〜１−３）は、表３にAとして示す鋼種を用いている。この鋼種ではCaの添加が無く、上述のように、MnSをCaSの形態にすることで表層酸化物の生成を抑制することができない。よって、表４に示すように比較例１−１〜１−３の全てにおいて表面欠陥が生じている。さらに、記号１−１および１−３に示す比較例は、鋼種だけでなく、スラブ加熱温度、熱間圧延条件についても本発明による数値範囲外であるため、鋼種以外の条件は本発明による数値範囲内で処理を行った比較例１−２と比較して磁気特性が悪い。加えて、比較例１−１ではスラブ加熱温度、熱間圧延条件に加えて、仕上げ焼鈍条件における水素濃度及び露点についても本発明による数値範囲外であり、比較例１−３よりも更に磁気特性が悪い。   The comparative examples shown in symbols 1-1 to 1-3 (Comparative Examples 1-1 to 1-3) use the steel types shown as A in Table 3. In this steel type, there is no addition of Ca, and as described above, formation of surface layer oxides cannot be suppressed by making MnS into the form of CaS. Therefore, as shown in Table 4, surface defects occur in all of Comparative Examples 1-1 to 1-3. Furthermore, since the comparative examples shown by the symbols 1-1 and 1-3 are not only the steel type, but also the slab heating temperature and hot rolling conditions are outside the numerical range according to the present invention, the conditions other than the steel types are numerical values according to the present invention. Compared with Comparative Example 1-2 in which processing was performed within the range, the magnetic properties were poor. In addition, in Comparative Example 1-1, in addition to the slab heating temperature and hot rolling conditions, the hydrogen concentration and dew point in the final annealing conditions are also outside the numerical ranges according to the present invention, and are further magnetic properties than Comparative Example 1-3. Is bad.

記号１−４に示す比較例（比較例１−４）は、スラブ加熱温度、熱間圧延条件、仕上げ焼鈍条件における水素濃度及び露点について、本発明の数値範囲外である。鋼種が本発明にて規定した数値範囲内の成分組成から成るものであるため、比較例１−１〜１−３と比べて磁気特性は比較的良好であるが、表面欠陥は発生した。他方、記号１−５および１−６に示す発明例のように、比較例１−４と同じ鋼種に対して本発明の製造条件を適用することで、鉄損は低減され磁束密度は上昇し、磁気特性は良好となった。更に、これらの発明例では表面欠陥も発生しなかった。   The comparative example (comparative example 1-4) shown by the symbol 1-4 is outside the numerical range of this invention about the hydrogen concentration and dew point in slab heating temperature, hot rolling conditions, and finish annealing conditions. Since the steel type has a component composition within the numerical range defined in the present invention, the magnetic properties are relatively good as compared with Comparative Examples 1-1 to 1-3, but surface defects occurred. On the other hand, the iron loss is reduced and the magnetic flux density is increased by applying the manufacturing conditions of the present invention to the same steel types as those of Comparative Example 1-4 as in the inventive examples indicated by symbols 1-5 and 1-6. The magnetic properties were good. Furthermore, no surface defects occurred in these inventive examples.

記号１−７に示す比較例は、スラブ加熱温度、仕上げ焼鈍条件における焼鈍温度が本発明の数値範囲外である。この例では、磁気特性が不良であり、表面欠陥も発生した。しかし、記号１−８および１−９に示すように、同様の鋼種に対して本発明の製造条件を適用することで、鉄損は低減され磁束密度は上昇し、磁気特性は良好となった。更に、これらの発明例では表面欠陥も発生しなかった。   As for the comparative example shown to the symbol 1-7, the annealing temperature in slab heating temperature and finish annealing conditions is outside the numerical range of this invention. In this example, the magnetic properties were poor and surface defects were also generated. However, as indicated by symbols 1-8 and 1-9, by applying the production conditions of the present invention to similar steel types, the iron loss was reduced, the magnetic flux density was increased, and the magnetic properties were improved. . Furthermore, no surface defects occurred in these inventive examples.

記号１−１０に示す比較例（比較例１−１０）は、仕上げ焼鈍条件における露点及び焼鈍温度が本発明の数値範囲外である。この例では、表面欠陥は発生しなかったが、磁気特性が不良であった。記号１−１３に示す比較例（比較例１−１３）では、スラブ加熱温度及び熱間圧延条件における仕上終了温度が本発明の数値範囲外である。この例では、表面欠陥が発生した。記号１−１６に示す比較例（比較例１−１６）では、熱間圧延条件における仕上終了温度、熱延板焼鈍温度、および仕上焼鈍条件における水素濃度及び露点が本発明の数値範囲外である。この場合、磁束密度は高いが鉄損も高く、更に表面欠陥も発生した。一方、比較例１−１０、比較例１−１３、及び比較例１−１６のそれぞれと同様の鋼種に対して本発明の製造条件を適用することで、磁束密度を更に上昇させると共に鉄損を低減させることができ、更に表面欠陥も発生しなかった。   In the comparative example (Comparative Example 1-10) indicated by symbol 1-10, the dew point and the annealing temperature in the finish annealing conditions are outside the numerical range of the present invention. In this example, no surface defects occurred, but the magnetic properties were poor. In the comparative example (comparative example 1-13) shown by the symbol 1-13, the finishing temperature in the slab heating temperature and the hot rolling conditions is out of the numerical range of the present invention. In this example, surface defects occurred. In the comparative example (Comparative Example 1-16) shown by the symbol 1-16, the finishing temperature in the hot rolling condition, the hot rolled sheet annealing temperature, and the hydrogen concentration and dew point in the finishing annealing condition are outside the numerical range of the present invention. . In this case, the magnetic flux density was high but the iron loss was high, and surface defects were also generated. On the other hand, by applying the production conditions of the present invention to the same steel types as those of Comparative Examples 1-10, 1-13, and 1-16, the magnetic flux density is further increased and the iron loss is reduced. In addition, no surface defects were generated.

このように、本発明の製造条件を満足する発明例はいずれも、表面欠陥の発生がなく、良好な磁気特性が得られていることがわかる。   Thus, it can be seen that all of the inventive examples satisfying the production conditions of the present invention are free from surface defects and have good magnetic properties.

表５に示す成分組成になる鋼スラブを、表６に示す条件で、スラブ加熱、熱間圧延して巻取り、熱延板焼鈍を施し、酸洗後、板厚：0.50mmまで冷間圧延を施したのち、仕上焼鈍・コーティング処理を行った。   A steel slab having the composition shown in Table 5 is slab-heated, hot-rolled and rolled under the conditions shown in Table 6, hot-rolled sheet annealed, pickled, and cold-rolled to a thickness of 0.50 mm. After finishing, finish annealing and coating treatment were performed.

Figure 0005263363
Figure 0005263363

得られた無方向性電磁鋼板から、磁気特性は圧延方向および圧延直角方向にエプスタイン試験片を切り出し、磁気特性を測定した。磁気特性はL+C特性で評価した。また、表面欠陥の発生程度も調査した。なお、表面欠陥の評価方法は実施例１と同様である。得られた結果を表６に併記する。   From the obtained non-oriented electrical steel sheet, Epstein test pieces were cut out in the rolling direction and the direction perpendicular to the rolling direction, and the magnetic characteristics were measured. Magnetic properties were evaluated by L + C characteristics. The extent of surface defects was also investigated. Note that the surface defect evaluation method is the same as in Example 1. The obtained results are also shown in Table 6.

Figure 0005263363
Figure 0005263363

記号２−１に示す比較例では、スラブ加熱温度、熱間圧延条件における巻取り温度、熱延板焼鈍温度、および仕上焼鈍条件における水素濃度が本発明の数値範囲外である。この場合鉄損が著しく高く、さらに表面欠陥を生じた。記号２−４に示す比較例では、スラブ加熱温度、熱間圧延条件における仕上終了温度、および仕上焼鈍条件における露点が本発明の数値範囲外である。この場合、磁気特性はさほど悪化しなかったが表面欠陥が生じた。記号２−７に示す比較例ではスラブ加熱温度及び熱延板焼鈍温度が本発明の数値範囲外である。この場合、鉄損が高く、更に表面欠陥が生じた。記号２−１０に示す比較例では仕上げ焼鈍条件における焼鈍温度が本発明の数値範囲外である。この場合、表面欠陥は生じなかったが磁気特性が悪化した。   In the comparative example shown by symbol 2-1, the hydrogen concentration in the slab heating temperature, the coiling temperature in the hot rolling condition, the hot rolled sheet annealing temperature, and the finish annealing condition is out of the numerical range of the present invention. In this case, the iron loss was remarkably high and surface defects were generated. In the comparative example shown by symbol 2-4, the slab heating temperature, the finishing end temperature under hot rolling conditions, and the dew point under finishing annealing conditions are outside the numerical range of the present invention. In this case, the magnetic characteristics did not deteriorate so much, but surface defects occurred. In the comparative example shown by symbol 2-7, the slab heating temperature and the hot-rolled sheet annealing temperature are outside the numerical range of the present invention. In this case, the iron loss was high and surface defects occurred. In the comparative example shown by symbol 2-10, the annealing temperature in the finish annealing condition is outside the numerical range of the present invention. In this case, no surface defects occurred, but the magnetic properties deteriorated.

しかし、本発明の製造条件を満足する発明例はいずれも、表面欠陥の発生がなく、同一の鋼種に対して本発明の製造条件を適用しなかった比較例よりも良好な磁気特性が得られていることがわかる。   However, all of the inventive examples satisfying the manufacturing conditions of the present invention have no surface defects, and better magnetic properties can be obtained than the comparative examples in which the manufacturing conditions of the present invention were not applied to the same steel type. You can see that

表７に示す成分組成になる鋼スラブを、表８に示す条件で、スラブ加熱、熱間圧延して巻取り、熱延板焼鈍を施し、酸洗後、板厚：0.25mmまで冷間圧延を施したのち、仕上焼鈍・コーティング処理を行った。   Steel slabs having the composition shown in Table 7 were slab heated, hot-rolled and rolled up under the conditions shown in Table 8, subjected to hot-rolled sheet annealing, pickled, and cold-rolled to a thickness of 0.25 mm. After finishing, finish annealing and coating treatment were performed.

Figure 0005263363
Figure 0005263363

得られた無方向性電磁鋼板から、磁気特性は圧延方向および圧延直角方向にエプスタイン試験片を切り出し、磁気特性を測定した。磁気特性はＬ＋Ｃ特性で評価した。また、表面欠陥の発生程度も調査した。なお、表面欠陥の評価方法は実施例１および２と同様である。得られた結果を表８に併記する。   From the obtained non-oriented electrical steel sheet, Epstein test pieces were cut out in the rolling direction and the direction perpendicular to the rolling direction, and the magnetic characteristics were measured. Magnetic characteristics were evaluated by L + C characteristics. The extent of surface defects was also investigated. The surface defect evaluation method is the same as in Examples 1 and 2. The obtained results are also shown in Table 8.

Figure 0005263363
Figure 0005263363

記号３−１に示す比較例では、熱間圧延条件における仕上げ終了温度、仕上げ焼鈍条件における露点および焼鈍温度が本発明の数値範囲外である。この場合、鉄損が高くなり、更に表面欠陥が生じた。記号３−４に示す比較例では、熱延板焼鈍温度が本発明の数値範囲外である。この場合、表面欠陥が生じた。記号３−７に示す比較例では、スラブ加熱温度、熱間圧延条件における仕上終了温度、および熱延板焼鈍温度が本発明の数値範囲外である。この場合も表面欠陥が生じた。記号３−１０に示す比較例では、スラブ加熱温度、熱間圧延条件、および仕上焼鈍条件における水素濃度が本発明の数値範囲外である。この場合、鉄損が高くなるとともに表面欠陥が生じた。   In the comparative example shown by symbol 3-1, the finishing end temperature in the hot rolling condition, the dew point in the finishing annealing condition, and the annealing temperature are outside the numerical range of the present invention. In this case, the iron loss increased and surface defects were further generated. In the comparative example shown by symbol 3-4, the hot-rolled sheet annealing temperature is outside the numerical range of the present invention. In this case, surface defects occurred. In the comparative example shown by the symbol 3-7, the slab heating temperature, the finishing end temperature in the hot rolling conditions, and the hot rolled sheet annealing temperature are out of the numerical range of the present invention. Again, surface defects occurred. In the comparative example shown by symbol 3-10, the hydrogen concentration in the slab heating temperature, the hot rolling condition, and the finish annealing condition is outside the numerical range of the present invention. In this case, the iron loss increased and surface defects occurred.

しかし、本発明の製造条件を満足する発明例はいずれも、表面欠陥の発生がなく、同一の鋼種に対して本発明の製造条件を適用しなかった比較例よりも良好な磁気特性が得られていることがわかる。   However, all of the inventive examples satisfying the manufacturing conditions of the present invention have no surface defects, and better magnetic properties can be obtained than the comparative examples in which the manufacturing conditions of the present invention were not applied to the same steel type. You can see that

本発明によれば、リサイクル性に優れるとともに、鋼板表面性状が良好な低鉄損かつ高磁束密度の無方向性電磁鋼板を提供することができる。   ADVANTAGE OF THE INVENTION According to this invention, while being excellent in recyclability, the non-oriented electrical steel sheet of the low iron loss and high magnetic flux density with favorable steel plate surface property can be provided.

Claims (2)

質量％で、C：0.005％以下、Si：1.5％以上4.5％以下、Al：0.005％以下、Mn：0.01％以上0.10％以下、Ca：0.0010％以上0.0050％以下、S：0.0030％以下およびN：0.0030％以下を、Ca/S≧0.80の下に含有し、残部Feおよび不可避的不純物の成分組成からなるスラブを、加熱後に熱間圧延を施して巻取り、ついで熱延板焼鈍を経て、冷間または温間にて圧延を施したのち、仕上焼鈍を施す一連の工程からなる無方向性電磁鋼板の製造方法において、
前記スラブ加熱温度を1050℃以上1150℃以下、前記熱間圧延の仕上げ圧延終了後の温度を800℃以上900℃以下、前記巻取り温度を500℃以上650℃以下、前記熱延板焼鈍温度を950℃以上前記スラブ加熱温度以下とし、更に仕上焼鈍を、水素を10vol％以上含有し、かつ露点が−20℃以下の雰囲気下にて950℃以上の温度で行うことを特徴とする無方向性電磁鋼板の製造方法。 In mass%, C: 0.005% or less, Si: 1.5% or more and 4.5% or less, Al: 0.005% or less, Mn: 0.01% or more and 0.10% or less, Ca: 0.0010% or more and 0.0050% or less, S: 0.0030% or less, and N : 0.0030% or less is contained under Ca / S ≧ 0.80, and the slab composed of the remaining Fe and the inevitable impurities is subjected to hot rolling after heating, and then subjected to hot-rolled sheet annealing, In the manufacturing method of non-oriented electrical steel sheet consisting of a series of steps to perform finish annealing after rolling cold or warm,
The slab heating temperature is 1050 ° C. or higher and 1150 ° C. or lower, the temperature after finish rolling of the hot rolling is 800 ° C. or higher and 900 ° C. or lower, the winding temperature is 500 ° C. or higher and 650 ° C. or lower, and the hot rolled sheet annealing temperature is Non-directional, characterized in that it is 950 ° C or higher and not higher than the slab heating temperature, and finish annealing is performed at a temperature of 950 ° C or higher in an atmosphere containing 10 vol% or more of hydrogen and a dew point of -20 ° C or lower. A method for producing electrical steel sheets. 前記成分組成は、さらに、質量％で、Sb：0.005％以上0.2％以下、Sn：0.005％以上0.2％以下、P：0.03％以上0.2％以下、Mo：0.005％以上0.10％以下、B：0.0002％以上0.002％以下、およびCr：0.05％以上0.5％以下の１種または２種以上を含有することを特徴とする請求項１に記載の無方向性電磁鋼板の製造方法。   The component composition is further in mass%, Sb: 0.005% to 0.2%, Sn: 0.005% to 0.2%, P: 0.03% to 0.2%, Mo: 0.005% to 0.10%, B: 0.0002 2 or more and 0.002% or less, and Cr: 0.05% or more and 0.5% or less of 1 type or 2 types or more, The manufacturing method of the non-oriented electrical steel sheet of Claim 1 characterized by the above-mentioned.
JP2011224006A 2011-10-11 2011-10-11 Method for producing non-oriented electrical steel sheet Active JP5263363B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2011224006A JP5263363B2 (en) 2011-10-11 2011-10-11 Method for producing non-oriented electrical steel sheet
PCT/JP2012/006496 WO2013054514A1 (en) 2011-10-11 2012-10-10 Manufacturing method for non-oriented magnetic steel sheet
TW101137494A TWI503417B (en) 2011-10-11 2012-10-11 Method for producing non-oriented electromagnetic steel sheet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2011224006A JP5263363B2 (en) 2011-10-11 2011-10-11 Method for producing non-oriented electrical steel sheet

Publications (2)

Publication Number Publication Date
JP2013082973A JP2013082973A (en) 2013-05-09
JP5263363B2 true JP5263363B2 (en) 2013-08-14

Family

ID=48081582

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2011224006A Active JP5263363B2 (en) 2011-10-11 2011-10-11 Method for producing non-oriented electrical steel sheet

Country Status (3)

Country Link
JP (1) JP5263363B2 (en)
TW (1) TWI503417B (en)
WO (1) WO2013054514A1 (en)

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014024222A1 (en) 2012-08-08 2014-02-13 Ｊｆｅスチール株式会社 High-strength electromagnetic steel sheet and method for producing same
JP5790953B2 (en) * 2013-08-20 2015-10-07 Ｊｆｅスチール株式会社 Non-oriented electrical steel sheet and its hot-rolled steel sheet
JP5995002B2 (en) 2013-08-20 2016-09-21 Ｊｆｅスチール株式会社 High magnetic flux density non-oriented electrical steel sheet and motor
JP2015131993A (en) * 2014-01-14 2015-07-23 Ｊｆｅスチール株式会社 Non-oriented silicon steel sheet having excellent magnetic property
WO2016027445A1 (en) * 2014-08-21 2016-02-25 Ｊｆｅスチール株式会社 Non-oriented electromagnetic steel sheet and method for manufacturing same
KR101650406B1 (en) 2014-12-24 2016-08-23 주식회사 포스코 Non-oriented electrical steel sheets and method for manufacturing the same
JP6020863B2 (en) 2015-01-07 2016-11-02 Ｊｆｅスチール株式会社 Non-oriented electrical steel sheet and manufacturing method thereof
US11225699B2 (en) 2015-11-20 2022-01-18 Jfe Steel Corporation Method for producing non-oriented electrical steel sheet
JP6451730B2 (en) * 2016-01-15 2019-01-16 Ｊｆｅスチール株式会社 Method for producing non-oriented electrical steel sheet
CN108004463A (en) 2016-10-28 2018-05-08 宝山钢铁股份有限公司 A kind of non-oriented electrical steel having excellent magnetic characteristics and its manufacture method
WO2018123558A1 (en) * 2016-12-28 2018-07-05 Ｊｆｅスチール株式会社 Non-oriented electromagnetic steel sheet having excellent recyclability
JP6624393B2 (en) * 2016-12-28 2019-12-25 Ｊｆｅスチール株式会社 Non-oriented electrical steel sheet with excellent recyclability
CN107164624B (en) * 2017-04-10 2020-02-21 首钢集团有限公司 Method for controlling pockmark defects on surface of phosphorus-containing cold-rolled high-strength steel
EP3904551A4 (en) * 2018-12-27 2022-04-06 JFE Steel Corporation Non-oriented electrical steel sheet and method for producing same
US20220186338A1 (en) * 2019-04-22 2022-06-16 Jfe Steel Corporation Method for producing non-oriented electrical steel sheet
CN110923581B (en) * 2019-11-26 2021-08-06 长春工业大学 Method for preparing high-magnetic-induction non-oriented silicon steel based on pre-annealing
TWI754548B (en) * 2021-02-19 2022-02-01 日商日本製鐵股份有限公司 Hot-rolled steel sheet for non-oriented electrical steel sheet and method for producing the same

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS644455A (en) * 1987-06-25 1989-01-09 Sumitomo Metal Ind Isotropic electromagnetic steel plate having high magnetic flux density
JP2971080B2 (en) * 1989-10-13 1999-11-02 新日本製鐵株式会社 Non-oriented electrical steel sheet with excellent magnetic properties
JPH0860311A (en) * 1994-08-22 1996-03-05 Nkk Corp Thin nonoriented silicon steel sheet reduced in iron loss and its production
JP3435080B2 (en) * 1998-10-23 2003-08-11 新日本製鐵株式会社 Non-oriented electrical steel sheet with excellent coating properties
JP4019577B2 (en) * 1999-12-01 2007-12-12 Ｊｆｅスチール株式会社 Electric power steering motor core
JP4681450B2 (en) * 2005-02-23 2011-05-11 新日本製鐵株式会社 Non-oriented electrical steel sheet with excellent magnetic properties in the rolling direction and manufacturing method thereof
CN101310034B (en) * 2005-12-15 2011-12-28 杰富意钢铁株式会社 Highly strong, non-oriented electrical steel sheet and method for manufacture thereof
EP2302095B1 (en) * 2008-06-20 2018-04-04 Nippon Steel & Sumitomo Metal Corporation Non-oriented electrical steel sheet and manufacturing method thereof
JP5884153B2 (en) * 2010-12-28 2016-03-15 Ｊｆｅスチール株式会社 High strength electrical steel sheet and manufacturing method thereof

Also Published As

Publication number Publication date
TWI503417B (en) 2015-10-11
TW201329244A (en) 2013-07-16
WO2013054514A1 (en) 2013-04-18
JP2013082973A (en) 2013-05-09

Similar Documents

Publication Publication Date Title
JP5263363B2 (en) Method for producing non-oriented electrical steel sheet
KR102095142B1 (en) Non-oriented electrical steel sheet and production method thereof
KR101940084B1 (en) Non-oriented electrical steel sheet and method for producing the same
JP5995002B2 (en) High magnetic flux density non-oriented electrical steel sheet and motor
JP5668767B2 (en) Hot rolled steel sheet for manufacturing non-oriented electrical steel sheet and method for manufacturing the same
JP6127440B2 (en) Hot rolled steel sheet for manufacturing non-oriented electrical steel sheet and method for manufacturing the same
KR101993202B1 (en) Method for manufacturing non-oriented electromagnetic steel sheet
KR20140113739A (en) Method for producing non-oriented magnetic steel sheet
JP6388092B1 (en) Non-oriented electrical steel sheet and manufacturing method thereof
JP6269970B2 (en) Non-oriented electrical steel sheet excellent in recyclability and manufacturing method thereof
JP6662501B1 (en) Non-oriented electrical steel sheet and manufacturing method thereof
JP5839172B2 (en) Method for producing grain-oriented electrical steel sheet
WO2016111088A1 (en) Non-oriented electromagnetic steel sheet and method for producing same
JP6801464B2 (en) Non-oriented electrical steel sheet
JP2016145376A (en) Nonoriented electromagnetic steel sheet
JP2018111847A (en) Nonoriented electromagnetic steel sheet
JP5768327B2 (en) Method for producing non-oriented electrical steel sheet with excellent high magnetic field iron loss
JP6852965B2 (en) Electrical steel sheet and its manufacturing method

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20130305

A871 Explanation of circumstances concerning accelerated examination

Free format text: JAPANESE INTERMEDIATE CODE: A871

Effective date: 20130305

A975 Report on accelerated examination

Free format text: JAPANESE INTERMEDIATE CODE: A971005

Effective date: 20130326

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: 20130402

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20130415

R150 Certificate of patent or registration of utility model

Ref document number: 5263363

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