KR100345697B1 - A Method of Manufacturing Hight Permability Oriented Electrical Steel Sheet by Heating its Slab at Low Tempreatures - Google Patents

A Method of Manufacturing Hight Permability Oriented Electrical Steel Sheet by Heating its Slab at Low Tempreatures Download PDF

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KR100345697B1
KR100345697B1 KR1019970053791A KR19970053791A KR100345697B1 KR 100345697 B1 KR100345697 B1 KR 100345697B1 KR 1019970053791 A KR1019970053791 A KR 1019970053791A KR 19970053791 A KR19970053791 A KR 19970053791A KR 100345697 B1 KR100345697 B1 KR 100345697B1
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slab
temperature
oriented electrical
steel sheet
electrical steel
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KR19990032692A (en
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우종수
한찬희
홍병득
이청산
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주식회사 포스코
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    • 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
    • C21D3/00—Diffusion processes for extraction of non-metals; Furnaces therefor
    • C21D3/02—Extraction of non-metals
    • C21D3/04—Decarburising
    • 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
    • C21D8/1233—Cold 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
    • C21D8/1261—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
    • C21D8/1277—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular surface treatment
    • C21D8/1283—Application of a separating or insulating coating
    • 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
    • C22C38/02—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
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper

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

Abstract

PURPOSE: A method for manufacturing a high magnetic flux density grain oriented electrical steel sheet is provided to obtain productivity by a low temperature slab heating method and obtain magnetic properties same as or superior to conventional ones. CONSTITUTION: A silicon steel slab is heated at 1100-1320 deg.C and hot-rolled. The silicon steel contains 0.025-0.08wt% of C, 2.5-4.5wt% of Si, 0.020-0.040wt% of Sol-Al, 0.0150wt% or less of N, 0.05-0.4wt% of Cu, 0.013-0.022wt% of S, 0.0005-0.0010wt% of B, and a balance of Fe and unavoidable impurities. The hot-rolled sheet is annealed and cold-rolled once with a thickness of a final product and decarbonized along with a first recrystallization. The resulting sheet is nitrided for a shot time under an ammonia containing atmosphere at a temperature of 1100-1320 deg.C and annealed at a high temperature and insulating-coated.

Description

슬라브 저온가열에 의한 고자속밀도 방향성 전기강판의 제조방법{A Method of Manufacturing Hight Permability Oriented Electrical Steel Sheet by Heating its Slab at Low Tempreatures}A Method of Manufacturing Hight Permability Oriented Electrical Steel Sheet by Heating its Slab at Low Tempreatures}

본 발명은 변압기, 정지기기, 회전기기 등의 철심재료로 사용되는 고자속밀도 방향성 전기강판의 제조방법에 관한 것으로써, 보다 상세하게는 슬라브 저온가열에 의해 보다 우수한 생산성을 확보하는 한편, 종래 대비 동등이상의 자기적특성을 확보하기 위한 고자속밀도 방향성 전기강판의 제조방법에 관한 것이다.The present invention relates to a method of manufacturing a high magnetic flux density oriented electrical steel sheet used as iron core materials for transformers, stop machines, rotary machines, etc., and more specifically, to ensure better productivity by slab low temperature heating, The present invention relates to a method of manufacturing a high magnetic flux density oriented electrical steel sheet to secure magnetic properties equal to or higher than that.

방향성 전기강판은 규소가 약 3%정도 첨가되고, 열간압연과 냉간압연 및 열처리에 의하여, 압연면에는 {110}면이, 압연방향으로는 철의 자화용이 방향인 <1>축이 배향된 재결정집합조직(고스조직이라고도 함)을 가지고 있는 연자성재료로서, 주로 변압기나 발전기의 철심으로 사용된다.About 3% silicon is added to the grain-oriented electrical steel sheet, and recrystallization is carried out by hot rolling, cold rolling, and heat treatment, in which the {1} axis is oriented in the rolled surface and the magnetization direction of iron in the rolling direction is oriented. It is a soft magnetic material with aggregate structure (also called goth structure), and is mainly used as iron core of transformer or generator.

방향성 전기강판에 요구되는 특성은 높은 자속밀도와 낮은 철손이다. 자속밀도는 <001>축이 압연방향으로 배열되어 있는 정도에 따라 결정되는 것으로서, 자속밀도가 높으면 철심재료를 적게 사용하더라도 같은 성능을 발휘할 수 있으므로 전기기기를 소형화할 수 있다.The properties required for oriented electrical steel sheets are high magnetic flux density and low iron loss. The magnetic flux density is determined by the degree in which the <001> axes are arranged in the rolling direction. When the magnetic flux density is high, the same performance can be exhibited even if fewer iron core materials are used, thereby miniaturizing the electric apparatus.

또한, 철손이란 철심재료에 의한 전기기기의 에너지 손실로서, 제품의 두께, 재료내의 불순물의 함량, 비저항, 결정립 크기 등에 의해 좌우된다. 일반적으로 자속밀도가 높을수록 철손은 낮아지며, 철손값이 작아지면 전기기기의 에너지 효율이 높아진다. 따라서, 전기기기의 소형화 및 에너지 절약차원에서 자속밀도가 높고, 철손이 낮은 방향성 전기강판의 필요성이 커지고 있다.In addition, iron loss is an energy loss of an electric device by the iron core material, and depends on the thickness of the product, the content of impurities in the material, the specific resistance, the grain size and the like. In general, the higher the magnetic flux density, the lower the iron loss, and the smaller the iron loss value, the higher the energy efficiency of the electric device. Therefore, in order to reduce the size of the electric equipment and save energy, there is a growing need for a oriented electrical steel sheet having high magnetic flux density and low iron loss.

한편, 방향성 전기강판은 제조방법과 성질에 따라 고자속밀도 방향성 전기강판과 일반 방향성 전기강판으로 나누어지며, 이는 각각의 가격과 용도에 따라 틀리다. 방향성 전기강판은 열간압연 및 냉간압연을 거쳐 최종두께로 한 후, 1차 재결정소둔을 한 다음에, {110}<1> 1차재결정립을 선택적으로 성장시키는 고온소둔을 함으로써, 즉 2차 재결정시킴으로서 방향성 전기강판을 제조할 수 있다. 이때, 고온소둔전에 MnS나 AlN과 같은 석출물을 강내에 미세하고 균일하게 분산시켜 2차 재결정 개시전에 1차재결정립이 조대하게 성장하는 것을 억제하고, {110}<001> 만을 선택적으로 성장시키는 것이 매우 중요하다.On the other hand, oriented electrical steel sheet is divided into high magnetic flux density oriented electrical steel sheet and general oriented electrical steel sheet according to the manufacturing method and properties, which is different depending on the price and use. The grain-oriented electrical steel sheet is subjected to hot rolling and cold rolling to a final thickness, followed by primary recrystallization annealing, and then by hot annealing to selectively grow {110} <1> primary recrystallized grains, that is, secondary recrystallization. By making it possible to produce a grain-oriented electrical steel sheet. At this time, the precipitates such as MnS and AlN are finely and uniformly dispersed in the steel before the high temperature annealing to suppress the coarse growth of the primary recrystallized grains before the start of the second recrystallization, and to selectively grow only {110} <001>. very important.

이와 같이 방향성 전기강판의 제조에 있어서 가장 중요한 기술은 2차재결정이 개시되기 전까지 1차재결정립의 성장을 억제하는 것에 관한 것이다. 억제제로는 MnS나 AlN 같은 화합물이 주로 이용되며, Sb, Sn과 같은 편석형 원소들이 보조적으로 이용된다. 1933년 미국의 N.P. Goss가 MnS를 억제제로 사용하는 수단을 개발한 이래 여러 가지 화합물이 시도되었지만, 현재 세계적으로 가장 많이 사용되는 억제제는 MnS단독 혹은 MnS + AlN 계이다.As such, the most important technique in the production of grain-oriented electrical steel sheet is to suppress the growth of primary recrystallized grains before the secondary recrystallization is initiated. As inhibitors, compounds such as MnS and AlN are mainly used, and segregation elements such as Sb and Sn are used as auxiliary. N.P. in 1933 Several compounds have been tried since Goss developed a means of using MnS as an inhibitor, but the most widely used inhibitors in the world are MnS alone or MnS + AlN system.

억제제가 갖추어야 될 필수적인 성질은 2차 재결정이 개시되는 온도전까지는1차 재결정립의 성장을 억제하여 2차재결정립이 크게 성장할 수 있는 환경을 만들어 주어야하고, 2차 재결정이 개시된 후에는 조대하게 성장하거나 고용 소멸되어 2차 재결정에 방해를 주지 말아야 한다. 그러기 위해서는 억제제가 미세하고 균일하게 분산되어 있어야 한다.An essential property of the inhibitor should be to suppress the growth of the primary recrystallization grains until the temperature at which the secondary recrystallization begins, to create an environment where the secondary recrystallization grains can grow significantly, and to grow coarsely after the secondary recrystallization is initiated. It should not be deterred or terminated by employment and interfere with the secondary re-decision. To do this, the inhibitor must be finely and uniformly dispersed.

종래 열간압연과정에서 슬라브를 1400℃전후로 고온 가열하여 MnS 나 AlN을 완전히 고용시킨 후 열간압연과정에서 미세하게 석출시키는 방법을 이용한 공지기술로는 일본특허공보 소51-13469로 대표되는 소위 Hi-B법에 의한 기술을 들 수 있다. 그러나, 이 방법은 자성을 얻기 위한 제조조건의 범위가 매우 좁고 제조방법이 매우 까다로와서 안정한 자성을 확보하기가 어렵다.In the conventional hot rolling process, the slab is heated to around 1400 ° C. at a high temperature to completely dissolve MnS or AlN, and then finely precipitates it in the hot rolling process. As a known technique using Hi-B represented by Japanese Patent Publication No. 51-13469 The technique by the law is mentioned. However, this method has a very narrow range of manufacturing conditions for obtaining magnetism and a very difficult manufacturing method, making it difficult to secure stable magnetism.

또한, 편석형 원소를 이용한 종래의 대표적인 방법으로 일본특허공보 소 51-13469에 제시된 방법이 있는데, 이 방법은 Sb, Se와 같이 고가이면서 독성이 있는 원소를 사용하여 제조비가 높고, 생산시 안전과 공해의 문제점을 안고 있다.In addition, a typical representative method using segregation elements is the method described in Japanese Patent Publication No. 51-13469, which uses high and toxic elements such as Sb and Se to produce high production costs, There is a problem of pollution.

특히, 위의 두 방법은 석출물을 완전히 고용시키기 위해 제강 및 연주를 거쳐 나온 슬라브를 1350℃이상의 온도에서 4시간이상 가열하여야 하는 문제점이 있다. 고온의 슬라브 가열은 에너지 소모가 많고, 특히 고온으로 슬라브를 가열하게 되면 표면에 융점이 낮은 규소산화물이 흘러내려 재료의 손실이 많고, 이 규소산화물이 가열로의 내화물을 침식시키므로 정기적으로 생산을 중지하고 내화물을 교체해야 하므로 비용이 많이 든다.In particular, the above two methods have a problem in that the slab from steelmaking and playing to heat the precipitate completely to be heated for more than 4 hours at a temperature of 1350 ℃ or more. High temperature slab heating consumes a lot of energy, especially when the slab is heated to a high temperature, silicon oxide with low melting point flows out of the surface, causing a lot of material loss, and the silicon oxide erodes the refractory to the heating furnace. And the refractory must be replaced, which is expensive.

이러한 문제점으로 인하여 슬라브를 저온으로 가열하고자 하는 연구가 최근에 많이 이루어졌으며, 그 대표적인 방법으로 일본공개특허 소59-56522, 일본공개특허 소 62-40315 등을 들 수 있다. 상기 슬라브 저온 가열방법은 통상의 억제제로 쓰는 AlN 와 MnS 대신에 AlN만을 이용하며, 열간압연단계에서 석출물을 미세하게 제어하는 통상의 방법에 비해, 1차 재결정후 질소를 주입하는 질화처리에 의해 고온소둔전에 미세한 AlN을 균일하게 분산시켜 2차 재결정을 일으키는 것이 특징이다. 따라서, 열간압연시 MnS 나 AlN을 제어하지 않으므로 슬라브의 고온가열이 필요 없다.Due to such a problem, a lot of researches have recently been made to heat the slab at a low temperature, and Japanese Patent Application Laid-Open No. 59-56522, Japanese Patent Application Laid-Open No. 62-40315, etc. are representative examples. The slab low temperature heating method uses only AlN instead of AlN and MnS used as conventional inhibitors, and compared with the conventional method of finely controlling the precipitate in the hot rolling step, the high temperature by nitriding treatment after the first recrystallization to inject nitrogen It is characterized by uniformly dispersing fine AlN before annealing to cause secondary recrystallization. Therefore, MnS or AlN is not controlled during hot rolling, and thus high temperature heating of the slab is not necessary.

이러한 슬라브 저온가열 방법은 슬라브 고온가열 방법에 비해 1280℃이하의 저온으로 슬라브 재가열이 가능한 혁신적인 방법이다. 그러나, 이 기술은 AlN 만을 1차 재결정립성장억제제로 이용하고 있으므로 종래의 방법에 비해 제조비용을 절약하는 잇점이 있으나 2차 재결정이 개시되기 전에 1차 재결정을 억제하는 수단으로서 AlN만을 사용해야 하므로 2차 재결정의 안정성을 해치는 원인이 되어 자성이 종래기술에 비해 동등이하의 수준이어서 만족스럽지 못하다.This slab low temperature heating method is an innovative method that can reheat the slab at a lower temperature than 1280 ℃ than the slab high temperature heating method. However, this technique uses AlN alone as the primary recrystallization growth inhibitor, which saves manufacturing cost compared to the conventional method, but only AlN should be used as a means of suppressing primary recrystallization before the second recrystallization starts. It is not satisfactory because the magnetism is less than or equal to that of the prior art, which causes the stability of the recrystallization.

즉, 상기 슬라브 저온가열방법은 통상의 억제제로 쓰는 AlN과 MnS 대신에 AlN만을 이용하기 때문에 2차 재결정전까지 1차 재결정립의 성장을 억제하는 억제력이 약하여 2차 재결정립의 방향성 즉, 압연방향으로의 <1>축의 배향성이 정밀하지 못하고 편차가 많이 있어서 자성을 해치게 되어 자기특성이 열악해지는 문제가 있다. 슬라브 저온가열방법에 있어 자성의 악화를 무릎쓰고 MnS를 1차 재결정립 성장억제제로 쓰지 않은 이유는 이미 언급한 바와 같이, MnS를 완전히 고용시키기 위해서는 1400℃전후의 높은 슬라브 가열온도가 필요하기 때문이다.That is, the slab low-temperature heating method uses only AlN instead of AlN and MnS, which are commonly used as inhibitors, and thus has a low inhibitory force that suppresses growth of primary recrystallized grains until secondary recrystallization. There is a problem in that the orientation of the < 1 > In the slab low temperature heating method, the deterioration of the magnetism and the use of MnS as the primary recrystallization growth inhibitor are not mentioned because, as already mentioned, the high slab heating temperature around 1400 ° C is required to fully employ MnS. .

따라서, 슬라브 저온가열방법에서는 MnS를 억제제로 사용하지 않으므로 S함량을 무게비로 0.007%이하로 관리한다.Therefore, the slab low temperature heating method does not use MnS as an inhibitor, so the S content is controlled to 0.007% or less by weight ratio.

종래의 슬라브 저온가열방법은, 열간압연과정에서 MnS나 AlN의 미세석출이 자성에 오히려 해로우므로, 슬라브 가열을 1200℃이하로 하여 석출물을 조대화 시킨다. 따라서, 통상에 비해 열간압연온도가 일반 탄소강보다 낮아 열간압연기의 부하가 많이 걸리고 탄소강과의 혼합생산시 생산 스케줄을 관리하기가 어려워 생산성이 저하되는 문제가 있다.In the conventional slab low temperature heating method, fine precipitation of MnS or AlN is rather harmful to magnetism in the hot rolling process, so that the precipitates are coarsened with slab heating at 1200 ° C or less. Therefore, the hot rolling temperature is lower than that of ordinary carbon steel compared to the general one, so that the load of the hot rolling mill is large, and it is difficult to manage the production schedule during the mixed production with the carbon steel, resulting in a decrease in productivity.

이에, 본 발명은 상기 종래기술의 문제점을 해결하기 위해 안출된 것으로써, Cu2S와 AlN 석출물을 1차 재결정립의 성장억제제로 이용하여 우수한 자성을 안정적으로 얻고, 종래의 고온슬라브 가열대신 1320℃이하의 저온슬라브 가열로 생산성이 혁신적으로 향상될 수 있는 고자속밀도 방향성 전기강판의 제조방법을 제공하고자 하는데 그 목적이 있다.Thus, the present invention was devised to solve the problems of the prior art, by using Cu 2 S and AlN precipitates as the growth inhibitor of the primary recrystallization to obtain excellent magnetic stability, 1320 instead of the conventional high temperature slab heating It is an object of the present invention to provide a method of manufacturing a high magnetic flux density oriented electrical steel sheet in which productivity can be improved with low temperature slab heating at below ℃.

상기 목적을 달성하기 위한 본 발명은 고자속밀도 방향성 전기강판의 제조방법에 있어서, 중량%로, C: 0.025 ~ 0.08%, Si: 2.5 - 4.5%, Sol-Al: 0.020 ~ 0.040%, N: 0.0150%이하, Cu : 0.05~0.4%, S: 0.013~ 0.022%, B: 0.0005~0.0010%, 및 잔부 Fe와 기타 불가피하게 첨가되는 불순물로 이루어지는 규소강 슬라브를 1100 ~ 1320℃의 온도에서 가열하고 열간압연한 후, 상기 열간압연판을 예비소둔하고, 이어 최종제품의 두께로 1회 냉간압연한 다음, 상기 냉간압연판을 1차 재결정을 겸한 탈탄소둔을 한 후, 600 ~ 800℃의 온도에서 암모니아가 포함된 분위기로단시간 질화처리한 다음, 고온소둔 및 절연코팅하는 것을 포함하여 구성되는 슬라브 저온가열에 의한 고자속밀도 방향성 전기강판의 제조방법에 관한 것이다.The present invention for achieving the above object in the method of manufacturing a high magnetic flux density oriented electrical steel sheet, in weight%, C: 0.025 ~ 0.08%, Si: 2.5-4.5%, Sol-Al: 0.020 ~ 0.040%, N: 0.0150% or less, Cu: 0.05-0.4%, S: 0.013-0.022%, B: 0.0005-0.0010%, and a silicon steel slab composed of the balance Fe and other unavoidable impurities at a temperature of 1100-1320 ° C. After hot rolling, the hot rolled sheet is preannealed, and then cold rolled once to the thickness of the final product, and then the cold rolled sheet is subjected to decarbonization annealing as primary recrystallization, and then at a temperature of 600 to 800 ° C. The present invention relates to a method of manufacturing a high magnetic flux density oriented electrical steel sheet by slab low temperature heating, which comprises nitriding a short time in an atmosphere containing ammonia, and then performing high temperature annealing and insulation coating.

이하, 본 발명에 대하여 상세히 설명한다.EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

본 발명은 MnS 보다 고용온도가 약 100℃ 낮은 Cu2S를 1차재결정립성장 억제제로 이용하여 저온슬라브 재가열이 가능하도록 함과 동시에 Cu2S와 AlN을 1차재결정립성장 억제제로 이용하여 2차 재결정을 안정화하는데, 그 특징이 있다.The present invention using, and at the same time Cu 2 S and AlN using the employment temperature of about 100 ℃ low Cu 2 S than MnS as the primary recrystallized grains growth inhibitor to be the low-temperature slab reheating to the primary recrystallized grains growth inhibitor 2 It is characterized by stabilizing vehicle recrystallization.

이를 위해 우선, 상기 C는 그 함량이 0.025%이하이면 열간압연에서 상변태가 충분히 일어나지 않아 슬라브의 주상정조직이 열간압연으로 파괴가 되지 않기 때문에 집합조직의 발달에 좋지 않으며, 그 함량이 0.08% 이상이면 탈탄이 제대로 일어나지 않아 자기시효가 일어나 자성이 좋지 않으므로 0.025-0.08%로 첨가하는 것이 바람직하다.To this end, the C is not good for the development of the aggregate structure because the phase transformation does not occur sufficiently in hot rolling when the content is less than 0.025%, the slab columnar tissue is not destroyed by hot rolling, the content is more than 0.08% If the decarburization does not occur properly because of the magnetic aging is not good magnetism is preferably added at 0.025-0.08%.

상기 Si는 2.5%이하이면 비저항이 낮아 철손이 높고, 4.5%이상이면 냉간압연성이 나쁘므로 2.5-4.5%로 첨가하는 것이 바람직하다.If the Si is less than 2.5%, the specific resistance is low, the iron loss is high, if more than 4.5%, cold rolling is bad, it is preferable to add 2.5-4.5%.

상기 Sol-Al은 0.020%이하이면 AlN에 의한 억제력이 약하고, 0.040%이상이면 AlN이 2차 재결정전에 조대해지기 쉬우므로 0.020-0.040%로 첨가하는 것이 바람직하다.If the Sol-Al is less than 0.020%, the inhibitory force by AlN is weak, and if it is more than 0.040%, AlN is likely to coarsen before the second recrystallization, so it is preferably added at 0.020-0.040%.

상기 N는 0.015%이상이면 냉간압연시 취성이 강해져서 깨지기 쉬우므로 0.015%이하로 첨가하는 것이 바람직하다.If the N is 0.015% or more, the brittleness during cold rolling is strong and brittle, so it is preferably added at 0.015% or less.

상기 Cu는 0.05%이하이면 Cu2S로 결합하지 않은 유리 S에 의해 취성이 생기기 쉽고, 0.4%이상이면 Cu2S가 조대해져 Cu2S에 의한 1차재결정립성장 억제력이 약해지므로 0.05-0.4%로 첨가하는 것이 바람직하다.When the Cu is 0.05% or less, brittleness is likely to occur due to the glass S which is not bonded with Cu 2 S, and when it is 0.4% or more, Cu 2 S is coarsened to weaken the primary recrystallized grain growth inhibition by Cu 2 S. Preference is given to adding in%.

상기 S은 0.013% 이하이면 Cu2S에 의한 1차 재결정립성장 억제력이 작고, 0.022%이상이면 슬라브 저온가열에 의한 제조가 어려우므로 0.013-0.022%의 범위로 첨가하는 것이 바람직하다.When the S is 0.013% or less, the primary recrystallization growth inhibition by Cu 2 S is small, and when it is 0.022% or more, it is difficult to manufacture the slab by low temperature heating, so it is preferably added in the range of 0.013-0.022%.

상기 B는 BN 석출물을 형성시켜 1차 재결정성장억제력을 보충하는 유효한 원소로 작용하는데, 그 함량이 0.0005%이하이면 B의 첨가효과가 없고, B가 0.0010%이상이면 자성이 나빠지고, 취성이 있어 압연이 어려우므로 0.0005- 0.0010%의 범위로 첨가하는 것이 바람직하다.B acts as an effective element to supplement the primary recrystallization growth inhibitory by forming a BN precipitate, if the content is less than 0.0005%, the effect of the addition of B is not effective, if B is more than 0.0010%, the magnetic properties are bad, brittle Since rolling is difficult, it is preferable to add in 0.0005 to 0.0010% of range.

상기와 같이 조성되는 규소강 슬라브는 1100 - 1320℃의 온도범위로 저온재The silicon steel slab formed as described above is a low temperature material in the temperature range of 1100-1320 ℃

가열하는 것이 바람직한데, 그 이유는 슬라브 가열온도가 1100℃이하이면 열간압연 종료 온도를 900℃이상으로 할 수가 없어서 자성이 나빠지고, 슬라브 가열온도가 1320℃이상이면 고온슬라브 가열에 의해 생산성이 악화되기 때문이다.It is preferable to heat, because the slab heating temperature is 1100 ℃ or less, the hot rolling end temperature can not be more than 900 ℃, the magnetism deteriorates, and if the slab heating temperature is 1320 ℃ or more, productivity deteriorates due to high temperature slab heating. Because it becomes.

상기와 같이 연주슬라브를 저온 재가열한 후 열간압연을 하는데, 열간압연은 조압연 및 사상압연으로 구성되며, 가열로 추출후 즉시 실시하면 된다. 이때, 열간압연종료온도는 Cu2S의 미세석출을 감안하면 900℃이상이 바람직하다.As described above, after reheating the slab at low temperature, hot rolling is performed. The hot rolling is composed of rough rolling and filament rolling. At this time, the hot rolling end temperature is preferably 900 ° C or higher in consideration of the fine precipitation of Cu 2 S.

상기와 같이 열간압연한후, 상기 열간압연판은 예비소둔후 1회냉간압연에 의해 최종제품두께로 한 후, 자기시효가 일어나지 않도록 탄소량을 30ppm 이하로 탈탄한다.After hot rolling as described above, the hot rolled plate is preliminarily annealed to a final product thickness by cold rolling once, and then decarburized to 30 ppm or less of carbon so that self aging does not occur.

상기 탈탄판은 암모니아가 함유된 분위기에서 600 ~ 800℃의 온도에서 단시간 질화처리하는데, 상기 질화처리후의 보다 바람직한 질소량은 200 - 800ppm이다. 200 ppm 이하이면 질화에 의한 AlN의 형성이 다소 부족하고, 800 ppm 이상이면 2차재결정 개시전에 AlN가 조대해지기 쉽다.The decarburized plate is subjected to nitriding for a short time at a temperature of 600 to 800 ° C. in an atmosphere containing ammonia, and a more preferable amount of nitrogen after the nitriding treatment is 200 to 800 ppm. If it is 200 ppm or less, AlN formation by nitriding is somewhat insufficient, and if it is 800 ppm or more, AlN tends to coarsen before starting secondary recrystallization.

상기 질화처리가 끝난 후에 MgO 코팅을 하고 수소와 질소의 혼합분위기에서 2차 재결정을 일으키는 고온소둔을 실시하고 절연코팅을 하여 최종 제품화한다.After completion of the nitriding treatment, MgO is coated and subjected to high temperature annealing, which causes secondary recrystallization in a mixed atmosphere of hydrogen and nitrogen, and subjected to insulation coating to produce a final product.

이하, 실시예를 통하여 본 발명을 상세히 설명한다.Hereinafter, the present invention will be described in detail through examples.

실시예 1Example 1

C: 0.045%, Si: 3.21%, Sol-Al: 0.027%, N: 0.0079%, B: 0.0032%를 기본으로 하고, 하기 표1에서와 같이 Cu과 S양을 변화시킨 슬라브를 1280℃에서 4시간 가열후 열간압연하여 2.3mm 두께의 열연판으로 만들었다. 상기 열연판을 예비소둔한 후 1회냉간압연에 의해 두께 0.30mm로 냉간압연한 다음, 830℃에서 수소와 질소가 혼합된 습윤분위기에서 3분간 탈탄소둔한 다음 700℃에서 3분간 암모니아가 수소와 질소가 혼합된 분위기에서 질화처리하였다. 상기 질화처리후 MgO 코팅하고, 이어 수소와 질소가 혼합된 분위기에서 고온 소둔한 다음 절연코팅처리한후, 자기적 특성을 측정하고, 그 결과를 하기표1에 나타내었다.Based on C: 0.045%, Si: 3.21%, Sol-Al: 0.027%, N: 0.0079%, and B: 0.0032%, the slabs in which the Cu and S amounts were changed as shown in Table 1 were 4 at 1280 ° C. After the heating time was hot rolled to make a hot rolled plate of 2.3mm thickness. After pre-annealing the hot rolled sheet was cold rolled to a thickness of 0.30mm by one cold rolling, and then decarbonized for 3 minutes in a wet atmosphere mixed with hydrogen and nitrogen at 830 ℃ and then ammonia and hydrogen at 700 ℃ for 3 minutes Nitriding was carried out in a mixed atmosphere of nitrogen. After the nitriding treatment, the MgO coating, followed by high temperature annealing in a mixed atmosphere of hydrogen and nitrogen, followed by insulation coating treatment, measured magnetic properties, and the results are shown in Table 1 below.

이때, 자기적 성질의 측정의 세기가 1000Amp/m일 때, 자속밀도의 값 B10(Tesla)와 B10이 1.7 tesla이고, 주파수가 50Hz일 때의 철손 W17/50(W/kg)으로 나타냈다. 자속밀도 값은 높을수록 전기기기의 효율이 좋고, 철손은 작을수록 철심에 의한 에너지손실이 작다.At this time, when the intensity of the measurement of the magnetic properties was 1000 Amp / m, the magnetic flux densities B10 (Tesla) and B 10 were 1.7 tesla and the iron loss was W 17/50 (W / kg) when the frequency was 50 Hz. . The higher the magnetic flux density value, the better the efficiency of the electric equipment, and the smaller the iron loss, the smaller the energy loss by the iron core.

S함량(%)S content (%) Cu함량(%)Cu content (%) 자속밀도B10(T)Magnetic flux density B 10 (T) 철손W17/50(W/kg) Iron loss W 17/50 (W / kg) 비교강Comparative steel 0.0070.007 0.240.24 1.8771.877 1.261.26 비교강Comparative steel 0.0100.010 0.190.19 1.8871.887 1.191.19 비교강Comparative steel 0.0140.014 0.040.04 1.8911.891 1.121.12 발명강Invention steel 0.0140.014 0.110.11 1.9241.924 0.990.99 발명강Invention steel 0.0140.014 0.180.18 1.9461.946 0.970.97 발명강Invention steel 0.0140.014 0.250.25 1.9561.956 0.940.94 발명강Invention steel 0.0140.014 0.350.35 1.9231.923 0.960.96 비교강Comparative steel 0.0140.014 0.450.45 1.9011.901 1.091.09 비교강Comparative steel 0.0140.014 0.550.55 1.8901.890 1.111.11 비교강Comparative steel 0.0170.017 0.040.04 1.9041.904 1.081.08 발명강Invention steel 0.0170.017 0.100.10 1.9261.926 0.990.99 발명강Invention steel 0.0170.017 0.200.20 1.9451.945 0.940.94 발명강Invention steel 0.0170.017 0.250.25 1.9591.959 0.940.94 발명강Invention steel 0.0170.017 0.340.34 1.9361.936 0.960.96 비교강Comparative steel 0.0170.017 0.440.44 1.9121.912 1.041.04 비교강Comparative steel 0.0240.024 0.080.08 1.9041.904 1.091.09 비교강Comparative steel 0.0240.024 0.140.14 1.8671.867 1.291.29

상기 표1 에서 알 수 있는 바와 같이 Cu: 0.05 - 0.4%, S: 0.013 - 0.022%의 조건을 만족하는 발명강의 경우가 자성이 우수한 것을 알 수 있었다.As can be seen from Table 1, the invention steel satisfying the conditions of Cu: 0.05-0.4% and S: 0.013-0.022% was found to have excellent magnetic properties.

실시예 2Example 2

C: 0.045%, Si: 3.15%, Sol-Al: 0.025%, N: 0.0077%, S: 0.013%, Cu:0.22%를 기본으로 하고, 하기 표2에서와 같이 B(보론)양을 변화시킨 슬라브를 1300℃에서 4시간 가열후 열간압연하여 2.3mm 두께의 열연판으로 만들었다. 열연판을 예비소둔후 1회 냉간압연에 의해 0.30mm로 한 다음, 830℃에서 수소와 질소가 혼합된 습윤분위기에서 3분간 탈탄소둔한 다음, 700℃에서 3분간 암모니아가 수소와 질소가 혼합된 분위기에서 질화처리하였다. 질화처리후 MgO 코팅한 다음 수소와 질소가 혼합된 분위기에서 고온소둔한 다음 절연코팅처리한 후, 자기적특성을 측정하고 그 결과를 하기 표2에 나타내었다.C: 0.045%, Si: 3.15%, Sol-Al: 0.025%, N: 0.0077%, S: 0.013%, Cu: 0.22% based on the amount of B (boron) changed as shown in Table 2 below. The slabs were heated at 1300 ° C. for 4 hours and hot rolled to form 2.3 mm thick hot rolled plates. After pre-annealing the hot rolled sheet to 0.30mm by cold rolling, and then decarbonized for 3 minutes in a wet atmosphere where hydrogen and nitrogen were mixed at 830 ° C, ammonia was mixed with hydrogen and nitrogen at 700 ° C for 3 minutes. Nitriding was performed in the atmosphere. After nitriding, after MgO-coating, high-temperature annealing in a mixed atmosphere of hydrogen and nitrogen, followed by insulation coating, magnetic properties were measured and the results are shown in Table 2 below.

B(보론)함량(ppm)B (boron) content (ppm) 자속밀도 B10(T)Magnetic flux density B 10 (T) 철손,W17/50(W/kg) Iron loss, W 17/50 (W / kg) 비교강Comparative steel 44 1.9001.900 1.121.12 발명강Invention steel 88 1.9201.920 1.081.08 발명강Invention steel 1818 1.9481.948 0.980.98 발명강Invention steel 4545 1.9541.954 0.960.96 발명강Invention steel 8282 1.9311.931 1.981.98 비교강Comparative steel 122122 1.9101.910 1.081.08 비교강Comparative steel 155155 1.8971.897 1.141.14

상기 표2에서 알 수 있는 바와 같이, B(보론)양이 5 - 100ppm 범위의 발명강의 자성이 우수하였다.As can be seen in Table 2, the B (boron) amount was excellent in the magnetic properties of the invention steel in the range of 5-100ppm.

실시예 3Example 3

C: 0.049%, Si: 3.21%, Sol-Al : 0.026%, N: 0.0082%, B: 0.0045%, Cu: 0.18%, S: 0.013%의 슬라브를 4시간 동안 여러가지의 가열온도조건에서 유지시켰다. 슬라브 가열이 끝난후, 열간압연하여 2.3mm 두께의 열연판으로 만들었다.Slabs of C: 0.049%, Si: 3.21%, Sol-Al: 0.026%, N: 0.0082%, B: 0.0045%, Cu: 0.18%, S: 0.013% were maintained at various heating temperature conditions for 4 hours. . After the slab heating was finished, it was hot rolled into a 2.3 mm thick hot rolled sheet.

열연판을 예비소둔한 후 1회냉간압연에 의해 0.30mm로 두께로 냉간압연한 다음, 830℃에서 수소와 질소가 혼합된 습윤분위기에서 3분간 탈탄소둔한 다음 700℃에서 3분간 암모니아가 수소와 질소가 혼합된 분위기에서 질화처리하였다. 질화처리후 MgO 코팅한 다음 수소와 질소가 혼합된 분위기에서 고온소둔한 다음 절연코팅처리한 후 슬라브 가열온도에 따른 자기적특성을 측정하고 그 결과를 하기표 3에나타내었다.After pre-annealing the hot rolled sheet, cold rolled to 0.30mm thickness by one cold rolling, and then decarbonized for 3 minutes in a wet atmosphere where hydrogen and nitrogen were mixed at 830 ° C, followed by ammonia Nitriding was carried out in a mixed atmosphere of nitrogen. After nitriding, MgO-coated, hot-annealed in a mixed atmosphere of hydrogen and nitrogen, followed by insulation coating, magnetic properties were measured according to the slab heating temperature and the results are shown in Table 3 below.

슬라브 가열온도Slab heating temperature 자속밀도B10(T)Magnetic flux density B 10 (T) 철손 W,17/50(W/kg) Iron loss W, 17/50 (W / kg) 비고Remarks 비교재Comparative material 1000℃1000 ℃ 1.8971.897 1.331.33 압연기부하가 큼Rolling mill load is high 발명재Invention 1150℃1150 ℃ 1.9321.932 1.071.07 발명재Invention 1200℃1200 ℃ 1.9351.935 0.950.95 발명재Invention 1300℃1300 ℃ 1.9401.940 0.930.93 비교재Comparative material 1350℃1350 ℃ 1.9371.937 0.960.96 에지크랙 일부발생Some edge cracks 비교재Comparative material 1400℃1400 ℃ 1.9161.916 1.051.05 에지크랙 전면발생Edge Crack Front

상기 표3에서 알 수 있는 바와 같이, 슬라브 가열온도가 1150 - 1300℃ 범위인 발명재의 경우가 자성이 우수하고, 제조가 용이하였다.As can be seen in Table 3, in the case of the invention material in the slab heating temperature range of 1150-1300 ℃ excellent magnetic properties, it was easy to manufacture.

상술한 바와 같이, 본 발명은 AlN 과 Cu2S석출물을 동시에 이용하는 슬라브 저온가열기술에 의하여, 종래의 고온 슬라브 가열에 의한 고자속밀도 방향성 전기강판의 제조방법에 비하여, 실수율 및 생산성 향상의 잇점이 있다.As described above, the present invention has the advantage of improving the realization rate and productivity by the slab low temperature heating technology using AlN and Cu 2 S precipitates at the same time, as compared with the conventional method of manufacturing high magnetic flux density oriented electrical steel sheet by high temperature slab heating. have.

특히, 본 발명에 의하면 종래의 슬라브 저온가열에 의한 고자속밀도 방향성 전기강판의 제조방법에 비하여 자성과 생산성이 우수한 고자속밀도 방향성 전기강판을 제공할 수 있으며, 본 발명에 의해 제공되는 고자속밀도 방향성 전기강판은 변압기 등의 전기기기제조분야에 적용될 수 있는 유용한 효과가 있는 것이다.In particular, according to the present invention, it is possible to provide a high magnetic flux density oriented electrical steel sheet having excellent magnetic properties and productivity as compared to a method of manufacturing a high magnetic flux density oriented electrical steel sheet by conventional slab low temperature heating, and the high magnetic flux density provided by the present invention. A grain-oriented electrical steel sheet has a useful effect that can be applied to the field of electrical equipment manufacturing, such as transformers.

Claims (1)

고자속밀도 방향성 전기강판의 제조방법에 있어서,In the manufacturing method of high magnetic flux density oriented electrical steel sheet, 중량%로, C: 0.025 ~ 0.08%, Si: 2.5 - 4.5%, Sol-Al: 0.020 ~ 0.040%, N: 0.0150%이하, Cu : 0.05~0.4%, S: 0.013~ 0.022%, B: 0.0005~0.0010%, 잔부 Fe와 기타 불가피하게 첨가되는 불순물로 이루어지는 규소강 슬라브를 1100 ~ 1320℃의 온도에서 가열하고 열간압연한 후, 상기 열간압연판을 예비소둔하고, 이어 최종제품의 두께로 1회 냉간압연한 다음, 상기 냉간압연판을 1차 재결정을 겸한 탈탄소둔을 한후, 600 ~ 800℃의 온도에서 암모니아가 포함된 분위기로 단시간 질화처리한 다음, 고온소둔 및 절연코팅하여 이루어지는 것을 특징으로 하는 슬라브 저온가열에 의한 고자속밀도 방향성 전기강판의 제조방법.By weight%, C: 0.025 to 0.08%, Si: 2.5 to 4.5%, Sol-Al: 0.020 to 0.040%, N: 0.0150% or less, Cu: 0.05 to 0.4%, S: 0.013 to 0.022%, B: 0.0005 ~ 0.0010%, the silicon steel slab consisting of the balance Fe and other unavoidable impurities are heated at a temperature of 1100 ~ 1320 ℃ and hot rolled, then pre-annealed the hot rolled plate, and then once to the thickness of the final product After cold rolling, the cold rolled sheet is subjected to decarbonization annealing as a primary recrystallization, and then nitrified for a short time in an atmosphere containing ammonia at a temperature of 600 to 800 ° C., followed by high temperature annealing and insulation coating. Method for manufacturing high magnetic flux density oriented electrical steel sheet by slab low temperature heating.
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Publication number Priority date Publication date Assignee Title
KR100431608B1 (en) * 1999-12-18 2004-05-17 주식회사 포스코 Manufacturing of high magnetic density grain oriented silicon steel

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KR890008334A (en) * 1987-11-20 1989-07-10 사이또오 유다까 Manufacturing method of oriented electrical steel sheet with high magnetic flux density
JPH02228425A (en) * 1989-02-28 1990-09-11 Nippon Steel Corp Production of grain-oriented silicon steel sheet with high magnetic flux density
JPH04183818A (en) * 1990-11-19 1992-06-30 Nippon Steel Corp Production of grain-oriented electrical steel sheet having high magnetic flux density and high quality of glass coating film

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Publication number Priority date Publication date Assignee Title
KR890008334A (en) * 1987-11-20 1989-07-10 사이또오 유다까 Manufacturing method of oriented electrical steel sheet with high magnetic flux density
JPH02228425A (en) * 1989-02-28 1990-09-11 Nippon Steel Corp Production of grain-oriented silicon steel sheet with high magnetic flux density
JPH04183818A (en) * 1990-11-19 1992-06-30 Nippon Steel Corp Production of grain-oriented electrical steel sheet having high magnetic flux density and high quality of glass coating film

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100431608B1 (en) * 1999-12-18 2004-05-17 주식회사 포스코 Manufacturing of high magnetic density grain oriented silicon steel

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