• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권5호
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• pp.250-257
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• 2006

It is well known that Grain-oriented electrical steel sheets have two dimensional magnetic properties according to the direction of exciting field such as non-linear phase difference between magnetic flux density and magnetic field intensity vectors, different iron loss and permeability even when an alternating magnetic field is applied. The measurement and application of the two dimensional magnetic properties of the Grain-oriented electrical steel sheets, therefore, are very important for the design and precise performance analysis of electric machines made of them. As the direction of exciting field changes, in this paper, the two dimensional magnetic properties of a Grain-oriented electrical steel sheet, i.e., non-linear B-H curves, phase difference between B and H, and iron loss characteristics, are measured using SST(Single Sheet Tester) which has two axes excitation. The measured results are presented in two ways: using $(B,\theta_B)$ method and using hysteresis loops along rolling and transverse directions, respectively.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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• pp.11-18
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• 2004

Asymmetric rolling, in which the circumferential velocities of the upper and lower rolls are different, can give rise to intense plastic shear strains and in turn shear deformation textures through the sheet thickness. The ideal shear deformation texture of fcc metals can be approximated by the <111> // ND and $\{001\}<110>$ orientations, among which the former improves the deep drawability. The ideal shear deformation texture for bcc metals can be approximated by the Goss $\{110\}<001>\;and\;\{112\}<111>$ orientations, among which the former improves the magnetic permeability along the <100> directions and is the prime orientation in grain oriented silicon steels. The intense shear strains can result in the grain refinement and hence improve mechanical properties. Steel sheets, especially ferritic stainless steel sheets, and aluminum alloy sheets may exhibit an undesirable surface roughening known as ridging or roping, when elongated along RD and TD, respectively. The ridging or roping is caused by differently oriented colonies, which are resulted from the <100> oriented columnar structure in ingots or billets, especially for ferritic stainless steels, that is not easily destroyed by the conventional rolling. The breakdown of columnar structure and the grain refinement can be achieved by asymmetric rolling, resulting in a decrease in the ridging problem.

• 한국결정성장학회지
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• 제10권2호
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• pp.152-158
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• 2000

상압 소결법(PLS, pressureless sintering) 및 방전가열 소결법(SPS, spark plasma sintering)으로 소결한 {{{{ {ZrB }_{2 } - ZrC }}}} 복합체의 미세구조를 SEM-EBSP 법에 의해 결정기하학적으로 분석하였다. PLS법에 의해 소결된 복합체에서 {{{{ { ZrB}_{2 } }}}}의 (1010) 면은ND(시편에 수직인 방향)로 배향되었고, ZrC 경우 (101) 및 (111)면이 ND방향으로 배향되었다. 한편 SPS법에 위해 소결된 {{{{ { ZrB}_{2 } }}}}의 (0001)A면은 ND방향으로 강하게 배향되었다. ZrC인 경우 (001) 면만이 ND방향으로 배향되었다. PLS법에 의한 소결체의 결정립은 특정방위에 대해 약한 배향을 갖으면서, {{{{ { ZrB}_{2 } }}}}와 ZrC상 계면의 구조적 조화가 우수한 반면, SPS법에 의한 소결체의 결정립들은 특정방향으로 강하게 배향되는 경향을 보인다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1281-1282
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• 2007

Effect of tension coating on reducing iron losses of thin grain-oriented 3% Si-Fe steel sheets was investigated. Conventional grain-oriented electrical steel sheets have a forsterite coating layer and a tension coating layer in order to apply tensile stress to the rolling direction of the sheets. However the proposed coating method in this paper is to form only a tension coating layer on the both surfaces of the sheets. Iron losses with the tension coating were reduced by 8% under the condition of 1.7 T and 60 Hz. Consequently the proposed tension coating is applicable to $80{\mu}m$-thick 3% Si-Fe steel sheets.

• 한국자기학회지
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• 제11권1호
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• pp.1-7
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• 2001

열연판을 모재로 하여 압연 및 열처리 공정을 조합한 공정을 3회 냉간압연법을 사용하여 최종두께 100$\mu\textrm{m}$로 제작한 방향성 규소강대에 대하여, 직류자기 특성 및 결정입자의 열처리 의존성, 결정방위 등을 조사하였다. 그 결과, (110)면이 거의 시료 전체표면에 성장하는 것이 관측되었으며, B$_{8}$은 1.9 T정도, 평균$\alpha$각은 약 4.6$^{\circ}$이었다. 향후 약간의 (001)조직의 집적도 개선이 추가된다면, 염가의 열연판을 모재로 사용하여 기존의 방향성 규소강판의 경우보다 훨씬 제조공정수를 단순화함으로써, 경제성이 우수한 방향성 극박 규소강대를 제작할 수 있는 가능성을 확인하였다.

• 전기학회논문지
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• 제60권9호
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• pp.1684-1692
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• 2011

Recently, several vector hysteresis models such as vector Preisach, vector Jiles-Atherton and dynamic E&S model have been proposed to describe vector magnetic properties of electrical steel sheets. However, it is still difficult to find an adequate vector hysteresis model in finite element application for both the Non-oriented and Grain-oriented electrical steel sheets under alternating and rotating field conditions. In this paper, an improved E&S vector hysteresis model is suggested to describe the vector magnetic properties of both Non-oriented and Grain-oriented electrical steel sheets under various magnetic field conditions including alternating and rotating magnetic field conditions. The validity of the proposed model is tested through comparisons with the experimental results under various magnetic field conditions.

• 한국자기학회지
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• 제6권3호
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• pp.165-169
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• 1996

극박 방향성 규소강판의 철손을 저감시킬 목적으로 열처리방법을 이용하여 결정 크기의 제어에 의해 자구폭을 변화시켰으며 결정립의 크기와 직류 자기특성, 철손, 자구폭과의 관계에 대해 검토하였다. 결정립 크기가 1 mm 이하로 작게되어도, $B_{8}$는 1.96 T 이상의 높은 값을 나타내었고 항자력 $H_{c}$는 결정립 크기의 감소에 따라 증가하였다. 결정립 크기가 1 mm 이하의 범위에서 결정립 크기를 감소시킴에 의해 자벽수가 증가하였으며 여자주파수가 높게 됨에 따라 증가하는 자벽수도 결정립 크기가 작을수록 많아지고 자구 세분화에 효과적이었다. 결정립 크기의 감소는 자구 세분화에 의해 와전류 손실을 저감시키지만 히스테리시스 손실이 지배적으로 낮은 여자주파수의 철손은 결정립 크기가 작은 시료일수록 높은 값을 나타내었다. 그러나 높은 주파수 영역의 철손은 와전류손실이 지배적이기 때문에 결정립 크기가 작은 시료일수록 낮은 값을 나타내었다. 이 결과로부터 결정립크기를 제어함에 의해 자구폭을 변화시킬수 있으며 극박방향성 규소강판의 저 손실화에 매우 유리한 수법인 것을 알았다.

• 열처리공학회지
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• 제31권6호
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• pp.269-274
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• 2018

Grain-oriented electrical steel sheets are mainly used as core materials for transformers and motors. They should have excellent magnetic properties such as low core loss, high magnetic flux density and high permeability. In order to improve the magnetic properties of the electrical steel sheet, it is important to form Goss oriented grains with a very strong {110}<001> orientation. Recently, efforts have been made to develop Goss grains by controlling processes such as hot rolling, cold rolling, and primary and secondary recrystallization. In this study, the sheets containing 3.2 and 3.4wt.% Si were used, which were rolled with 1 and 10 passes with total thickness reduction of 89%. Heating was carried out for primary recrystallization with different heating rates of $25^{\circ}C/s$ and $24^{\circ}C/min$ until $720^{\circ}C$. The behavior of Goss-, {411}<148>-, and {111}<112>-oriented grains were analyzed using X-ray diffraction(XRD) and electron back-scatter diffraction(EBSD) analysis. The area fraction of Goss-oriented grains increased with the number of rolling passes during cold rolling; however, after the primary recrystallization, the area fraction of the Goss grains was higher and exact Goss grains were found in the specimens subjected to rapid heating after one rolling pass.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.18-21
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• 2000

A nonconstact technique for reducing the core loss of a grain oriented silicon steel has been developed by the use of mechanical scribing Q-switched laser plasma jet or electron beam irradiation. Among these methods electron beam irradiation has advantages of domain refining without any deformation or damage of insulating film on the surface of a grain criented Si-Fe. Over the past years this processing was performed in vaccum of 10-4 Torr or below causing the problem of high cost and difficulty of continuous works. In this paper a miniature electron permeable window through which electron beam energy 4-80keV and average current 0.1-2mA. were obtained for electron beam irradiating on air was designed and manufactured.

• 대한전기학회논문지
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• 제38권3호
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• pp.173-181
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• 1989

A split-phase induction motor with asymmetrical magnetizing reactance axes develops starting torque and its efficiency can be high under certain conditions. In this paper, one method of producing the asymmetry of magnetizing reactance axes is described. The grain-oriented silicon steel core is used to produce the asymmetric axes instead of non-oriented silicon steel core which is used in general motors. The optimum design method for the motor is suggested and analyzed. To verify this suggestion, the permanent capacitor run type induction motors are designed to be driven at balanced condition by its asymmetrical effect, and then the oscillating torque due to the asymmetry of motor structures are analyzed. Tests of the sample motor have shown good performance comparable to ordinary types. This motor structure can be used where high effciency and reliability are required, and also the amount of core materials can be reduced due to its high permeability.