• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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• pp.208-211
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• 1995

This proper focuses on results of relative permeability(${\mu}$$\sub$r/), core loss(W) and magnetic induction [B] measurements on some of the most commonly used core materials(PN-18, 20, 30, 60, Pohang Iron '||'&'||' Steel Co., Ltd.) In case of Stress Relief Annealing(SRA). Results of magnetic induction[B] showed weak variations but core lass reduced strongly after SRA Core loss reduced from 3.071 ∼7.819(W/kg) and 11.377~3.988[W/kg] to 2.88~5.492[W/kg] and 1.213~2.134[W/kg] at 1.5[T] 50 Hz and 1.0 [T] 50Hz respectively after SRA. This SRA process leads to significant changes In magnetic properties and core loss of non-oriented silicon steel sheet.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권2호
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• pp.165-170
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• 2013

This paper presents the iron loss prediction of rotating electric machines taking account of the vector hysteretic properties of electrical steel sheet. The E&S vector hysteresis model is adopted to describe the vector hysteretic properties of a non-oriented electrical steel sheet, and incorporated into finite element analysis (FEA) for magnetic field analysis and iron loss prediction. A permanent magnet synchronous generator is taken as a numerical model, and the analyzed magnetic field distribution and predicted iron loss by using the proposed method is compared with those from a conventional method which employs an empirical iron loss formula with FEA based on a non-linear B-H curve. Through the comparison the effectiveness of the presented method for the iron loss prediction of the rotating machine is verified.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1071-1073
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• 2005

This paper investigates magnetic field behavior and its iron losses in the stator core using electrical steels. The analysis model is a brushless motor with the permanent magnet. The elliptical rotating and alternating flux distributions with non-sinusoidal waveforms are obtained by Finite Element Method and then their harmonic components are extracted. Based on these results, the local iron losses in the stator core caused by the harmonic flux are calculated. Furthmore, this paper explains the relation between the complex flux waveform and iron loss produced in each part of the stator core.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.253.2-253.2
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• 2008

• 비파괴검사학회지
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• 제23권4호
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• pp.315-321
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• 2003

고온, 고압에서 운용되고 있는 설비의 안전성을 평가하기 위해서는 사용시간 동안 열화된 물성을 정기적으로 점검하여 설비의 잔여수명을 평가해야 한다. 본 연구에서는 교류 섭동 자기장을 인가하여 구한 가역투자율 값을 이용하여 1Cr-1Mo-0.25V 강의 잔여수명을 평가하기 위한 자기적 방법을 제시하고자 한다. 이 방법은 자기이력곡선의 미분값인 가역투자율이 보자력에서 첨두 값을 갖는 특성을 이용하였으며, 측정원리는 교류 섭동 자기장의 주파수에 동조된 록-인 증폭기를 사용하여 탐지코일에 유도된 제 1 고조파의 전압을 측정하는 것이다. 가역투자율의 첨두값 간격 (peak interval of reversible magnetic permeability: PIRMP)과 비커스 경도는 열화가 진행됨에 따라 감소하였다 따라서 비커스 경도와 PIRMP상관관계에 의해 연화곡선을 구할 수 있고, 이 연화곡선에 의해 터빈로터 강의 잔여수명을 평가할 수 있다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1993년도 추계연구발표회 논문개요집
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• pp.56-57
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• 1993

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1555-1557
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• 1998

In order to investigate the core material for over-head transmission line with non-magnetic and high strength nitrogen steel, microstructure and several basic properties of Fe-Mn-Cr-Ni-N steel have been studied. It is necessary that core material have a $\gamma$ phase to have a non-magnetic characteristics. To acquire a $\gamma$ phase, Mn, Ni and C are added as a alloying element. It was found that Fe-25Mn-16Cr-1Ni-N alloy have a stable $\gamma$ phase. The precipitate from this alloy system was $(Cr, Fe)_7C_3$. High Mn and N steel satisfies Sievert's relation that solubility of nitrogen increases with the square root of partial pressure of gas in metal-gas system and the hardness have proportional relation with nitrogen concentration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.819-821
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• 2001

This paper describes a characteristics of MFL according to the position of Hall sensor Magnetic Flux Leakage(MFL) Method is used to detect surface defect in ferromagnetic plate. A plate has a surface defect and magnetizing equipment are producted to perform Non-Destructive Testing(NDT) using MFL. The SM 45C carbon steel plate is adopted to this experiment. there is a artifical defect with a twice of thickness and a half of depth of plate. Magnetizing equipment is composed of yoke made by layer-built of silicon sheet steel, NdFeB magnetic and iron brushes. Detecting defect is performed by MFL NDT using Hall sensor. It is shown that magnetic flux detected by Hall sensor is affected according to the position of Hall sensor through MFL experiment and numerical analysis.

• 한국분말재료학회지
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• 제9권4호
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• pp.203-210
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• 2002

A new PIM in-process joining technique has been developed for more complicated and functional PIM components by application of the exuded wax from the green compacts during solvent debinding step. At first, various stainless steels and iron compacts with rectangular shape were combined, and the joining behaviors and properties were investigated by shear and tensile test, and microscopic observation. Subsequently, perfect joined three pieces of thin and hollow compacts were obtained for the combination of same and different stainless steels, and it was difficult to join the iron and stainless steel compacts in hydrogen atmosphere because of the different starting temperature of shrinkage. However, pretty good joined iron and stainless steel compacts were obtained by consideration of particle size and vacuum atmosphere. Finally, for the combination of ferro-silicon and austenitic stainless steel compacts, high functionality (magnetic (1.60Tes1a) & non-magnetic) and perfect joint were obtained.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.779-782
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• 2000

An internal finishing process by the application of magnetic abrasive machining has been developed as a new technology to obtain a fine inner surface of pipe. In this paper, the finishing process of a non-ferromagnetic pipe by a static magnetic field method is introduced and its finishing characteristics is discussed with effective factors by various experiments. From these experimental results, it is found that the proper suppling quantity of magnetic abrasives per diameter of pipe is important, and the inner surface roughness of pipe is not changed much after certain critical finishing time. As a result of this investigation the 3.2$\mu$m Rmax in inner surface roughness of stainless steel pipe is improved to 0.7$\mu$m Rmax after 6 minutes finishing.