• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.311-317
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• 2009

In this paper deals with behavior of the magnetic abrasive using Ba-Ferrite on polishing characteristics in a new internal finishing of STS304 pipe applying magnetic abrasive polishing. The magnetic abrasive using Ba-Ferrite grain WA used to resin bond fabricated low temperature. And Ba-Ferrite of magnetic abrasive powder fabricated that Ba-Ferrite was crused into 200 mesh. The previous research have made an experiment in the static state the movement of magnetic abrasive grain is nevertheless in the dynamic state. In this paper, We could have investigated into the changes of the movement of magnetic abrasive grain. In reference to this result, we could have made the experiment which is set under the condition of the magnetic flux density, polishing velocity according to the form of magnetic brush.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.319-329
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• 2004

The electrorefining experiments with an anode composed of U, Y, Gd, Nd and Ce (or U, Gd, Dy and Ce) were carried out in the KC1-LiCl eutectic melt at $500^{\circ}C$, Uranium was the major component in the cathode deposits at the high initial uranium concentration, and the separation factors of the uranium with respect to the rare earths (REs) were calculated according to the applied voltage and the uranium concentration in the molten salt. The current efficiency was inversely in proportion to the applied voltage in the range of 1.0 V to 1, 9 V (vs. STS304L). The dependency of the applied voltage on the current efficiency as well as the deposition rate was discussed in terms of the microstructural feature and crystal structure of the deposit.

• Journal of the Korean institute of surface engineering
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• v.29 no.4
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• pp.261-267
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• 1996

The characteristics and adhesion strength of TiN layer deposited by D. C. magnetron sputtering were investigated. Three types of TiN layers were deposited on STS304 stainless steel. Scratch tests were performed to determine the effect of deposition temperature, the thickness of coated TiN layer and the titanium inter-layer on the adhesion strength. TiN multilayer with titanium inter-layer showed the highest critical load in the deposition temperature range of $25^{\circ}C$ to $300^{\circ}C$. Adhesion strength of TiN multilayer with titanium inter-layer was raised from 15N to 20N by raising deposition temperature from $25^{\circ}C$ to $400^{\circ}C$. Adhesion strength was raised from 18N to 38N by increasing the thickness of outer layer of TiN multilayer from 2.1 $\mu\textrm{m}$ to 9.5 $\mu\textrm{m}$.

• Journal of the Korean Society for Heat Treatment
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• v.22 no.5
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• pp.298-306
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• 2009

Gas nitriding and post oxidation were performed on stainless steels and SACM 645 steel. With increasing gas nitriding time, the increasing rate of nitrided layer was most rapid on SACM 645 steel and the nitriding depth of nitrided layer was most narrow on STS 304 steel among three steels. Corrosion resistance was increased with post oxidation on stainless steels and with increasing time the effect of corrosion resistance was decreased to compare with relatively short gas nitriding time. An improvement effect of corrosion resistance was consisted of predominantly on austenitic stainless steel by post oxidation after gas nitriding among three steels and it was relatively less influenced on martensitic stainless steel.

• Proceedings of the KWS Conference
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• v.43
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• pp.243-245
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• 2004

가속기의 저장링 및 빔라인에는 방사광을 차단 혹은 일부 통과 둥의 목적으로 Photon Absorber와 같은 진공 부품이 사용되고 있으며, 이는 일반적으로 구리와 스테인리스 스틸 등의 이종재료를 브레이징 공정을 이용하여 제작함으로써 부품이 구조적 건성의 확보와 더불어 진공환경 및 수밀을 유지하고 있다. 그러나, Photon Absorber는 사용 용도에 따라 구조적 형상이 서로 다르기 때문에 브레이징 공정을 적용하는 경우, 상대적으로 제품 생산가격의 상승, 유지보수 및 제작불량에 따른 공정 제어의 어려움이 나타나고 있다. 본 연구에서는 스테인리스 스틸 (STS 304)과 구리(OFHC Copper)의 이종금속에 접합에 GTAW 용접 공정 기술을 적용하여 제반 용접공정에 따른 용접부 성능 및 진공 특성 등을 검토하였다. 용접봉 (ER CuSi-A)을 직접 사용하여 이종 재료의 시험편에 GTAW 용접을 적용한 결과, 진공 누설율은 $1{\times}10^{-10}\;Torr{\cdot}l/s$ 이하를 얻을 수 있었으며, 용접 접합부의 인장강도 210 MPa로써 구리 모재와 유사한 기계적 특성을 나타내었다.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.3
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• pp.75-81
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• 1997

Automatic monitoring the cutting state is one of the important problems to increase the reliability of modern machining processes. In this study, cutting force signals were used in order to monitor the tool wear and fracture in the turning process. Turning experiments were performed using cemented carbide insert tools(K20) and STS304 steel as a workpiece. Cutting force signal characteristics and histogram analysis method were used to recognize the cutting states. It was found that tool wear and fracture can be diagnosed from the cutting force signal coefficient of variation(C.V.) and histogram analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.473-476
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• 2000

Recently, many studies focus on mixed-mode fatigue-fracture characteristics of characteristics of materials. In order to reveal crack initiation and propagation mechanisms in combined -mode fatigue. This paper investigates the initiation and propagation behavior of the fatigue crack of the STS304 specimens under mixed mode loading conditions. moreover crack arrest and branch phenomena were analyzed with respect to the change do the angle of inclined loading. The relationship between the angle of inclined loading and the angle of branched crack was studied. A greate number of cycles are necessary to initiate a new crack from the initial crack. The direction of the new crack propagation is determined by MTS theory.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.77-80
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• 2004

In this paper, we have investigated the characteristics of the magnetic abrasive using sludge on polishing of internal finishing of seamless stainless steel (STS304) tube applying magnetic abrasive polishing. Either white alumina (WA) or green carborundum (GC) grain was used to resin sludge at a low temperature, and the sludge of magnetic abrasive powder was synthesized and crushed into 200 meshes. Surface roughness was measured before and after polishing, and more than 40% of improvement of surface roughness was achieved when WA grain was used under a specific condition. Even though some degree of surface roughness due to deeper scratches still exist, but the result showed a prospective magnetic abrasive polishing using sludge with WA or GC grains.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.1
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• pp.26-31
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• 2002

In this study an experimental investigation was conducted to find the grinding characteristics of ceramics, STD11 and STS304 materials. The grinding force and the microscopic observation of the workpieces were obtained in surface grinding. Grinding characteristics of ceramics were inspected through the microscopic examination the cutting force, and the surface roughness. It has been found that the finding force of ceramics is relatively low as compared to that of steels and that CBN wheel has an excellent performance. The surface roughness was measured according to the feedrate and the depth of out.

• Journal of Korea Foundry Society
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• v.8 no.4
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• pp.429-436
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• 1988

The influences of some casting conditions on bonding ratio and state at bonding zone of stainless steel-cast iron dual tube produced by centrifugal casting process were investigated to estimate fabrication technics. 1) Bonding ratio is increasing such as increasing of inner surface temperature of outer metal(stainless steel STS 304), if pouring temperature of inner metal (cast iron) is constant. 2) The more pouring temperature of inner metal (cast iron) increase, the more bonding ratio increase when inner surface temperature of outer metal (cast iron) is constant. 3) As the mold rotary speed is increase, the hatching area of bonding map (perfect bonding area) goes down to the low pouring temperature of inner metal. 4) In order to predict bonding state of two different metal, we are able to make and use the bonding map about casting conditions such as inner surface temperature of outer metal, pouring temperature of inner metal and mold rotary speed.