• Digital Contents
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• no.4 s.47
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• pp.50-60
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• 1997

최근 국내에서는 미국에서 시효가 만료돼 공개한 정보를 국내 언론에서 공개한 사안을 두고 갑론을박의 상황이 일어났다. 미국, 일본 등은 정보는 원칙적으로 모두 공개돼야 한다는 개념을 기반으로 정부 정보 제공에 대해 접근하고 있다. 본 기사는 일본의 조사단이 미국의 정부정보 서비스 업체 및 업계를 방문해 수집한 관련자료를 정리한 것이다.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.234-234
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.295-296
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• 1999

• Proceedings of the KWS Conference
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• 2001.05a
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• pp.285-288
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• 2001

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.362.1-362.1
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• 2003

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1997.04a
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• pp.33-33
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• 1997

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1139-1140
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• 2011

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.3
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• pp.519-527
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• 1997

AISI 316 steel has been used extensively for heater and boiler tube of the structural plants such as power, chemical and petroleum plants under severe operating conditions. Usually, material degradation due to microcrack or precipitation of carbides and segregation of impurity elements, is occured by damage accumulated for long-term service at high temperature in this material. In this study, the effect of aging time on fracture toughness was investigated to evaluate the measurement of material degradation. The elastic-plastic fracture toughness behaviour of AISI 316 steel pipe aged at $550^{\circ}C$for 1h-10000h (the aged material) was characterized using the single specimen J-R curve technique and eletric potential drop method at normal loading rate(load-line displacement speed of 0.2mm/min) in room temperature and air environment. The fracture toughness data from above experiments is compared with the $J_{in}$ obtained from predicted values of crack initiation point using potential drop method.

• Journal of Ocean Engineering and Technology
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• v.23 no.6
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• pp.87-92
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• 2009

The effect of aging on the precipitation of the $\sigma$ phase and the corrosion resistance in tungsten substituted super duplex stainless steels was investigated. The volume fraction of the $\sigma$ phase and the current density increased with aging at temperatures up to $750^{\circ}C$ and then decreased. With an increase in aging time, the volume fraction of the $\sigma$ phase and the current density also increased. The $\sigma$ phase hardly influenced the corrosion resistance. With the substitution of tungsten for molybdenum in super duplex stainless steel, the volume fraction of the $\sigma$ phase and the current density decreased remarkably.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.10 no.1
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• pp.82-89
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• 2014

In this study, the metallurgical analysis and mechanical property measurement have been performed to investigate the effect of long-term thermal aging on the microstructural evolution in the fusion boundary region between weld metal and low alloy steel in dissimilar metal welds. A representative dissimilar weld mock-up made of Alloy 690-Alloy 152-A533 Gr. B was fabricated and aged at $450^{\circ}C$ for 2,750 hours. The microstructural characterization was conducted mainly near in a weld root region by using optical microscopy, scanning electron microscopy, transmission electron microscopy. And the mechanical properties were measured with Vickers microhardness test and nanoindentation method. A steep gradient was shown in the chemical composition profile across the interface between A533 Gr. B and Alloy 152. Type-II boundaries were found in weld side of DMW and the hardness was the highest at the narrow zone between Type-II boundary and fusion boundary.