• 연구논문집
• /
• 통권33호
• /
• pp.167-174
• /
• 2003

Alloy 713LC was developed to improve the tensile strength and ductility by reducing the carbon content of Alloy 713C. As Alloy 713LC was designed to minimize the mechanical property change with process conditions, it is generally utilized in the parts which have thick and thin sections simultaneously. In the thick and the thin sections, quite different properties are required. Consequently it is essential to crucially control the local mechanical properties of a parts by optimizing the process condition and heat treatment. In this research, high temperature mechanical properties including creep-rupture and strain-control low cycle fatigue were investigated together with the microstructural variations with heat treatment. Failure mechanism was also analyzed by observing the fracture surface to correlate the variation of mechanical properties with the microstructural change.

• 한국해양공학회지
• /
• 제19권2호
• /
• pp.53-59
• /
• 2005

The effect of pH on the corrosion characteristics in the dissimilar friction welded zone of IN713LC-SCM440 in the loaded torsional stress was studied. The corrosion experiment was performed for 120 hours on the specimens with five steps of pH. The surface corrosion pattern of the SCM440 area showed global corrosion and narrow pitting, which was caused by galvanic corrosion between friction welded IN713LC and SCM440, but corrosion did not proceeded from the IN713LC area. The average relative electrode potential gradually tends to decrease with the elapse of the immersion time in the acidity area. The average corrosion current also gradually tend to decrease The corrosion rate showed a larger value when the average relative electrode potential was higher and the average relative current was lower. The corrosion rate showed a larger value when the average relative electrode potential was higher in the acidity area, and it showed large when the average relative electrode potential was lower in the alkalinity area.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2003년도 추계학술대회논문집
• /
• pp.207-210
• /
• 2003

The purpose of this work is to find an appropriate welding approach for rotor assembly of a marine turbocharger. The friction welding and laser welding of dissimilar materials, IN713LC and SCM440 were investigated. The quality of the welded joints obtained from two welding processes was evaluated by microstructure observation, micro-hardness and tensile tests. The friction welded joint indicated a good bonding structure in the weld interface. On the other hand, the laser welded joint showed the weld defects and non-welded area in the weld interface.

• 한국재료학회지
• /
• 제16권9호
• /
• pp.557-563
• /
• 2006

The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. So, it is essential to choose the optimum material for the process equipment handling molten salt. In this study, corrosion behavior of Inconel 713LC, MA 754, X-750 and 718 in the molten salt $LiCl-Li_2O$ under an oxidizing atmosphere was investigated at $650^{\circ}C$ for $72{\sim}216$ hours. Inconel 713LC alloy showed the highest corrosion resistance among the examined alloys. Corrosion products of Inconel 713LC were $Cr_2O_3,\;NiCr_2O_4$ and NiO, and those of Inconel MA 754 were $Cr_2O_3\;and\;Li_2Ni_8O_{10}$ while $Cr_2O_3,\;NiFe_2O_4\;and\;CrNbO_4$ were produced from Inconel 718. Also, corrosion products of Inconel X-750 were found to be $Cr_2O_3,\;NiFe_2O_4\;and\;(Cr,Nb,Ti)O_2$. Inconel 713LC showed local corrosion behavior and Inconel MA 754, 718, X-750 showed uniform corrosion behavior.

• 대한금속재료학회지
• /
• 제46권9호
• /
• pp.577-584
• /
• 2008

The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. So, it is essential to choose the optimum material for the process equipment handling molten salt. In this study, corrosion behavior of Inconel 713LC, Inconel MA 754, Nimonic 80A and Nimonic 90 in the molten salt $LiCl-Li_2O$ under an oxidizing atmosphere was investigated at $650^{\circ}C$ for 72~216 hrs. Inconel 713LC alloy showed the highest corrosion resistance among the examined alloys. Corrosion products of Inconel 713LC were $Cr_2O_3$, $NiCr_2O_4$ and NiO, and those of Inconel MA 754 were $Cr_2O_3$ and $Li_2Ni_8O_{10}$ while $Cr_2O_3$, $LiFeO_2$, $(Cr,Ti)_2O_3$ and $Li_2Ni_8O_{10}$ were produced from Nimonic 80A. Also, corrosion products of Nimonic 90 were found to be $Cr_2O_3$, $(Cr,Ti)_2O_3$, $LiAlO_2$ and $CoCr_2O_4$. Inconel 713LC showed local corrosion behavior and Inconel MA 754, Nimonic 80A, Nimonic 90 showed uniform corrosion behavior.

• 동력기계공학회지
• /
• 제9권1호
• /
• pp.50-56
• /
• 2005

The corrosion experiment was performed for 120 hours on the specimens in the natural seawater tank with four steps of the loaded torsional stress. The surface corrosion pattern of SCM440 area was showed global corrosion and narrow pitting, that was cause by galvanic corrosion between friction welded IN713LC and SCM440. But corrosion does not proceeded from IN713LC area. Initially, the average relative electrode potential and corrosion current were decreased suddenly, by and large, it was stabilized gradually tend to decreasing with the elapse of the immersion time. The corrosion rate was decreased by increasing the load stress, but 200 MPa specimen was showed most large value.

• 한국도서관정보학회지
• /
• 제41권2호
• /
• pp.147-169
• /
• 2010

이 연구는 LCSH에 수록된 주제명표목 가운데 한 중 일 관련 주제명의 변천과정 및 특성을 LCSH 초판 (1914)부터 제31판(2009)까지 종합적으로 비교 분석하여 <표 1>과 <표 2>에 제시하였다. 분석결과 LCSH 초판에서는 한 중 일 관련 주제명이 각각 4개, 49개, 24개였지만 제31판에서는 713개, 1,742개, 2,647개로 늘어났으며, 한국의 '6.25 전쟁'과 '3개의 국가명'(1948년 이전, 남한, 북한), 일본의 '사적'과 '다도', 중국의 '소수민족 관련 언어 및 문학'과 '무역' 등이 특징적인 주제명으로 나타났다. 한편 한국 관련 주제명이 누락되었거나 세목이 부족한 것은 전적으로 LC의 장서수집 정책과 관련이 있지만 필요한 한국 관련 문헌이 LC에 골고루 많이 수집될 수 있도록 기증을 하는 등 우리의 보다 적극적인 노력이 필요하다고 생각된다.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2005년도 추계학술발표회
• /
• pp.219-220
• /
• 2005

• 대한금속재료학회지
• /
• 제46권10호
• /
• pp.646-651
• /
• 2008

The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. It is essential to choose the optimum material for the process equipment handling molten salt. IN713LC is one of the candidate materials proposed for application in electrolytic reduction process. In this study, yttria-stabilized zirconia (YSZ) top coat was applied to a surface of IN713LC with an aluminized metallic bond coat by an optimized plasma spray process, and were investigated the corrosion behavior at $675^{\circ}C$ for 216 hours in the molten salt $LiCl-Li_2O$ under an oxidizing atmosphere. The as-coated and tested specimens were examined by OM, SEM/EDS and XRD, respectively. The bare superalloy reveals obvious weight loss, and the corrosion layer formed on the surface of the bare superalloy was spalled due to the rapid scale growth and thermal stress. The top coatings showed a much better hot-corrosion resistance in the presence of $LiCl-Li_2O$ molten salt when compared to those of the uncoated superalloy and the aluminized bond coatings. These coatings have been found to be beneficial for increasing to the hot-corrosion resistance of the structural materials for handling high temperature lithium molten salts.

• 방사성폐기물학회지
• /
• 제8권1호
• /
• pp.33-39
• /
• 2010

산화물 사용 후 핵연료를 처리하는 전해환원공정에서는 LiCl 용융염계에서 산소가 생성되는 반응을 수반하게 되며, 생성된 산소로 인해 반응기의 구조재료를 상당히 부식시킬 수 있는, 화학적으로 심각한 반응환경을 조성한다. 따라서, 고온 용융염을 다루는 전해환원 공정장치를 위해서는 최적의 재료를 선택하는 것이 필수적이다. 본 연구에 서는 리튬용융염, $675^{\circ}C$, 216시간동안 산화분위기에서 코팅이 안 된 초합금과 코팅된 초합금 시편의 고온 부식연구를 수행하였다. IN713LC 초합금 시편에 aluminized NiCrAlY bond 코팅 후 $Y_2O_3$ top 코팅을 하였다. 코팅이 안 된 초합금은 부식층의 빠른 성장응력과 열적응력에 의한 부식층의 박리로 명확한 무게손실을 보인다. 탑 코팅의 화학적 및 열적 안정성으로 인해 고온 리튬용융염을 다루는 구조재료의 부식 저항성이 증가함을 확인할 수 있었다.