• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.905-906
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• 2004

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.334-335
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• 2005

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.91-92
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• 2005

• Corrosion Science and Technology
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• 제6권4호
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• pp.170-176
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• 2007

Iodine-induced stress corrosion cracking (ISCC) properties and the associated ISCC process of Zircaloy-4 and an Nb-containing advanced nuclear fuel cladding were evaluated. An internal pressurization test with a pre-cracked specimen was performed with a stress-relieved (SR) or recrystallized (RX) microstructure at $350^{\circ}C$, in an iodine environment. The results showed that the $K_{ISCC}$ of the SR and RX Zircaloy-4 claddings were 3.3 and 4.8MPa\;m^{0.5}, respectively. And the crack propagation rate of the RX Zircaloy-4 was 10 times lower than that of the SR one. The chemical effect of iodine on the crack propagation rate was very high, which was increased $10^4$ times by iodine addition. Main factor affecting on the micro-crack nucleation was a pitting formation and its agglomeration along the grain boundary. However, this pitting formation on the grain-boundary was suppressed in the case of an Nb addition, which resulted in an increase of the ISCC resistance when compared to Zircaloy-4. Crack initiation and propagation mechanisms of fuel claddings were proposed by a grain boundary pitting model and a pitting assisted slip cleavage model and they showed reasonable results.

• Nuclear Engineering and Technology
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• 제42권2호
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• pp.193-202
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• 2010

In order to study the cladding properties of zirconium after a loss-of-coolant accident (LOCA)-simulation oxidation and water quenching test, commercial Zircaloy-4 and two kinds of HANA claddings were oxidized at temperatures ranging from $900^{\circ}C$ to $1250^{\circ}C$ and exposed for 300 s, and then cooled to $700^{\circ}C$ before quenching. Microstructural observations were made to evaluate the matrix characteristics with the chemical compositions after the LOCA-simulation test. Ring compression testing was then performed to compare the ductile behaviour of the HANA and Zircaloy-4 claddings. An X-ray diffraction (XRD) analysis was carried out for temperatures ranging from room temperature to $1250^{\circ}C$ for the oxide layer to verify the oxide crystal structure at each oxidation temperature.

• 한국표면공학회지
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• 제47권1호
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• pp.7-12
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• 2014

The characteristics of oxidation for the Zry-4 was measured in the $800^{\circ}C$ and high steam pressure (50 bar, 75 bar, 100 bar) conditions, using an apparatus for high pressure steam oxidation. The effect of accelerated oxidation by high-pressure steam was increased more than 60% in hydrogen-charged cladding than normal cladding. This difference between hydrogen charged claddings and normal claddings tends to be larger as the higher pressure. The accelerated oxidation effect of hydrogen charging cladding is regarded as the hydrogen on the metal layer affects the formation of the protective oxide layer. The creation of the sound monoclinic phase in Zry-4 oxidation influences reinforcement of corrosion-resistance of the oxide layer. The oxidation is estimated to be accelerated due to the creation of equiaxial type oxide film with lower corrosion resistance than that of columnar type oxide film. When tetragonal oxide film transformed into the monoclinic oxide film, surface energy of the new monoclinic phase reduced by hydrogen in the metal layer.

• 열처리공학회지
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• 제17권6호
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• pp.356-364
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• 2004

The hydrides in cladding affect the corrosion and tensile properties. In this study corrosion and tensile properties were evaluated with varying the hydrogen concentration. The charged hydrogen contents were ranged from 200 to 1000 ppm. The corrosion rate in water and LiOH solution increases with the hydrogen concentration. The hydride did not affect the corrosion mechanism in the pre-transition region, but in the post-transition region the corrosion rate was accelerated. Cladding E contained higher Niobium content was slowly accelerated compared with other claddings. The yield and ultimate strengths were independent on the hydrogen content. However, the total elongation decreased gradually with increasing the hydrogen content. SEM observation of fracture surface showed that an average of depth of voids decreased with increasing the hydrogen content and small secondary crack are observed.

• 대한건축학회논문집:구조계
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• 제34권11호
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• pp.3-10
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• 2018

Cladding that finishes the exterior of a building could enhance the value of the building, and shape control is an important factor. With the recent development of 3D printing, cementitious claddings were printed by 3D printer in China, U.S.A and elsewhere. On the other hand, the structural safety of the exterior panel should be examined, as casualties occur when the exterior panel fails due to typhoon or impact. Cement-based cladding is reinforced by wire mesh to improve safety. Introducing 3D printing composite system with polymer and cement, makes it possible to produce claddings fast and accurate. Prior to the development of 3D printing cementitious cladding, the major parameters influencing the optimal shape were identified based on structural performance. The wind load, joint, and bond behavior between polymer and cement were considered. Polymer laminate shape, order, and thickness were variables, and finite element analysis was performed.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.415-416
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• 2005

• 한국강구조학회 논문집
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• 제20권5호
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• pp.591-599
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• 2008

내후성강은 자연대기환경에 대하여 무도장 상태로 사용되고, 강재표면에 도막의 역할을 하는 밀실한 녹층은 자연환경에 의해 수년간 에 걸쳐 형성되며, 그 녹 층으로 강재의 부식 진행을 억제한다. 내후성강의 녹상태는 부식환경에 의존한다. 내후성강의 유지관리측면에서 녹상태가 어느정도 인가를 판단하는 것은 중요하다. 따라서, 국내에 있는 건축용 내후성 외장재의 외관조사결과를 바탕으로, 다변량해석에 의한 부식량(녹의 상태)과 외장재 주변환경과의 상관을 분석하고자 한다. 본 논문에서, 외장재의 지리적 데이터, 기상데이터를 이용한 다변량 분석이 수행되었고, 부식 량과 환경요인에 대한 예측식이 제안되었다. 부가적으로, 제안된 부식량 예측식을 이용하여 기호지역(서울, 경기 및 충청)에 적용한 건축용 내후성강 외장재의 부식량 추이를 평가하였다.