• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.279-284
• /
• 2004

In this study, we suggested the ring creep test using the ring specimen of Arsene for estimating the burst creep properties of the cladding in stead of burst creep test. For this objective, we used the load-displacement conversion relationship of ring specimen called LCRR which had been determined on our previous study at high temperature by performing the ring tensile test and the numerical analysis. Then we carried out both the ring creep test and the burst creep test between 350 $^{\circ}C$ and 600$^{\circ}C$ which were higher then the in-service temperature of the cladding in a reactor. The creep properties from the ring creep test with applying LCRR were compared with those from the burst creep test of closed-end specimens. From the results, it could be seen an very strong relationship between them, especially in Larson- Miller parameter. So, it is expected that we can easily anticipate the creep properties of not only claddings but also various small pressure pipes using the ring creep test.

• 대한기계학회논문집A
• /
• 제29권7호
• /
• pp.964-969
• /
• 2005

In this study, we suggested the ring creep test using the ring specimen of Arsene for estimating the burst creep properties of the cladding in stead of burst creep test. For this objective, we used the load-displacement conversion relationship of ring specimen called LCRR which had been determined on our previous study at high temperature by performing the ring tensile test and the numerical analysis. Then we carried out both the ring creep test and the burst creep test between $350^{\circ}C$ and $600^{\circ}C$ which were higher than the in-service temperature of the cladding in a reactor. The creep properties from the ring creep test with applying LCRR were compared with those from the burst creep test of closed-end specimens. From the results, it could be seen an very strong relationship between them, especially in Larson-Miller parameter. So, it is expected that we can easily predict the creep properties of not only claddings but also various small pressure pipes using the ring creep test.

• 대한공업교육학회지
• /
• 제31권1호
• /
• pp.200-210
• /
• 2006

초기 응력부식균열에 대한 감수성 평가 시험법인 C링 시험법(C-ring Test)은 용접부의 후열처리 균열감수성을 평가하는 시험법으로 적합하다고 알려져 있다. C링 시험법은 실제 용접부 열영향부에 노치를 제작하여 잔류응력이 열영향부에 미치는 영향을 평가할 수 있다는 장점을 가지고 있다. 따라서 본 연구에는 C링 시험법을 이용하여 원자력 발전소 압력용기에 사용되는 Co-Mo강의 용접부 결함 발생 현상을 검토 하고자 Co-Mo강에 대하여 후열처리를 실시하였으며, C링 시험법을 통하여 용접 열영향부의 후열처리 균열을 평가하고자한다. 결론은 다음과 같다. 바나듐 모디파이 합금(AMAX 3Cr-1Mo­-0.1V, JSW 3Cr-­1Mo-­V-­Ti-­B 및 JSW $2\frac{1}{4}Cr$-1Mo-­V-­Ti-­B강)은 Berkeley $3Cr-1\frac{1}{2}Mo-\frac{1}{2}Ti$ 및 $2\frac{1}{4}Cr$-­1Mo합금강보다 후열처리 균열에 대한 감수성 보다 높게 나타났다. C-ring 시험에 있어서 바나듐 모디파이 합금은 2종의 후열처리조건과 3종의 응력조건에서 모두 균열을 나타냈으나 Berkeley $3Cr-1\frac{1}{2}Mo-\frac{1}{2}Ni$강과 Luken $2\frac{1}{4}Cr-1Mo0.1C$재료는 690MPa와 더 이상의 응력조건에서 2종의 후열처리를 실시하는 조건에서도 균열이 발생하지 않았다. C-ring 시험결과, 균열깊이는 바나듐 모디파이 재료인 경우, 낮은 후열처리온도와 비교해서 높은 후열처리온도인 경우가 감소하고 있다. C-ring 시험에 대한 SEM분석결과 균열은 오스테나이트 결정 입계를 따라 파괴되는 파괴양상을 나타내고 있으며 연성파면은 나타나지 않았다.

• Tribology and Lubricants
• /
• 제14권4호
• /
• pp.108-113
• /
• 1998

In order to investigate the characteristics of top ring groove deposit formation in diesel engine, engine test and simulation test were performed. From component analysis of used oils sampled from actual running engines, soot content in engine oil was selected as a main parameter for evaluating oil degradation. Deposit formation is highly related to soot content in lubricating oils. And high soot content oil accelerates deposit formation even in low temperature region below 26$0^{\circ}C$. In low temperature region below 26$0^{\circ}C$, deposit formation rate is mainly affected by top ring groove temperature. However, in high temperature region above 26$0^{\circ}C$, deposit formation rate is affected by soot content as well as top ring groove temperature. Therefore, soot content as well as top ring groove temperature should be kept a certain level in order to prevent troubles due to carbon deposit formation.

• Tribology and Lubricants
• /
• 제16권1호
• /
• pp.33-38
• /
• 2000

Abstract- In this paper tribological characteristics of solid and liquid phase sintered W/C-35%Ni tappets were investigated. Three test methods were performed to investigate the wear and surface damage mechanism of sintered tappets. First, block-on-ring wear test was performed to investigate the wear characteristics under pure sliding condition. Second, simplified cam and tappet tests (called component wear test hereafter) were carried out to simulate the real contact history of cam and tappet. Also, after the test, contact surfaces were analyzed with scanning electron microscope to study the wear mechanism. As a final screening, engine dynamo tests were performed. Results showed that in the block on ring sliding wear test, solid phase sintered specimens showed superior wear resistance to liquid phase sintered specimens. The component wear tests and engine dynamo tests also showed the same results. Therefore, in these tests, solid phase sintered tappet material revealed superior wear resistant properties to liquid phase sintered one.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 1992년도 제3회 학술발표회 논문개요집
• /
• pp.113-114
• /
• 1992

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 1998년도 특별강연 및 추계학술발표 개요집
• /
• pp.288-291
• /
• 1998

Inconel 600 alloy is used as the material of nuclear steam generator tubing because of its mechanical properties, formability, and corrosion properties. According to reports, the life time of nuclear power plants decreases because of the pitting, intergranular attack, primary water stress corrosion cracking(PWSCC), and intergranular stress corrosion cracking(IGSCC), and denting in the steam generator. The SCC test is very important because of SCC appears in various environment such as solutions, materials, and stress. The C-Rig specimen was made of the steam generator welded sleeve repairing by the pulsed Nd:YAG laser. In the corrosion invironment, corrosion solutions are Primary Water, Caustic, and Sulfate solution and corrosion time is 1624-4877hr. The permitted stress is 30-60ksi.In this C-Ring SCC test is the relationship between corrosion depth, crack and corrosion environment is evaluated. SCC was happens in Sulfate and Corrosion solution but doesn't happen in Primary Water. The corrosion time and stress is very affected by the severely environment of Sulfate or Caustic solution. The microstructure observation indicates that SCC causes interganular failure in the grain boundary of vertical direction.

• 대한수의학회지
• /
• 제9권2호
• /
• pp.55-59
• /
• 1969

For the establishment of simpler and more reliable methods for the diagnosis of Brucellosis, diagnostic antigen for Milk Ring Test (M.R.T.) was prepared according to working document recommended by Ministry of Agriculture U.S.A., and applied in the field for the test of its's applicability. The results are summarized as follows. 1. Of fifty two dairy cattle ranches in the vicinity of Seoul, five ranges were shown positive reaction to M.R.T. 2. Even though one volume of positive milk was mixed with five to ten volumes of negative milk, the positive reactions were also observed. 3. Antigenicity of the antigen was maintained without deteriolation for 13 months at $5^{\circ}C$ and three months at both $22^{\circ}C$ and $37^{\circ}C$. 4. Three positive cows to M.R.T. were also shown suspective reaction by Serum Agglutination Test.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제7권1호
• /
• pp.31-43
• /
• 2007

The function of O-ring seals is to prevent leakage during the service life of the components in which they are installed. The life prediction of O-ring is very important at various industry fields. Generally, to evaluated the long-term performance of O-ring in severe environments has applied a life prediction technique based on accelerated life test (ALT). In this work, Accelerated thermal aging test(l20, 130, 140, $150^{\circ}C$) of O-ring was applied for life prediction of O-ring. The property changes after thermal aging test was measured using TGA, DSC, FT - IR, Video Microscope and SEM. Shape parameter and life prediction were obtained using MINITAB program.

• 한국지반공학회논문집
• /
• 제16권6호
• /
• pp.35-41
• /
• 2000

Residual stress is defined as a minimum stress with a large displacement of specimens and the residual stress after peak shear stress appears with displacement volume but there is no provision to select the residual stress. In the previous study, residual stress was recorded when the change of shear load is small in the condition of the strain more than 15%. But, in this study, hyperbolic function((No Abstract.see full/text), b=experimental constant) of soil test is adapted to joint of rock and the propriety is investigated. In a landslide and landsliding of artificial slope, wedge failure of tunnel with a large displacement, tests are simulated from peak stress to residual stress for safety analysis. But now. direct shear stress and triaxial compressive tests are usually performed to find out characteristics of shear stress about joint. Although these tests get a small displacement, that data of peak stress and residual stress are used for safety analysis. In this study, we tried to determine failure criteria for joints of rock using ring shear test machine. The residual stress following shear behavior was determined by the result of ring shear test and direct shear test. In conclusion, after comparing the results of the two test, we found that cohesion(c) and internal friction angle(ø) of ring shear test are 30% and 22% respectively of those of the direct shear test.