• 제목/요약/키워드: High temperature salt

검색결과 415건 처리시간 0.032초

Ti-6Al-4V의 피로균열성장거동에 관한 연구(I) (A Study on the Fatigue Crack Growth Behavior in Ti-6Al-4V Alloy(I))

  • 우흥식;한지원
    • 한국안전학회지
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    • 제16권4호
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    • pp.52-57
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    • 2001
  • Fatigue crack growth behaviour of Ti-6A-4V alloy is investigated in air and salt solution environment at room temperature and $200^{\circ}C$. Fatigue crack growth rate is blown to be fast for the formation of corrosive product in hot salt environment. For the effect on corrosion fatigue crack growth behaviour of region II. fatigue crack growth rate in atmosphere had a little gap to both case, $200^{\circ}C$ and room temperature. However, it showed very fast tendency in salt corrosive atmosphere, and it was remarkably accelerated in $200^{\circ}C$ temperature salt environment. When $\Delta$K was approximately 30MPa(equation omitted), fatigue crack growth rate had a little difference between at room temperature and at $200^{\circ}C$ high temperature, however in case of salt corrosive environment the room temperature was 3.5 times Inter and $200^{\circ}C$ high temperature for 16 times than air environment respectively.

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800℃ 용융염 환경에서 부식된 재료의 마모 성능 평가 (Evaluation of Wear Performance of Corroded Materials in an 800℃ Molten Salt Environment)

  • 최용석;박경렬;강성민;김운성;정경은;이지하;하태웅;이경준
    • Tribology and Lubricants
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    • 제40권3호
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    • pp.97-102
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    • 2024
  • The next-generation Molten Salt Reactor is known for its high safety because it uses nuclear fuel dissolved in high-temperature molten salt, unlike traditional solid atomic fuel methods. However, the high-temperature molten salt causes severe corrosion in internal structural materials, threatening the reactor's safety. Therefore, it is crucial to investigate the high-temperature corrosion resistance and wear performance of materials used in reactors to ensure safety. In this study, the high-temperature corrosion resistances and wear performances of corrosion samples in a NaCl-MgCl2-KCl (20-40-40 [wt%]) molten salt are investigated to evaluate the applicability of economically viable stainless steels, 316SS and 304SS. Hastelloy C276 and a new alloy containing a small amount of Nb are used as reference samples for comparative analysis. The mass loss, mass loss rate per unit volume, and surface roughness of each sample are measured to understand the corrosion mechanisms. Scanning electron microscopy and energy-dispersive spectroscopy analyses are employed to analyze the corrosion mechanisms. Wear tests on the corroded samples are also conducted to assess the extent of corrosion. Based on the experimental results, we predict the lifespans of the materials and evaluate their suitability as candidate materials for molten salt reactors. The data obtained from the experiments provide a valuable database for structural materials that can enhance the stability of molten salt reactors and recommend high-temperature corrosion-resistant materials suitable for next-generation reactors.

Influence of Heat Treatment on the Physicochemical Property and Mineral Composition of Various Processed Salts

  • Han, Sung-Hee;Lee, Seog-Won;Rhee, Chul
    • Food Science and Biotechnology
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    • 제17권5호
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    • pp.1010-1015
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    • 2008
  • The effects of heat treatment on the physicochemical properties and mineral composition of sun-dried salt were investigated. The salts parched at high temperature were appeared the higher alkalinity and the lower oxidation-reduction potential (ORP) than the samples without heat treatment. The commercial salts (bamboo salt and yellow loess salt) and the sun-dried salt parched at high temperature had relatively higher sodium ion content (418-450 ppm) compared to that (418.0 ppm) of refined salt. The increase of calcium ion occurred in the salts parched at high temperature compared to the sun-dried salt without heat treatment, but the magnesium ion was vice versa. The commercial salt, yellow loess salt had highest turbidity (0.973) whereas sun-dried salt showed lowest level (0.097) among the tested samples. Turbidity of heat treatment samples decreased as solubility increased. The maximum concentration of dialyzed salt was reached after 4 hr regardless of various processed salts, but those had no difference significantly among the tested samples. The X-ray diffraction patterns of the parched sun-dried salts showed different peak intensity with common salts, and they were similar to the patterns of oxide salts, especially MgO. The maximum value (2.56%) of MgO appeared in the sun-dried salt parched at $1,400^{\circ}C$.

Employing high-temperature gas flux in a residual salt separation technique for pyroprocessing

  • Kim, Sung-Wook;Heo, Dong Hyeon;Kang, Hyun Woo;Hong, Sun-Seok;Lee, Sang-Kwon;Jeon, Min Ku;Hur, Jin-Mok;Choi, Eun-Young
    • Nuclear Engineering and Technology
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    • 제51권7호
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    • pp.1866-1870
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    • 2019
  • Residual salt separation is an essential step in pyroprocessing because its reaction products, as prepared by electrochemical unit processes, contain frozen residual electrolyte species, which are generally composed of alkali-metal chloride salts (e.g., LiCl, KCl). In this study, a simple technique that utilizes high-temperature gas flux as a driving force to melt and push out the residual salt in the reaction products was developed. This technique is simple as it only requires the use of a heating gun in combination with a gas injection system. Consequently, $LiNO_3-ZrO_2$ and $LiCl-ZrO_2$ mixtures were successfully separated by the high-temperature gas injection (separation efficiency > 93%), thereby demonstrating the viability of this simple technique for residual salt separation.

염(鹽)의 종류(種類)에 따른 격염구(隔鹽灸)의 열전달(熱傳達) 특성(特性)에 관한 실험적(實驗的) 연구(硏究) (The Experimental Study of Various Salts on the Characteristics of Heat Transfer in Indirect Moxibustion with Salt)

  • 이건목;이건휘;서은미
    • Journal of Acupuncture Research
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    • 제21권1호
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    • pp.119-135
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    • 2004
  • Objective: The purpose of this study is to investigate the mechanism and effect of moxibustion with salt objectively, to be used as the quantitative data through the measurement of temperature, and to grasp the thermodynamic characteristics of moxibustion with salt. Methods: We have selected of the moxibustion with salt of indirect moxibustion. We make a comparative study of the thermodynamic characteristics of moxibustion with salt as a kind of the 4 salt. We examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa. Results: 1. We make out that it is not significantly change the time of thermal conduction of moxibustion with salt as a kind of 4 salt. 2. The heating period of Refined Salt was long and that of Sun-dried Salt was a short time respectively. The heating period of maximum tamperature is high Sun-dried Salt, Mechanical Salt and Refined Salt orderly. Maximun heating speed in the heating period was $0.151{\sim}0.184^{\circ}C/sec$ and at the same tendency of the maximum temperature in the heating period. 3. The retaining period was shorter than the heating period respectively, that is 15~24% of the combustion time of in the heating period. We make out that it is not significantly different the time of the retaining period as a kind of 4 salt. The mean temperature of retaining period was $43.2{\sim}48.1^{\circ}C$, that was extraordinarily high temperature. 4. We make out that it is not significantly different the time of the cooling period as a kind of 4 salt. The cooling period was measured 223~233sec. Beacuse the same density and size of moxa combustion was made an experiment. 5. The effective combustion time of Refined Salt is longer(259sec) than that of Sun-dried Salt(173sec). It is significantly different the time of the combustion time as a kind of 4 salt. 6. It is significantly different the Sample deviation of the combustion time as a kind of 4 salt because of the water content of the 4 salt individually. Conclusions: As the base on this study, we obtained the conclusion as the follows. The salt of moxibustion with salt was fitted for Sun-dried Salt due to making to Mechanical Salt recently. The Refined Salt is composition rate to another and small size comparatively. So It was fitted for the salt of moxibustion with salt. It is necessary to study continuously about the more suitable moxibustion with salt and quantitative analysis about the moxibustion with salt.

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태양열 발전을 위한 고온 축열 물질의 열전달 특성 (Heat Transfer Characteristics of High Temperature molten salt storage for Solar Thermal Power Generation)

  • ;김기만;한귀영;서태범;강용혁
    • 한국태양에너지학회 논문집
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    • 제27권3호
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    • pp.63-69
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    • 2007
  • The heat transfer characteristics of inorganic salt for high temperature heat storage material of solar power system were examined. The inorganic salts employed in this study was a mixture of $NaNO_3$ and $KNO_3$ and the operating temperature range was determined by measuring the melting temperature with DSC and by measuring the thermal decomposition temperature with TGA. The heat transfer characteristics was qualitatively obtained in terms of temperature profiles of salt in the tanks during the heat storage and heat release process as a function of steam flow rates, steam inlet temperature and the inlet position of steam. The effects of steam flow rates and inlet temperature of steam were experimentally determined and the effect of natural convection was observed due to significant density difference with temperature.

고온숙성에 의한 저급육의 연도개선과 그 이용 (Tenderness Improvement and Utilization of Low Quality Meat by High Temperature Aging)

  • 성삼경
    • 한국식품과학회지
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    • 제21권4호
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    • pp.549-555
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    • 1989
  • 저급육인 한우숫소의 앞다리고기를 도살직후 $16{\pm}2^{\circ}C$에서 고온숙성하여 연도개선 효과를 검토하였다. 또한 24시간 고온숙성한 후, 재구성육을 조제하여 결착성 개선방법을 모색하였다. 시료의 처리는 소금(0, 0.5, 1.0%), pyrophosphate(0, 0.3, 0.5%)와 이들의 혼용효과를 검토하였고, 소금(0.5%)과 pyrophosphate(0.3%)를 혼용한 원료에 succinic anhydride(0, 0.1, 0.2, 0.3%)를 첨가하여 석시닐산의 첨가효과를 검토하였다. 얻어진 결과는 다음과 같다. 1. 고온숙성은 저온숙성에 비하여 전단력이 낮았고, 근원섬유소편화지수가 높았으며, 연도개선의 효과가 뛰어났다. 전자현미경에 의한 형태학적 변화의 결과도 이들 결과 일치하였다. 2. 재구성육의 파단응력은 소금과 인산염의 첨가수준이 증가할수록 높아졌고, 소금과 인산염을 혼용할 경우, 현저히 증가하였다. 3. 조리수율은 소금과 인산염의 첨가수준이 증가할수록 낮아졌고, 소금과 인산염을 혼용할 경우, 현저하게 감소하였다. 4. TBA가는 소금 첨가수준에 비례하여 증가하였으며, 인산염 및 인산염과 소금혼용의 경우는 약간 증가하는 경향이었다. 5. 석신산은 재구성육의 결착력과 품질개선에 전혀 도움이 되지 않았다.

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페라이트계 스테인리스강의 고온염 부식특성에 관한 연구 (High Temperature Salt Corrosion Property of Ferritic Stainless Steels)

  • 송전영;박중철;안용식
    • Journal of Advanced Marine Engineering and Technology
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    • 제33권6호
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    • pp.860-866
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    • 2009
  • It is very important to choose optimal material having good corrosion resistance and capabilities for the part materials such as the automotive exhaust system under a hot salt corrosion atmosphere. Generally, two types of corrosion come into the automotive exhaust system. One is 'Condensate Corrosion', which is occurred by exhaust gas condensate formed at the inner surface of exhaust system heated up during driving, which results in the acid condensate pitting. The other is 'High Temperature Salt Corrosion' occurring from the interaction between the chloride ion coming from salt at the seaside district or snow salt and the outer surface of exhaust system. By the corrosion attack, the main muffler is firstly damaged and the life cycle of an automobile is significantly decreased. It has been investigated that the hot salt corrosion properties of a STS 409L and 436L ferritic stainless steels which are well-known for the materials of the automotive exhaust system. In addition, the corrosion properties of hot dip aluminum coated STS 409L have been compared with uncoated steels. Aluminum coated STS 409L showed a superior corrosion resistance than uncoated STS 409L, and futhermore showed a better corrosion resistance than a STS 436L, which is an expensive ferritic stainless steel having a excellent corrosion resistance caused from more chromium content of an alloying element.

금속도 공구강의 기계적 성질에 미치는 진공열처리와 염욕열처리 조건의 영향 (Effects of Vacuum Heat Treatment and Salt bath Heat Treatment Conditions on Mechanical Properties of High Speed tool Steel)

  • 김제돈;김경식
    • 열처리공학회지
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    • 제26권1호
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    • pp.7-13
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    • 2013
  • Vacuum heat treatment(indirect heating method) has long exposure time at high temperature and low quenching rate. Contrarily salt bath heat treatment (direct heating method) has short exposure time at high temperature and fast cooling rate. With these different features of processes, mechanical properties such as hardness, tensile strength and impact strength of products show very different results. In this study, Salt bath heat treated products showed higher tensile strength and impact strength than vacuum heat treated products but hardness was not much different. These lower mechanical properties of vacuum heat treated products are due to differences in heat process and secondary hardening with high temperature tempering process. Consequently, It indicates that salt bath heat treatment is better way than vacuum heat treatment for product to have high mechanical properties.

Effect of Different Salt Concentrations and Temperatures on the Lactic Acid Fermentation of Radish Juice

  • Kim, Soon-Dong;Kim, Mee-Kyung;Ku, Yeun-Soo
    • Preventive Nutrition and Food Science
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    • 제4권4호
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    • pp.236-240
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    • 1999
  • The characteristics of natural lactic acid fermentation of radish juice were investigated at different salt concentrations (0~2%) and temperatures (10~3$0^{\circ}C$). Major lactic acid bacteria isolated from the radish juice fermented at 2% slat concentration were Leuconostoc mesenteroides, Lactobacillus plantarum, and Lactobacillus brevis. The percentage of lactic acid bacteria against total microbe in the fermented radish juice was over 80% at 0~1% salt concentrations, suggesting the possibility of fermentation even at low salt concentration, but was still active even at 1$0^{\circ}C$. The time to reach pH 4.0 during fermentation of juice of 1% salt concentration was 281~301 hrs at 1$0^{\circ}C$ and 50-73 hrs at 3$0^{\circ}C$. The concentrations of sucrose and glucose in the fermented juice were low at high temperatures and were the lowest at a 1.0% salt concentration. However, the content of mannitol showed the opposite trend. Although sour taste, ripened taste, and acidic odor of the fermented juice showed no significant differences among various temperatures and salt concentrations, sensory values of ripened taste and sour acidic were high at high temperatures. The overall quality was the best at 1.0% salt concentration, irrespective of the temperature.

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