• 제목/요약/키워드: corrosion products

검색결과 392건 처리시간 0.026초

용선예비처리용 $Al_2O_3-SiC-C$계 내화물 개발 (Development of $Al_2O_3-SiC-C$ Refractory for Hot Metal Pretreatment)

  • 김의호;이석한;이석향;서병길;박정민;이재옥
    • 한국세라믹학회지
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    • 제23권5호
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    • pp.86-92
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    • 1986
  • As there is a growing trend to make high quality steel improving production efficiency and utilizing slag as resources the technologies of hot metal pretreatment have been progressed to meet these demands. Although mill scale $Na_2CO_3$ and CaO used as fluxes proved to be excellent agents then can severely corrode refractories such as chamotte and high alumina for torpedo or open ladle car. Thus it was considered necessary to develop new refractories which can endure suchy conditions. Desulfurization fluxes vastly used in POSCO are $CaCO_3$ and CaO Recent trials have been made by testing phenol resin bonded $Al_2O_3-SiC-C$ bricks in torpedo ladle car for hot metal pretreatment. The results showed that the life of this brick became about 1.2 times longer than that of foreign products. And the crushing strength M.O.R corrosion resistance and oxidation resistance were tested.

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New Water-soluble Cutting Fluids Additives Derived from the Thermal Reaction Products of Unsaturated Fatty Acids with Acrylic Acid and Maleic Anhydride

  • Watanabe, Shoji
    • 한국응용과학기술학회지
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    • 제20권4호
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    • pp.372-376
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    • 2003
  • Water-soluble cutting fluids are used for processing of aluminium materials. This short article describes properties of new additives of water-soluble cutting fluids for aluminium materials. Various Diels-Alder adducts of unsaturated fatty acids with acrylic acid of maleic anhydride were prepared by thermal reactions. Triethanolamine salts of Diels-Alder adducts of dehydrated castor oil fatty acids with acrylic acid or maleic anhydride showed excellent anti-corrosion property of aluminium materals. These thermal adducts showed anti-rust property for cast-iron chips, too.

Physical/Chemical Characterization of Ordinary Portland Cement/Ground Granulated Blast Furnace Slag Pastes Containing Low Carbon Steel as Reinforcements

  • Hwang, Jin-Ha
    • 한국재료학회지
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    • 제13권2호
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    • pp.94-100
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    • 2003
  • The interface between low carbon steel and blended cement pastes containing slag was investigated using impedance spectroscopy. In addition, the pastes were characterized by several analytical methods (XRD, EDX, electrode potential, pH and ICP). The electrical behavior of the interface in the blended slag systems is correlated to its corresponding pore solution chemistry and the products present in the interface. Passivation occurred at the paste/steel interfaces, in cement pastes up to containing from 0 to 75% slag content. 100% slag paste induced corrosion of the low carbon steel, which could be explained by the influence of sulfur on the system.

Metal Injection Molding Process of $Mo_2FeB_2$ Boride Base Cermets

  • Tashiro, Hirofumi;Hirata, Kourou;Yamasaki, Yuji;Takagi, Ken-ichi
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.765-766
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    • 2006
  • [ $Mo_2FeB_2$ ] boride base cermets produced by a novel sintering technique, called reaction boronizing sintering through a liquid phase, have excellent mechanical properties and wear and corrosion-resistances. Hence, the cermets are applied to the injection molding die-casting machine parts and so on. We investigated that the effect of deoxidization and sintering temperature on mechanical properties and deformation of the MIM processed cermets. As a result, deoxidization temperature of 1323K and sintering temperature of 1518K were suitable. The MIM products of the cermets showed allowable dimensional accuracy and the same mechanical properties as the press-sintered ones.

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소장 금속유물의 과학적 보존처리-보물 제930호 및 이완장군 유품을 중심으로 (Scientific study for conserving ancient metallics antiques-Pole(Treasure No. 930) and Helmet(General of Lee Wan))

  • 문환석;정기정;김선덕
    • 보존과학연구
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    • 통권16호
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    • pp.1-17
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    • 1995
  • We conserved efficiently artifacts such as Pole(Treasure No. 930)and Helmet(General of Lee, Wan:1602∼1674) which are housed in the historical department, Kyonggi-do provincial office. It were carrying out physical and chemical methods for removing corrosion products at the same time. During the treatment, the spear was proved to coat gold amalgam on the surface and the pole restored its original state as a result using X-ray fluorescence analysis and Radiography, in addition, we could find their skill and technology by examining the section painted lacquer with wooden by microscopy.

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Theoretical study of cross sections of proton-induced reactions on cobalt

  • Yigit, Mustafa
    • Nuclear Engineering and Technology
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    • 제50권3호
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    • pp.411-415
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    • 2018
  • Nuclear fusion may be among the strongest sustainable ways to replace fossil fuels because it does not contribute to acid rain or global warming. In this context, activated cobalt materials in corrosion products for fusion energy are significant in determination of dose levels during maintenance after a coolant leak in a nuclear fusion reactor. Therefore, cross-section studies on cobalt material are very important for fusion reactor design. In this article, the excitation functions of some nuclear reaction channels induced by proton particles on $^{59}Co$ structural material were predicted using different models. The nuclear level densities were calculated using different choices of available level density models in ALICE/ASH code. Finally, the newly calculated cross sections for the investigated nuclear reactions are compared with the experimental values and TENDL data based on TALYS nuclear code.

알루미나 세라믹스 순도에 따른 수윤활기구에 관한 연구 (Effect of Purity of Alumina Ceramics on the Water Lubrication Mechanism)

  • 진동규;박흥식;전태옥
    • Tribology and Lubricants
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    • 제11권4호
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    • pp.13-20
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    • 1995
  • The present study was undertaken to investigate the purity variation of the alumina ceramics on the water lubrication mechanism. The annular surface of wear testing specimens of the alumina ceramics with different alumina purity against STB2 was rubbed in the distilled water under various sliding speed, contact pressure and sliding distance. The friction coefficient decreased lowered with formation of corrosion products due to the tribochemical reation as the sliding speed and contact load was increased. With increased sliding speed, the lower purity of 85 percent contribute largely to even degree of the friction surface, even it have about $\mu$ of 0.3 degree by the influence of a pore and impurities SiO$_{2}$. The friction surface of ceramics protacted by oxide was transfer from STB2.

A5083 합금의 머시닝센터 가공에서 표면거칠기 특성에 관한 실험적 연구 (Experimental Research on the Surface Roughness Characteristics in Machining Center Machining of A5083 Alloy)

  • 최진우
    • 한국기계가공학회지
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    • 제20권9호
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    • pp.57-62
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    • 2021
  • CNC machining is used to fabricate various components. This has led to the development of processing-based industries for the production of automobile, appliances, semiconductors, and rockets. Additionally, this machining has enabled economical mass production of high-quality products in industries. Magnesium alloy with a hexagonal closed packed configuration is prone to difficulties during plastic machining, has a high oxygen affinity, and exhibits poor corrosion resistance to seawater and the atmosphere. In this research, Al alloy A5083 was used to investigate and analyze the surface roughness with a certain depth of cut fixed by the machining center (DVM-500II) and various feed rates, speeds, and processing methods after modeling and simulated machining with Gibbs CAM.

Shielding analyses supporting the Lithium loop design and safety assessments in IFMIF-DONES

  • Gediminas Stankunas ;Yuefeng Qiu ;Francesco Saverio Nitti ;Juan Carlos Marugan
    • Nuclear Engineering and Technology
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    • 제55권4호
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    • pp.1210-1217
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    • 2023
  • The assessment of radiation fields in the lithium loop pipes and dump tank during the operation were performed for International Fusion Materials Irradiation Facility - DEMO-Oriented NEutron Source (IFMIF-DONES) in order to obtain the radiation dose-rate maps in the component surroundings. Variance reduction techniques such as weight window mesh (produced with the ADVANTG code) were applied to bring the statistical uncertainty down to a reasonable level. The biological dose was given in the study, and potential shielding optimization is suggested and more thoroughly evaluated. The MCNP Monte Carlo was used to simulate a gamma particle transport for radiation shielding purposes for the current Li Systems' design. In addition, the shielding efficiency was identified for the Impurity Control System components and the dump tank. The analysis reported in this paper takes into account the radiation decay source from and activated corrosion products (ACPs), which is created by d-Li interaction. As a consequence, the radiation (resulting from ACPs and Be-7) shielding calculations have been carried out for safety considerations.

Iron hydrolysis and lithium uptake on mixed-bed ion exchange resin at alkaline pH

  • Olga Y. Palazhchenko;Jane P. Ferguson;William G. Cook
    • Nuclear Engineering and Technology
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    • 제55권10호
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    • pp.3665-3676
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    • 2023
  • The use of ion exchange resins to remove ionic impurities from solution is prevalent in industrial process systems, including in the primary heat transport system (PHTS) purification circuit of nuclear power plants. Despite its extensive use in the nuclear industry, our general understanding of ion exchange cannot fully explain the complex chemistry in ion exchange beds, particularly when operated at or near their saturation limit. This work investigates the behaviour of mixed-bed ion exchange resin, saturated with species representative of corrosion products in a CANDU (Canadian Deuterium Uranium) reactor PHTS, particularly with respect to iron chemistry in the resin bed and the removal of lithium ions from solution. Experiments were performed under deaerated conditions, analogous to normal PHTS operation. The results show interesting iron chemistry, suggesting the hydrolysis of cation resin bound ferrous species and the subsequent formation of either a solid hydrolysis product or the soluble, anionic Fe(OH)3-.