• Title, Summary, Keyword: Vanadium addition

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Strengthening of Steel by Small Addition of Nb. V. etc.

  • Imai, Yunoshin;Shono, Yoshio
    • Nuclear Engineering and Technology
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    • v.2 no.4
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    • pp.279-287
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    • 1970
  • An an element vanadium is most effective and next is noibium to strengthening the low carbon steels by small addition both on fine precipitation and five grain. The combination effect of vanadium plus niobium or vanadium plus molybdenum is much more effective than adding on element.

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A Study on the Leaching of Vanadium and Nickel from Heavy Oil Fly Ash (중유회로부터 바나듐과 니켈 침출에 관한 연구)

  • 박경호
    • Journal of the Korean Institute of Resources Recycling
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    • v.1 no.1
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    • pp.29-36
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    • 1992
  • The extration of vanadium and nickel from heavy oil fly ash was carried out by using water ans sulfuric acid as leaching agent. In the leaching with water, vanadium and nickel were extracted 86% and 88% respectively under pulp density of 25g/l, room temperature and leaching time of 60 minutes, but extraction of vanadium decreased with increasing leaching time. Addition of oxidant decreased the extractions of vanadium and nickel, and roasting of fly ash at temperature higher than $300^{\circ}C$ before water leaching decreased the vanadium extraction to about zero. In the leaching with 1N sulfuric acid, the extractions of vanadium and nickel both increased to 96% and the addition of oxidant did not affect the extraction of these metals.

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Synthesis and Thermoelectric Properties of the B-Site Substituted SrTiO3 with Vanadium

  • Khan, Tamal Tahsin;Mahmud, Iqbal;Ur, Soon-Chul
    • Korean Journal of Materials Research
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    • v.27 no.8
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    • pp.416-421
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    • 2017
  • V-substituted $SrTiO_3$ thermoelectric oxide materials were fabricated by the conventional solid state reaction method. From X-ray diffraction pattern analysis, it can be clearly seen that almost every vanadium atom incorporated into the $SrTiO_3$ provided charge carriers. The electrical conductivity ${\sigma}$, Seebeck coefficient S, and thermal conductivity k were investigated in a high temperature regime above 1000 K. The addition of vanadium significantly reduced the thermal conductivity and enhanced the Seebeck coefficient, as well as the electrical conductivity, thus enhancing the ZT value. A maximum ZT value of 0.084 at 673 K was observed for the sample with 1.0 mole% of vanadium substitution. In this study, the reason for the enhanced thermoelectric properties via vanadium addition was also investigated.

Effects of Mo, V addition on Linear Thermal Expansion Coefficient and Hardness of Low Thermal Expansion Cast Steel (주강계 저열팽창 주조합금의 열팽창 계수와 경도에 미치는 Mo, V 첨가의 영향)

  • Kim, Young-Han;Yoon, Eui-Park;Moon, Byoung-Moon;Hong, Young-Myung
    • Journal of Korea Foundry Society
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    • v.18 no.5
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    • pp.467-473
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    • 1998
  • For enhancing the mechanical properties of LTE (low thermal expansion) cast steel, systematic researches have been carried out. The effects of alloying elements such as vanadium, molybdenum and carbon on the hardness and linear thermal expansion coefficient were investigated. In the range of $0.5{\sim}2.3\;wt%$ carbon, addition of 1.73 wt% carbon caused hardness increase due to the formation of eutectic carbide having high hardness but over the range of 1.73 wt% carbon, hardness was decreased. Thermal expansion coefficient increases with carbon contents. In the LTE cast steel containing 0.6 wt% carbon, hardness increased up to 1.96 wt% vanadium addition. But over the range of 1.96 wt% vanadium hardness was decreased by coarse eutectic carbide. Thermal expansion coefficient of LTE cast steel containing 0.6 wt%carbon moderately increased with increasing vanadium contents. There was no significant variation of hardness and thermal expansion coefficient according to molybdenum content in LTE cast steel.

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The Influence of Vanadium Addition on Fracture Behavior and Martensite Substructure in a Ni-36.5at.%Al Alloy (Ni-36.5at.%Al 합금에서 V 첨가가 파괴거동 및 마르텐사이트 내부조직에 미치는 영향)

  • Kim, Young Do;Choi, Ju;Wayman, C. Marvin
    • Analytical Science and Technology
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    • v.5 no.2
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    • pp.203-211
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    • 1992
  • Fracture behavior and martensite substructure of Ni-36.5at.%Al alloy were investigated with the addition of vanadium which is known as scavenging element of grain boundary. The fracture surfaces were examined by scanning electron microscopy and the EDX spectrometer was applied for composition analysis of fracture surfaces. The substructure of martensite was studied by transmission electron microscopy. By addition of vanadium, fracture surfaces show mixed modes of intergranular and transgranular fracture and more Al content is found on the grain boundaries. For Ni-36.5at.%Al alloy, the planar faults observed in the martensite plates are the internal twins. By increasing the vanadium content, the modulated structure with stacking faults and dislocations dominates while the twinned martensite disappears. The stacking fault is determined to be extrinsic due to the substitution of V for Al. It is concluded that the segregation of sulfur on the high-energy state stacking fault area suppresses the intergranular fracture.

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Effect of Vanadium Addition on the Cavitation Erosion Resistance of Fe-Cr-Ni-Si-C Hardfacing Alloy (Fe-Cr-Ni-Si-C계 경면처리 합금의 Cavitaon Erosion 저항성에 미치는 Vanadium 첨가의 영향)

  • 김경오;김준기;장세기;김선진;강성군
    • Journal of the Korean institute of surface engineering
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    • v.31 no.5
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    • pp.297-303
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    • 1998
  • The influences of vanadium addition on the cavitation erosion resistance pf Fe-Cr-Ni-Si-C hardfacing alloy were investigated using a vibratory apparatus up to 30 hrs. It was shown that 1wt.%V additioned alloy improved the resistance to cavitation damage. However, further increase in V content up to 2wt.% reduced the cavitation erosion resistance. It was considered that the addition of V developed the cavitation erosion resistance by reducing the stacking fault energy of Fe-Cr-Ni-Si-C alloy. However, the further increase in V content seemed to reduce the cavitation erosion resistance by increasing the matrix/carbide interfacial area, which was the preferential sites of the cavitation damage.

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Improvement of bolometric properties of vanadium oxide by addition of tungsten (텅스텐 첨가에 의한 적외선 소자용 바나듐 옥사이드의 특성 향상)

  • Han, Yong-Hui;Choi, In-Hun;Kim, Geun-Tae;Shin, Hyeon-Jun;Chi, En;Moon, Seong-Uk
    • Proceedings of the Materials Research Society of Korea Conference
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    • pp.207-207
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    • 2003
  • Uncooled infrared(IR) detectors that use a microbolometer with a large focal-plane array(FPA) have been developed with surface micromachining technology. There are many materials for microbolometers, such as metals, vanadium oxide, semiconductors and superconductors. Among theses, vanadium oxide is a promising material for uncooled microbolometers due to it high temperature coefficient of resistance(TCR) at room temperature. It is, however, is very difficult to deposit vanadium oxide thin films having a high TCR and low resistance because of the process limits in microbolometer fabrication. In general, vanadium oxides have been applied to microbolometer in mixed phases formed by ion beam deposition methods at low temperature with TCR in the range from -1.5 to -2.0%K.

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NMR Studies on the Isomerization of Vanadium(V)-Propylenediaminetetraacetate Complex in Solution

  • Han, Sang-Gyu;Park, Sam-Soo;Lee, Man-Ho;Park, Heai-Ku
    • Bulletin of the Korean Chemical Society
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    • v.25 no.1
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    • pp.106-108
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    • 2004
  • In this paper we have determined the thermodynamic parameters for the isomerization between the ${\alpha}$-cis and the ${\beta}$-cis isomers in vanadium(V)-propylenediaminetetraacetate complex in water by $^{51}V$ NMR spectroscopy. In addition, the effects of organic solvents (methanol, formamide and dimethylsulfoxide) and inorganic salts (NaCl, $NaClO_4\;and\;NH_4Cl$) on the isomerization in solution have been investigated.

Electrochemical Behavior of Vanadium Trungsten Oxide Thin Films Deposited by Sputtering (스퍼터링으로 증착한 바나듐 텅스텐 산화물 박막의 전기화학적 거동)

  • 박영신;이병일;주승기
    • Journal of the Korean institute of surface engineering
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    • v.30 no.2
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    • pp.121-127
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    • 1997
  • Vanadium tungsten oxide thin films were formed by RF magnetron sputtering and the effects of tungsten addition on the crystallinity and on the electrochemical behavior were investigated. X-ray analysis revealed that amorphized films could be obtained by tungase addition. In order to investigate the electrochemical behavior of the vanadium tungsten oxide films, electrochemical insertion and extraction of lithium were out in 1m $LiCIO_4$-PC-DME electrolyte using litium metal as a counter electrode. When the tungsten was added to the $V_2O_5$ films, cycling reversibility was considerably improved. Electrochemical test showed the cell capacity of about $70\mu\;Ah/\textrm{cm}^2-\mu\textrm{m}$ when the amount of additive tungseten reached 30 atomic percent. No appreciable degradation of the cell capacity could be observed after hundred cycles of insertion and extration od Li.

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