Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 55, Issue 12
Displaying 1-9 of 9 articles from this issue
  • [in Japanese]
    1969 Volume 55 Issue 12 Pages 963-964
    Published: October 01, 1969
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • Tsuzuru NUIBE, Nobuo SANO, Yukio MATSUSHITA
    1969 Volume 55 Issue 12 Pages 965-980
    Published: October 01, 1969
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    Chemical transport reactiOn of silicon from a sintered silicon carbide disc to Fe-C melt by SiO gas medium at 1450 to 1600°C was investigated in the view of kinetics.
    The results were interpreted by a mass transport equatiOn derived from the mixed control theory, topochemical reactiOn theory and unreacted core model. Numerical values of all coefficients included in the equatiOn were experimentally determined as follows._??_
    The most important factor for the silicon transfer by gaseous medium was found to be an activity of carbon in Fe-C melt. Therefore, the possibility of gaseous silicon absorptiOn into freely falling liquid'iron droplets in a blast furnace was concluded to depend upon the carbon content in droplets.
    The derived general equatiOn is expected to be applicable to other conditiOns than experimentally undertaken.
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  • Kiichi NARITA, Toshio ONOYE, Katsutoshi IWAMOTO
    1969 Volume 55 Issue 12 Pages 981-1006
    Published: October 01, 1969
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
    Electro-slag remelting is one of the most suitable processes for the production of special steels.
    In order to clarify the refining reactions of the process, carbon steels with further addition of various alloying elements and some commercial steels were remelted in a small scale furnace.
    Further, to confirm the effect of electro-slag remelting on the mechanical properties of steels and to examine the industrialization of the process, stainless steels, low alloy steels, high speed steels and bearing steels were remelted in a large scale furnace. The results are as follows:
    (1) Under same proper conditions, the remelted ingot shows a good skin condition and has homogeneous structures.
    Moreover, the segregation, the size and amounts of the non-metallic inclusions are reduccd.
    (2) Using CaF2-based slags, even in the case of the electrode of 0 01% S, the desulphurization reaction is observed.
    (3) In the mechanical properties of the electro-slag remelted steels, the ductility in the transverse direction increases noticeably, namely, the anisotropy reduces. For the high speed steel and the bearing steel, improvement of tool life and bearing life are respectively expected.
    (4) The use of cast electrode and returned slag in the electro-slag remelting causes the cost down of the process.
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  • Kazuhiro GOTO, Minoru SASABE, Masahiro KAWAKAMI, Mayumi SOMENO, Yukio ...
    1969 Volume 55 Issue 12 Pages 1007-1029
    Published: October 01, 1969
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    An oxygen concentration cell with zirconia and lime electrolyte has two characteristics in its performance at elevated temperature; First, the cell shows good reversibility against the change of oxygen pressure and temperature at the interface of the solid electrolyte and the electronic-conductor electrode. Second, the response time of the electromotive force is very short against the change of oxygen pressure and temperature.
    The two characteristics have been applied to kinetic study of heterogeneous reactions at elevated temperature as follows:
    (1) Gas composition profiles in the vicinity of the reaction surface have been continuously measured during the decarburization of liquid iron by carbon dioxide gas at 1550°C. It was shown that there is concentration gradient of carbon dioxide in the vicinity of the reaction surface and the gas phase is in unstable motion under the present experimental condition.
    (2) Intraparticle gas composition of metal oxide powders has been continuously measured during the reduction by hydrogen gas and carbon monoxide gas. The change of the electromotive force demonstrated the step-wise change of the intraparticle gas composition in relation to the two intermediate phases equilibria.
    (3) The rate of the change of oxygen pressure in the liquid metal and liquid oxide phases has been measured, when the oxygen pressure in the gas phase is quickly changed.
    The micromechanism of the reactions under consideration was discussed from both results obtained by the electromotive force method and by other methods.
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  • Shigeo ASAI, Iwao MUCHI
    1969 Volume 55 Issue 12 Pages 1030-1040
    Published: October 01, 1969
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    In order to predict the differences in process variables which would be caused by altering operating conditions, a part of the mathematical model of oxygen top blowing converter proposed previously has been modified, and on the basis of this modified model, numerical calculations have been conducted with the aid of digital computer (HITAC 5020E) for various operating conditions. The operating conditions considered to alter in this work are as follows:
    1) feeding conditions of ore, lime and limestone, 2) back pressures of oxygen, 3) temperatures and carbon concentrations of pig iron charged into converter.
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  • Zenji NISHIYAMA
    1969 Volume 55 Issue 12 Pages 1041-1050
    Published: October 01, 1969
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • Kimio KIMURA, Akira SAKAMOTO
    1969 Volume 55 Issue 12 Pages 1051-1070
    Published: October 01, 1969
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1969 Volume 55 Issue 12 Pages 1071-1086
    Published: October 01, 1969
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    Download PDF (6351K)
  • 1969 Volume 55 Issue 12 Pages 1087-1102
    Published: October 01, 1969
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
    Download PDF (5342K)
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