Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 50 , Issue 5
Showing 1-15 articles out of 15 articles from the selected issue
  • Kozo MORINAGA, Teruo IKENO, Iwao IWASAKI
    1964 Volume 50 Issue 5 Pages 743-752
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    Pelletizing and sintering have historically been developed out of the necessity of treating different types of raw materials, of which screen analyses define the respective fields of application; thus they act as supplementary rather than competitive methods.
    Diminishing supply of high-grade iron ores will call for the utilization of ores with wider variety, and the fines from beneficiation plants are expected to increase.In order to meet this situation more attention should be paid to the study of extending the fine limit of sintering, particularly on such processes as the semi-pellet sintering, the use of drum mixers and sintering with limestone addition.At the same time recognition of pellets as a superior blast furnace charge would call for consideration about the possibility of better utilizing even relatively coarse fines as ground to make pellets than as they are to make sinters.
    This article purports to make further consideration on raw material problems in the future such as the fine limit of sintering, the method of estimating the power consumption to grind three types of fines represented by magnetite, hematite and limonite to their respective optimum sizes for pelletizing, technical problems involved in pelletizing, and comparison of some physical and chemical properties of pellets and sinters.On the basis of the present study it may be concluded that, if they are fired at optimum temperatures, pellets will aquire better quality than sinters with respect to bulk density, strength, reducibility, strength under reduction, etc., and particularly self-flux pellets will show much promise as blast furnace charge.
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  • Ryozo SATO, Nofu TABATA
    1964 Volume 50 Issue 5 Pages 753-760
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    In previous reports, the authors reported the investigation on the permanent-wall-type furnace with compulsory cooling, and many advantages of this method confirmed through the experimental work.
    Based on this investigation a new type of oxygen converter with all water cooling wall was designed and installed to estimate the possible applications of this method.The results obtained were as follows: Application of water cooling method to the protection of all lining walls of oxygen converter was very effective and a permanent refractory layer formed by the slag at the surface of cooling plate was obtained under violent action of the streams of molten metal, slag and gas. As this lining was retained permanently during the blow, the operation was performed with great uniformity.
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  • Taira NAKANO, Hisashi TAKADA, Tadataka GOTO, Isamu OKA
    1964 Volume 50 Issue 5 Pages 761-766
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    The fog-quenching is very profitable for quenching of cast or forged steel pieces, because it can control the cooling rate in a wide range, and make uniform cooling at various sections of a material with complicated shape by controlling the flow rates of water and compressed air. We studied the effect of the flow rates of water and compressed air and the distance between the nozzle and the quenched end of a test piece on the uniformity of fogquenching and the quenching ability, by using experimental fog-quenching apparatuses. The results obtained were as follows.
    The uniformity of quenching could be improved by decreasing the flow rate of water or by increasing that of compressed air, but greatly improved by increasing the distance between nozzle and quenched end, though, in both cases, the quenching ability decreased.
    With an increase in the flow rates of water and compressed air, the quenching ability increased remarkably at first, but saturated gradually.
    From the severity of quench factor (h-value) calculated from experimental data by using E. Schmidts'diagram, it was found that the fog-quenching method could cover a wide range of cooling rates from that of oil quenching to that of air cooling.
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  • Etsuro SHUTO
    1964 Volume 50 Issue 5 Pages 766-773
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    The effects of the hot rolling condition, soaking temperature and line speed on the hardness of the low carbon steel sheet after continuous annealing and electrolytic tinning were studied, and the relations between these processing conditions and the grain size, the carbide distribution and the approximate dissolved carbon content measured by the electric resistivity method were discussed. It was made clear that the uniformity in hardness obtained in the continuously annealed low carbon steel was mainly due to the mutual cancellation between the effects of grain size and of dissolved carbon content.
    It was concluded that the line speed was an effective factor for the hardness control.
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  • Kingo NAGAOKA
    1964 Volume 50 Issue 5 Pages 773-781
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    During cyclic heating in the austenite-region grey cast irons increase their volume irreversibly without transformation and graphitization. In this study some experimental facts were obtained on the growth in air, but they could not be explained by the oxidation theory.
    Therefore a new mechanism, suggested by the author, of the growth was applied to explain them. The results obtained are summarized as follows.
    (1) Growth in austenite-region depends mainly on the difference in the temperature of cyclic heating.
    (2) Even the hard grey cast iron that does not grow in the critical range may grow in austenite region.
    (3) The dilatometer curves of nodular graphite cast iron show that this iron grows gradually in a loop in austenite-region during cyclic heating.
    (4) Preheating in air promotes the growth in austenite region, but retards it in the cycle including transformation.
    (5) Growth characteristics of cast iron may differ in critical-range and in austenite-region. And growth occurring in the cycle covering both regions is the sum of growth in individual regions.
    (6) Growth by transformation can not be examined separately, and it is usually accompanied with growth in austenite region.
    (7) Experimental facts on the growth in austenite region are not explainable by the earlier theories, and it is suggested that the migration of graphite carbon during cyclic heat treatment in austenite region may create irreversible volume changes.
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  • Shigehiro INOUE, Takashi TSUCHIYA
    1964 Volume 50 Issue 5 Pages 781-787
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    Cast 18-8 stainless steels normally contain δ-ferrite, the amount of which depends mainly on the chemical composition.
    In this report, the effects of various alloying elements on the amount of ferrite and on the properties of the steels investigated by tensile, microscopic and corrosion tests were investigated with the following results.
    (1) The strength of the cast steels increased in proportion to the amount of ferrite in austenite, but the elongation lowered inversely.
    (2) For the same amount of ferrite, the alloying elements Si, Mn and Mo strengthened the cast steels in that order.
    (3) The corrosion resistance was not affected by the amount of ferrite, but it was vastly dependent on the variation and content of alloying elements.
    (4) No definite relation was observed between mechanical properties at 800°C and the amount of ferrite.
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  • Takeji KOIZUMI, Fujio TSUGANE, Masataka KAMAKURA
    1964 Volume 50 Issue 5 Pages 787-793
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    The authors made some experiments to study the effects of various alloying elements on the analytical values of N and O in steels by the vacuum fusion method. Obtained results are as follows.
    (1) As for the N gas, by the vacuum fusion the samples containing Cr, Mo, or V make the extraction incomplete and the values obtained are lower than those by the chemical (Kjeldahl) method. This is considered to be caused by the increase of N solubility in molten steels.
    (2) As for the CO extraction, it is known that the samples containing Al or Mn give lower values and that the metal film condensed on the inner wall of apparatus adsorbs the CO gas. The authors analysed capsule shaped pure iron specimens to which Al or Mn were added and ascertained that the O values decreased qantitatively with increases of such elements.
    The Mo-hood effectively prevented the formation of the condensed metal film and recovered O values.
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  • Iku UCHIYAMA
    1964 Volume 50 Issue 5 Pages 794-812
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • Kanichiro KATSURA, Takashi ISOBE
    1964 Volume 50 Issue 5 Pages 813-829
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • Takehiko SAKATA, Teinosuke YAGI
    1964 Volume 50 Issue 5 Pages 830-831
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    In view of very high content of phosphor found in a part of undersea iron sand which is recently developed in Japan as an unused mineral, enthusiastic efforts are being made at each research institute concerned to discover phosphor-containing minerals mixed in iron sand as the basic study of dephosphorization method.
    Since the author discovered experimentally, in connection with this, an interesting instance of surface adsorption of phosphor, he will report here on it.
    1) When iron sand concentrate was burned unground and daubed on its surface with ammonium molybdate solution, plenty of phosphor was observed to get separated from the surface of iron sand.
    2) When concentrate was boiled unground in 5% HNO3 solution, the value of the greater part of phosphor could be obtained from the solution.
    3) There are various kinds of phosphorous compounds at sea bottom, which seem to have been adsorbed on the surface of iron sand that has strong affinity by nature.
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  • 1964 Volume 50 Issue 5 Pages 832-834
    Published: May 01, 1964
    Released: December 22, 2010
    JOURNALS FREE ACCESS
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  • 1964 Volume 50 Issue 5 Pages 834
    Published: 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • 1964 Volume 50 Issue 5 Pages 835-837
    Published: May 01, 1964
    Released: December 22, 2010
    JOURNALS FREE ACCESS
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  • 1964 Volume 50 Issue 5 Pages 840-842
    Published: May 01, 1964
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • 1964 Volume 50 Issue 5 Pages 865-866
    Published: May 01, 1964
    Released: December 22, 2010
    JOURNALS FREE ACCESS
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