Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 46, Issue 6
Displaying 1-14 of 14 articles from this issue
  • [in Japanese]
    1960 Volume 46 Issue 6 Pages 641-642
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • Studies on carbon and heat consumption in blast furnace-I
    Takeo Yatsuzuka, Jun Sawamura, Susumu Ota, Takahiro Fukuda
    1960 Volume 46 Issue 6 Pages 643-652
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    The consumption of carbon and the heat in an operating blast furnace constitutes a basic factor for a theoretical evaluation of the pig-iron manufacturing operation, together with the material consumption.
    This report gives the result of studying how the carbon consumption is performed in each part of a blast furnace, how the calory thus generated is distributed and to what extent the calory consumption of charged materials will amount, referring also to the application of those results to the blast furnace operation based on the studies from both theoretical and practical aspects.
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  • Hiroshi Nakai
    1960 Volume 46 Issue 6 Pages 652-657
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    Experiments on the sulphurization of cast iron in H2S gas current at high temperatures were conducted and the following results were obtained.
    (1) The sulphurization product of cast iron was composed of pyrrhotite Fe1-xS and pyrite FeS2, which were the same as those of iron and steel. In the outer layer of sulphurization product, carbon and phosphor didn't diffuse, on the contrary manganese diffused freely, silicon did a little.
    (2) The sulphurization rate was controlled by the parabolic rate law, and the following formula was obtained:
    W2=1.15×10-6t
    W: sulphurization rate, g/cm2
    t: sulphurization time's
    (3) Between the sulphurization rate and temperature, the exponential law was found and the following formula was obtained.
    K=10-2·e-33500/RT
    K: sulphurization rate constant, (g/cm2) 2/s
    R: gas constant
    T: sulphurization temperature, °K
    (4) The structure of cast iron did not affect the sulphurization rate.
    (5) Carbon expedited the sulphurization rate of cast iron, on the contrary silicon and manganese did not expedite it.
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  • Harujiro Sekiguchi, Michio Inagaki
    1960 Volume 46 Issue 6 Pages 657-665
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    The authors performed a series of researches on continuous cooling transformation diagrams of structural steels used for welding and reported them successively in Journal of Japan Welding Society (1957-1959, vols. 26-28). In these reports, the continuous cooling transformation diagrams were obtained with small specimens in the case of rapid-heating to maximum temp. 1350°C, cooling by various processes immediately after reaching its temp. and without holding at its temp. They gave fundamental data for tha sake of selecting the weldable steels and determined the conditions when welding these steels. Therefore, such continuous cooling transformation diagrams were presumed very important and useful.
    In the hresent report, on the basis of the results of the above researches, further determinations were made on the continuous cooling transformation diagrams for high tensile steels 2H which were of Mn-Si type and showed the tensile strength enhanced to about 60kg/mm2 by the heat-treatment of water-quenching and tempering.
    For those 2H steels could be adopted also, a diagram that was plotted to show the relation between critical cooling-time Cz', Cf' or 50% martensite cooling-time and the carbon equivalent of mild steels and Mn-Si type high tensile steels as rolled or normalized. And then, using this diagram the critical cooling-time Cz', Cf' and 50% martensite cooling-time and the carbon equivalent were determined with mild steels and Mn-Si type high tensile steels as rolled or normalized And then, based on this diagram the critical cooling-time Cz', Cf' and 50% martensite cooling times of arbitrary steel grades could be predicted from the carbon equivalent Ceq= (C+1/12Mn+1/24Si) % of those steels.
    Next, the various types of high tensile steel having 60kg/mm2 tensile strengths were compared with each other, From stand points of the buctility and crack-sensitivity of the weld heat affected zone, the critical cooling-time Cf' which began to reveal existance of primary ferrite was important, and the steels having smaller value of Cf' were found desirable. For this purpose, even with any type of steels, it was necessary that the carbon content of a steel was lowered to a mimimum.
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  • Study on austenitic high manganese steels-I
    Yunoshin Imai, Toshio Saito
    1960 Volume 46 Issue 6 Pages 665-673
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    Carbide precipitations in isothermal and continuous heated Hadfield steel after solution-treatment were studied. Results obtained were as follows:
    1) Solution-treateds steel precipitated primary carbide isothermally in accordance with an C-curve which has the nose at about 650-700°C, and also precipitated secondary pearlitic constituent isothermally with an C-curve which has the nose at about 600°C
    2) At the primary stage, carbide films were formed at austenitic grain boundary. In the low temperature range, carbide film formations were delayed markedly, and then, platelet carbide were formed along the cleavage plane of grains. In the high temperature range, carbide films changed to granular particles and gradually takes coherent shapes.
    3) The nucleations of pearlitic constituents were most rapid at about 600°C, but growth velocities of pearlite has max. value at about 500°C.
    4) Secondary precipitates, pearlitic constituents, were very fine lamellar pearlite, and lower temperature precipitates has finer lamellar than precipitates at higher temperature.
    5) In continuous heating, steels precipitated boundary carbides, platelet carbides and pearlitic constituents at about 500-600°C. It suggested that no pearlites were precipitated when heated at a velocity of above about 15°C/mn and also no carbides were precipitated when heated at a velocity of above about 45°C/mn.
    6) Mechanical properties were injured by heating at above about 350°C, since platelet carbide precipitations began at that temperature. Tensile strength lowered to minimum value at 750°C, since carbide films markedly grew at that temperature, and impact value, elongation and reduction fo area lowered to minimum value at pearlite precipitation range. Increased hardness were mainly affected by platelet carbide precipitations.
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  • Studies on nickel-base heat-resisting alloys-VII
    Taro Hasegawa, Osamu Ochiai
    1960 Volume 46 Issue 6 Pages 673-677
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    Effects of Ti, Al, C and Mo contents on stress-rupture properties of alloy M252 were investigated.
    There seemed to be a peak stress-rupture life at 1.2% Al when Ti was 3.1%, and stress-rupture life was decreased in the case of specimens containing over 1.2% Al. Ti+Al atm. %=6.5 gave the peak of stress-rupture and creep ductility.
    Effect of Ti and Al on stress-rupture characteristics was clear in the case of heat treatment B (1065°C×8h W.Q., 800°C×2.5h A.C. and 700°C×18h A.C.) but it was not clear in the case of heat treatment G (1065°C×8h. A.C., 760°C×15h. A.C.).
    Carbon did not affect the short-time stress-rupture test, but it did so in the long time stress rupture test, and stress rupture life was decreased by the increase of carbon. Hardness after heat treatment was increased by carbon and nitrogen, but it seemed that overaging at high temperature was promoted by them and the decrease of long time stress rupture life was affected by overaging.
    Ultimate strength of short-time tensile test between room temperature and 750°C, and stress-rupture strength less than 500 hours of the alloy containing 11% Mo was higher than those of the alloy containing 10% Mo. But strength was not increased by increasing Mo content up to 15%, although these values were higher than the alloy containing 10% Mo. The effect of Mo on increasing strength of alloy was not clear in the case of testing temperature of 816 and 850°C.
    There was no embrittling effect by increasing Mo content in these test. But the net work which precipitates at grain boundaries was increased by heating 11% Mo alloy for 1000 hours at 850°C, and it lowered Charpy's impact value.
    The resistance to oxidation in the air below 900°C was good enough, and it was not affected by increasing the Mo content.
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  • Shizuya Maekawa, Yoshio Yoneyama
    1960 Volume 46 Issue 6 Pages 678-682
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    In case of trying to decompose sulphide in basic slags by means of the electric resistance heating furnace, the authors have sometimes failed to release and recover it as SO2. It took a many time especially the high basic sample because of the strong affinity of sulphur to its matrix. So, they used the high frequency induction heating combustion apparatus to decompose the sample with pure iron in O2 flow. Consequently, sulphur was completely decomposed and released in the flow out gas, as SO2, which was absorbed into H2O and caught as H2SO3.
    Then, HC1 and starch solution were added in the absorbed water and titrated by M/1000 KIO3.
    The influence of pH, aquous temperature, combustion time and O2 flow upon SO2 yields were also examined. The combustion was over in 3mn. and 94% of sulphur was recovered with the aid of one absorption bottle, and 97%, two bottles. The authors examined the behavior of sulphur on the synthetic sample prepared by sulphide, sulphate and etc., and comfirmed that even high contents sample of 1% sulphur could be recovered almost stoichiometrically.
    Analytical time is about 8mn. for one sample.
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  • Kozo Morinaga
    1960 Volume 46 Issue 6 Pages 683-700
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
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  • Herbert Briefs
    1960 Volume 46 Issue 6 Pages 701-710
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • 1960 Volume 46 Issue 6 Pages 711-721
    Published: June 01, 1960
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
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  • 1960 Volume 46 Issue 6 Pages 722-726,622
    Published: June 01, 1960
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
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  • 1960 Volume 46 Issue 6 Pages 727-730
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • 1960 Volume 46 Issue 6 Pages 731-732
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • 1960 Volume 46 Issue 6 Pages 735-736
    Published: June 01, 1960
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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