Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
Volume 37, Issue 10
Displaying 1-11 of 11 articles from this issue
  • Yoshio Shimokawa, Toyosuke Tanoue
    1951 Volume 37 Issue 10 Pages 503-511
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
    (1) The rate of solidification of rimming-steel ingots is represented by the next formula.
    d=0.50+0.9t (d=in., t=min.)
    (2) During solidification the S, P, C and Mn of molten metal increase gradually, but the O2 decreases. The rate of increase is affected by evolution of gases; and the C and O2 content of molten metal approach to the equilibrium value rapidly and then vary in the equilibrium state approximately.
    (3) The composition of scum is FeO (20-30%), MnO (45-55%), SiO2 (10-20%) and Al2O3 (5-10%) and similar to that of acid slag. The FeO in scum is larger than the equilibrium value computed by the O2 in molten metal, but the MnO is approximately in equilibrium with the Mn in metal.
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  • ON TAE CHANGE OF MACROSTRUCTURE BY DIFFUSION ANNEALING TREATMENT
    Hideo Mikashima
    1951 Volume 37 Issue 10 Pages 512-516
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
    The change of macrostructure on the diffusion of dendritic segregation were studied by means of normal annealing and high temperature normalizing treatment. Repeated normadizing test were applied to the various specimens, among which were contained Si, Ni Mn and Cr-Mo Cast steels (1% Cr, 0.25-0.35% Mo).
    The dendritic segregation is not affected by the normal annealing or quenching at just above the Ac3 transformation point, but is diffused and destroyed by the normalizing treatment at higher temperature.
    Though the rate of diffusion of dendritic segregation increases rapidly as the normalizing temperature elevates, it has some difficulties in diffusion according with the degree of coarseness or refinement of it.
    In general the addition of Si to Cr-Mo cast steel gives a considerable difficulty upon the diffusion of dendritic segregation. The larger the Si content, in these cast steels, the more diffiicult will be the diffusion, on the contrary the addition of Ni to these steels does not shows any significant change.
    Though the diffusion are easy in a finely dendritic structure; it shows a remarkable difficulty, When the dendrites are developed. In such case the high temperature normalizing must be carried out, though it is undesirable, lest grains should grow and toughness should rapidly decreases. Therfore repeated normalizing is preferable to high temperature normalizing.
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  • Hajime Nagao
    1951 Volume 37 Issue 10 Pages 517-519
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
    The pressure of gas on the surface of iron and the Al castings during solidification were measured immediately. Some relations were found between this pressure and (1) the casting temperature, (2) the moisture content in the skin sand, (3) the permeability of the molding sand in frame, (4) the thickness of castings and others.
    For obtaining sound castings, it is necessary that pressure is kept as small as possible duringsolidification.
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  • Masazo Okamoto, Tomojiro Tottori
    1951 Volume 37 Issue 10 Pages 520-523
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
    The graphitizing phenomena were studied by annealing the magnesium-treated (0.1%-1.0%Mg) and sandcast iron having the composition of C 2.56%, Si 1.13%, Mn 0.421%, P 0.118%, S 0.149%, Cr 0.01%, Cu 0.312%, and the following resulta obtained.
    (1) The sand cast iron castings treated with small amount of magnesium (0.1%-0.3%) in the form of Mgalloys have mottled structures including flaky graphite, although they are white if not treated with Mg-alloys. The above phenomenon is caused by the strong desulphurization effect of magnesium as well as by alloying of the graphitizationpromoting elements in the Mgalloys.
    (2) If the added amount of magnesium exceeds 0.6%, the structure becomes white or mottled, the graphite in the iron being spherulitic and not flaky. This phenomenon is caused by strong desulphurization of the molten iron and by alloying of the magnesium in its amount sufficient to apheroidize graphite.
    (3) The magnesium aiioyed has not only a tendency to chill the molten iron, but also re tards the graphitization in the annealing slightly.
    (4) Temper carbon in the iron treated with magnesium is rounder in form than that in the iron not treated with magnesium.
    (5) Quick malleablizing will surely be achieved by annealing the magnesiumtreated iron containing a dequate amount of carbon and silicon, and the iron casting malleablized has, for example, tensile strength 50kg/mmmm2 and elongation 8% By this method even the high phosphor iron (-0.1%P) can be used for making ductile iron, and the castings of larger section size than the maximum size applied up to the present in malleable iron products can be manufactured.
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  • Tetsutataro Mitsuhashi, Manabu Ueno
    1951 Volume 37 Issue 10 Pages 524-527
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
    The "Metal Progress" 1948 (P. 648) reported that the fatigue limit is improved by the "martemper and temper."
    It seems to differ from the "martemper" called in our country, but it means to bold an object for a time at a temperature just above Ar" transformation and to cool it gradually in this critical range of the Ar" transformation and temper.
    The fact that the fatigue limit is improved by the "martemper and temper" is probably due to being free from the microcrack by quenching, but its problem has not been solved yet. The authors reported the comparison of the mechanical properties in the martemper and temper, the austemper, and the oil quenching and temper on the hardness, the tensile strength, the elongation, the fatigue limit and the simple torque test.
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  • Seiji Tanaka, Takaaki Yoshida, Kineo Takagi
    1951 Volume 37 Issue 10 Pages 527-532
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
    Effect of supersonic waves on the various changes of steel was studied at high temperatures. The specimens used in the experiments were 1.2% carbon steel strip and the supersonic waves of 100 K.C. were propagated by the magneto-striction vibrater from one end of the specimen to the other which was put into the electric furnace and heated to temperatures required. The results obtained were as follows.
    (1) It was found in the thermal analysis that transformation was remarkably accelerated.
    (2) Some spots of troostite were found in martensite layer at almost fixed places, grain growth was not uniform, and the so called mixed grain structure was obtained. The phenomena were probably caused by interference of the supersonic waves.
    (3) The distribution of cementite was not uniform and coagurated in grain boundaries or other parts.
    (4) Oxydation and decarburization in air at high temperature was remarkably accelerated.
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  • Sadao Koshiba
    1951 Volume 37 Issue 10 Pages 532-536
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
    In the first report in the same title, the author made clear the effect of C, Cr and W on high speed steels containing high chromium. In the present investigation, the author studied the effect of 0-4% V and 0-10% Co on high speed steels containing high cromium.
    As results of this investjgation, it was ascertained that the steels containing 1.3-1.4%C, 10% Cr, 4%W, 5%Co becomes most efficient at the content of 1.8-2.0%V, and that the cutting durabi-lity is enhanced as the cobalt content is increased in the range of 0-10%
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1951 Volume 37 Issue 10 Pages 537-541
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese]
    1951 Volume 37 Issue 10 Pages 542-546
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
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  • 1951 Volume 37 Issue 10 Pages 547-548
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
    Download PDF (88K)
  • 1951 Volume 37 Issue 10 Pages 550
    Published: October 25, 1951
    Released on J-STAGE: July 09, 2009
    JOURNAL FREE ACCESS
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