Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 61, Issue 14
Displaying 1-13 of 13 articles from this issue
  • [in Japanese]
    1975 Volume 61 Issue 14 Pages 2921-2922
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
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  • Akira MORIYAMA, Kazuo ARAKI
    1975 Volume 61 Issue 14 Pages 2923-2932
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
    Data on the temperature of tuyeres in operation, hitherto reported, were analysed to estimate some thermal properties of the tuyere and its environment.
    For any material, thermal behaviors of the tuyere were theoretically discussed during the stationary blast furnace operation, as well as just after and in subsequently contacting with molten pig iron. The methods and their results are useful in searches for materials and in designing proper thickness of the tuyere.
    Copper, aluminum and steel tuyere, as examples, were calculated and shown to be safely applicable to ordinary blast furnace conditions. It may be not preferable to reduce the wall thickness for preventing burning-out of copper and aluminum tuyeres.
    Contrarily, a definite thickness of the wall of steel tuyere remains unmelted in contact with molten pig iron: the surface temperature of its nose wall, particularly less than 0.9 cm of thickness, cannot attain to melting point of the material.
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  • Shiro BAN-YA, Mikio SUZUKI
    1975 Volume 61 Issue 14 Pages 2933-2942
    Published: November 01, 1975
    Released on J-STAGE: March 25, 2010
    JOURNAL FREE ACCESS
    The activity of phosphorus in liquid iron and iron-carbon alloys has been measured by distribution experiments between the immiscible liquid iron and silver at temperatures of 1300°-1600°C and in the composition range up to 21.0 weight percent phosphorus. The results obtained were treated by the model of interstitial solution proposed by J. CHIPMAN. It has been found that the apparent distribution constant of phosphorus is expressed with a linear function which has a inflection at the composition of Fe3P at constant temperature.
    The results obtained are summarized as follows:
    The distribution constant of phosphorus:
    logK (=aAgp/aFep) =-7180 /T+0.54
    The activity coefficient:
    logψpp=0.982yp…0yp<0.33
    logψpp=-2.32+7.96yp…0.33yp<0.5
    logψcp=1.18ycyp<0.33, yc<0.17
    The interaction parameter:
    εpp= (∂lnγp/∂Xp) XFe→1=4.26±0.5
    εcp= (∂lnγp/∂Xc) XFe→1=4.72±1.1
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  • Kiichi NARITA, Toshio ONOYE, Teruo ISHII, Ken'ichiro UEMURA
    1975 Volume 61 Issue 14 Pages 2943-2951
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
    The electrical conductivity of CaO-SiO2-FetO slag in contact with iron was measured at 1300°C using AC bridge (1000 Hz). A drastic increase of the electrical conductivity was observed with increase of FetO content. The Arrhenius relation between the conductivity and the temperature were satisfied in both high and low FetO slag (33.6 mol% and 67.5 mol% respectively).
    Experiments were also carried out on the effect of additives on the electrical conductivity of the slag. From the results obtained for the fayalite composition, of which SiO2 was substituted for additives, CaO and MgO were found to contribute to the conductivity by almost the same degree as equivalent FetO. TiO2 changed the conductivity only a little, which means that TiO2 can be substituted for equivalent SiO2. The conductivity of the slag, where SiO2 was substituted for Al2O3, was equal to that of the slag, where Al2O3 was assumed to fix equivalent FetO. CaF2showed a minor increase of the conductivity.
    The electrical conductivities were also measured varying the basicity (CaO/SiO2) of the slag with constant FetO and additives such as MgO, CaF2, B2O3, Al2O3 and TiO2.
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  • Kazumi MORI, Tadashi HIRAIWA, Hiroyuki NOMURA
    1975 Volume 61 Issue 14 Pages 2952-2961
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
    Two series of experimental studies have been made of uni-directional solidification of iron for the variation of intensity of CO formation at the solidification velocity of 5 mm/min: one was solidification from inductively stirred melts, and the other from quiescent melts. In the latter case a molybdenum tube was used as the susceptor of high frequency induction.
    The transitional concentration range for the formation of elongated blowholes was unaffected by the stirring and was found to be [%O] t, l=0.003-0.004 ([%C] L=0.11-0.13) to [%O] t, u=0.010-0.011 ([%C] L=0.14-0.17).
    Elongated blowholes observed in the solidified specimens were classified into three types: cylindrical, beads-like, and discrete beads-like. It was found that the formation of blowholes was unaffected by the stirring.
    In the case of solidification without CO formation, the effective distribution coefficient k* melts was nearly equal to one, whereas in the presence of stirring it was 0.90-0.95. In contrast to this, in the case of solidification with the formation of CO, the stirring produced no detectable effect on k* With the onset of CO blowhole formation, k* tion, k*
    It is shown that the present data give a reasonable explanation to macrosegregation occurring during solidification of a riming steel.
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  • Akira UEDA, Kimio FUJIMURA, Toshisada MORI
    1975 Volume 61 Issue 14 Pages 2962-2971
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
    The activity of iron in liquid iron-carbon solutions has been determined in the whole range of carbon concentration up to its saturation at 1 550° and 1 630° by measuring the rate of effusion of iron vapor through the orifice of alumina cells. It is found that the rate of effusion of iron through the orifice per unit time and unit orifice area at a constant temperature is constant independent of the orifice area.
    The logarithm of activity coefficient of iron expressed in atom fraction unit is proportional to the square of atom ratio of carbon to iron at each temperature.
    The activity coefficient of carbon is calculated from the value of that of iron by integrating the Gibbs-Duhem equation. The interaction parameters of carbon in liquid iron-carbon solutions have been expressed as a function of temperature and the concentration of carbon either in atom fraction or in weight percentage unit in the whole range of carbon up to its saturation.
    Partial molar enthalpy and entropy of mixing of carbon in iron-carbon solutions are calculated as the function of atom fraction of carbon.
    The obtained thermodynamic values are compared with those of other authors.
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  • Hitoshi IWATA, Katsuhiko YAMADA, Teruo FUJITA, Kyozo HAYASHI
    1975 Volume 61 Issue 14 Pages 2972-2981
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
    Two-pole rotary field type electromagnetic stirring was applied in the secondary cooling zone in order to reduce center-line segregation of continuously cast high carbon steel billets.
    The results obtained are summarized as follows.
    (1) A homogeneous macrostructure of equi-axial crystals are obtained by the stirring.
    (2) It is proved that the stirring is more effective at higher casting temperatures, by a statistical method which is presented to accurately evaluate the degree of center-line segregation of continuously cast billets.
    (3) Tensile properties of products, PC wire, are improved by the stirring.
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  • Shinobu OKANO, Takashi NISHIMURA, Hirohi OOI, Tatsukichi CHINO
    1975 Volume 61 Issue 14 Pages 2982-2990
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
    It is well known that the columnar dendrite grows in a direction opposing the liquid flow. Therefore, in order to make clear the fluid flow within liquid pool, the solidification structures of steel slabs cast continuously by the curved mould bending type machine were investigated. At the same time, the amount of large inclusions trapped within the upper part of slab was measured by the method of X-ray radiography. The following results were obtained;
    (1) The deflection angle of columnar dendrite, depending on the solidification rate and the flow velocity along the solidified shell, is large at the edge of slab, but smaller near to the center of slab.
    (2) The amount of large inclusions in the accumulated zone of slab increases in proportion to its deflection angle of columnar dendrite.
    (3) In case of the asymmetrical flow from nozzle pores, the distribution of large inclusions in the direction of slab width becomes asymmetrical, and the amount of large inclusions extremely increases at the edge of strong flow side.
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  • Shunichi TANAKA, Hideo UCHIBORI, Masayuki HANMYO, Shigetaka UCHIDA
    1975 Volume 61 Issue 14 Pages 2991-2997
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
    The technique of aluminum addition into molton steel is very important on the steel processing of low carbon aluminum killed steels. In the first place, the yield of aluminium from a given addition is not constant since these steels are usually in the low carbon ranges, furthermore a very narrow range of Sol. Al value is required in such steels in view of the formability of their end products.
    The steelmaking shop at Fukuyama Works, Nippon Kokan K. K. has been producing large quantities of continuously cast slabs having stable Sol. Al value and excellent surface and interior quality from those killed steels treated with ladle additions of aluminium wire by means of the “Al-wire feeder” developed by the company. As a result of application of this method, the standard deviation of Sol-Al content in steel has been reduced from 0.011 to 0.008 percent.
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  • Isao KOZASU
    1975 Volume 61 Issue 14 Pages 2998-3021
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
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  • Heiji IKEGAMI, Yasuo MORI
    1975 Volume 61 Issue 14 Pages 3022-3034
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1975 Volume 61 Issue 14 Pages 3035-3038
    Published: November 01, 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
    Download PDF (915K)
  • 1975 Volume 61 Issue 14 Pages N182
    Published: 1975
    Released on J-STAGE: February 22, 2010
    JOURNAL FREE ACCESS
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