Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 56 , Issue 1
Showing 1-15 articles out of 15 articles from the selected issue
  • [in Japanese]
    1970 Volume 56 Issue 1 Pages 1-2
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • Takeshi YAMAOKA
    1970 Volume 56 Issue 1 Pages 3-13
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • Sumio SHIOMI, Nobuo SANO, Yukio MATSUSHITA
    1970 Volume 56 Issue 1 Pages 14-19
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    By the use of laboratory scale rocking furnace, carbon saturated liquid iron ([%S]=0.5-0.7) was desulphurized by calcium carbide powder in the temperature range from 1250 to 1450°C with rocking speed of 0 to 36%c/min, and mechanism of the reaction was investigated.
    The mass transfer coefficient K obtained by the experimental results may be expressed by the following equation.
    K= (1.6×1010·Rc+1.1×1010) 1/2exp (-40000/RT)
    where Rc is rocking speed, R and T are gas constant and temperature (°K), respectively.
    However, it could not be definitely determined whether the chemical reaction or the diffusion controls the desulphurization process from the value of apparent activation energy obtained.
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  • Kanae SUZUKI, Shiro BAN-YA, Tasuku FUWA
    1970 Volume 56 Issue 1 Pages 20-27
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    The reaction of dissolved oxygen with silicon in liquid iron was studied by using silica, alumina and magnesia crucibles to know the effect of the contamination of reaction product with refractory materials on the deoxidation constant. The concentration product [%Si]·[%O] 2 in liquid iron held in silica crucibles is expressed by the following equation and agrees well with previous studies:
    log [%Si]·[%O] 2=24600/T+8.40.(1)
    ΔG°=113000-38.4T.(1′)
    The deoxidation constant with silicon was 0.5-0.6×10-5 in alumina crucibles and 0.13-0.14×10-5 in magnesia crucibles at 1600°.
    Silicon is one of the important elements for the deoxidation in 18-8 stainless-steelmaking practice.
    The detailed studies of deoxidation with silicon have been carried out in iron-nickel, iron-chromium and iron-nickel-chromium systems at the temperature of 1550°, 1600° and 1650°. Chromium increases the deoxidation constant while nickel decreases it. The results obtained are represented by the following two equations empirically:
    (3)
    From these results the following parameters were given:(5)
    The deoxidation constant with silicon in 18-8 stainless steel was fairly good consistent with the value calculated from the summation of activity coefficients of each element dissolved in the liquid alloys.
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  • Kazuo MATSUDO, Takayoshi SHIMOMURA
    1970 Volume 56 Issue 1 Pages 28-43
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    The deep drawability (R-value) was studied in rimmed steel sheets melted in air. The variables examined were the carbon content, the cold rolling reduction (50-90%) and annealing conditions (700° and 800°×5hr in non-decarburizing atmosphere and 750°×10hr in decarburizing atmosphere).
    The following results have been obtained:
    1. The R-value not only has the well-known dependence upon the texture but also the dependence upon the grain size d, which can be expressed by the formula.
    R=R0+k (d-1/2-d0-1/2)
    In this formula,
    (1) the R0-value at the completion of recrystallization is mainly determined by cold rolling reduction and carbon content;
    (2) |k| is almost constant at 50-80% cold reduction, and decreases over 85%;
    (3)(d-1/2d0-1/2)(the term expressing the effect of grain growth after the completion of recrystallization) is affected by the factors such as carbon and oxygen contents and annealing conditions;
    (4) the high R-value can be obtained in the low-carbon material in non-decarburizing annealing condition, and in the high carbon (that is low oxygen) material in the decarburizing condition; and
    (5) the R-value of the low carbon material can be raised through the increase in R0 and that of the high carbon material through the increase in |d-1/2-d0-1/2|.
    2. When carbon content is low or annealing temperature is high, the cold rolling reduction for getting maximum R-value is high.
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  • Hiroshi ARAI
    1970 Volume 56 Issue 1 Pages 44-54
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    It is well known that the occurrence of intergranular corrosion in austenitic stainless steel is caused by the chromium depletion at the grain boundary, where the chromium carbide formed. However, no clear physical interpretations for the formation of carbide and chromium depleted layer have been given yet.
    The purpose of this paper is to summarize mathematically what is the rate determing process for the formation of carbide.
    It is concluded that: 1) the diffusion of carbon to the grain boundary is too rapid to be the rate determing process; 2) as the chromium diffusion is relatively slow below 500°C, the supply of chromium to the grain boundary determines the rate of precipitation; and 3) above 550°C, the formation of carbide itself is the rate determing process.
    From the above conclusions, the Time-Temperature-Sensitization (TTS) diagram can be calculated under certain assumptions.
    The theoretical TTS diagram agrees well with the experimental results.
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  • Takuro SAGA, Ohmi MIYAGAWA, Mitsuyuki KOBAYASHI, Dai FUJISHIRO
    1970 Volume 56 Issue 1 Pages 55-68
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    It was found that the grain boundary serration could be produced when commercial 21-12N steel was furnace-cooled from various solution temperatures.
    In this study, the condition required to serrate the grain boundaries in high Cr-Ni steel was determined and the effect of the furnace cooling on the creep rupture roperties of 21-12N steel was investigated.
    In order to serrate the grain boupdaries, high Cr-Ni steel, in which C or N more than 0.2% or 0.3% was contained respectively, had to be transferred from solution temperatures to the higher temperature region around 900 and then held for a certain time at the same region in which the nucleation rate of precipitates was not so fast, but both nucleation growth and grain boundary migration were ready to occur, without passing through the lower temperature region around 700°C in which precipitates were ready to nucleate.
    Smooth and notched creep rupture properties at 600°C of 21-12N steel were improved remakably by the furnace cooling, while at 700°C the effect of the furnace cooling was decreased gradually as the rupture life increased.
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  • Heitaro YOSHIDA, Kisaburo KOIKE, Renpei YODA
    1970 Volume 56 Issue 1 Pages 69-79
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    The effect of boron on high temperature properties of 10M6N (10%Mn, 6%Ni, 20%Cr, 2%Mo, 2.5%W, 1%Nb, 0.2%C, N>0.6%, and the balance Fe) type alloys and the proper amount of boron in view of the forgeability were examined.
    Results obtained are as follows.
    1) The rate of age hardening and that of the precipitation with a mode of the grain boundary reaction are delayed by the addition of boron.
    The addition of boron is not effective for the improvement of the static and dynamic ductilities at room temperature, but is good for at high temperatures.
    2) The improvements of creep rupture strength at 700°C, 1000hr are about 1.5kg/mm2, 2kg/mm2 and 2.5kg/mm2 by the addition of 0.01%, 0.04% and 0.06% of boron respectively in the range of nitrogen content of about 0.5%-0.6%. These effects are mainly due to the fact that the addition of boron delays the beginning of the 3rd stage in creep of this type alloy.
    3) The proper amount of boron to be added to this type alloy is about 0.01% in view of the forgeability and the resistance to oxidation.
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  • Minoru SASAKI, Hiroki HAMADA, Hiromu SOGA, Ohiko KAMIMORI
    1970 Volume 56 Issue 1 Pages 80-85
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    Oxide inclusions in a Fe-Cr-Ni steel sample were classified in four types; they are those composed of mainly silicate glass, wollastonite and silicate glass, dendritic crystals and silicate glass, and the aggregate of fine crystals. Main constituent phases were analysed by X-ray microanalyser to presume the chemical composition of the inclusions. In addition, a correction method for estimating the actual size distribution of spherical inclusions from that of sectional radii of the inclusions on polished surface of steel was investigated. This method was applied to microscopic analysis of the inclusion of each type in the steel sample.
    These analytical results are discussed with relation to the steelmaking conitions.
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  • Masuta OHKUBO, Yoshio MIYASHITA, Akira MASUI, Hisami TOKUNAGA
    1970 Volume 56 Issue 1 Pages 86-92
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
    A FORTRAN computer program for calculating the chemical composition of a specimen from X-ray data measured with an electron probe microanalyzer is described. In the program, all data are corrected for dead time, background, absorption due to Philibert, atomic number due to Poole and Thomas and fluorescence due to Reed. Elements less than ten can be corrected at the same time in a specimen.
    The effects of the absorption, atomic number and fluorescence correction of each element in the specimen are easily seen from the output results. The computer output is used not only to know the composition but to classfy and store the X-ray data and the composition of the specimen. The program facilitates the comparison of calculating procedures as well as the evaluation of errors caused by uncertainties in the methods of correction and in the parameters used.
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  • Hiroshi ISHIZUKA, Ryuichi CHIBA
    1970 Volume 56 Issue 1 Pages 93-111
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • Yoshiaki KANAI, Katsuyuki UCHIBORI
    1970 Volume 56 Issue 1 Pages 112-120
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese]
    1970 Volume 56 Issue 1 Pages 121-123
    Published: January 01, 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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  • 1970 Volume 56 Issue 1 Pages 124-136
    Published: January 01, 1970
    Released: December 22, 2010
    JOURNALS FREE ACCESS
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  • 1970 Volume 56 Issue 1 Pages 144
    Published: 1970
    Released: October 12, 2010
    JOURNALS FREE ACCESS
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