Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 68 , Issue 2
Showing 1-21 articles out of 21 articles from the selected issue
  • Hideo KANEKO
    1982 Volume 68 Issue 2 Pages 193-199
    Published: February 01, 1982
    Released: June 19, 2009
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  • Masashi KASE
    1982 Volume 68 Issue 2 Pages 200-210
    Published: February 01, 1982
    Released: January 18, 2010
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  • Yasuhiro FUKUNAKA
    1982 Volume 68 Issue 2 Pages 211-220
    Published: February 01, 1982
    Released: June 19, 2009
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  • Shigeo OWAKU
    1982 Volume 68 Issue 2 Pages 221-225
    Published: February 01, 1982
    Released: June 19, 2009
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  • Ryohei TANAKA, Takashi MATSUO
    1982 Volume 68 Issue 2 Pages 226-235
    Published: February 01, 1982
    Released: January 18, 2010
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  • Mutsumi IHIDA, Toshimitsu SATO
    1982 Volume 68 Issue 2 Pages 236-243
    Published: February 01, 1982
    Released: June 19, 2009
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  • Taira OKAMOTO, Zen-ichiro MORITA, Akio KAGAWA, Toshihiro TANAKA
    1982 Volume 68 Issue 2 Pages 244-250
    Published: February 01, 1982
    Released: June 19, 2009
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    In order to investigate carbon distribution between solid and liquid phases in Fe-C binary system, austenite-liquid phases equilibrated in the temperature range from 1150 to 1 400°C were quenched and the carbon concentrations in each phase were determined by EPMA analysis.
    The results obtained are summarized as follows :
    (1) Solidus and liquidus obtained coincided well with the curves given in other recent works.
    (2) Diffusion distance of carbon from liquid-solid interface into solid phase during quenching was calculated. From the results of the calculation, it became clear that carbon concentration in the center of solid phase was not influenced by the carbon diffusion during quenching.
    (3) Equilibrium distribution coefficient of carbon in Fe-C system was determined thermodynamically. Solidus corresponding to the liquidus obtained experimentally was calculated by using the above coefficient and it was in good agreement with the experimental one.
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  • Jae-Dong SHIM, Shiro BAN-YA
    1982 Volume 68 Issue 2 Pages 251-260
    Published: February 01, 1982
    Released: June 19, 2009
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    A study has been made of the distribution equilibria between liquid iron and the slags of FetO-MgO, FetO-SiO2-MgO and FetO-SiO2-CaO-MgO systems saturated with MgO in the temperature range of 1 550° to 1 650°C by using magnesia crucible to clarify the influence of magnesia in the slags. The distribution ratio, S-O ratio and the sulphide capacity of these slags were determined as the function of the slag composition. The order of the desulphurization power of the basic oxides was CaO<FeO<MgO, and SiO2 remarkably decreased the distribution ratio of sulphur. The results obtained are summarized as follows :
    1. FetO-MgO(sat) binary slags log { (%S) [a0]/[aS]} =-4560/T+ 2.22
    2. FetO-SiO2-MgO and FetO-SiO2-CaO-MgO slags log (NS2-[a0]/NO2-[aS]) =-1.47N'Ca2+-1.92N'Fe2+-3.15N'Mg2+
    log (NS2-P1/2O2 /NO2-P1/2S2) =-2.35N'Ca2+-2.79N'Fe2+-4.03N'Mg2+
    log C's =log {NS2-(PO2/PS2)1/2}=-2.35N'Ca2+-2.79N'Fe2+-4.03N'Mg2+ + log (1-NSiO44-)
    log (NS2/[aS]) =-936/T+ 1.375+ log C's-log [a0]
    Where Ni and N'M are ionic fraction and electrically equivalent fraction in the slags respectively, and C's is the sulphide capacity of slags expressed with mole fraction.
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  • Shiro BAN-YA, Retsu NAGABAYASHI
    1982 Volume 68 Issue 2 Pages 261-268
    Published: February 01, 1982
    Released: June 19, 2009
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    As a fundamental study on the physico-chemical properties of phosphate slags, a measurement has been made on the equilibrium of hydrogen-water vapor gas mixtures with the phosphate slags of FetO-P2O5-CaO and FetO-P2O5-MgO ternary systems contained in solid iron crucible at 1 400°C. From the results obtained, the activity of iron oxide and the ratio of ferrous to ferric iron (Λ= Fe3+/Fe2+) have been determined as a function of slag composition. The activity of iron oxide in these slags markedly deviated to the direction of the composition of 3CaO·P2O5 and 3MgO·P2O5 compound respectively.
    In view of ionic theory, the approximate validity of regular solution model for cations were examined to evaluate the thermodynamic properties of these ternary slag containing P2O5. It was confirmed that the regular solution model was satisfied within experimental error except for extremely FeO rich region. The values of interaction energy concerning P2O5 are as follows,
    α34 (P5+Ca2+) =-50900 ± 400 cal/mol
    α35 (P5+Mg2+)=-32200 ± 700 cal/mol
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  • Shiro BAN-YA, Nobutoshi MARUYAMA, Shinji FUJINO
    1982 Volume 68 Issue 2 Pages 269-276
    Published: February 01, 1982
    Released: January 18, 2010
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    The vapor pressure of phosphorus in liquid Fe-P alloys has been measured by the transportation method at the temperatures of 1473-1773 K and in the composition range from 4.5 to 18.7 weight percent phosphorus.
    The free energy of solution and the activity of phosphorus in iron were determined by applying the interstitial model to the experimental results.
    The results obtained are summarized as follows :
    Equilibrium constant :
    log K1(=√PP2/aP) =-6 120 T-1/K-1+2.33
    Activity coefficieni of phosphorus :
    logψP=0.538YP(aPP·ZP)YP≤0.33
    Interaction coefficient :
    εPP = (∂ln γP/∂XP) XFe→1= 3.24 ± 0.4
    ePP= (∂ log fP/∂ [%P]) [ %Fe]→100 = 0.022 ± 0.003
    where YP and ZP are the mole ratio and lattice ratio of phosphorus in liquid iron respectively.
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  • Kazuhiro NAGATA, Kyoji NAKANISHI, Fumio SUDO, Kazuhiro S. GOTO
    1982 Volume 68 Issue 2 Pages 277-283
    Published: February 01, 1982
    Released: June 19, 2009
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    The oxygen potential (represented by Po2) and temperature in liquid iron, slag and gas phases in a Q-BOP converter during blowing were measured by using different types of oxygen concentration cell with ZrO2-base solid electrolyte for each phase. Po2 and temperature in liquid iron continuously increased from 1 × 10-14 atm at 1 400°C at the initial stage of oxygen blowing to 1 × 10-10 atm at 1 600 °C at the end of blowing. Po2 in slag at the end of blowing was about 10-9 atm, being close to Po2 in equilibrium with Fe2+ and Fe3+ and closely rinked with the ratio of wt%Fe3+ to the sum of wt%Fe3+ and wt%Fe2+. Because slags were solid at the initial and middle stages of blowing, Po2 in slag was estimated 10-4 to 10-6 atm from the value of the above-mentioned ratio.Po2 in gas phase was 3 × 10-13 atm at the initial stage and it remained lower than that in liquid iron after the middle stage. On the basis of experimental findings, the reaction mechanism of the elements in steel with slag was discussed and the characteristic of Q-BOP as a reaction vessel was compared with that of LD converter.
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  • Hirooki NAKAJIMA, Satoshi WATANABE, Shigeo YAMAMOTO, Muneyuki KOORI
    1982 Volume 68 Issue 2 Pages 284-291
    Published: February 01, 1982
    Released: June 19, 2009
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    The effect of hot working on the hardenability of steels was investigated. 0.4%C-1%Cr steels were used and hot working was carried out by means of rolling. The following results were obtained.
    The heating temperature for hot working affected the hardenability of steels. An increase in the temperature from 1050°C to 1250°C decreased the Vickers hardness by about 50 in the cooling condition in which the hardness after cooling from the austenitizing temperature decreased most steeply with a decrease of cooling rate. Effect of the working temperature and working ratio was small.
    These results were due to the change of austenite grain size in relaition to the condition of hot working. When the heating temperature for hot working is higher and all aluminum nitrides dissolve into austenite, fine aluminum nitrides precipitate in the heating for normalizing after rolling and suppress the growth of austenite grain. When the heating temperature is lower and a part of aluminum nitrides does not dissolve, large particles of aluminum nitride distribute scatteringly and austenite grain grows larger. The hardenability of steels is varied according to the austenite grain size.
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  • Minoru UMEMOTO, Nobuo NISHIOKA, Imo TAMURA
    1982 Volume 68 Issue 2 Pages 292-300
    Published: February 01, 1982
    Released: June 19, 2009
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    A quantitative prediction of hardenability of eutectoid steels from the corresponding isothermal tranformation diagram is considered. A general equation expressing the transformation kinetic during continuous cooling of eutectoid steel is derived by combining the isothermal transformation kinetics with the cooling curves under the assumption that the transformation is additive over the whole transformation temperature range. Based on this equation, the simple equations expressing the values of critical cooling rate αu and α1, Jominy distance J0 and ideal critical diameter DI using the values obtained from the isothermal transformation diagram are developed. The relationships between DI and J0 and DI, H and D0 which had been derived by Grossmann et al. based on the half temperature time are reconsidered from the continuous cooling transformation point of view. The main results obtained are as follows :
    (1) The transformed fraction X of pearlite during continuous cooling can be expressed as,
    X=1-exp[-{∫T=T T=Te e-a/n(T-b)2/dT/dt dT}n 1n2/tn0]
    (2) Upper and lower critical cooling rate αu and α1, Jominy distance J0 and ideal critical diameter DI can be expressed as,
    αu = 1/Ζ (69)1/n, α1 = 1/Ζ(0.15)1/n
    J1.40=3.12×10-5 (T1-T2) (b-T2
    D2I=2.56 × 10-2 f2(T1-T2) (b-T2)Ζ where Ζ=t0a/nπ
    (3) The values of DI derived from J0 and D0 derived from DI and H using Grossmann's method may be smaller and larger respectively than the actual ones.
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  • Fumio MATSUNO, Shunichi NISHIKIDA
    1982 Volume 68 Issue 2 Pages 301-308
    Published: February 01, 1982
    Released: June 19, 2009
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    Si-killed steel and five kinds of Fe-550%Ni alloys containing small amounts of Mn and Si were internally oxidized in the temperature range between 1 000° and 1 300°C, and the permeability of oxygen through the alloys were studied. The results obtained were as follows :
    (1) In the temperature range lower than about 1 100°C, both the intergranular permeation and the transgranular permeation of oxygen progressed. The rate of the former was larger than that of the latter.
    (2) At 1 000°C, the rate of the intergranular permeation in the Si-killed steel was smaller than the rates in 5, 15 and 20%Ni alloys. Among the alloys, the permeation rates decreased with increasing the Ni content.
    (3) In the temperature range higher than about 1 100°C, the transgranular permeation was predominant. The permeation rate in the Si-killed steel was larger than the rates in the Fe-Ni alloys. Among the alloys, the permeation rates decreased with increasing the Ni content.
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  • KO SOENO, Masatoshi TSUCHIYA
    1982 Volume 68 Issue 2 Pages 309-314
    Published: February 01, 1982
    Released: June 19, 2009
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    Tensile properties and resistivity changes during isothermal aging have been investigated for Fe-10Ni-1.8Ti, Fe-15Ni-1.8Ti and Fe-20Ni-1.8Ti maraging steels. In order to investigate the effect of strain rate on elongation, a crosshead speed has been varied from 0.005 to 10 mm /min.
    Two stage precipitation appears in the resistivity curves of the maraging steels. Embrittlement caused by the decrease in strain rate is found in the maraging steels containing fine and coherent precipitates, formed in the first precipitation stage. Brittle fracture irrespective of strain rate is also found in the Fe-10Ni-1.8Ti and Fe-15Ni-1.8Ti maraging steels strengthened fully by the first precipitation stage. When the second precipitation stage progresses, elongation increases with the decrease in tensile strength. The embrittlement caused by the decrease in strain rate is not found in the maraging steels containing precipitates formed in the second precipitation stage. It is considered that slip bands produced in plastic deformation are less intense in the maraging steels containing precipitates which are difficult to be cut by movement of dislocations.
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  • Toshie OKUNO
    1982 Volume 68 Issue 2 Pages 315-323
    Published: February 01, 1982
    Released: June 19, 2009
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    In this study, effects of bainite structure on high-temperature strength, precipitation and aggregation behaviors of carbides during tempering are investigated for 0.2C-3Cr-W-Mo-V-Co steel comparing with martensite structure obtained by particularly rapid quenching.
    The results obtained are as follows :
    (1) During cooling from austenitized temperature at the rate lower than the rate of half temperature time being 10 min, granular upper bainite structure, without carbide precipitation in boundary is obtained with about 15% stable retained austenite.
    (2) During tempering of this structure,
    (i) precipitation of M3C and transformation of M3C→M7C3 in situ are suppressed, while those phenomena take place in martensite tempering,
    (ii) boundary precipitation and aggregation of M6C are suppressed until higher tempering temperature because of the rarer distribution density of bainite grain boundary than martensite lath boundary, and through above (i), (ii),
    (iii) increasing of volume of MC, M2C precipitated, their homogeneous distribution and suppressing of aggregation of them, which are all effective to the strengthening of the steel, are promoted.
    (3) As the results, this upper bainite structure shows excellent high-temperature strength, compared with martensite structure.
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  • Mitsuo CHIGASAKI, KO SOENO, Yutaka FUKUI
    1982 Volume 68 Issue 2 Pages 324-332
    Published: February 01, 1982
    Released: June 19, 2009
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    Pack cementation process has been applied for depositing aluminide and platinum-aluminide coatings on a nickel-base superalloy IN-738LC. In order to investigate hot corrosion behaviors of the coatings, specimens covered with a Na2SO4 salt containing 25%NaCl have been heated in the air in the temperatures ranging from 750 to 980°C.
    As aluminide coating after pack cementation at 750°C mainly consists of brittle Ni2Al3, diffusion treatment is necessary to convert Ni2Al3 to more ductile and stable NiAl. Aluminide coating after pack cementation at 1120°C mainly consists of NiAl, and chromium precipitates contained in the coating are relatively small in quantity. The hot corrosion resistance of the coating made at 1120°C is inferior to that of the coating diffusion-treated after pack cementation at 750°C.
    Platinum-aluminide coating has been made by electroplating of platinum plus pack cementation. When the pack cementation is carried out at 750°C, PtAl2 is formed as a thin layer at the surface of coating after diffusion-treatment. While the mixture of PtAl2 and NiAl in the outer layer is obtainable after pack cementation at 1120°C. Hot corrosion resistance of the platinum-aluminide coating is excellent at 980°C, but inferior at 850°C or less to that of the aluminide coating diffusion-treated after pack cementation at 750°C.
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  • Akihiro ONO, Takashi OTSUKI
    1982 Volume 68 Issue 2 Pages 333-341
    Published: February 01, 1982
    Released: June 19, 2009
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    A new chemical method for determination of micro amounts of sulfur in steel has been developed. It is found that H2S is easily evolved during sample dissolution with strong H3PO4 containing Fe (II) ions, and the solution absorbing H2S shows the characteristic absorption at 232 nm in ultraviolet region.
    The developed apparatus is mainly consisted of reaction vessel for sample dissolution and H2S evolution, scrubbing vessel for removal of evolved water vapour and iron phosphite mist, absorption vessel for H2S and constant flowrate pump for transferring the absorbing solution to flowcell of U. V. meter.
    The analytical procedure is performed as follows: 0.500 g of sample and 20 ml of strong H3PO4 containing Fe (II) ions are put into the reaction vessel. The sample is dissolved by heating in N2 stream. H2S is evolved in the reaction vessel, scrubbed with 6N HCl in the scrubbing vessel and absorbed with 5.00 ml of 0.05N NaOH. The absorbing solution is circulated through flowcell of U. V. meter by the pump. Absorbance is continuously measured at 232 nm until it becomes constant.
    Above 0.5 ppm of micro amounts of sulfur can be easily determined with high accuracy. The time required for analysis of one sample is less than 10 min. The analytical results of steel samples are in good agreement with those obtained by the conventional method. Moreover, the proposed method has been improved for the higher sensitivity by concentration of sulfide ion with the anion exchange resin.
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  • Kimihisa ITO, Masakazu YANAGISAWA, Nobuo SANO
    1982 Volume 68 Issue 2 Pages 342-344
    Published: February 01, 1982
    Released: June 19, 2009
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    The equilibrium distribution ratio (Lp) of phosphorus between solid 2CaO·SiO2 and molten CaO-SiO2-Fe2O3 and CaO-SiO3-FeO slags were determined in the temperature ranging from 1350°C to 1450°C.
    It was found that Lp increased with increasing total iron content, regardless of the valency of iron. No dependence of Lp on temperature and CaO/SiO2 in slags was observed.
    These findings indicate that the ferrous and ferric oxides increase the activity coefficient of 3CaO·P2O5 in slags in the composition range studied. The data obtained by the present work confirmed that about 80% of phosphorus be removed from LD slags to 2CaO·SiO2 which primarily precipitates on solidification.
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  • [in Japanese]
    1982 Volume 68 Issue 2 Pages 357
    Published: February 01, 1982
    Released: June 19, 2009
    JOURNALS FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1982 Volume 68 Issue 2 Pages 365-368
    Published: February 01, 1982
    Released: June 19, 2009
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