Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 69, Issue 9
Displaying 1-20 of 20 articles from this issue
  • Paul Hideo SHINGU, Kei-ichi N. ISHIHARA
    1983 Volume 69 Issue 9 Pages 1087-1094
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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  • Yasuya OHMORI
    1983 Volume 69 Issue 9 Pages 1095-1100
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
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  • Shogo NAKAMURA
    1983 Volume 69 Issue 9 Pages 1101-1108
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
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  • Hideo KIMURA
    1983 Volume 69 Issue 9 Pages 1109-1112
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
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  • Kensuke SASSA, Takao CHOH
    1983 Volume 69 Issue 9 Pages 1113-1120
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The effect of phosphorus vapor on the reduction process of iron oxide with CO-N2 or CO-CO2 gas mixtures was measured by thermobalance. It was found that the rate of reduction increased with increasing partial pressure of phosphorus vapor in reducing gas. However, the apparent reduction rate decreased above a partial pressure of phosphorus vapor of 10-3 atm. Then, by using the wustite pellet exposed in P-N2 atmosphere before reduction, the reduction rate was measured at 900°C. The reduction rate was observed to be accelerated by absorbed phosphorus.
    On the other hand, it was found from the microstructural observation of reduced pellet that the size of pores and the number of large open pores in the reduced pellet increased with adding the phosphorus vapor to reducing gas or exposing the pellet in P-N2 gas. Accordingly, it was considered that the resistance for mass transfer in the gas phase through the pores in the reduced iron layer decreased with the addition of phosphorus vapor, resulting in the increase in the reduction rate of iron oxide pellet.
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  • Kunihiro HIRONAKA, Akibumi FUJIWARA, Masayuki FUJINO, Koji SHIMOMURA, ...
    1983 Volume 69 Issue 9 Pages 1121-1128
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    To study the fracture mechanism of the refractories of blast furnace by thermal stress, a model furnace of hearth and bottom of Kakogawa No. 2 B. F. was constructed. The model furnace was heated to about 1 500°C, twice.
    Thermal stress (strain), displacement of refractories and those of shell were measured during the heating test. Crack behaviour of the refractories was detected by A. E. during the heating test and also by visual inspection after the test.
    The results are summarized as follows:
    1. High stress was observed in refractories and in shell at the first heating test. The stress observed at the second heating test was less than that of the first. Also, displacement of shell and refractories was fairly affected by heat hysterisis. These phenomena may be caused mainly by irreversible shrinkage of joint mortal and carbon stamp.
    2. Cracks were detected at side face of carbon blocks, by visual inspection. The result of A. E. signal indicated that these cracks probably occurred at the final stage of heating process of the first heating test.
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  • Ryo INOUE, Hideaki SUITO
    1983 Volume 69 Issue 9 Pages 1129-1136
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The oxidation behaviors of silicon, phosphorus and niobium in carbon-saturated iron melt have been studied at 1 300°C by using soda flux (Na2CO3, Na2CO3-Fe2O3) and lime flux (CaO-CaF2-Fe2O3).Phosphorus and niobium were oxidized after the retardation of initial oxidation when flux was added by installments. The reversion of phosphorus and niobium occurred along with the desiliconization reaction after the end of flux addition. In comparison with the results obtained in the addition of soda flux by a lump, the retardation of initial oxidation was explained by the fact that the reversion rate of phosphorus and niobium was considerably fast. The effect of Fe2O3 addition to the flux was found to be significant in both experiments using a lump and installments additions. The extensive removal of silicon and niobium was observed in the addition of Fe2O3 by installments, while no dephosphorization took place.
    From the experiment using the Na2CO3 or Fe2O3 flux which was added to the carbon-saturated iron melt containing silicon, phosphorus, manganese and niobium, it was found that the removal of niobium was possible without oxidation of manganese if silicon was oxidized to a lower value as much as possible.
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  • [in Japanese], [in Japanese], [in Japanese]
    1983 Volume 69 Issue 9 Pages 1136-1136,1182
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
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  • Kyoji SATO, Yasunori NISHIKAWA, Isamu TAMURA
    1983 Volume 69 Issue 9 Pages 1137-1144
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    A sample sphere of hematite, 3.3 cm in diameter, was reduced by H2 and the variations of pressure and temperature within the sphere were continuously measured. At a reduction temperature of 895°C, the pressure and the temperature at the center of the sphere became 116 mmHg higher and 23°C lower respectively than those in the ambience. The variations of the pressure increase and the temperature fall were simulated according to the unreacted-core shrinking model with 3 reaction interfaces using a concept of the dynamic effective diffusivity. The calculated results were consistent well with the experimental results and the following conclusions were obtained.
    1) The variations of pressure and temperature within the sphere reflected the progress of the reduction steps of Fe2O3 and gave useful information for the analysis of the consecutive reaction proceeding with multiple reaction interfaces.
    2) The effect of the pressure increase on the overall reduction rate was considered to be remarkable, because the rate calculated on the isobaric assumption was much faster than the experimental one.
    3) The difference in temperature between the center and the ambience of the sphere was not so large that the calculated results for isothermal and non-isothermal conditions gave almost the same overall reduction rate.
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  • Masamitsu WAKO, Yasutaka IGUCHI, Shiro BAN-YA, Yuichiro NISHINA, Tasuk ...
    1983 Volume 69 Issue 9 Pages 1145-1151
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    A Raman spectral study has been carried out on the structures of glassy and transparent CaO-MeO- SiO2 ternary slags (MeO : Li2O, Na2O, K2O, MgO, SrO, and BaO), and of glassy and dark colored MnO-SiO2 and FeO-SiO2 slags.
    Main Raman peaks are observed at the certain wavenumber shifts in all meta-or ortho-silicates of CaO-MeO-SiO2 ternary system, and degrees of the shift do not depend on the species of alkali or alkaline earth elements, but do on the composition of a basic oxide. As a result, the structures of the ternary slags can be deduced from those of the binary ones.
    A back scattering method is applied for the measurement of dark colored samples, MnO-SiO2 and FeO-SiO2 slags, which has not been carried out yet, and clear Raman spectra are successfully obtained.
    Relation between variations in the Raman spectra and thermodynamic stabilities of silicates or ionic properties of oxides is discussed.
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  • Shigeta HARA, Masahisa IKUTA, Mitsuaki KITAMURA, Kazumi OGINO
    1983 Volume 69 Issue 9 Pages 1152-1159
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Foaminess and foam life were measured by gas injection into molten slags containing iron oxide. The results obtained in this work are as follows : (1) Foams observed in iron oxide slag melts are essentially unstable, and the foaminess of the slag melts depends on the rate of foaming by gas injection and decay rate of the foams. So the foam height at constant gas flow rate increases with increasing foam life. (2) The foaminess and foam life of the slags increase rapidly by decreasing O/Si ratio of the slags below 3.5. (3) Foam life has a relation to the surface tension of the slags, and the decrease of the surface tension of the slags contributes to the increase of the foam life. (4) Foaminess and foam life with Ar+ 3%H2 gas are higher than with Ar gas. It can be explained by lowering the coalescing rate of foams caused by reduction of foam size and existance of metal particle on the foam surface during the injection of the gas containing hygrogen. (5) Addition of P2O5, Na2O or CaF2 to the FeO-CaO-SiO2 slags contributes to increase in the foaminess and foam life. It may be shown that the Maragoni effect is responsible for the increase in foam stability by those additions. While the addition of MgO has no effect on foam stability.
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  • Yoshio WATANABE, Ji-Cheng HE, Shigeo ASAI, Iwao MUCHI
    1983 Volume 69 Issue 9 Pages 1160-1166
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    The theoretical correlation between mixing time (τ) and mixing power density (ε) which was presented in the previous work is confirmed through water model experiments for bottom blowing ladle, LD converter and RH degassing process. In the flow controled predominately by inertia force or turbulent viscous force, τ is proportional to ε-1/3Lγ in the three vessels where the power (γ) to vessel size (L) depends on the vessel type. The value of γ reflects the turbulent structure of agitated liquid and it is an essential factor for scale-up. Thus, the precise information of turbulence, i. e., the velocity variation is measured by a hot-wire anemometer and a spectral analysis of the velocity fluctuation is computed by the method of FFT (Fast Fourier Transform). The dissipation energy of turbulence (ε') can be evaluated from the information of the spectral analysis. A correlation between τ and ε' is presented in a unified foshion without regard to the kind of vessels.
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  • Yasuo SHIMOKAWA, Hidetake ISHIKAWA, Kango SAKAI, Hajime NITTO
    1983 Volume 69 Issue 9 Pages 1167-1174
    Published: July 01, 1983
    Released on J-STAGE: February 16, 2010
    JOURNAL FREE ACCESS
    In the surface finishing line of cold rolled steel sheet, it is desirable that a strip runs stably without vibration and without being supported by rolls in order to prevent the surface defects.
    An investigation was carried out to clarify the effect of the air cushion method on the prevention of the strip vibration in order to develop the technics of stable running of a steel strip. The following conclusions are obtained,
    (1) Stable running of a steel strip is possible by the air cushion method with the economical amount of air from nozzles.
    (2) Vibration behavior of a strip can be estimated by a theoretical calculation under various conditions of factors such as thickness of strip, length of strip between rolls, tension, and frequency of vibration.
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  • Yasuo SHIMOKAWA, Hidetake ISHIKAWA, Kango SAKAI, Hajime NITTO
    1983 Volume 69 Issue 9 Pages 1175-1182
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    A basic investigation was presented in the previous report about the vibration prevention of the static strip by the air cushion method.
    In this paper, the theoretical and experimental examinations are carried out to clarify the effect of running speed on the vibration prevention of the running strip and to know the cause of the phenomena of resonance caused by the air cushion in the strip which is supported with a pair of long span rolls. These are important problems when the air cushion method is applied to commercial lines.
    The following conclusions are obtained
    (1) Prevention of strip vibration by the air cushion method is possible at any line speed.
    (2) The cause of the phenomena of resonance are clarified and the undesirable influence on the prevention of strip vibration can be negligibly small by selecting the setting position of the air nozzles.
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  • Toshiro KOBAYASHI, Hitoshi MATSUBARA, Yoshisada UEDA
    1983 Volume 69 Issue 9 Pages 1183-1189
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    Analyses of the date obtained from the instrumented impact test and of its correlation with static and dynamic J integral values and various tensile properties are made in this study.
    It is shown that a dynamic bending yield load recorded in the instrumented Charpy V test can be easily converted to a dynamic tensile yield stress using Server's equation. It is also possible to estimate a true fracture strain, COD value, and SZW easily if the load point displacement is recorded. Temperature dependency of Charpy V energy and J integral values is rather well simulated by a curve fitting method. However, a half value transition temperture obtained in that method has no physical meaning. Dynamic JId is larger than a static JIc in the ductile fracture range in this study. This rise is proportional to the yield stress ratioσ ydy (1.2 -1.3). It is found, therefore, that the following relation exists in the both cases; JI/ σ y = 1. 6COD. Correlation between the fracture toughness and tensile properties proposed by Hahn and Rosenfield shows a good result, but ROLFE-NOVAK'S equation on the impact value gives a poor one.
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  • Eiji SUGIE, Masanori MATSUOKA, Toshiya AKIYAMA, Hiroshi MIMURA, Yoshio ...
    1983 Volume 69 Issue 9 Pages 1190-1197
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
    High Strength Line Pipe Research Committee in the Iron and Steel Institute of Japan has conducted five full scale burst tests with air pressure of 12.0 MPa on pipes of 48 in. in diameter and 0.720 in. in wall thickness of API. grade X 70, made with both controlled rolled steels and quenched and tempered steels. The arrestability of the pipes for the propagating shear fracture can be evaluated by Charpy absorbed energy and is not influenced by the existence of separation. The critical Charpy energy for arresting the shear fracture depends on the distance in which the crack should be arrested, and this phenomenon is well explained by solving the equation which governs the change in the crack velocity. Under the present test condition, the critical Charpy energy is 180 J for the arrest within one pipe length and 130 J for the arrest within two pipe length.
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  • Yoshizumi NISHI, Yutaka SHINATA, Yoichi ARAKI
    1983 Volume 69 Issue 9 Pages 1198-1205
    Published: July 01, 1983
    Released on J-STAGE: February 15, 2010
    JOURNAL FREE ACCESS
    In order to study the behavior of hot corrosion of mechanical alloy MA 754 induced by Na2SO4-NaCl mixtures in comparison with that of conventional wrought alloy having similar chemical composition, modified coating tests were conducted in still air in the temperature range from 900 to 1 100°C. The extent of corrosion was estimated by corrosion loss and total depth of penetration. The mixing rate of NaCl was varied from 0 to 100wt%. Results obtained were as follows :
    1) Corrosion loss of MA 754 increased abruptly at 25% NaCl, then increased gradually with an increase in NaCl content.
    2) Total depth of penetration of MA 754 increased with increasing NaCl content and had a maximum value at about 75% NaCl.
    3) For the corrosion of MA 754, internal penetration in the longitudinal direction was more significant than that in the transverse direction. This tendency was recognized markedly at 900 and 1 000°C, but at 1 100°C there was no difference between two directions because of little internal penetration.
    4) The corrosion loss and the total depth of penetration for MA 754 were larger than those of wrought alloys especially in mixed salt. The poor corrosion resistance of MA 754 was due to grain coarsening treatment.
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  • Akira SATO, Goro ARAGANE, Nobuo SAKUMA, Ryuichi NAKAGAWA, Shiro YOSHIM ...
    1983 Volume 69 Issue 9 Pages 1206-1208
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese], [in Japanese]
    1983 Volume 69 Issue 9 Pages 1209-1211
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1983 Volume 69 Issue 9 Pages 1212-1213
    Published: July 01, 1983
    Released on J-STAGE: June 30, 2009
    JOURNAL FREE ACCESS
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