Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 77 , Issue 2
Showing 1-17 articles out of 17 articles from the selected issue
  • Hiroshi YOKOYAMA, Tadaatsu MUKAE, Hiroshi WATABE
    1991 Volume 77 Issue 2 Pages 187-196
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
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  • Eiji ICHISE
    1991 Volume 77 Issue 2 Pages 197-200
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
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  • Sachio TAKAHASHI
    1991 Volume 77 Issue 2 Pages 201-208
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
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  • Takashi IKEDA, Masafumi MAEDA
    1991 Volume 77 Issue 2 Pages 209-216
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    The solubility of carbon dioxide has been measured by the thermogravimetric technique for CaO-CaF2-SiO2 molten fluxes at temperatures from 1 200 to 1 500°C. The values of carbonate capacity (CC=wt%CO32-/PCO2) were calculated by the solubilities and the partial pressure of carbon dioxide.
    Carbonate capacities were compared with the sulfide capacities appearing in the literature. A linear relationship was obtained for CS2- and CC as log CS2-=1.1 log CC -3.3 at 1 200 °C.
    With increasing CaF2 from 29.0 to 88.2wt% at constant XCaO/XSiO2 of three at 1 400°C, CC increased from 0.53 to 0.89.
    The influence of the replacement of CaO by CaF2 on CC at various SiO2 content has been investigated. With increasing CaF2, CC decreased for fluxes of XCaO/XSiO2 smaller than three, while it increased for fluxes with a ratio larger than three.
    Carbonate capacities of slags of XCaO/XCaF2=1.56 decreased with increasing SiO2 content from 8.3 to 25wt%. In fluxes of which the ratio was 0.68, CC decreased with an increase of SiO2 more than 5wt%. There was a maximum of CC at 0.8wt%SiO2 for the fluxes of a ratio of 0.14.
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  • Bong-Hoon PARK, Hideaki SUITO
    1991 Volume 77 Issue 2 Pages 217-223
    Published: February 01, 1991
    Released: January 18, 2010
    JOURNALS FREE ACCESS
    The Fe2+/Fe3+ and Mn2+/Mn3+ redox equilibria in the Na2O-B2O3 melts have been individually measured as a function of the melt compositions, temperatures, oxygen partial pressures, and dopant element concentrations. The mutual interaction of these two redox couples has been studied by Electron Spin Resonance (ESR) in the Na2O·2B2O3 melts.
    The redox ratios of Fe and Mn in the Na2O-B2O3 melts tend to decrease with increasing the dopant concentration.A plot of log[(M2+)/(M3+)] versus -logPO2 indicated a straight line of the slope of 8 and 4 for Fe and Mn, respectively. The values for the reduction enthalpy of Fe and Mn in Na2O-B2O3 melts were found to be 80-120 kJ/mol and 40-60 kJ/mol, respectively. The redox ratio of Fe and Mn decreased with increasing the XNa2O /XB2O3 ratio. It was shown by ESR spectroscopy that the electron exchange reaction:Fe2++Mn3-=Fe3++Mn2+ proceeded to the right.
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  • Norio IMAI, Toshihiro TANAKA, Toshitaka YUKI, Takamichi IIDA, Zen-ichi ...
    1991 Volume 77 Issue 2 Pages 224-230
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    The equilibrium distribution coefficients of Sn between solid and liquid phases in Fe-Sn binary and Fe-C-Sn ternary alloys have been determined experimentally, and the distribution behavior of Sn between solid and liquid phases was discussed thermodynamically. Furthermore, the activity of Sn in coexisting solid and liquid phases has been measured on Fe-C-Sn ternary alloy at the temperature near eutectic. The equilibrium distribution coefficient of Sn between solid and liquid phases in Fe-C-Sn ternary alloy increased remarkably as carbon concentration increased. It was found that carbon concentration might contribute the equilibrium distribution of Sn between solid and liquid phases significantly and Sn had positive interaction for carbon in high carbon concentration range near eutectic.
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  • Tomohiro AKIYAMA, Gaku OGURA, Hiromichi OHOTA, Reijiro TAKAHASHI, Yosh ...
    1991 Volume 77 Issue 2 Pages 231-235
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    Thermal conductivities of dense pure hematite, magnetite, wustite and iron have been measured by the laser flash method in the temperature range from room temperature to 1 553 K. The relatively high thermal conductivities of dense pure hematite, magnetite and wustite at low temperature were found and these values decreased with increase of temperature. The thermal conductivity of wustite was half to fifth as large as that of hematite or magnetite.
    The results obtained were summarized in the form of an empirical equation k=1/(AT+B). Thermal resistivities, defined by reciprocal thermal conductivity, of three iron oxides change linearly as a function of temperature up to Tammann temperature which is about half of melting temperature.
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  • Koichiro SHIBATA, Masakata SHIMIZU, Sin-ichi INABA, Reijiro TAKAHASHI, ...
    1991 Volume 77 Issue 2 Pages 236-243
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    Gas-powder two phase flow in packed beds were investigated by using a one-dimensional cold model and a mathematical model for clarifying the behavior of powders in a blast furnace. Following results were obtained;
    (1) Two phase flow showed higher pressure drop compared to clean gas flow. The increase in the pressure loss was mainly caused by the increase in the hold-up of powders in the region of low gas velocity and by the interaction force between powders and packed particles in the region of high gas velocity.
    (2) A mathematical model of gas-powder two phase flow in packed beds was developed considering an interaction force between gas and powders expressed by the drag force and the Richardson-Zaki's voidage function.
    (3)An interaction coefficient between powders and packed particles which was defined on the basis of the momentum balance equation of powders in packed beds was obtained from the experimental data.
    (4) Blockade occured at the certain gas velocity where the hydraulic diameter of packed bed including powders was below 6 times as long as powder diameter.
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  • Masaru SAGIYAMA, Akira HIRAYA, Tsutomu WATANABE
    1991 Volume 77 Issue 2 Pages 244-250
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    The electrochemical behavior of electrodeposited Zn-Fe alloys in neutral (pH =5.6) 5%NaCl solution was investigated as a basis to elucidate the corrosion behavior of Zn-Fe alloy electroplated steel.
    (1)Electrodeposited Zn-Fe alloys containing 427%Fe exhibited the suppression action of oxygen reduction reaction in neutral 5%NaCl solution. The corrosion current density of the alloys was remarkably decreased due to the suppression of oxygen reduction reaction compared with that of electrodeposited Zn and Zn-Fe alloys containing more than 30%Fe.
    (2)The suppression action of oxygen reduction reaction was considered to be attributed to suppression of electron transfer through the initial oxide film formed on the alloys, because the suppression occurred in the presence of the surface oxide film and anomalously large Tafel slope of ca. -4RT/F equivalent to that explained by dual barrier model was observed.
    (3)The initial oxide film was not stable in 5%NaCl solution, thus losing most of the suppression action after several hour immersion. The suppression action, however, was recovered after a short time exposure to the air, indicating that the oxide film having the suppression action was formed again.
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  • Masaru SAGIYAMA, Akira HIRAYA, Tsutomu WATANABE
    1991 Volume 77 Issue 2 Pages 251-257
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    As a basis to elucidate the mechanism of underfilm corrosion of Zn-Fe alloy electroplated steel, the electrochemical behavior of electrodeposited Zn-Fe alloys was investigated in alkaline solution of pH ranging from 9.5 to 13.6.
    (1)In 5%NaCl solution of pH=9.5 and 11.7, low corrosion current density was observed in the range of low Fe content in the alloy due to the suppression action of oxygen reduction reaction caused by the initial oxide film formed on the alloys, which was observed also in neutral 5%NaCl solution.
    (2)In 5%NaCl solution of pH=13.6, the corrosion current density tended to increase with increasing Fe content in the alloy in the range of 50% or less Fe content and it significantly increased compared with that in the solution of pH=9.5 and 11.7 in the same Fe content range as above, presumably resulting from the change in both anodic and cathodic reactions.
    (3)In NaCl-free solution of pH=12, electrodeposited Zn and Zn-Fe alloys were passivated, thus leading to anodic control of corrosion. Furthermore, the corrosion current density decreased with increasing Fe content in the alloy in the solution. It was suggested that the decrease in the corrosion current density resulted from reinforcement of the surface film by iron in the alloys and passivation of iron in the alloys.
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  • Seijun HIGUCHI, Ken'ichi ASAKAWA
    1991 Volume 77 Issue 2 Pages 258-265
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    The effect of conditions of corrosion test and nature of corrosion product on corrosion resistance of aluminized steel under salt corrosive environment was studied. We obtained the following result.
    (1) In continuous salt spray test condition, corrosion rate is high because of bulky corrosion product which was mainly constituted by boehmite (γ-AlOOH) and bayerite (β-Al(OH)3).
    (2) In condition which salt spray test and humidity cabinet test was repeated reciproally, fine and amorphous corrosion product was produced. Because it acts as a protection film which restrain the cathode reaction, corrosion rate is restrainted remarkablely.
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  • Seijun HIGUCHI, Ken'ichi ASAKAWA
    1991 Volume 77 Issue 2 Pages 266-273
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    The influence of Cr content in substrate steel on corrosion resistance of aluminized steel sheet applied to be the exhaust system of automobile in salt corrosive environment was studied, and the following results were obtained.
    (1)Corrosion resistance of aluminized steel became better with increase of Cr content in steel.
    (2)Cr in steel diffused into coating layer in aluminizing process. With the effect of Cr, the aluminized steel shows excellent corrosion resistance. Cr in coating layer helps the generation of protective film which restrains cathodic reaction.
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  • Michiko YOSHIHARA, Tetsuya SUZUKI, Ryohei TANAKA
    1991 Volume 77 Issue 2 Pages 274-281
    Published: February 01, 1991
    Released: June 19, 2009
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    The improvement of oxidation resistance for intermetallic compound TiAl and TiAl containing 1.5 mass% manganese was investigated by means of surface treatments ; heat treatment under a low partial pressure oxygen atmosphere, aluminum diffusion coating, and combined surface treatment composed of two stated above. The effect of the surface treatments was evaluated from the results of the cyclic oxidation tests carried out at 900°C and 950°C in static air. Heat treatment under the low partial pressure oxygen atmosphere was very effective to improve the resistance for the cyclic oxidation of TiAl at 900°C, but not sufficient for TiAl at 950°C or for TiAl-1.5%Mn alloy at 900°C and 950°C. Aluminum diffusion coating was effective for both the specimens at 900°C and 950°C, but large cracks were found in every specimen at the edges. The specimens with combined surface treatment showed a superior oxidation resistance to the nickel-base superalloy Inconel 713C. Especially, specimens heat treated under the low partial pressure oxygen atmosphere followed by aluminum diffusion coating were found to have a tight diffused layer with smaller cracks, compared to ones with diffusion coating only.
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  • Takahiro KASHIMA, Shunichi HASHIMOTO, Hiroshi INOUE, Naotsugu INAKAZU
    1991 Volume 77 Issue 2 Pages 282-289
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    The influence of the lubrication condition during hot-rolling in non-crystallization ferrite region on r-value and texture for cold rolled and annealed steel sheet has been studied. Hot rolling was carried out under the condition applying tallow lubricant, applying boron-nitride lubricant or non-lubricating.
    Textures through the thickness have investigated by mainly used vector method (3D crystal orientation analysis). In the case of hot rolling without lubricating, the texture of the hot rolled sheet is heterogeneous through the thickness. However when cold rolling is introduced after hot rolling, the heterogeneity through the thickness decreased.
    Furthermore, the transition in the surface texture of the steel sheets during cold rolling was investigated.
    Consequently, even though in the case of non-lubricating hot rolling in non-recrystallization ferrite region, heterogeneity through the thickness decreased applying cold rolling after hot rolling and the advantageous texture for r-value is formed homogeneously through the thickness. However the luburicating condition during hot rollig affects on disappearence of the shear texture in the surface during cold rolling.
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  • Norio MARUYAMA, Masae SUMITA, Kozo NAKAZAWA
    1991 Volume 77 Issue 2 Pages 290-297
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    The analysis of factors controlling fretting fatigue life has been tried using a Ti-6Al-4V alloy under a number of environments. The failure mechanism of fretting fatigue was related to friction force and the environments.
    At a contact pressure of 50 MPa in air and argon, "elastic slip" arose between the pad and the contacting surface and the main crack was initiated at the outer area of the contacting surface.
    At a contact pressure of 50 MPa under liquid environments such as pure water, synthetic sea water, CH3OH, and LiCl-CH3OH, and at a contact pressure of 20 MPa in air, "macro slip" arose and the main crack was initiated at the middle area of the contacting surface. The fretting fatigue life in synthetic sea water or CH3OH from which the effect of friction force was eliminated was the same as that in air. The life in pure water, however, was longer and the life in LiCl-CH3OH was shorter, compared with the life in air. It seemed that the former was caused by the removal of micro carcks due to wear particles in fretting and the latter was caused by the stress concentration due to the adhesion of wear debris to the contacting surface.
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  • Hideshi SUMIYOSHI, Tachio TAKANO, Chitoshi MASUDA
    1991 Volume 77 Issue 2 Pages 298-305
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    Computer image processing technology was applied to cleavage fracture surface analysis and an algorithm for the estimation of 3-dimensional cleavage facet boundaries and 3-dimensional facet areas were developed. An angle αi, j between relative normal vectors of a mesh plane Mi, j and the adjacent mesh plane Mi+1, j along X axis was calculated and αi, j was compared to α threshold angle αth. If αi, j is larger than αth and αi+1, j is smaller than αth, the mesh plane Mi+1, j was decided to be the facet boundary. The same calculation was continued along both X- and Y-axes to obtain facet numbers contained in the analyzed area. After the estimation of facet boundaries, 3-dimensional facet areas were calculated from the 2-dimensional facet areas divided by cosβi, j, which is the angle between average normal vector of α facet and vertical vector. The algorithm developed in this study was applied to analyze the cleavage fracture surfaces of mild steel and HT80 steel and the effect of the threshold angle on the estimated facet numbers, distribution of the values of α and the 3-dimensional facet areas were discussed. The developed method is very useful for analyzing the cleavage facet size and for discussing a relationship between cleavage fracture and microstructures of steels, such as ferrite and the prior austenite grain sizes.
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  • Satoshi WATANABE, Shoji SATO, Ippei NAKAGAMI, Shinichi NAGASHIMA
    1991 Volume 77 Issue 2 Pages 306-313
    Published: February 01, 1991
    Released: June 19, 2009
    JOURNALS FREE ACCESS
    Fe-Ni-Mn alloys having appropriate value of stacking fault energy possess good damping characteristics at plastically deformed conditions.
    5 types of the alloys containing 37 wt%Ni and 1115 wt%Mn were investigated with an intention of development of high damping ferrous materials. A transversal vibration method was used to examine their characteristics evaluated by a logarithmic decrement δ.
    For a Fe-5 wt%Ni-15 wt%Mn alloy deformed by 15%, the highest δ, 1×10-2, was obtained at 4×10-5 as the maximun strain amplitude. The value is not enough for the practical use, but is was expected that the alloys would have more high damping potentials from the fact that the δ has been remarkably increased with increasing of strain amplitude on the specimen. Because of an unsufficient power of the apparatus used here, experiments were limited to a very small range of amplitude.
    A model is proposed for the mechanism of energy consumption in the alloy where recombination of half dislocations to a perfect one is caused at the intersection of two different slip planes during vibration and vice versa.
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