Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 64 , Issue 2
Showing 1-26 articles out of 26 articles from the selected issue
  • [in Japanese]
    1978 Volume 64 Issue 2 Pages 185-186
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
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  • Saburo KOBAYASHI, Yasuo OMORI
    1978 Volume 64 Issue 2 Pages 187-195
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    The diffusion of gaseous reactant in pores is one of the processes essentially influencing the rate of the solution loss reaction of lumpy coke, if the reaction proceeds by partial internal burning. Then, the effective diffusion coefficient of carbon dioxide in lumpy coke was estimated through analysing the over all rate of the reaction by the application of the rate equations for complete internal burning.
    Concerning slab samples, the diffusibility, (De/D) of carbon dioxide was respectively evaluated to be 1.8×10-2 and 1.2×10-2 for conventional metallurgical coke and formed cokes which had the porosities being 0.52 and 0.33 respectively.
    The characteristic size of crushed coke depended on the estimation standard used. For instance, the sphere-equivalent size differed considerably from the size defined as the ratio of volume to external surface area of a particle, owing to the irregular shape of the crushed materials. The value of the diffusibility obtained by the use of the sphere-equivalent size was 2 to 3 times that according to the other size estimation and was nearly constant at 3.2×10-2 regardless of temperature above 1000°C for both kinds of coke, while it decreased with increase of temperature above 1000°C according to the other estimation.
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  • Toshiharu FUJISAWA, Kazuya IMAOKA, Hiroshi SAKAO
    1978 Volume 64 Issue 2 Pages 196-205
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    The equilibrium relationship between solid and liquid has been studied for Fe-Mn-Si ternary system.
    The solid-1iquid equilibrium temperature can be related to the concentrations of Mn and Si in liquid iron alloy as follows:
    From measured solid-liquid equilibrium distribution ratio, the activity coefficients of Mn and Si in δ-iron are calculated. The results obtained are as follows:
    where pure solid Mn and Si are taken as the standard states.
    Using these results, the composition of δ-iron in equilibrium with liquid Fe-Mn-Si alloy can be calculated.
    T=te+273
    [% i (S) ]: Weight percentage of component i in solid phase (δ-iron)
    [% i (l) ]: Weight percentage of component i in liquid phase
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  • Minoru ARITA, ST. PIERRE
    1978 Volume 64 Issue 2 Pages 206-214
    Published: February 01, 1978
    Released: March 15, 2010
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    Ratios of the vapor concentrations of Mn to Fe have been determined for Fe-Mn binary alloys having 50 at% Mn or less at 1833K by a vapor transport method. In the present transport method, vapor saturation needs not be satisfied in order to measure vapor concentration ratios. The thermodynamic activities were calculated with the aid of the Gibbs-Duhem equation. The calculation has shown that a maximum of the Mn activity coefficient (yMn) exists near 17 at% Mn, and that negative deviation of yMn from ideality below 6 at% Mn and positive deviation above 6 at% Mn are seen. It has been shown that the experimental results are in qualitative agreement with the behaviors of other physical chemical properties such as inter-diffusivity, viscosity, and electrical resistivity. The existence of a maximum of yMn has been accounted for by considering a plausible variation of the liquid structure of Fe-Mn alloys in connection with the phase diagram. On combining the present data and other data, the most reliable values of the activities in Fe-Mn alloys at 1833K have been presented in tabular and graphical forms.
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  • Kusuhiro MUKAI, Hirofumi FURUKAWA, Takashi TSUCHIKAWA
    1978 Volume 64 Issue 2 Pages 215-224
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    An approach based on the thermodynamics of irreversible processes has been applied to the study of the interfacial tension σ′ms between liquid dilute Fe-Si-O alloys and CaO-SiO2-FeO slags of nonequilibrium state during iron transfer through the interface. Behaviours of the σ′ms obtained by experiments could be explained reasonably from the phenomcnological equation, which describes the coupling phenomena between surface flow and mass flow. Surface transfer coefficients M and phenomenological coefficients, L22 and L21 (=L12) were evaluated from the experimental results of σ′ms. Relations between the iron transfer rate and the values, M, L22, and L12 could be explained reasonably from the movements of the metal-slag interface and the direction of the iron transfer by considering the physicochemical properties of the system. The values, M and L12 in the case of the iron transfer from the metal to the slag in steady state indicate the possibility of the actual increase in the iron transfer rate by the interfacial movements.
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  • Kazumi OGINO, Hidehiro HASHIMOTO, Shigeta HARA
    1978 Volume 64 Issue 2 Pages 225-231
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    In order to measure the electrical conductivities of fluloride melts at high temperature, fbur electrodes method with AC has been developed. Various conditions in measurement of solution resistance were determined by use of potassium chloride aqueous solution at room temperature. The electrical condulctivities of pure calcium fluoride and those of commercial fluxes such as ANF-1P, ANF-6 and ANF-7 were measured in the temperature range from 1450 to 1750°C. The rcsults showed that the use of graphite crucible was unfavourable fbr those melts and the sufficient dehydration of samples and atomospheric argon gas were desirable. The specific conductivities of calcium fiuoride melts obtaincd at the temperatures of 1500, 1600 and 1700°C were 6.15, 6.40 and 6.60 mho/cm, respectively. Those results were compared with that of previous investigations.
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  • Kazumi OGINO, Shigeta HARA, Hidehiro HASHIMOTO
    1978 Volume 64 Issue 2 Pages 232-239
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    Electrical conductivities of CaF2-based fluxes for electroslag remelting were measured and the effects of the additions on the conductivity of CaF2 melt were studied. From the results, conduction mechanism of CaF2-based melts were discussed in the term of molar conductivity. The additions of alkali earth metal fluorides and oxides, such as MgF2, BaF2, MgO, CaO and BaO, varied the molar conductivities of CaF2-based melts in accordance with the intensity of cation-anion attraction. It seems that those additions have a tendency to make an ionic pair in the melts. The additions such as Al2O3, TiO2 and ZrO2, may react with fluorine ions to make oxy-fluoride complex ions and then remarkable decreace of electrical conductivity by those additions can be explained.
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  • Shigehiro KIMURA, Mitsuo FURUYA, Hiroyuki KATAYAMA, Hiroyuki KAJIOKA, ...
    1978 Volume 64 Issue 2 Pages 240-249
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    As a means of preventing hydration of lime, a partial carbonation method is tried and the condition for the carbonation and properties of carbonated lime are investigated.
    (1) The course of carbonation is expressed by ΔWCO2=ktn (ΔWCO2: weight increase by carbonation, t: time, k, n, : constants depending on temperature, CO2% in atmosphere and so on). Beyond a value of WCO2, which depends on temperature, the rate of weight increase becomes small abruptly. In order to prevent the hydration effectively, lime at the end of CO2-treatment must reach this state.
    (2) The degree of hydration of lime treated in an adequate condition (ΔWCO2: 5-7%) is 1/10 to 1/20 of that of ordinary lime.
    (3) Hydrogen content in molten steel does not increase during fluxing of CO2-treated lime. In an arc furnace, however, in which hydrogen is apt to be absorbed from atmosphere, it is desirable to control the arc atmosphere as well as to use CO2-treated lime.
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  • Yoshihiro SAITO, Yoichi TAKAHASHI, Kenzo KATO
    1978 Volume 64 Issue 2 Pages 250-259
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    By means of laboratory hot rolling test of mild steel bars, those chracteristic values of the pass rollings shown in the title were measured under the wide range of rolling conditions.
    Through the treatment of experimental data, it has been found for each pass sequence that 1) the spread exponent (k) defined to determine spread and elogation of metals may be expressed as a function of shape factor (US), and 2) mean forward slip (φ) defined to determine the effective roll radius may be expressed as a function of elongation (λ-1), and 3) non dimensional roll force (Q) and torque arm coefficient (φ) may be expressed as functions of mean roll gap ratio (m).
    Making use of these empirical expressions, a new calculation mass-model was presented, which enabled to predict those characteristic values of rolling with very high accuracy for any arbitrary rolling conditions of those pass sequences.
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  • Akinori MATSUDA
    1978 Volume 64 Issue 2 Pages 260-267
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    Observations were made on the plastic deformation of iron single crystals subjected to the simple shear on the single and multiple slip systems to examine the work hardening behavior. When the applied shear stress was matched to the single slip systems, the easy glide in stage I was clearly observed in the stressstrain curves. On the other hand, when the applied shear stress coincided with the multiple glide system, the linear hardening in stage II was clearly recongnized from the early stage of deformation.
    To examine the work hardening mechanisms, the strain rate-cycling tests were performed on crystals in easy glide and linear hardening regions and the average effective and internal stresses were estimated as a function of strain in these regions.
    In the easy glide in stage I. the effective stress is essentially independent of the strain whilst the internal stress increases with strain. The work hardening in stage I resulted from the increased long range internal stress field due to dislocation tangles and cell walls. On the other hand, the work hardening in stage II is caused by the increase in both internal and effective stresses. The ratio of the internal and effective stresses is approximately 2.6. This result suggests that the work hardening in stage II is associated with the long range internal stress field as well as the hardening in stage I.
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  • Susumu HORIBE, Ryuhei SAGAWA, Toshio FUJITA, Toru ARAKI
    1978 Volume 64 Issue 2 Pages 268-277
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    The relationships between microstructures and cyclic properties such as the Bauschinger effect, fatigue damage, crack initiation, and crack propagation in carbon steels were investigated. For each heat treatment the cyclic stress or strain response was measured until the crack initiation. Optical metallography and transmission microscopy were used to characterize the microstructural changes during testing. Fatigue crack propagation properties were reported using the empirical equation da/dN=C (ΔK) m.
    It was found that Bauschinger behaviour was well reflected in low cycle fatigue properties, and the higher was Bauschinger stress of the structure, the more remarkable was the softening. During high cycle fatigue process the dispersion of the fine pearlite and cementite is found to facilitate the cross slip and to result in high plastic strain, but the existence of subboundaries tends to restrict the increase of the plastic strain. Fatigue crack initiation sites depended on the heat treated structures for one steel. It was found that at the low ΔK level fatigue crack propagation properties were not affected by various strengthening structural factors, but generally controlled only by the mechanical properties of matrix.
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  • Susumu HORIBE, Yuichi SEKI, Toshio FUJITA, Toru ARAKI
    1978 Volume 64 Issue 2 Pages 278-287
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    An attempt has been made to survey the fatigue behaviour of three different austenitic steels. The materials tested are an Fe-3ONi alloy as metastable austenite, an Fe-38Ni alloy as stable austenite, and an Fe-25Ni-16Cr alloy of low stacking fault energy. It was found that at low stress amplitudes the fatigue life of the metastable steel was longer than that of the stable ones, while at high stress amplitudes the metastable steel was inferior to the stable ones. This is probably attributed to the differences of the rate and period of martensite formation. The fatigue life of the Fe-25Ni-16Cr alloy was less than that of the Fe-38Ni alloy at only high stress amplitude. The Fe-30Ni alloy was cyclically hardened remarkably with martensite formation, but its cyclic strain behaviour except the hardening resulted from the martensite formation was extremely similar to that of the Fe-38Ni alloy, that is, at high stress amplitudes the hardening occured remarkably and at low stress amplitudes softening occured slightly. Fatigue crack propagation properties of the Fe-30Ni alloy was also better than that of the Fe-38Ni alloy at low ΔK level, but at high ΔK level the former was inferior to the latter.
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  • Shigeo NOMURA, Masayoshi HASEGAWA
    1978 Volume 64 Issue 2 Pages 288-296
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    The damage of austenitic stainless steels heated at high temperature and high pressures of hydrogen was investigated with reference to the metallurgical factors. Main results obtained are as follows:
    1) The solubility of hydrogen (wtppm) in 304 steel hydrogenated at T: 473-723 (K) under P: 10-300 (atm) is given by the following Sieverts' equation,
    [H] =9.261/√P exp (-1470/RT)
    where, R is the gas constant (cal/mol).
    2) The embrittlement of 304 steel increased rapidly with increasing hydrogen content until about 30 wtppm above which the influence of hydrogen content weakens.
    3) The sensitivity to hydrogen embrittlement (HE) of austenitic stainless steels increased largely with decreasing Ni equivalent less than about 25% and the better correlation between the sensitivity to HE and the volume of stress-induced martensite produced under tensile testing can be obtained.
    4) The sensitivity to HE of austenitic stainless steels increased remarkably with increasing the grain size and the volume of carbide precipitated at grain boundary or ferrite phases precipitated in austenitic matrix. The existence of notch in the tensile specimen can also increase it.
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  • Toshihiko HATA, Yoshihisa KONO, Yoko BANNO
    1978 Volume 64 Issue 2 Pages 297-302
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
    There is in Japanese Industrial Standard the method for determination of nitrogen oxides (NOx), JIS K 0104 in which the mesuring range of phenol disulfonic acid method (PDS method) is described to be between 10 and 2000ppm. However, it is known that this method shows considerably lower values in the range of low concentration of NOx and requires very long time for analysis.
    Therefore, the authors devised a gas sampling apparatus in which NO was oxidized with oxdizing gas to remove these weak points. Two methods, the oxidation method with oxygen and oxidation method with ozone, for the determination of NOx have been experimented.
    The following results were obtained.
    (1) Analytical results of NO balanced with nitrogen by this method agreed closely with those by chemiluminescent method (NOx meter) and standard deviation for 10ppm NO and 50ppm NO were 0.126 and 0.293 respectively.
    (2) The time required for analysis was shortened from 1/5 to 1/7 by the use of this method.
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  • Kazuo TANOSAKI
    1978 Volume 64 Issue 2 Pages 303-309
    Published: February 01, 1978
    Released: March 15, 2010
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    In order to develop a low alloy heat resistant steel which has a higher creep-rupture strength than that of 21/4Cr-1Mo steel for boiler main steam pipe, the effects of cooling rates at quenching (1400°C/h-300°C/h) and of thermal cycle on the high temperature strength of 1Cr-1Mo-1/4V steel have been investigated. The thermal cycle is designed so as to simulate the thermal condition encountered in the hot bending of the main steam pipe. The high temperature strength of the welded joint of the steel has also been investigated. It is found from the results that this steel is unsuitable for main steam pipe.
    A trial, therefore, has been made on the improvement of the hardenability and the high temperature strength of 1Cr-1Mo-1/4V steel, and the effects of increase in the content of C, Cr and Mn, and the effects of Ni or B addition on the microstructure and the high temperature strength of this steel have been investigated. Experimental results show that 1Cr-1Mo-1/4V steel with 0.003wt%B has a favourable structure (all bainite) and high temperature strength even at the cooling rate as low as 300°C/h.
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  • Kazuo TANOSAKI
    1978 Volume 64 Issue 2 Pages 310-316
    Published: February 01, 1978
    Released: March 15, 2010
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    For the purpose of application to boiier main steam pipes, the continuous cooling transformation, high temperature strength, weldability by restrained crack test, creep-rupture strength and the oxidation resistance of a newly-developed 1Cr-1Mo-1/4V-0.003B steel have been investigated.
    This steel has a better hardenability than 1Cr-1Mo-1/4V steel. The high temperature strength of this steel does not decrease with the decrease of cooling rate from 1400°C/h to 300°C/h and does not change appreciably by the hot bending thermal cycle. The 105h creep-rupture strength at 600°C of this steel as the base metal is 8.4kg/mmmm2 and that as a welded joint is 6.1kg/mmmm2. These values are 2 times and 1.5 times higher than those of 21/4Cr-1Mo steel respectively. The improvement of high temperature strength is mainly due to the upper bainite structure with uniformly dispersed fine VC carbides. Furthermore, the weldability and the oxidation resistance at temperatures below 650°C of this steel are comparable to those of 21/4Cr-1Mo steel. Thus this steel is favourable for the boiler main steam pipe application.
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  • Akira AZUSHIMA
    1978 Volume 64 Issue 2 Pages 317-330
    Published: February 01, 1978
    Released: March 15, 2010
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  • Masateru OHNAMI, Masao SAKANE
    1978 Volume 64 Issue 2 Pages 331-337
    Published: February 01, 1978
    Released: March 15, 2010
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  • Imao TAMURA
    1978 Volume 64 Issue 2 Pages 338-347
    Published: February 01, 1978
    Released: March 15, 2010
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  • [in Japanese], [in Japanese]
    1978 Volume 64 Issue 2 Pages 348-352
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1978 Volume 64 Issue 2 Pages 353-359
    Published: February 01, 1978
    Released: March 15, 2010
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1978 Volume 64 Issue 2 Pages A1-A16
    Published: February 01, 1978
    Released: March 15, 2010
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1978 Volume 64 Issue 2 Pages A17-A36
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1978 Volume 64 Issue 2 Pages A37-A56
    Published: February 01, 1978
    Released: March 15, 2010
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1978 Volume 64 Issue 2 Pages A57-A72
    Published: February 01, 1978
    Released: March 15, 2010
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1978 Volume 64 Issue 2 Pages A73-A88
    Published: February 01, 1978
    Released: March 15, 2010
    JOURNALS FREE ACCESS
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