Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 66, Issue 8
Displaying 1-20 of 20 articles from this issue
  • [in Japanese]
    1980 Volume 66 Issue 8 Pages 1055
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
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  • Osamu TSUCHIYA, Ken OHTUKI, Takeshi SUGIYAMA, Mamoru ONODA, Isao FUJIT ...
    1980 Volume 66 Issue 8 Pages 1057-1065
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    This paper describes experimental results of physical and reducing properties of pellets up to 1 100°C of reduction temperature as a function of basicity, SiO2 contents and indurating temperature during the addition of limestone. These properties are closely correlated to the bonding structures of indurated pellets which are classified into 6 types.
    Those are hematite (A), hematite+low-basicity silicate slag (B), hematite+calcium ferrite (C), hematite+high basicity silicate slag+di-calcium silicate (D), A+B, and C+D bonding structures.
    A-type pellets have lower crushing strength and higher open porosity, swelling index and reduction degree, B-type ones have the highetst crushing strength and swelling index and the lowest open porosity and reduction degree, C-type ones have the highest open porosity and reduction degree and the lowest swelling index, and D-type ones have much higher crushing strength and reduction degree and much lower swelling index.
    Therefore, physical and reducing properties of pellets change remarkably by adding limestone.
    Pellets with (C+D)-bonding structures give the highest levels of crushing strength and reduction degree, and the lowest swelling index.
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  • Mitsuo SUMITO, Nobuo TSUCHIYA, Kyoji OKABE, Koji SANBONGI
    1980 Volume 66 Issue 8 Pages 1066-1074
    Published: July 01, 1980
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    The solubilities of titanium and carbon in Fe-Csat-Ti alloys were determined at temperatures from 1300°C to 1500°C. Some of the previously reported solubility values of titanium were determined by measuring the acid-soluble titanium contained in rapidly cooled samples in which the sedimentation of titanium carbide was inevitable. This sedimentation resulted in the difficulty in determining the accurate solubility of titanium. In order to overcome the difficulty, two methods were newly devised to measure the total titanium content in rapidly cooled samples.
    The results obtained were as follows:
    (1) The solubility of titanium at temperatures from 1300°C to 1500°C was expressed as, log[%Ti]=(-6760/T)+3.965
    (2) By the use of the carbon solubility at different contents of titanium, the temperature dependence of interaction coefficient, eCTi, at temperatures from 1350°C to 1500°C was determined as,
    eCTi=(-221/T)-0.072
    (3) The change of standard Gibbs free energy for the reaction, Ti+Csat=TiC(s), was obtained as ΔG°=-30500+13.3T
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  • Eiji ICHISE, Toshiaki MARUO, Hiroyasu SASHO, Yoshiyuki UESHIMA, Toshis ...
    1980 Volume 66 Issue 8 Pages 1075-1083
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    The ion intensities of iron in Fe-Mo alloys have been measured at 1 823K over the whole range of composition by the Knudsen cell-mass spectrometric method, and the activities of iron and molybdenum in this binary system were determined. In this method silver or iron was used as the internal standard substance to cancelthe constants which are intrinsic in the measurement and can not be determined. The activity coefficients of molybdenum and iron in the infinitely dilute solutions are as follows:
    γoMo(1)=1.54(+0.32-0.26), γoMo(s)=0.70(+0.39-0.37) and γoFe(1)=6.0(±1.1)
    The first and second order interaction parameters of molybdenum in liquid iron, ε(Mo)Mo and ε(Mo)2Mo in atomic fraction unit and e(Mo)Mo and e(Mo)2Mo in weight percent unit are represented as follows:
    ε(Mo)Mo=4.1(±1.4), ε(Mo)2Mo=-11.0(±4.1) and
    e(Mo)Mo=1.21×10-2(±0.35×10-2), e(Mo)2Mo=-1.1×10-4(±0.8×10-4).
    Furthermore, the heat of sublimation at 298K and fusion of pure iron have been determined by the second law method as follows:
    ΔHs(α)298=414kJ/g-atm
    ΔHm1809=15.1kJ/g-atm.
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  • Takaho KAWAWA, Ryoichiro IMAI, Yasunobu KUNISADA, Kiyomi TAGUCHI
    1980 Volume 66 Issue 8 Pages 1084-1092
    Published: July 01, 1980
    Released on J-STAGE: May 25, 2010
    JOURNAL FREE ACCESS
    A fairly simple model is proposed, which explains the formation mechanism of equi-axed crystals and predicts the profile of equi-axed zone in ingots. The validity of the model is proved by comparing the results of the experiments with that of the calculation according to the model.
    The results are as follows:
    (1) Profiles of equi-axed crystal zone in ingots, calculated by the above model, well coincide with that observed on the macro solidification structure of ingots.
    (2) The model is based on the assumption that the rate of equi-axed crystal formation is proportional to the volume of liquid/solid zone (interdendritic zone).
    (3) Therefore, equi-axed crystals in ingot are formed mainly at solidification front (liquid/solid zone) and sediment to the bottom of ingot to form equi-axed crystal zone, when the pouring temperature of steel is high enough and the steel meniscus is well covered with the exothermic powder, which excludes "showering" from the meniscus.
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  • Yukiyoshi ITOH, Tadaharu OKAJIMA, Kiyoshi TASHIRO
    1980 Volume 66 Issue 8 Pages 1093-1102
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    Refining of the solidification structures of Type 430 stainless steel by the mechanical vibration and the liquid surface vibration was tried. The structures of 15 kg test ingots were remarkable improved by these vibration methods. Change of structure into the equiaxed one starts after the superheat of liquid steel disappears.
    The liquid surface vibration was applied to 6t ingots for practical use and its effect on structure refining was confirmed. By the investigation of size of crystals and negative segregation in the equiaxed zone, it was concluded that the structure refining was caused by the showering of the free crystals.
    In the case of continuously cast slabs, the liquid surface vibration was effective only under low superheat.
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  • Kenji CHIJIIWA, Yotaro HATAMURA, Tetsuro SUZUKI
    1980 Volume 66 Issue 8 Pages 1103-1112
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    A new experimental method for stress analysis of a steel slab in hot rolling or continuously cast slab by plasticine is developed. When plasticine is used for simulation of steel in high temperature, it is thought that not only the simulation of deformation, which has been made conventionally, but also the simulation of stress and force is capable. First, many kinds of stress detectors-miniature pressure cell, miniature frictional stress cell, and internal stress cell- are developed with success. Then an apparatus of simulation with 2 stand rolls equipped with above detectors is made, and it is possible to measure the following items:
    (i) Distribution of stresses (pressure, circular frictional stress and axial frictional stress) on thesurface of a roll.
    (ii) Distribution of internal stress (direction and magnitude of principal stress) in a workpiece.
    (iii) Deformation of workpiece and load or torque acting on a roll.
    Finally an experiment of rolling by single stand is made as an example. Deformation, load and torque, distributions of many kinds of stresses are clarified and the precision of the experimental method is confirmed.
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  • Mahito KOIZUMI, Tuyosi KIKUTI, Seisirô BANDÔ
    1980 Volume 66 Issue 8 Pages 1113-1122
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    Until recently, conventional grain oriented silicon steel strip was made exclusively from ingots. In conventional procedures, reheating to exceedingly high temperature is necessary to assure solution of MnS in the slab prior to hot rolling.
    In this paper, therefore, the authors investigated the morphology changes of MnS in the manufacturing process without being reheated in exceedingly high temperature for solution treatment. It was found out that the MnS inclusions were broken into small particles, or deformed and recrystalized into small crystals. On the other hand, the temperature at which all the manganese sulphide was dissolved depended on the product of the concentrations of sulphur and manganese in solution in the 3% silicon steel.
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  • Mahito KOIZUMI, Tuyosi KIKUTI, Seisiro BANDO
    1980 Volume 66 Issue 8 Pages 1123-1132
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    In an attempt to produce grain oriented silicon steel sheets without conventional high temperature slab reheating and hot rolling processes, series of experiments were carried out using two types of cast slabs of 5 mm and 40 mm thick. Relationship between the magnetic properties and the morphology of MnS was investigated for various processing conditions.
    In the cast slab of 40 mm thick, the changes in magnetic properties were examined after processing without reheating to an exceedingly high temperature for solution of MnS.
    In the cast slab of 5 mm thick, good magnetic properties were obtained without slab reheating or hot rolling. This is due to the fine MnS particles distributed uniformly in the matrix by rapid cooling in the solidification process. In the conventional casting, coarse MnS particles and segregation bands are formed due to the slow cooling rate in the solidification process which necessitates a high temperature slab reheating to dissolve these particles.
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  • Tadamiti SAKAI, Haruo KAJI
    1980 Volume 66 Issue 8 Pages 1133-1141
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    Effects of impurities P, S, As, and Sb and those of alloying elements Si and Cu on the density and growth of methane bubbles formed on grain boundaries in 2.25Cr-1Mo steel by hydrogen attack were investigated.
    The results are summarized as follows:
    (1) The addition of 0.016 wt%Sn to the high-purity steel increased the bubble density and diameter by factors of 2.7 and 1.15 respectively.
    (2) The addition of 0.016 wt%Sb increased the bubble density by a factor of 2 to 3, but reduced the bubble diameter to 0.8.
    (3) The addition of either 0.016wt%P or 0.017wt%As decreased the bubble density by a factor of 0.750.5, while the growth rate was unchanged.
    (4) Phosphorus and arsenic, however, could not relieve the above effects of tin and antimony.
    (5) The bubble density and diameter of 0.26wt%Si steel were 1.3 and 1.4 times those of 0.016 wt%Si steel respectively, where both the steels contained all of the impurities by 0.01wt% each.
    (6) The addition of 0.2wt%Cu decreased the bubble density but could not relieve the effects of tin and antimony when added together, while it increased the growth rate.
    (7) Temper-embrittlement treatment further reduced the bubble density in 0.016wt%P steel magnifying the effect of phosphorus, while the effect of tin was not magnified by the treatment in 0.016 wt%Sn steel.
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  • Tetsuo KATO, Katsushi KUSAKA, Tatsuo HISADA
    1980 Volume 66 Issue 8 Pages 1142-1149
    Published: July 01, 1980
    Released on J-STAGE: May 07, 2010
    JOURNAL FREE ACCESS
    An investigation was made of the influence of pressing and sintering conditions, and S addition up to 0.4% on the machinability of 304L sintered stainless steels manufactured by the water-atomized powders.
    The results were as follows.
    (1) The sintered density gave remarkable influence on cutting resistance. The resistance got smaller first, and then larger with increasing density, having the minimum value around 7g/cm3 of density.
    (2) There occurred a change of the shape and the density of cutting chips with the density of materials. The resistance got larger in proportion to ΔD=|Ds-Dc|, where Ds, Dc were the density of specimens and chips, respectively.
    (3) Sulphur addition had no influence on original powder characteristics. Cutting resistance decreased with increasing amount of S, and accordingly, tool life could be remarkably improved.
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  • Hiroo NAGANO, Masamichi KOWAKA
    1980 Volume 66 Issue 8 Pages 1150-1159
    Published: July 01, 1980
    Released on J-STAGE: January 18, 2010
    JOURNAL FREE ACCESS
    Since type 329 Jl duplex alloys have good resistance to pitting, crevice corrosion and stress corrosion cracking in chloride media, they have widely been used in the heat exchangers of chemical plants or seawater condensers. However, it has often been said that type 329 Jl duplex alloys are susceptible to welded joint corrosion.
    Therefore, this study is aimed at investigating the corrosion behavior of welded joints in duplex alloys in various kinds of corrosive environments compared with base metals. Tests include acid immersion, intergranular and crevice corrosion tests, and also electrochemical measurements.
    The test results are described as follows:
    (1) Distribution of principal alloying elements in 25Cr-6Ni-2Mo-N and 25Cr-6Ni-0.4Cu-3Mo-N duplex alloys have been observed, i. e., Cr and Mo concentrate in α phase, and Ni, N, and Cu do in γ phase.
    (2) Welded joints having a poor area ratio of γ phase in 25Cr-6Ni-0.4Cu-2Mo-low N steel are more severely been attacked than base metal, because chromium depletion at grain boundaries due to chromium carbide or nitride precipitation has induced intergranular attack both in acid and chloride media.
    (3) Selective dissolution of γ phase in base metal occurs in 25Cr-6Ni-2Mo-N steel at crevice, whereas no selective corrosion does in 25Cr-6Ni-0.4Cu-3Mo-N steel.
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  • Koji YAMAGUCHI, Kenji KANAZAWA
    1980 Volume 66 Issue 8 Pages 1160-1169
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    The effects of strain rate and strain wave shape on the fatigue life of SUS 316 and SCMV 3 (11/4Cr-1/2Mo)steels have been investigated using several types of strain wave shapes such as triangular, truncated and sawtooth wave shapes. The data have been analyzed by the strainrange partitioning method proposed by MANSON, HALFORD, and HIRSCHBERG. A new method has been proposed and used for partitioning the inelastic strain range in applying the strainrange partitioning method. Four component strain range versus life relationships have been obtained by both interaction damage rule and conventional damage rule.
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  • Tetsumori SHINODA, Shizuka SHIMANUKI, Ryoichi SASAKI
    1980 Volume 66 Issue 8 Pages 1170-1176
    Published: July 01, 1980
    Released on J-STAGE: May 25, 2010
    JOURNAL FREE ACCESS
    Stress relaxation data for some commertial steels were obtained by means of the ring method originated by Oding, and were compared with that obtained by the conventional tensile method. The date obtained by the ring method agreed with the tensile data within an error 10%, comparing the remeining stress ratio, RSR (residual stress/initial stress). This agreement, however, was imparied when the ring specimen was loaded to an initial stress greater than its yield strength. The initial stress in the ring test specimen was capable of being set to an arbitrary value to an error of less than 6% by using the unique relationship between the initial gap spacing of the ring specimen and the shape constant, A. The stress relaxation tests under an-isothermal conditions were easy to perform using the ring test method. The value of RSR in isothermal part of the test was influenced by the heating rate to reach the test temperature, within only the first 3 or 4 hours of the test.
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  • Seiichi MUNEKI, Yoshikuni KAWABE
    1980 Volume 66 Issue 8 Pages 1177-1186
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
    In order to strengthen and toughen the 350kgf/mm2grade maraging steel through thermomechanical treatment, the effects of processing variables in thermomechanical treatment such as total reduction, start and finish temperatures of rolling, on the properties of 10Ni-18Co-14Mo and 10Ni16.5Co-12.5Mo steels have been investigated. Austenite grain refinement is promoted with increasing the degree of total reduction. When 91% of total reduction is given, austenite grain is refined to 6μm, leading to the tensile strength of 337 kgf/mm2 and the reduction of area of 0%. When the finish temperature of rolling is lowered, grain refinement is also promoted but a large amount of precipitate occurs during thermomechanical treatment. These precipitates have the marked detrimental effect on ductility and toughness in the condition before aging, but does not clearly show the detrimental effect on properties after aging. It is made clear that these precipitates are formed by being promoted due to working during thermomechanical treatment. Therefore, it is so difficult to obtain the extremely fine grained structure with no precipitates and to achieve the 350 kgf/mm2 strength level, by applying thermomechanical treatment for these higher Mo-containing steels.
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  • Yukio ARITA, Katsuya KAJIMOTO
    1980 Volume 66 Issue 8 Pages 1187-1198
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
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  • Masatane KOKUBU
    1980 Volume 66 Issue 8 Pages 1199-1205
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
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  • Hisashi KISHITAKA
    1980 Volume 66 Issue 8 Pages 1206-1214
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese]
    1980 Volume 66 Issue 8 Pages 1215-1216
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1980 Volume 66 Issue 8 Pages 1217-1221
    Published: July 01, 1980
    Released on J-STAGE: June 19, 2009
    JOURNAL FREE ACCESS
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