Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Volume 60, Issue 12
Displaying 1-14 of 14 articles from this issue
  • [in Japanese]
    1974 Volume 60 Issue 12 Pages 1583-1584
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • Hideo ABE, Kineo TAKAGI
    1974 Volume 60 Issue 12 Pages 1585-1590
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    The maximum enhancement of {111}‹110› plus {554}‹225› components in the recrystallization texture of a low-carbon aluminum-killed steel sheet is attained when the process is so controlled that gives the minimum nucleation rate of recrystallization in the final annealing.
    Precipitation-annealing at an intermediate stage of cold rolling is found to be effective to give the minimum nucleation rate. It is concluded that the nucleation rate of recrystallization depends on the size and distribution of fine aluminum-nitride particles that precipitate preferentially on dislocations and the dislocation density of the matrix is an important factor to attain an appropriate state of precipitation for the inhibition of nucleation of recrystallized grains.
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  • Kazuo SAKAI
    1974 Volume 60 Issue 12 Pages 1591-1598
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    The paper presented a calculation of thrmal stress in a cylindrical steel induced during cooling by introduction of strain-history into Hara's calculation method.
    Calculation was based on elastic-plastic theory and total strain was calculated by non-linear integral equation through a successive integration. Plastic strain was calculated by total strain theory and stress-strain diagram.
    A calculation was made for a cylindrical steel bar with 1500mm in diameter quenched in mist from 850°C, and the results are as follows.
    (1) Tensile stresses (δt, δz, ) at surface of bar are the largest, when temperature difference between surface and core was the largest.
    (2) Stresses (δt, δz) at starting point of transformation always show the maximum tensile values.
    (3) Reverse of stresses (δr, δt, δz) takes place after completion of transformation of core.
    (4) At final stage of cooling, core has tensile stresses (δr, δt, δz) and surface layer has compressive stresses (δt, δz) of characteristic pattern.
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  • Fukunaga TERASAKI, Teruo KANEKO
    1974 Volume 60 Issue 12 Pages 1599-1612
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    To clarify the effect of texture on the toughness of irons and steels, mechanical behaviors of pure irons having a strong {100}‹011› texture component were investigated.
    It is revealed that the texture has a notable influence on the Charpy impact properties; the stronger the {100} component parallel to the fracture surface, the higher the impact transition temperature. The ratio of unit crack path lc to grain size la in the textured sample is larger than the ratio of about 2 obtained in a previous paper. It can be concluded that the unit crack path is more reasonable than the grain size as a characteristic of the structure affecting on the toughness of irons. The difference of the fractographic appearance of unit crack path between the textured sample and the random one is discussed.
    The elongation and the reduction in width show the planar anisotropy due to the preferred orientations, while the strength is not influenced by the texture under the experimental conditions of this study.
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  • Yoshikuni KAWABE, Kozo NAKAZAWA, Masao KANAO, Seiichi MUNEKI
    1974 Volume 60 Issue 12 Pages 1613-1623
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    In the previous paper, the authors reported about the peculiar phenomena with regard to an 18 Ni maraging steel with low temperature aged structure, that KIC was strongly dependent upon the prior γ grain size and the delayed failure crack was observed in front of the fatigue precrack. This study has been made in order to investigate these phenomena in more details and to discuss the mechanism by which KIC is increased.
    It is made clear that an increment in KIC is completely associated with slow crack growth of delayed failure which precedes the unstable fracture. However, its increment is not an increment in true KIC as a material constant but an increment in apparent KIC.
    This may be due to the blunting at crack front caused by the microbranching of the delayed failure crack, the degree of which also depends upon the prior γ grain size.
    Tensile ductility also markedly decreases under the same condition in which an apparent KIC increases. This is attributed to the occurence of the delayed failure crack at the specimen surface adjacent to or in the necking region. Thus, the 18Ni margaing steel with low temperature aged structure shows the complicated behavior on toughness and ductility because of the high sensitivity to delayed failure.
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  • Yoshiro YAMADA
    1974 Volume 60 Issue 12 Pages 1624-1638
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    The aging process of patented, rapidly cooled, and subsequently slowly cold drawn eutectoid carbon steels has been investigated by the methods of internal friction, electrical resistivity, and room temperature tensile test.
    The results obtained are summarized as follows.
    The strain aging occurs in three stages.
    The first stage aging occurs below about 150°C. Supersaturated carbon and nitrogen in α iron lock dislocations. In fine lamellar pearlitic steel, dissolved carbon content in a iron is small after patenting and drawing, and there is no significant contribution to the first stage by carbon. Large amounts of nitrogen can, on the contrary, dissolve in lamellar pearlitic ferrite and cause the increase of tensile strength by aging at this stage.
    The second stage appears only in heavily prestrained specimens at temperatures from about 150°C to 230°C The dissolution of some portion of lamellar cementite and the dislocation locking or pinning by carbon supplied therefrom take place. An appreciable increase of tensile strength results. The activation energy of 28 kcal/mol was obtained experimentally. This value is believed to be the sum of the activation energy of carbon diffusion in ferrite and the binding energy of cementite in ferrite.
    The third stage corresponds to overaging from the view point of tensile strength.
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  • Yoshio TOKIHIRO, Imao TAMURA
    1974 Volume 60 Issue 12 Pages 1639-1645
    Published: October 01, 1974
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
    Hardness values of a steel can be estimated from the CCT diagram if the cooling curve of the specimen is known. By the use of the master cooling curve previously obtained by the present anthors, it was found that the cooling curve at any position from the quenched end of a Jominy specimen and hence the Jominy hardenability curve could be estimated accurately. These estimated curves of several steels well coincided with the measured results. Several estimation methods proposed by other researchers were compared with the one from the master cooling curve.
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  • Haruo SHIMADA, Kazuhiro MIIDA, Teruo YOKOOJI
    1974 Volume 60 Issue 12 Pages 1646-1654
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    The relation between the corrosion behaviour of steels in various oceanic environments and characteristics of sea water was studied.
    The results are as follows:
    (1) In the unpolluted sea water, the corrosion rate (2 meters below the surface and on the sea bed, 30, 60, 90, meters deep) increased with increase of the oxygen content. On the other hand, in the polluted sea water, the corrosion was accelerated with increases of microorganisms and the temperature of sea water. In addition, local corrosion of the steels tended to be more pronounced than in the unpolluted sea water.
    (2) The corrosion resistances of low-alloy steels containing Cu, Cr, Si, and Mo were extremly superior to that of carbon steel. This is considered to be due to the coexistence of Si and Cr in steels, which is effective in suppressing detrimental effect of sulphate reducing bacteria, and due to the coexistemce of Si, Cr, and Cu in the adherent product effective in decreasing the rapid growth of the rust crystals in any ocean environments.
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  • Mizuo SAIKAKIBARA, Ikuo BANNO, Shozo SEKINO
    1974 Volume 60 Issue 12 Pages 1655-1660
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
    An investigation was made to clarify the corrosion of several superalloys in impure helium.
    The corrosion in helium was more severe than in air. This corrosion was due to the insufficiency in supply of oxidizing species to form a continuous protective scale. For this reason, the severe corrosion occured with the formation of Cr-denuded zone and with internal oxidation.
    This oxidation could be reduced by the surface treatment, such as calorizing and pre-oxidizing in air to form a protective film on the surface.
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  • Takesaburo NISHIOKA, Kanji EMOTO
    1974 Volume 60 Issue 12 Pages 1661-1681
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • Mikio OBAYASHI
    1974 Volume 60 Issue 12 Pages 1682-1697
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • Shunzo FUJIKI
    1974 Volume 60 Issue 12 Pages 1698-1705
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • Ryukiti HASIGUTI
    1974 Volume 60 Issue 12 Pages 1706-1713
    Published: October 01, 1974
    Released on J-STAGE: October 12, 2010
    JOURNAL FREE ACCESS
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  • 1974 Volume 60 Issue 12 Pages 1714-1721
    Published: October 01, 1974
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
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