JOURNAL OF THE JAPAN WELDING SOCIETY
Online ISSN : 1883-7204
Print ISSN : 0021-4787
ISSN-L : 0021-4787
Volume 48, Issue 1
Displaying 1-6 of 6 articles from this issue
  • Tomokazu Godai
    1979 Volume 48 Issue 1 Pages 7-16
    Published: January 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
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  • Isao Masumoto, Takashi Shinoda, Jun Takano, Atsushi Yoshida
    1979 Volume 48 Issue 1 Pages 17-21
    Published: January 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    An algorithm and program for determination of welding parameters of CO2 I-butt one-pass welding is proposed. The parameters are ranged in the globular transfer.
    Calculated parameters were confirmed to give the full penetration and good bead appearance by welding experiments.
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  • Kunihiko Satoh, Masao Toyoda, Yoshiharu Mutoh
    1979 Volume 48 Issue 1 Pages 21-27
    Published: January 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    The processes of ductile fracture in KD32 steel specimens subjected to prestrain at elevated temperature are observed in detail by using fractographic and sectioning techniques. A criterion of ductile fracture and a mechanism of decrease in ductility with prestraining at elevated temperature are also investigated. The results are summarized as follows.
    (1) The processes of ductile fracture in KD32 steel specimens are as follows: Although several large voids are observed at a relatively small strain level, they have no important role in fracture processes. As soon as microvoids nucleate at some strain level, which is the stage just before fracture, they rapidly grow and coalesce.
    (2) Ductile fracture of KD 32 steel specimens occurs when the value of equivalent stress reaches to a critical one.
    (3) It seems that the most important factor of decrease in ductility with prestraining at elevated temperature is the work hardening according to amount of prestrain and prestraining temperature.
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  • Measurements of Vibration Distribution along the Specimens
    Jiromaru Tsujino, Eiji Mori, Junichi Saneyoshi
    1979 Volume 48 Issue 1 Pages 27-33
    Published: January 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    In the case of ultrasonic welding of metal specimens, the vibration direction of welding tip is parallel to specimen surfaces.
    The weld strength by ultrasonic welding is directly affected by specimens vibration characteristics.
    The purpose of the study is to measure directly the vibration distribution of welding specimens, and to show clearly the effects of specimens vibration and fatigue fracture by vibration on the weld strength.
    The automatic vibration amplitude and phase distribution measuring equipment with X-tal cartridge is used. The vibration amplitude and phase distributions are measured with aluminum specimens (thickness=0.5 & 1.0 mm), and welding tip amplitude 0.5, u is used.
    The results obtained are as follows;
    1) Specimen length has direct affects on the weld strength, when the specimens are at anti-resonance condition of longitudinal vibration and the weldment is a vibration node.
    2) The vibration distributions of welding specimens measured are complex and with rather small vibration amplitude, except the case at resonance or anti-resonance condition of longitudinal and bending vibration of specimens with large amplitude.
    3) The vibration amplitude of longitudinal and bending mode at welding becomes so large as to cause vibration fatigue fracture of specimens.
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  • Yukio Ueda, Keiji Fukuda, Iwao Nishimura, Hideaki Iiyama, Naomichi Chi ...
    1979 Volume 48 Issue 1 Pages 34-39
    Published: January 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    Lamellar tearing of opening type and root cracking occasionally occur in multipass welded corner joints.
    In this paper, a relation between the occurrence of these weld cracks and the intensity of bending restraint is examined with the aid of the CJC-test. Furthermore, welding residual stresses in corner joints are analyzed and measured. Dynamical conditions for the occurrence of these weld cracks are investigated.
    The summary of the results obtained from this study are as follows.
    (1) In the case where the intensity of bending restraint is large: The lamellar tearing of opening type occurs at the position about 10 mm away from the toe, but root cracking does not occur. Large tensile welding residual stresses are induced on the edge surface of the vertical plate at the position about 10 mm away from the toe, but large compressive stresses are induced near the root.
    (2) In the case where the intensity of bending restraint is small: The lamellar tearing does not occur but root cracking occurs. Tensile stresses on the edge surface are less than those in the case of the intensity of bending restraint being large, but very large tensile stresses are induced near the root. Accordingly, the tendency of the occurrence of weld cracking in multipass welded corner joints is closely related to welding residual stress distribution, and can be explained well from the dynamical point of view.
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  • 1979 Volume 48 Issue 1 Pages 41-70
    Published: January 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    Download PDF (1735K)
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