JOURNAL OF THE JAPAN WELDING SOCIETY
Online ISSN : 1883-7204
Print ISSN : 0021-4787
ISSN-L : 0021-4787
Volume 20, Issue 4-5
Displaying 1-12 of 12 articles from this issue
  • I. Onishi, M. Mizuno, K. Omura
    1951 Volume 20 Issue 4-5 Pages 133-138
    Published: 1951
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    The authors studied the square and the bevel cutting of 18-8 stainless clad steel having a total thickness of 6 mm with 1 mm for the clad layer.
    The results show:
    1) Cutting can be done from the mild steel side by a little inclination of the nozzle, e. g. at the angle of 10-20 deg. to the vertical (See Fig. 1).
    2) Compared with the cutting of non-clad mild steel of equivalent thickness,
    i) a larger size of the nozzle is preferable;
    ii) pressure of cutting oxygen must be increased to 150-200%;
    iii) speed of cutting is around 80% of mild steel cutting.
    3) A small amount of double carbide precipitation on the cut edge is unavoidable, although cooling water has been used during the cutting operation.
    (C<0.08%, Cr 17-20% and Ni 7-10% constitute the clad metal)
    4) Cutting to irregular curved figures is difficult.
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  • S. Kondo, T. Furukawa
    1951 Volume 20 Issue 4-5 Pages 139-146
    Published: 1951
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    It is considered that the flash-butt welding used for long drawing of short rails needs heat tratment after the operation. And it is generally discussed whether appropriate heat treatment is necessary or not, and if so what method is to be used. This report deals experimentally with the problem from the view-point of mechanical and microscopic examinations.
    According to the result of the experiment, it is desirable to practice the high temperature heat treatment at the temperatures from 800°C to 850°C which are necessary for normalization.
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  • The theoretical analysis of the foregoing experimental results
    M. Okada
    1951 Volume 20 Issue 4-5 Pages 146-149
    Published: 1951
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    Summarizing the experimental results through the theoretical analysis, our conclusion is as follows; i. e., the nature of ice flower like structure and three important conditions for the formation of ice flower like structure and also our theoretical ground for the prevention of the formation of this structure are explained.
    The following three are considered to be the necessary and sufficient conditions for the formation of the ice flower like structure.
    (1) The deposited metal-shall be kept under the cooling condition so as to form the columnar crystals.
    (2) The fine blow holes shall be formed by the effect of hydrogen dissolved in the deposited metals. Considering that the pressure of hydrogen is 1 atm., ice flower like structure is formed under the condition that the amount of hydrogen dissolved in the molten metal is more than that of solid metal at the melting point.
    (3) The refractory deoxidized products, such as SiO2, Al2O3, and Cr2O3 whose melting points are considerably higher than that of steel, shall be in the dispersed state of a colloid or micro-particles.
    The above three conditions are essential factors for the formation of ice flower like structure as mentioned in our definition. In other words, if any one of the three conditions is not satisfied, the ice fower like structure will not be formed in the deposited metal of mild steel.
    The necessary and sufficient three conditions for the formation of ice flower like structure have been obtained through the studies from various stand-points. The nature of the structure and the method of prevention have been clarified.
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  • I. Onishi, H. Ikawa, Y. Hukuzono
    1951 Volume 20 Issue 4-5 Pages 149-156
    Published: 1951
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    Thermal expansions of 18-8 multiple-deposited mletal have been measured by the dilatometer. Thermal expansion of the piled-up direction of beads is the least, compared with other directions, i.e., the direction of beads and the direction rectangular to the beads. It is due to the Cr-carbide precipitations along the calumnar crystals. Or, the contrary, thermal expansions of the multiple-deposited metals gained by mild steel electrodes have no unequal properties for the three directions.
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  • 1951 Volume 20 Issue 4-5 Pages 149a
    Published: 1951
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
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  • 1951 Volume 20 Issue 4-5 Pages 149b
    Published: 1951
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
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  • 1951 Volume 20 Issue 4-5 Pages 149c
    Published: 1951
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
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  • 1951 Volume 20 Issue 4-5 Pages 149d
    Published: 1951
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
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  • On the removal of distortion in welded thin plate structures
    M Otani, K. Kanematsu
    1951 Volume 20 Issue 4-5 Pages 156-161
    Published: 1951
    Released on J-STAGE: December 10, 2009
    JOURNAL FREE ACCESS
    It is usually adopted to spot heat the warped plate by oxyacetylene flame followed by subsequent water cooltng, in order to remove distoations in welded thin structures. The purpose of this report is to explain the theoretical foundations of this practice, and at the same time determine the best condition of heating operations.
    The experiments were made about the models shown in Fig. 1, and test results analysed theoretically. The thermal stress due to temperature changes were elastically calculated at first, and then corrected by the graphical method considering plastic yieldings around the locally heated part. Using tnus determined stress distributions, the displacement a could be calculated during heating and cooling by trial method taking the mininmm strain energy condition, accordingly the amounts of removable distortions were determined. In those calculations, the mean values of mechanical constants (Young's modulus, yielding stress, coefficient of thermal expansion) were adopted for each small temperature intervals to derive the accurate results. As in Figs. 4 and 5, the good coincidences were indicated between the test results and calculated values. Einally, the following conditions were theoretically determined to be most recomendable:
    heating temperature 500-550°C
    radius of heating 20-25mm
    pitch of heated spots 57-70mm
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  • H. Ogawa
    1951 Volume 20 Issue 4-5 Pages 162-173
    Published: 1951
    Released on J-STAGE: December 10, 2009
    JOURNAL FREE ACCESS
    The author studied some time ago on the weldability of electrode core and found that weldability was seriously affected by the non-metallic inclusions rather than by the chemical constituents such as C, Si. Mn etc. He discussed further how the melting process for the core should be operated.
    He has since been trially making middle coated electrodes with cores of different weldabilities. It has been confirmed through the experience that the properties of electrodes consist of algebraic summation of its core and flux; substantial quality improvement of the electrode with a core cannot be effected only by adjusting the flux composition.
    As an example for the standard mild steel core, tension tests of deposited metals obtained by poor cores gave merely 28-30% elongations, but the tests with those by good cores showed the maximum values of 37%.
    On the other hand, the tests by pure iron cores of good quality produced up to 40% elongations. Besides, the author investigated arc-stability, bead-appearance and degree of fillet crack etc., with the conclusion reached that the quality of core affected seriously the quality of electrode, namely that it was necessary to use core having excellent weldability to the end of obtaining the superior quality of-electrode.
    Finally production of such electrodes was accomplished with the use of the Hitachi M flux composition.
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  • [in Japanese]
    1951 Volume 20 Issue 4-5 Pages 173-174
    Published: 1951
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese]
    1951 Volume 20 Issue 4-5 Pages 174-176
    Published: 1951
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
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