JOURNAL OF THE JAPAN WELDING SOCIETY
Online ISSN : 1883-7204
Print ISSN : 0021-4787
ISSN-L : 0021-4787
Volume 21, Issue 5-7
Displaying 1-7 of 7 articles from this issue
  • A. Tsuruta, Y. Arai, R. Tanaka
    1952 Volume 21 Issue 5-7 Pages 144-149
    Published: 1952
    Released on J-STAGE: December 10, 2009
    JOURNAL FREE ACCESS
    The purpose of this paper is to present some design data obtained from experiments on the statical and fatigue strengths of plug welding of thin steel sheets, extensively.used in the manufacture of roll ing stock at present. This investigation consisted of three different groups of experiments.
    Group 1 experiments. In this group of experiments, the plug weld test specimens were prepared by three welding operators, two of whom were qualified as 1st class operators and the other a 2nd class operator. Two kinds of medium coated electrodes and one kind of thin coated electrode were used.
    Group 2 experiments. 28 weding operators, consisting of 1st and 2nd class operators, welded the test specimens under working conditions using medium coated electrodes which gave satisfactory results in Group 1 experiments.
    Group 3 experiments. The fatigue strength of plug welds under repeated loading wag compared with that for riveted joints of comparable statical strength.
    In these experiments two types of test specimens were prepared and tested. Type A specimens consisted of a 2.3 mm base steel on which a 3.2 mm steel sheet with two plugs was welded on. Type B specimens consisted of a 6mm thick base steel on which a 2.3mm thick steel sheet with two plugs was welded on. The diameter of the plug was 10mm and all welding was done in the vertical position.
    The results obtained are as follows :
    (1) In both Group 1 and Group 2 experiments, the strength of plug welds of 3.2mm sheet welded on 2.3mm sheet was weaker than that of 2.3 mm sheet welded on 6mm sheet. The strength of type A specimens was about 80% of type B specimens.
    (2) The average strength of one plug weld was 1938 kg for type A and 2398 kg for type B specimens.
    (3) Comparing the results of Group 1 and Group 2 tests, the strength of plug welds by the same operator gave different values depending on the care of welding. The strength of plug welds under working conditions was about 20% less than when welding was carefully done.
    (4) The following results were obtained from the fatigue tests:
    (a) For the riveted joints, the fatigue strength is about 54% of the statical strength.
    (b) For the plug weld joints, the fatigue strength is about 35% of the statical strength.
    (c) The strength of plug welded joints is about 2/3 of riveted joints under repeated loading, both types of joints having the same strength under statical load.
    The results for Group 3 experiments are those obtained from a small number of test specimens and further investigation is desirable.
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  • I. Onishi, Y. Kikuta
    1952 Volume 21 Issue 5-7 Pages 150-157
    Published: 1952
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    It is reliable that the potential hydrogen (or available hydrogen) in electrode coating has much influences upon the volume. of the disolved hydrogen in molten steel during metallic arc welding. The relation between them was reported by Sloman and his co-workers who showed linear proportion among them.
    However, the disolved hydrogen does not depend directly upon the potential hydrogen in coating, but upon the partial pressure of hydrogen in arc atmosphere generated from coating during welding.
    Then, even each potential hydrogen in various coating are contained same volume, the compositions of arc, atomosphere are changed by another components of coatings, and so the volumes of disolved hydrogen in deposit are necessarily changed.
    As Reeve already pointed out this problem, he did not study the relation of the three.
    We studied the relation between the potential hydrogen in coatings, partial pressure of hodrogen in arc atmosphere and disolved hydrogen in deposit metal using various coated electrodes previously reported.
    The results and conclusions obtained are as follows;
    (1) The more the potential hydrogen in coatings contained, the more the partial pressure of hydrogen in arc atmosphere and the disolved hydrogen in deposit metal are found, only when same type electrode coatings were used.
    (2) When we compared the different types of coatings for example, limestone type to deoxide type of coatings, the partial pressure of hydrogen and volume of disolved hydrogen in deposit collected with grycelin method indicate more with the latter than with the former, while almost same volumes of potential hydrogen in coating contained in both types.
    Then, when potential hydrogen in coating changed to the hydrogen component in atmosphere by lime type, it was diluted with CO and CO2 produced from limestone, while deoxide type its dilution was much less than limestone type.
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  • Relations between welding current, amount of penetration, penetration ratio and hardness and microstructure of austenitic stainless steel weld metal, etc.
    M. Okada, H. Ikawa
    1952 Volume 21 Issue 5-7 Pages 157-166
    Published: 1952
    Released on J-STAGE: December 10, 2009
    JOURNAL FREE ACCESS
    In the present report, relations between welding current, amount of penetration or penetration ratio of base metal to the austenitic stainless steel weld metal and hardness of austenitic weld metal and microstructure, etc., in each single bead which was deposited on four kinds of carbon steel plates with commercial 18-8 austenitic stainless steel electrode containing about 5 percent of manganese in core wire of 4 mm in diameter, were studied. D. C. reverse polarity was used. And welding speed and thickness of base metal were constant, 200 mm/min and 10. mm respectively. The results obtained are as follows:
    (1) Penetration variables such as the amount of penetration and penetration ratio, etc. tend to increase linearly as welding current increases. And in this case, the obtained penetration ratio increases from about 20 to 50 percent as welding current increases from 95 to 180 amperes.
    (2) Penetration ratio has a little tendency to increase, as carbon content of base metal increases.
    (3) Vickers hardness of austenitic stainless steel weld metal is comparatively lower (Hv is appro ximately from 200 to 220) for the range of smaller penetration ratio, but becomes higher (Hv is max. 400) as penetration ratio becomes larger. But in the case when penetration ratio is the same for the range of larger one, Vickers hardness of austenitic weld metal containing high carbon base metal is lower than that of the metal containing low carbon base metal. This result obtained in the present experiment is different from that of the Ist. report.
    (4) Micro-hardness at the side of austenitic stainless steel weld metal of the vicinity of weld fusion line increases, for the most part, linearly as welding current increases. Consequently, the above tendency of micro-hardness change is somewhat different from that of Vickers hardness change.
    (5) Both maximum Vickers hardness of the heat-affected zone in base metal and micro-hardness of the vicinity of weld fusion line of that same zone have a tendency to decrease as welding current increases.
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  • On the Arc Welding
    Y. Kuriyama
    1952 Volume 21 Issue 5-7 Pages 167-171
    Published: 1952
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    The author conducted the bead test and mechanical test of welds using the welding core of nodular graphite cast iron, Al-cast iron and ordinary cast iron with a flux added with Mg-alloy. The results follow:
    1) The results were not so satisfactory as in gas welding, but by the fully preheated and deep cured welding, high strength of weld joint was obtained and additional annealing further ensured high toughness.
    2) Such a welding core was excellent as Al-cast iron which included high contents of C, Si and Al, or nodular graphite cast iron with high C and Si contained. In order to have graphite spheroidized, flux was required to contain some Mg-alloy.
    3) Certainly pre-heating was a necessity for welding and it is important to be very careful in controlling the welded parts.
    The problems of crack will be treated in following experiments.
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  • Relation between gas-inclusions in weld metal and mechanical properties
    N. Nagai, H. Shioya, K. Yano, K. Kunii, Y. Kawakami, T. Okauchi
    1952 Volume 21 Issue 5-7 Pages 172-182
    Published: 1952
    Released on J-STAGE: December 10, 2009
    JOURNAL FREE ACCESS
    As regards the essential investigation of gas-inclusion in mild-steel weld deposits, a few informations have been published. However even at present the constituents, combined state and behaviour of gas-inclusion have many ambiguous points yet to be clarified. In order to determine the contents of oxide inclusion in weld metal, the authors after studying the various experimental results, adopted two analytical methods i. e., vacuum fusion method and Fitterer's residual method, which give a comparatively good stability of analytical value.
    On the other hand the hydrogen in weld metal was analysed by vacuum extraction method at high temperature (800°C), and the nitrogen was analysed by distillation method in addition to vacuum fusion method. In 1st report, they have been able to make clear some relations between these gas-inclusions and mechanical properties of weld metal.
    (A) In case of absence of hydrogen
    1) The hyrogen in weld metal was removed by normalizing and annealing at 950°C.
    2) Owing partly to difference in quantities of the alloy elements in weld metal, it was impossible to clarify the relation between gas-inclusion and the hardness, yield point and tensile strength of all-weld metal.
    3) The relation between gas-inclusion and percentage of elongation or reduction in area of allweld metal had no appreciable tendency.
    4) The lowering rate of impact value by "anneal-brittleness" (as named by Mr. Kikuchi) was nearly proportional to the difference between the oxygen obtained by vacuum fusion method and that by Fitterer's residual method. That is, it was found that the more the contents of the oxygen indeterminable by Fitterer's residual method increase, the higher the lowering rate by anneal-brittleness" becomes.
    (B) In case of presence of hydrogen (as welded)
    1) When the fractured tensile specimen showed a severe occurrence of "fisheyes" in an arc weld ; percentage of elongation and reduction in area of all-weld metal decreased.
    2) Contrary to expectation, the relation between the occurring rate of "fisheyes" and contents of hydrogen obtained by vacuum extraction method at high temperature (800°C) had no appreciable tendency.
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  • [in Japanese]
    1952 Volume 21 Issue 5-7 Pages 182-190
    Published: 1952
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
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  • 1952 Volume 21 Issue 5-7 Pages 193-194
    Published: 1952
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
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