JOURNAL OF THE JAPAN WELDING SOCIETY
Online ISSN : 1883-7204
Print ISSN : 0021-4787
ISSN-L : 0021-4787
Volume 21, Issue 2
Displaying 1-7 of 7 articles from this issue
  • Specifically on the snake and shaft of "Kinion-pump"
    M. Asano, T. Tawara
    1952 Volume 21 Issue 2 Pages 35-38
    Published: 1952
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    In current practice "Kinion-pump" snakes and shafts are surfaced with hard-facing filler metal in order to avoid thier abrasion and heat-softening. A most famous grade of hard-facing filler metal is called "Stellite" containing 40-50% Cobalt, 20-30% Chromium, 0.2-0.8% Tungsten and others.
    There are many difficulties, however, in the execution of this treatment, i. e, cracking of filler metal, distortion of shaft and so on.
    To get rid of these troubles, the writers conducted some experiments and good results have been obtained through the following countermeasures taken:
    1) Provide a perfect preheating of the base metal.
    2) Avoid overheating of the base metal and over cooling after welding.
    2) Select the right kind of filler metal for the base metal.
    4) Prevent impurities from entering into deposit metal, as a result of unstable gas flame used.
    5) Adopt the proper method of welding operation and procedure.
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  • M. Ozawa, M. Hoshino
    1952 Volume 21 Issue 2 Pages 39-42
    Published: 1952
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    Previously the authors proposed a method for electrically measuring the eccentricity of the covered electrode and the paper on this subject was already published in the journal issued by the Association of the Welding Research.
    It is most delightful to the authors that the proposed method has won a wide reputation, being in use now at many plants throughout Japan.
    To say the truth, however, the previous method was applicable only for checking whether the produced welding electrode was good or not, but not as the process of their production; so that it could not help in positively reducing the eccentricity. Recently there have been increasing demands for the improvement of the covered welding electrodes, especially for the diminishing of their eccentricity, which not only affects the weld through the instability of the arc, but also is the only factor by which to determine quantitatively the electrode quality. These demands have been urging the manufacturers to install the instrument proposed by the authors' method on the automatic electrode-covering machine.
    Now, as the difference in the thickness on the electrode must be detected to the order of 1/100mm, the higher stability of the source voltage is required for the purpose ; and for installation on the machine, the instrument has to be designed much more carefully so as not to be exposed to the influence of the variation of source voltage than it is the case with a portable.
    Unluckily it is not seldom that source voltages vary always from 60 to 100V in almost all the plants.
    As things stand, efforts should be made to control the variation of the voltages to the minimum in the wide range of the voltages, but none of the stabilizers which have been formally published satisfies this condition and very much inconvenience has been felt in this respect.
    The authors who standing on the ground that the instrument needs only a small power, has studied to solve the problem, at last succeeded in putting the method into practice with the aid of the proper circuit including the "balast-lamp".
    Field applications have had good results, showing that the variation of 70% in the voltage corresponds to a mere 2.3% in the load.
    It is observed that the variation as such work a negligible effect upon the instrument and does not disturb the Practical working.
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  • H. Tenkumo, I. Kimura
    1952 Volume 21 Issue 2 Pages 43-46
    Published: 1952
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    The most important problem in oxy-acetylene gas cutting practice, is related to the consumption of oxygen and acetylene, i. e., economical use of gas. It has been generally said and understood that drag length brings the lower consumption of both.
    The writers tried to analize this problem by investigating drag length on the cutting sections of mild steel having the thickness of 12, 19, 25 and 32mm respectively under various oxygen pressures and at different cutting speeds.
    The results are as follows :
    (1) Drag length should be standardized at 15 to 20% of the thickness of steel plate.
    (2) To keep drag length standard, the proper values of oxygen pressure as swell as cutting speed shuld be applied, varying in accordance with the thickness of the plate.
    (3) Cutting sections are obtained with the most beautiful and smooth surface by the above-mentioned operation.
    (4) Consumption of oxygen per unit area is about 55% as compared with that of the case when drag length is zero.
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  • Relations between polarity and welding current, amount of penetration, penetr ation ratio, hardness of austenitic stainless steel weld metal and microstructure, etc.
    M. Okada, H. Ikawa
    1952 Volume 21 Issue 2 Pages 47-58
    Published: 1952
    Released on J-STAGE: December 10, 2009
    JOURNAL FREE ACCESS
    There are many practical applications in which austenitic stainless steel electrodes are utilized in welding of various plain carbon and alloy steels (low and high). Since the above joining is also considered as a so-called disimilar-metal welding from the standpoint of chemical composition, it is naturally expected that penetration ratio of base metal to the austenitic stainless steel weld metal, in other words, the degree of dilution of austenitic stainless steel weld metal by base metal may depend upon several welding conditions, and the mechanical and chemical properties may accordingly he different, too. The present researches were conducted in order to disclose, systematically and fundamentally, the relation between the above properties of austenitic stainless steel weld metal and several welding conditions.
    In this report, relations between polarity and welding current, amount of penetration and penetration ratio of base metal to the austenitic stainless steel weld metal, hardness of austenitic weld metal and microstructure, etc., in each single bead which was deposited on four kinds of carbon steel plates with plain 18-8 austenitic stainless steel electrode consisting of commercial 18-8 austenitic stainless steel core wire of 4mm. in diameter and suitable coating, were studied. D. C. (straight and reverse polarity) and a. c. were used. Welding speed and thickness of base metal were constant, 203mm/min and 10 mm respectively. The results obtained are as follows :
    (1) In either d. c. (straight and reverse polarity) or a. c., the amount of penetration and penetration ratio, . etc., have a tendency to increase linearly as welding current increases. And also in this case, the above penetration ratio increases from about 20 to 60 percent as welding current increases from 95 to 175 amperes.
    (2) Penetration ratio has a little, tendency to increase, as carbon content of base metal increases.
    (3) Penetration ratio with a. c. is smaller than with d. c., in the same welding current value. (4) There is only a little difference between penetration ratio in d. c. straight polarity and that' in d. c. reverse polarity. In this experiment, however, penetration ratio in d. c. straight polarity is larger than that in d. c. reverse polarity for the range of lower welding current value. On the contrary, penetration ratio in d. c. reverse polarity is larger than in d. c. straight polarity for the range ot higher welding current value.
    (5) Vickers hardness of austenitic stainless steel weld metal is comparatively high. And Vickers hardness of austenitic weld metal containing high carbon base metal is lower for the range of smaller penetration ratio, but higher for the iange of larger penetration ratio, than that of the metal containing low carbon base metal.
    (6) Micro-hardness at the side of austenitic stainless steel weld metal of the vicinity of weld fusion line increases linearly as welding current increases, and is higher in the weld metal containing high carbon base metal than in the one containing, low carbon base metal. Consequently, the tendency of the above micro-hardness change is clearly different from that of Vickers hardness change.
    (7) Both maximum Vickers hardness of heat-affected zone and micro-harness of the vicinity of weld fusion line of that same zone in base metal, tend to decrease as welding current increases.
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  • S. Ando
    1952 Volume 21 Issue 2 Pages 58-66
    Published: 1952
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    There are available some literatures treating of carburized structures, normal and abnormal, of mild steel arc deposits. However, systematic investigations of the relations between properties of mild steel arc deposits and carburized structures have seldom been reported, The author carried out several characteristic tests with 40 kinds of mild steel covered electrodes (4 mm dia) obtainable after World War II, followed by the carburizing test on impact specimens after being fractured, in accordance with the SCJ procedure (Mc Quaid Ehn Test).
    On the basis of test results, relations between properties of mild steel arc welds and carburize structure were studied with the following conclusions.
    (1) Carburized structures of deposit metals may be roughly divided into three groups ; normal ; fine, abnormal ; and coarse, abnormal.
    (2) Close relations exist between properties of mild steel arc deposits and carburized structure. (3) These facts have a significant bearing upon degree of deoxidation, e. g., Mn and Si contents and further upon the quantity, form and dispersion of nonmetallic inclusions in deposit metals. (4) The relationship between Mn-Si contents and carburized structures has been clarified and the boundary line shown in a diagram.
    (5) The relationship between Mn-Si contents and mechanical properties has also been clarified and the cause of the development of carburized structure studied from the standpoint of deoxidation. (6) These data make it possible to estimate with a fair degree of accuracy the quantities of mild steel arc deposits by observation of carburized structures.
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  • [in Japanese]
    1952 Volume 21 Issue 2 Pages 66-69
    Published: 1952
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    Download PDF (292K)
  • 1952 Volume 21 Issue 2 Pages 70
    Published: 1952
    Released on J-STAGE: June 12, 2009
    JOURNAL FREE ACCESS
    Download PDF (96K)
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