Online ISSN : 1883-7204
Print ISSN : 0021-4787
ISSN-L : 0021-4787
Volume 28 , Issue 4
Showing 1-8 articles out of 8 articles from the selected issue
  • [in Japanese]
    1959 Volume 28 Issue 4 Pages 215-220
    Published: April 25, 1959
    Released: June 12, 2009
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  • S. Ando, S. Terada, S. Mori
    1959 Volume 28 Issue 4 Pages 221-228
    Published: April 25, 1959
    Released: June 12, 2009
    In accordance with the crack test procedure with cylinder type specimens as advocated by K. Kautz, influences of chemical composition of specimen (particularly C content), electrodes (mainly ilmenite, some low-hydrogen type) and, welding conditions (welding speed and current) on crack sensitivity of test bead were studied. The relationship between the chemical composition mainly of bead (C, Mn/S, Mn/Si) and cracking degree was considered and some scruting of the test procedure carried out.
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  • K. Nakane, T. Muramoto, H. Kan, T. Yokoi
    1959 Volume 28 Issue 4 Pages 229-235
    Published: April 25, 1959
    Released: June 12, 2009
    An experimental study was made on the hot-crack sensitivites of 5 kinds of rolled steel plates and 7 kinds of coated electrodes by means of "the modified Murex Hot-Crack Testing Method." In this testing method, the crack sensitivity is determined by examining cracks in the test fillet weld bead which has been laid in the groove constructed by two end surfaces of the two test steel plate pieces, one of which being fixed and the other being forced to turn simultaneously with the progress of welding in the opposite direction to the natural cooling contraction of the test fillet bead.
    The main results were as follows :
    ( i ) The hot crack sensitivity became larger as the bending angular speed of test fillet bead became larger (from 30°/34.4 sec to 30°/17.2 sec). The large parts of hot-cracks revealed were oxidised or nonoxidised iceflower-like structures (intergranular crackings in primary dendritic structures).
    (ii) The shot-crack sensitivities of test steels as well as electrodes could be determined clearly by this test. The results on hot-crack sensitivities of test materials were analysed statistically.
    (iii) It may be said that the modified Murex Hot-Crack Testing Method is a very useful method to test hot-crack sensitivities of steels as well as electrodes.
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  • M. Inagaki
    1959 Volume 28 Issue 4 Pages 236-243
    Published: April 25, 1959
    Released: July 14, 2010
    The cooling curve from 800°C and the cooling time from 800°C to 500°C near the fusion line in case of C.S. arc welding process were measured for various welding conditions. Welding conditions such as type of welded joint, plate thickness, welding current, the proceeding rate of bead, arc voltage or open voltage, diameter of filler wire, volume per unit time of supplied gas, volume percentage of oxygen in supplied mixed gas CO2-O2, and bead length were changed and-effects on cooling time were observed. However the main factors which influence the cooling time are type of welded joint, plate thickness and arc energy per unit bead length J=60EI/v, as those in case of the other arc welding processes.
    In case of C.S. arc welding of carbon steels or high tensile steels (or low alloy steels), the relations between the welding conditions and cooling time from 800°C to 500°C near fusion line are presented by the following formula.
    where E : arc voltage, Volt
    I : welding current, Amp.
    v : the proceeding rate of bead, cm/min.
    t : plate thickness, mm
    1 for bead on a plate,
    1.7 for T-fillet joint.
    This formula is applied when the bead length is above about 10cm. The nomograph of this formula is constructed in Fig. 19. The cooling time can be read easily from the welding conditions by this nomograph.
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  • M. Inagaki
    1959 Volume 28 Issue 4 Pages 244-249
    Published: April 25, 1959
    Released: June 12, 2009
    The Cooling time in case of C.S. arc welding process is approximately equal to that of submerged arc welding process, and the cooling is slower remarkably than that of manual arc welding process with covered electrodes. The above mentioned fact, coupled with the fact that the welded part by C.S. arc welding shows a low hydrogen content, is extremely advantageous, because the tendencies of embrittleness and cracking in the heat-affected zone are remarkably relieved by these facts.
    If a welding process and the welding conditions are known, the cooling time can be obtained by the nomograph or the curve based on the experimental formula. When the cooling curve corresponding to the cooling time obtained above is searched in the C-C-T diagram in case of max. heating temperature 1300°-1400°C the hardness and the microstructure shown by the same cooling curve is considered to be the same as the max. hardness and microstructure in the heat-affected zone by welding.
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  • M. Ozawa, T. Morita, K. Omura
    1959 Volume 28 Issue 4 Pages 250-254
    Published: April 25, 1959
    Released: June 12, 2009
    It is our aim to measure the consumption-rates of anode and cathode of tungsten arc in air, argon, oxyargon, nitrogen, and chloride.
    In order to investigate the behaviors of their consumption-rates in small arc current, our experiments are performed in comparatively wide range of arc current, e.g. 1.3-208amp.
    The results are summarized as follows :
    1. Below 40A, as the current decreases, the consumption-rates of anode and cathode increase under all of the conditions.
    2. The consumption-rate of anode in argon is nearly equal to that in nitrogen, while it is higher in air, oxyargon, and chlorine than that in argon. It seems to be due to the oxide or chloride produced at the hot electrode.
    3. The consumption-rates of cathode in various gases are evidently different by the use of the kinds of gases surrounding arcs. It is partly because the gases have their own ionization potentials and partly because oxide or chloride is produced at the surface of cathode.
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  • T. Nakamura, E. Maeda
    1959 Volume 28 Issue 4 Pages 255-260
    Published: April 25, 1959
    Released: June 12, 2009
    This paper describes the study on the relationship between mash seam welding variables and weld characteristics, and on the some physical and chemical properties of the weld in the mash seam welding of stainles steel 1mm thickness. That is to say, before an systematic experiment, some welds were made without taking data. Thereafter, among the welding condition, welding time and rest time were held constant, and welding current, welding pressure, initial over lap, and welding speed were varied, then breaking load, joint thickness and nugget penetration were measured. Also, corrosion resistance test, pressure test and bending test were accomplished.
    The results obtained are as follows ;
    (1) If optimum welding conditions are selected and sheet thickness is comparatively thin, stainless steel sheet may be statisfactorily mash seam welded.
    (2) Welding current and initial over lap must be severely selected.
    (3) Electrode force must be very large.
    (4) Corrosion resistance of the weld joint is very good whicherer heat-treated or nonheat-treated.
    (5) Nugget formation is not along the faying surface but parallel to sheet surface.
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  • H. Sekiguchi, I. Masumoto
    1959 Volume 28 Issue 4 Pages 261-266
    Published: April 25, 1959
    Released: June 12, 2009
    In order to prevent the elevation of dew point of supplied gas for CO2-O2 arc welding, the cylinders of carbon dioxide of 3rd grade and of super-dried oxygen must be used, as previously reported. But it is not always easy to get the cylinders of such grade.
    If it will be able to use an ordinary cylinder, which may cont ain free water, and to prevent simply the elevation of dew point of flowing gas, it will be very convenient for the CO2-O2 arc welding or the other gas-shield-arc welding processes.
    For such purpose, flowing gases from the cylinders containing free water were desiccated with silica gel, activated alumina or pure calcium chloride. And the efficiencies of desiccation with such desiccants were compared.
    According to the results of experiments, it is easy to supply a simple gas or mixed gas with dew point below -40°C, when supplied gas is desiccated with silica gel. or activated alumina.
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