JOURNAL OF THE JAPAN WELDING SOCIETY
Online ISSN : 1883-7204
Print ISSN : 0021-4787
ISSN-L : 0021-4787
Volume 48, Issue 8
Displaying 1-13 of 13 articles from this issue
  • 1979 Volume 48 Issue 8 Pages 565
    Published: 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    Download PDF (18K)
  • Mamoru Hirose, Koichiro Shimoda
    1979 Volume 48 Issue 8 Pages 578-589
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    Download PDF (676K)
  • Hideo Nakata
    1979 Volume 48 Issue 8 Pages 590-597
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    Download PDF (6735K)
  • Yoshiaki Arata, Fukuhisa Matsuda, Yutaka Shibata, Yoshihisa Ono, Mitsu ...
    1979 Volume 48 Issue 8 Pages 598-605
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    The effects of bead width, hardness in electron beam (EB)-weld metal or shape of test specimen on the fracture path transition temperature in Charpy impact test (ITF) were studied in this investigation by using HT50 and 80 steels. The remarkable conclusions are as follows:
    (1) The ITF for the E13-weld metals tended to be raised in general with an increase of ab parameters, weld heat input, depth of V notch in impact test specimen or annealing temperature for the welds.
    (2) The ITF was basically influenced by the two main parameters, that is, "Fracture path parameter, " Fp=dB/h and "Hardenability parameter, " δHv=(Hv, w-Hv, B)/Hv, B. Furthermore it had a tendency which is raised with an increase of the Fp value, or with a decrease of δHv-value.
    (3) The isothermal line for ITF; 100°C was separately made clear on the HT50 and 80 weld metals by means of the settlement of ITF, in which the two basic parameters of Fp, and δHv are used.
    (4) A special attention should be paid for the decision in the size of Charpy test specimen in order to investigate the true impact toughness of the EB-weld metal which has a narrow head width and a high hard-ness. Moreover the criterion for the decision of it was individually established on the EB-weld metals of HT50 and 80 steels in this investigation.
    Download PDF (1976K)
  • Hiroshi Kimura, Takuji Yamaguchi, Tetsuro Shiraishi, Masakazu Tsubokaw ...
    1979 Volume 48 Issue 8 Pages 605-610
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    In this paper we describe an experimental study on the tensile characteristics of welded acrylic polyvinyl chloride at low temperature. This study intends to clarify the low temperature characteristics of welded part comparing with those of base material. The results of some measurements on the tensile properties from room temperature down to the neighborhood of -195°C are reported and the appearances of tensile fracture surfaces observed by scanning electron microscope are shown, and the changes in tensile properties under low temperature atmosphere are discussed from a microscopic point of view. Furthermore, notch and load velocity effects on the brittle fracture tendency are also discussed. Material used for this experiment was acrylic polyvinyl chloride (Kydex #7300 type) board of 2 mm in thickness, and welding was carried out by a semi-automatic heat plate welder. Tension tests were carried out by using Autograph IS-2000, and low temperature atmosphere was prepared by dry ice and liquid nitrogen.
    Conclusions obtained in this study are summarized as follows;
    1) Both welded part and base material of acrylic polyvinyl chloride become brittle at low temperature.
    2) Welding joint efficiency of acrylic polyvinyl chloride gradually decreases as temperature becomes low.
    3) Notch and load velocity effects are observed both on the base and the welded materials, and low temperature brittleness becomes great when specimen is notched and load velocity is high.
    4) Correlations are observed between fracture surfaces and mechanical testing results.
    5) Impact energy for tensile fracture of acrylic polyvinyl chloride is very high even at low temperature, but that of welded acrylic polyvinyl chloride becomes very low both at room temperature and low temperature.
    Download PDF (1922K)
  • Wettability and Bond Strength in Brazing (2nd report)
    Takehiko Watanabe, Isao Okane, Ken Sasabe
    1979 Volume 48 Issue 8 Pages 611-615
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    In this report, the relationship between wettability, bond strength and mutual solubility was discussed on the basis of experimental results shown in the previous report. Consequently, taking a microscopic view of bonded layer of brazed joint, it may be said that wettability has a close relation to mutual solubility and bond strength of brazed joint has also, that is, the greater mutual solubility is, the better wettability is and the larger bond strength is. So, it may be given as a conclusion that wettability and bond strength in brazing are related closely through a factor of mutual solubility between solid base metal and liquid filler metal.
    Download PDF (3774K)
  • Kunihiko Satoh, Toshio Terasaki, Tadashi Tanaka
    1979 Volume 48 Issue 8 Pages 616-620
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    This report deals with the residual stress distributions in weld metal or weld line. Residual stress and strain are analyzed by two dimensional finite difference method based on thermo-elastoplastic theory.
    The results obtained in this report are summarized as follows:
    (1) Weld or plate length largely influences residual stress perpendicular to weld line on weld line in groove-welded plate.
    (2) There is a considerable difference between residual stresses analyzed under plain strain and stress conditions.
    (3) Maximum residual stresses in multipass welded joints are considered to be a function of parameter Q/h2.
    Download PDF (302K)
  • A Study on the Wind Resistance in a Gas Shielded Arc Welding (Part 4)
    Masami Futamata, Tetsuo Toh
    1979 Volume 48 Issue 8 Pages 621-626
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    This paper is a part of a study on the wind resistance in a gas shielded arc welding. In this paper, we show the effect of the gas shielding conditions against the wind on the welding arc phenomena with a short circuiting arc welding.
    The results obtained are summarized as follows:
    (1) The short circuit frequency of A type is increased about 30 (%) but B type is almost unchanged in deficient shielding conditions.
    (2) The short circuit frequency is distributed the range of 0-15 × 3-3 (see) in short circuit time and the peak point of the distribution is 4 × 10-3 (see) in sufficient shielding conditions. But the range of distribution becomes shorter and the peak point is changed to 6 × 10-3 (see) in deficient conditions.
    (3) In dificient shielding conditions, the spatter weight ratio (Wn/W20) increases about 6 times and the spatter seems to become smaller in grain size and to fade in brightness.
    (4) The frequency spectrum of the welding arc sound has a very wide range. The sound pressure level (SPL) increases about 4-5 (dB) in deficient shielding conditions.
    Download PDF (3159K)
  • Deoxidation in Submerged-Arc Welding (Rport II)
    Hisaei Terashima, Junichiro Tsuboi
    1979 Volume 48 Issue 8 Pages 626-632
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    Effects of carbonate and fluorides in agglomerated fluxes on silicon and manganese deoxidation in submerged-arc weld metal have been examined using the bead-on-plate tests with CaO-MgO-Al2O3-SiO2 system fluxes. Slag-off rate of deoxidation products from the oxygen rich molten metal has been deter-mined using a tungsten arc in Ar atmosphere.
    With the wire containing sufficient amounts of silicon, calcium carbonate in fluxes scarcely increases the oxygen content in weld metal. However, CaF2 or Na3Al6 in fluxes effectively decreases the oxygen content in weld metal. This effect of fluoride is deduced not to be derived from the evaporation of fluorine gas during welding. Ratio of oxygen content in weld metal to FeO content in slag keeps a constant value independently of the fluoride content in flux. During submerged-arc welding process deoxidation pro-duct of 50 to 100 ppm seems to be separated from molten weld pool within the solidifying. Slag-off of the deoxidation products in tungsten arc melted metal is completed within about 20 seconds.
    Download PDF (439K)
  • Estimation of Crack Growth Rate by Effective K, Keff and the Sphere of Application of K Concept to Stress Corrosion Cracking
    Yoshihiko Mukai, Masato Murata
    1979 Volume 48 Issue 8 Pages 632-639
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    The corelation curve between crack growth rate, da/dt and stress intensity factor K could be devided roughly into two regions, region I and II in stress corrosion cracking (SCC) of SUS 304 stainless steel in 42 % MgCl2 solution (143°C). In region I, da/dt was approximately proportional to the square of K, and in region II, after discontenious dropping of da/dt, da/dt increased again with K increasing. It would be sure that this transition was caused by decreasing of K by crack branching. Decreasing rate of K with crack branching (branching angle θ=30°) was about 0.7 which was calculated with FEM. i.e. Keff=0.7Kapp (Keff: effective K at the tip of branching crack, Kapp: apparent K which was calculated by projective length of branching crack) Itwas made clear that crack propagation feature was characterized more stririctly by Keff. The empirical formula was as follows.
    da/dt = C(K2eff-K2SCC) C: Const.
    The sphere of application of linear fracture mechanics to SCC was studied. It was made clear that da/dt in single crack was well characterized with K in small scale yielding and in almost large scale yielding conditions. In general yielding condition, da/dt increased immediately and could not be defined with K. But, even in slightly over general yielding condition, da/dt was approximately proportional to CTOD.
    Download PDF (514K)
  • Toshio Kitani, Hideyuki Yamamoto
    1979 Volume 48 Issue 8 Pages 640-644
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    In the case of submerged arc welding using conventional wire, bead width becomes narrow and penetration becomes deep when high current is used.
    If an electrode has rectangular section, good welding results are obtained without welding defectseven at higher current and welding speed.
    From the observation on the arc phenomena, it is made clear that arc roots move from one edge to another edge of the electrode in the direction of electrode width.
    The penetration is formed by thermal transfer caused by molten metal news.
    In the low current region, surface flow of molten metal makes wide bead.
    When welding current is increased, bottom flow is becomes active and makes deep penetration. Then, the nuggest becomes bowl section type.
    By skewing the electrode, the center of bead deviates from the weld line and cross section of penetration is shows unsymmetrical bowl shape.
    This deviation bead process is applied to the multi-pass welding in the narrow-gap butt joint, resulting in less welding defects.
    Download PDF (5341K)
  • Effect of Chemical Composition on Hot Cracking Sensitivity
    Takeshi Nishi, Shoji Saito, Taketo Nakano, Yukihiko Horii
    1979 Volume 48 Issue 8 Pages 645-650
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    In this report, an investigation was carried out to determine the effect of chemical composition on the hot crack sensitivity of 40% Ni-6% Mn-10% Cr type weld metal for welding 9% Ni steel. The hot crack occurred in 40% Ni type weld metal can be classified as solidification cracking.
    Experimental results on coated electrodes are summarized as follows: Sulfur and silicon were found to have a highly detrimental effect when the sulfur content was increased from 0.01% to 0.02% and the silicon content was raised from 0.2% to 0.8%. Phosphorus was found to have a detrimental effect similar to, but not as severe as, that of sulfur when the phosphorus content was raised from 0.01% to 0.02%.
    According to the test results on experimental MIG wires which phosphorus contents were kept at low level, the occurrence of hot crack in weld beads proper was highly dependent on the contents of sulfur and silicon. Molybdenum had beneficial effect on the hot cracking sensitivity when its content was increased from 2% to 9%. Therefore, it is possible to add molybdenum as the alloying element for streng-thening 40% Ni type weld metal.
    It can be considered that the harmful effect of silicon and sulfur was attributed to a high degree of microsegregation which was confirmed, using ion microprobe massanalyzer, on the longitudinal fractured surface in the center of weld metal.
    Download PDF (1828K)
  • Improvement of the Weld Strength Fluctuation by Specimens Vibration
    Jiromaru Tsujino, Eiji Mori
    1979 Volume 48 Issue 8 Pages 650-655
    Published: August 05, 1979
    Released on J-STAGE: August 05, 2011
    JOURNAL FREE ACCESS
    The weld strength of ultrasonic welding is affected by the vibration characteristics of specimens, and the welding is almost impossible in the case the upper specimen is at anti-resonance condition of longitudinal vibration.
    Weldment surface conditions have direct effects on the weld strength, and the adequate inserted materials to the welding surfaces such as grease or certain kind of polymers are very effective to weld successfully.
    The purpose of the study is to investigate the effects of the inserted materials on the weld strength fluctuation by specimens vibration and to find out the methodes effective to improve the weld strength fluctuation by specimens vibration.
    The welding equipment with vibration frequency auto-tracking and constant vibration velocity controller is used, and the input high frequency current, input power to welding system and tip vibration amplitude etc. are measured and recorded.
    The results obtained are as follows;
    1) The inserted materials to welding surfaces are effective to improve the weld strength fluctuation by lower specimens longitudinal anti-resonance vibration.
    2) The upper specimen length effect impossible to weld is not improved by inserted materials.
    3) Adequate change of welding tip vibration direction is effective to avoid the difficulties caused by upper specimen longitudinal anti-resonance vibration.
    4) Phase change of reflected wave along the specimens with metal block clamping of upper specimen at the adequate positions etc. is effective to avoid the welding difficulties caused by upper specimen vibration.
    Download PDF (1718K)
feedback
Top