• Title/Summary/Keyword: Tandem welding

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A Study on the Size Evaluation of Disc and Band Type Flaw by Ultrasonic Tandem Testing (초음파(超音波)TANDEM사각법(斜角法)에 의한 원형(圓形) 및 띠형결함(形缺陷)의 크기 평가(評價)에 관한 연구(硏究))

  • Han, E.K.;Eom, H.S.;Kim, J.J.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.5 no.2
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    • pp.12-21
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    • 1986
  • Generally, butt welds with plate thickness $30{\sim}40mm$ are welded with groove angle $40^{\circ},\;60^{\circ},\;70^{\circ}$, etc. In the detection of internal weld defects, oblique testing with single probe has been mainly used. But, recently, in acccordance with enlargement of welded structure, thick plate with 100-200mm are frequently required. Thus I-groove welding method was lately developed and often used. In this case, most frequently generated defects are the lack of weld penetration and incomplete fusion between base metal and welding material. If we would detect by oblique testing with single probe, detecting flaw is occassionally impossible or very underestimated. In this study, the limit for applying tandem method was studied in dise and band type flaws. The estimation of flaw size could be within 10% error compared to real flaws.

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Numerical Studies on Submerged Arc Welding Process

  • Kiran, Degala Ventaka;Na, Suck-Joo
    • Journal of Welding and Joining
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    • v.32 no.4
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    • pp.1-9
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    • 2014
  • A quantitative understanding on the effect of the welding conditions on weld joint dimensions and weld thermal cycle is difficult through experimental studies alone. The experimental realization of temperature distribution in the weld pool is proved to be extremely difficult due to the small size of welds, high peak temperature and steep temperature gradients in weld pool. This review deals with the heat transfer and fluid flow analysis to understand the parametric influence of a single wire submerged arc welding (SAW) and multi-wire SAW processes on the weld bead dimensions, temperature and fluid flow distribution in the weldment.

RECENT DEVELOPMENTS OF WELDING AUTOMATION AND ROBOTICS IN SHIPBUILDING

  • Jukka, Gustafsson;Mikko, Veikkolainen
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.732-736
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    • 2002
  • The introduction of newly developed intelligent and user-friendly robotics has opened a new era in shipbuilding. Together with traditional and low-cost mechanization a record level of welding automation rate has been achieved in the construction of cruise vessels. In the paper modem applications and recent developments of welding automation and robotics in shipbuilding have been described and some forecast for the future trends are given. Development in the field of shipyards will be continued with accelerated speed and we shall have interesting prospects for the near future. New laser techniques can boost the shipyards in a revolutional way when production is rapidly changing, materials will be lighter and quality demands are becoming more strict.

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Application of high heat input(wider bead width) for hull structural welding with semi-automatic FCAW (선체 반자동 FCAW 적용 시, 대입열(비드폭 확대) 용접 적용)

  • Nam, Seong-Gil;Jang, Tae-Won;Yun, Dong-Ryeol;Han, Jeong-Seok
    • Proceedings of the KWS Conference
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    • 2006.10a
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    • pp.142-143
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    • 2006
  • The use of hull structural steel with heavy thickness has been enlarging due to the increase of ship volume. High heat input welding methods like EGW, FGB and SAW tandem are applied in field of ship-building. However the application of high heat input methods is clearly limited because welding method to be most widely used is semi-automatic FCAW but heat input for FCAW is limited in order to obtain impact property at low temperature. This paper will introduce the application of 30mm bead width of FCW with Ni free & low Ni content.

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