• Title/Summary/Keyword: Fillet welding

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The Comparison of Thermal Characteristics in FCAW & Hybrid Welded Joint for Fillet Welding of Ship Structure A-Grade Steel (조선용 강재 A-Grade의 Fillet 용접에 대한 FCAW 및 하이브리드 용접부의 열적 특성 비교)

  • O, Jong-In;Park, Ho-Gyeong;Rajesh, S.R.;Jeong, Eun-Yeong;Bang, Han-Seo
    • Proceedings of the KWS Conference
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    • 2006.10a
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    • pp.48-50
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    • 2006
  • Recently many research are going on in the field of application of Laser-Arc hybrid welding for superstructures such as ship-structures, transport vehicles etc. however, the study on heat distribution and welding residual stress of hybrid weld by numerical simulation leaves much to be desired. Therefore a Finite Element based numerical comparison of heat distribution and thermal history in both the FCAW and Hybrid welding been made in this study. Based on this thermal outputs from the present model could be sequentially coupled to suitable mechanical models to predict appropriate mechanical characteristics such as residual stress.

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Determination of Preheating Temperature for Box Girder Welding (강교용 박스거더의 용접예열 온도 선정에 관한 연구)

  • Cho, Jae-Hun;Moon, Seung-Jae;Yoo, Hoseon
    • Plant Journal
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    • v.7 no.1
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    • pp.49-55
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    • 2011
  • This study analyzed causes and status of cracks to suggest preventives for welding cracks generated on fillet welding zone of atmosphere corrosion resisting steel box girder. Penetrant testing, a sort of non-destructive testing, was conducted for inspection of crack status on welding zone. As a result of test, welding cracks were found on the point of start, center and end to fillet welding zone of 32 mm-thickness. The result of carbon equivalent composition of materials was 0.452%. According to welding specification, to preheat prevent welding crack, preheat temperature of $100{\sim}200^{\circ}C$ should be kept before welding execution. It was failed to keep preheat temperature because it had been executed on winter season and the structure of box girder had wide heat transfer area. As a result of examination of time varying preheating temperature of 32mm-thickness material, it was understood that preheat temperature of above $230^{\circ}C$ on both 130mm-long sides of welded joint can prevent welding crack.

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A Study of the Thermal Analysis of Horizontal Fillet Joints by Considering the Bead Shape in GMA Welding (GMA 용접에서 비드형상을 고려한 수평필릿용접부의 온도해석에 관한 연구)

  • Jo, Si-Hun;Kim, Jae-Ung
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.8
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    • pp.71-78
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    • 2001
  • In GMA(Gas Metal Arc)Welding, the weld size that is a locally melted area of a workpiece is one of the most important considerations in determining the strength of a welded structure. Variations in the weld power and the welding heat flux may affect the weld pool formation and ultimately the size of the weld. Therefore, an accurate prediction of the weld size requires a precise analysis of the weld thermal cycle. In this study, a model which can estimate the weld bead geometry and a method for thermal analysis, including the model, are suggested. In order to analyze the weld bead geometry, a mathematical model was developed with transformed coordinates to apply to the horizontal fillet joints. A heat flow analysis was performed with a two dimensional finite element model that was adopted for computing the base metal melting zone. The reliability of the proposed model and the thermal analysis was evaluated through experiments, and the results showed that the proposed model was very effective for predicting the weld bead shape and good correspondence in melting zone of the base metal.

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