• Title/Summary/Keyword: Back Gouging

Search Result 7, Processing Time 0.018 seconds

Welding Residual Stress and Strength of Thick 9% Nickel Steel Plate (9% 니켈강 후판 용접부의 강도 및 잔류응력)

  • Kim, Young-Kyun;Kim, Young-Wann;Kim, Jae-Hoon
    • Journal of Power System Engineering
    • /
    • v.18 no.4
    • /
    • pp.85-90
    • /
    • 2014
  • In this paper, the transient thermal and residual stress analysis of the welding of 9% Ni steel plates using the FEA software ABAQUS are presented. The 9% Ni steel plates are welded manually with welding consumables of 70% Ni based Inconel type super-alloys (YAWATA WELD B (M)), producing a multi-pass/multi-layer butt weld. For these materials, temperature dependant mechanical and thermal material properties are used in the analysis. The back gouging is considered in welding process simulation. The FE thermal results are validated by comparing the real fusion profile and heat affected zone (HAZ). In addition, the continuous indentation test was conducted to measure the strength of base metal, HAZ and weld metal.

Residual Stress and Fracture Analysis of Thick Plate for Partial Penetration Multi-Pass Weldment

  • Kim, Seok;Shim, Yong-Lae;Song, Jung-Il
    • Journal of Mechanical Science and Technology
    • /
    • v.16 no.9
    • /
    • pp.1033-1039
    • /
    • 2002
  • Partial penetration welding joint refers to the groove weld that applies to the one side welding which does not use steel backing and to both side welding without back gouging, that is, the partial penetration welding joint leaves an unwelded portion at the root of the welding area. In this study, we analyzed the residual stress and fracture on the thick metal plates that introduced the partial penetration welding method. According to the above-mentioned welding method, we could draw a conclusion that longitudinal stress and traverse stress occurred around the welding area are so minimal and do not affect any influence. We also performed the fracture behavior evaluation on the partial penetration multi pass welding with 25.4 mm thick plate by using the J-integral, which finally led us the conclusion that the partial penetration multi-pass welding method is more applicable and effective in handling the root face with less than 6.35 mm.

Tack welding for One Side $CO_2$ Arc Welding ($CO_2$ 편면 용접 의 가접 방법)

  • 김화연
    • Journal of Welding and Joining
    • /
    • v.2 no.1
    • /
    • pp.1-3
    • /
    • 1984
  • $CO_2$ 편면 용접은 편면 잠호 용접과 함께 작업 능률 향상, 작업 환경 개선 등의 잇점을 가지고 있어 국내의 조선소에서 많이 사용하고 잇는 용접 기법 중의 하나이다. $CO_2$ 편면 용접을 시공하기 위해서 가접보다는 strong back을 많이 사용하는데 strongback의 부착은 전 면과 후면에 부착시키는 2가지 경우가 있다. strongback을 전면에 부착할 경우 아아크는 strongback의 위치마다 중단된다. 후면에 부착할 경우 strongback으로 인한 아아크 중단은 없 어지나 용접사가 자세를 바꾸지 않고 한 번에 용접할 수 있는 최대 용접장은 1m정도이다. 이때 용접장 1m마다 아아크는 중단되게 된다. 이러한 아아크 중단부에는 용착 금속의 수축으로 인한 수축공(shrinkage hole)이 내재되어 용접 금속의 품질을 떨어뜨리므로 이를 제거하기 위해 용접 중 또는 용접 후에 gouging을 해야할 필요가 생긴다.

  • PDF

Fracture Analysis of Thick Plate for Partial Penetration Multi-pass Weldment Using J-integral (J-적분을 이용한 후판 부분용입 다층용접재의 파괴 해석)

  • Kim, Seok;Song, Jung-Il
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.26 no.2
    • /
    • pp.300-307
    • /
    • 2002
  • Partial penetration welding joint is defined as groove welds welded from one side, without steel backing or groove welds welded from both sides but without back gouging. So it has an unwelded portion at the root of the weld. Study of partial penetration weldment fracture behavior includes residual stress analysis and fracture analysis. The J-integral loses its path independency in residual stress field. Therefore, it is necessary to introduce a new J-integral, J, which is defined including the effect of plastic deformation and thermal strain. In this study, theoretical formulation and program were developed for the evaluation of J-integral for the crack tip located in the weldment. Evaluations of fracture behavior were performed for partial penetration multi-pass weldment of 25.4mm thick plate by J-integral. From a point of fracture in partial penetration multi-pass welding, it seemed to be better to control root face smaller than 6.35mm.

Residual Stress and Displacement Analysis of Thick Plate for Partial Penetration Multi-Pass Weldment (후판의 부분용입 다층용접에 대한 잔류음력 및 변형해석)

  • Kim, Seok;Bae, Sung-In;Song, Jung-Il
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.25 no.11
    • /
    • pp.1813-1819
    • /
    • 2001
  • Partial penetration welding Joint defines that groove welds without steel backing, welded from on side, and groove weeds welded from both sides but without back gouging, that is. it has an unwelded portion at the root of the weld. In this study we analysed fur residual stress and displacement distribution on partial penetration welding condition of thick plate metal. For 25.4mm thick plate, theoretical residual stress and displacement analysis by finite element method using ABAQUS was carried out and compared with the experimental result using hole-drilling method. In results of the condition of partial penetration, it appeared that longitudinal stress at welding area was a little difference and transverse stress did not have any effect by partial penetration multi-pass welding. From a point of welding distortion in partial penetration multi-pass welding, it seemed to be better to control root face smaller than 6.35mm.

Residual Stress and Fracture Analysis of Thick Plate for Partial Penetration Multi-pass Weldment (후판 부분용입 다층용접의 잔류음력 및 파괴 해석)

  • Kim, Seok;Shim, Yong-Lae;Bae, Sung-In;Song, Jung-Il
    • Journal of Welding and Joining
    • /
    • v.19 no.6
    • /
    • pp.636-642
    • /
    • 2001
  • Partial penetration welding joint defines the groove welds that applies the one side welding which does not use steel backing and both side welding without back gouging, that is, the partial penetration welding joint leaves an unwelded portion at the root of the welding area. In this study, we analyzed the residual stress and fracture on the thick metal plates that introduced the partial penetration welding method. As results of using above mentioned welding method, we could draw a conclusion that longitudinal stress and traverse stress occurred around the welding area was so minimal and did not affect any influence. We also performed the fracture behavior evaluation on the partial penetration multi-pass welding with 25.4mm thick plate by using theJ-integral, which finally led us the conclusion that the partial penetration multi -pass welding method is more applicable and effective in handling the root face with less than 6.35mm.

  • PDF