• 제목/요약/키워드: Trans-Varestraint test

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Ni기 초내열합금 용접부의 고온균열에 관한 연구(I) - 용접금속의 응고균열 감수성에 미치는 Fe의 영향 - (A Study on Hot Cracking in Ni-Base Superalloy Welds (I) - Effect of Fe Contents on Solidification Cracking Susceptibility in Weld Metal -)

  • 우인수;강정윤
    • Journal of Welding and Joining
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    • 제19권6호
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    • pp.614-621
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    • 2001
  • A study was carried out to determine the solidification cracking susceptibility of Ni-base superalloy as a function of Fe content in base metal. Three kinds of Ni-base superalloys with three different levels of Fe content were used. The solidification cracking susceptibility was evaluated by the Trans-Varestraint test at four different strain levels. Quantitative analysis of crack revealed that the solidification crack length and the temperature range in which hot cracking occurred in fusion zone (Brittle Temperature Range, BTR) decreased with a decrease in Fe content. Further, the thermo-calc data indicated that the solidification temperature range also decreased with decreasing Fe content. From these results, it was deduced that the improvement of the solidification cracking susceptibility with decreasing Fe content was attributed to the decrease of the solidification temperature range.

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HY계 고강도 고인성강의 용접성 (Weldability of HY type High Strength-Toughness Steel)

  • 이종봉;안상곤;심인옥
    • Journal of Welding and Joining
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    • 제13권3호
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    • pp.65-76
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    • 1995
  • Weldability of DS100 and HY type high strength-toughness steel plates, tentatively produced as domestic production, was investigated. DS100 and DS130A had nearly same hardenability in HAZ in spite of its difference in Ceq. Based upon the y-groove test results, cold cracking susceptibility of DS130 was superior to that of DS100 because of its lower hydrogen level in weld metal. Solidification cracking tested by the Trans-Varestraint test was occured in all of the weld metals, and its susceptibility was high in the row of DS100, DS130A and DS130B. However, no liquation cracking and ductility-dip cracking tested by the Longi-Varestraint test with 6.0% augmented strain were detected in base metal and reheated weld metal. Toughness in the GMA welding joint was satisfied with the relative Mill Spec, even though welded joint of DS100 had relatively low impact energy especially at the weld metal.

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