Journal of Welding and Joining

The Korean Welding and Joining Society (대한용접접합학회)
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Effect of Nitrogen Volume in Ar-N2 Shielding Gas on Microstructure and Hardness of GTA Welded Pure Ti

순 Ti GTA 용접부의 미세조직과 경도에 미치는 Ar-N2 보호가스 중 질소량의 영향

  • 안현준 (부산대학교 하이브리드소재솔루션 국가핵심연구센터) ;
  • 전애정 (부산대학교 하이브리드소재솔루션 국가핵심연구센터) ;
  • 홍재근 (한국기계연구원 부설 재료연구소) ;
  • 정보영 (POSCO 기술연구소) ;
  • 이종섭 (POSCO 기술연구소) ;
  • 강정윤 (부산대학교 하이브리드소재솔루션 국가핵심연구센터)
  • Received : 2012.04.16
  • Accepted : 2012.04.27
  • Published : 2012.04.30
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Abstract

In this study, effect of nitrogen volume in the shielding gas of Ar-$N_2$ mixing gas on the bead shape, hardness and microstructure of GTA welds of 3mm thick Commercial Pure Ti was investigated. As the nitrogen volume increased, the welding current for full penetration was reduced and hardness in the fusion zone significantly increased compared with that of the base metal, but there is no difference in the hardness of HAZ. Microstructure in the fusion zone with pure Ar gas changed from equiaxed alpha of the base metal to serrated alpha. On the other hand, microstructure using Ar-$N_2$ mixing gas changed to acicular alpha. With the increasing of nitrogen content, the amount of acicular alpha increased and the size of that was fine.

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References

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