Browse > Article
http://dx.doi.org/10.5781/KWJS.2012.30.2.174

Effect of Nitrogen Volume in Ar-N2 Shielding Gas on Microstructure and Hardness of GTA Welded Pure Ti  

An, Hyun-Jun (National Core Research Center (NCRC), Pusan National University)
Jeon, Ae-Jeong (National Core Research Center (NCRC), Pusan National University)
Hong, Jae-Keun (Korea Institute of materials Science)
Jeong, Bo-Young (Technical Research Laboratories, POSCO)
Lee, Jong-Sub (Technical Research Laboratories, POSCO)
Kang, Chung-Yun (National Core Research Center (NCRC), Pusan National University)
Publication Information
Journal of Welding and Joining / v.30, no.2, 2012 , pp. 70-75 More about this Journal
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.
Keywords
CP Ti; GTAW; Shielding gas; Ar-$N_2$ mixing gas; Microstructure; Hardness;
Citations & Related Records
연도 인용수 순위
  • Reference
1 W. A. Baeslack III, J. R. Davis and C. E. Cross : Selection and Weldability of Conventional Titanium Alloys, in: ASM Handbook, 6, Welding, Brazing and Soldering, Materials(9th Ed.), ASM International, Metals Park, OH, USA, 1993, 507-508
2 W. S. Chang, M. Y. Lee and B. H. Yoon : High Current Keyhole GTAW for Stainless Steels and Ti Alloys, Journal of KWS, 22-6 (2004), 6-9 (in Korean)
3 S. Lathabai, B. L Jarvis and K. J. Barton : Comparison of Keyhole and Conventional Gas Tungsten Arc Welds in Commercially Pure Titanium, Materials Science and Engineering A, A299 (2001), 81-93
4 B. H. Yoon, S. H. Kim and W. S. Chang : Recent Trends of Welding Technology for Ti and Ti Alloys, Journal of KWJS, 25-5 (2007), 22-28 (in Korean)
5 W. A. Baeslack III, J. M. Gerken, C. Cross, J. Hanson, P. S. Liu, J. C. Monses, J. Schley and L. Showalter : Titanium and Titanium Alloys, in: J.M. Gerken (Ed.), Welding Handbook, 4, 8th ed., American Welding Society, Miami, Florida, USA, 1998, 488
6 D. R Mitohell and N. G. Feige : Welding of Alpha-beta Titanium Alloys in One-inch Plate, Welding Journal, 46-5 (1967), 193
7 Shanping Lu, et al : Numerical study and comparisons of gas tungsten arc properties between argon and nitrogen, Computational Materials Science, 45 (2009), 327-335   DOI   ScienceOn
8 H. A. Wriedt and J. L. Murray : The N-Ti system, Bulletin of alloy Phase Diagrams, 8 (1987), 378   DOI
9 H. T. Clark : The Lattice Parameters of High Purity Alpha Titanium; The Effects of Oxygen and Nitrogen on Them, Trans. AIME, 185, 1949, 588-589