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Porosity Reduction in Laser Welding of Nitrided Carbon Steel

질화처리된 저탄소강 레이저 용접부의 기공 감소

  • Ahn, Young-Nam (Welding & Joining Research Group, Korea Institute of Industrial Technology) ;
  • Kim, Cheolhee (Welding & Joining Research Group, Korea Institute of Industrial Technology) ;
  • Lee, Wonbeom (Heat Treatment & Plating Technology Center, Korea Institute of Industrial Technology) ;
  • Kim, Jeonhan (Korea Ppuri Industry Center, Korea Institute of Industrial Technology)
  • 안영남 (한국생산기술연구원 용접접합연구그룹) ;
  • 김철희 (한국생산기술연구원 용접접합연구그룹) ;
  • 이원범 (한국생산기술연구원 열표면기술센터) ;
  • 김정한 (한국생산기술연구원 뿌리산업진흥본부)
  • Received : 2013.11.01
  • Accepted : 2013.12.19
  • Published : 2013.12.31

Abstract

Gas nitriding is a surface hardening process where nitrogen is introduced into the surface of a ferrous alloy. During fusion welding of nitrided carbon steel, the nitride inside weld metal is dissolved and generates nitrogen gas, which causes porosities - blow holes and pits. In this study, several laser welding processes such as weaving welding, two-pass welding, dual beam welding and laser-arc hybrid welding were investigated to elongate the weld pool to enhance nitrogen gas evacuation. The surface pits were successfully eliminated with elongated weld pool. However blowholes inside the weld metal were effective reduced but not fully disappeared.

Keywords

References

  1. ASM International: ASM Handbook, Vol. 4, Heat Treating, 1991
  2. C. Kim and Y.-N. Ahn: Laser Weldability of Carbon Steel for Automotive Auto-transmission Parts, Journal of KWJS, 28-3 (2010), 237-242 (in Korean)
  3. Y.-N. Ahn and C. Kim: Laser Welding of Automotive Transmission Components, Journal of KWJS, 29-6 (2011), 665-668 (in Korean)
  4. J. Yu, T. Jung, S. Kim and S. Rhee: Laser Welding of Cast Iron and Carburized Steel for Differential Gear, Journal of Mechanical Science and Technology, 25-11 (2011), 2887-2893 https://doi.org/10.1007/s12206-011-0809-x
  5. J. Cho, I. Chang, C. Jeong and C. Lim: Study on Laser Welding for Differential Gear & Case for Filler wire, Journal of Korean Society of Laesr Processing, 14-4 (2011), 1-8
  6. H. Gu, G. Yin and S. Shulkin: Laser Beam Welding of Nitride Steel Components, Physics Procedia, 12 (2011), 40-45 https://doi.org/10.1016/j.phpro.2011.03.006
  7. A. Matsunawa, J.-D. Kim, N. Seto, M. Mizutani and S. Katayama: Dynamics of Keyhole and Molten Pool in Laser Welding. Journal of Laser Applications, 10-6 (1998), 247-254 https://doi.org/10.2351/1.521858
  8. R. Fabbro and K. Chouf: Dynamic Description of the Keyhole in Deep Penetration Laser Welding, Journal of Laser Application, 12-4 (2000), 142-146 https://doi.org/10.2351/1.521924
  9. A. Matsunawa: Problems and Solutions in Deep Penetration Laser Welding, Science and Technology of Welding and Joining, 6-6 (2001), 351-354 https://doi.org/10.1179/stw.2001.6.6.351
  10. A. Punkari, D. C. Weckman and H. W. Kerr: Effects of Magnesium Content on Dual Beam Nd:YAG Laser Welding of Al-Mg Alloys. Science and Technology of Welding and Joining, 8-4 (2003), 269-281 https://doi.org/10.1179/136217103225005516
  11. S. Katayama, Y. Naito, S. Uchiumi and M. Mizutani, Penetration and Porosity Prevention Mechanism in Laser-Arc Hybrid Welding. Proceedings of the 3rd International WLT Conference on Lasers in Manufacturing (LIM 2005), 2005, 193-198