Journal of Welding and Joining

The Korean Welding and Joining Society (대한용접접합학회)
권호 표지
DOI QR코드

DOI QR Code

Characteristics of Plasma Emission Signals in Fiber Laser Welding of API Steel (II) -The Relationship between Welding Conditions and Emission Signals-

API강재의 파이버레이저 용접시 유기되는 플라즈마의 방사특성 (II) -용접조건과 방사신호의 관련성-

  • Received : 2012.05.29
  • Accepted : 2012.08.30
  • Published : 2012.08.30
Download PDF
⟨ Previous Next ⟩

Abstract

Laser welding by fiber laser accompanied by a lot of spatter and humping bead. This is because the deep and narrow keyhole usually form due to high beam quality. So the weld bead is formed defects, because the plasma jet with a high vapor pressure make the molten pool on keyhole wall scattered. For such a reason, unstable behavior of keyhole is difficult to monitor laser welding by using the laser induced plasma. Mostly, fiber laser welding of thick plates most be influenced by this effect. Therefore, fiber laser welding has been difficult to apply the sole. Thus, laser welding monitoring based on plasma measurements have much difficulty in measurements and analysis of signal. In this study, influence of the plasma emission signal according to welding speed and laser power in fiber laser welding analysed by using RMS and FFT analysis. We can verify that RMS value of the plasma emission signal changes with welding parameters in fiber laser welding, and aspect ratio greater than 1, the peak of FFT frequency had been moved in accordance with welding parameter.

Keywords

References

  1. Young-Nam Ahn, Cheolhee Kim : Laser Welding of Automotive Transmission Components, Journal of KWJS, 29-6 (2011), 45-58 (in Korean)
  2. K. H. Park : Fiber Laser Application to Precision Processing Industries, High Power $CO_{2}$ Laser Systems and Applications, Abstracts of the 2011 Autumn Annual Meeting of KWJS, 83-87 (in Korean)
  3. You-Hie Han, Joo-Young Park : Fiber Laser Applications-Welding, Cutting and Drilling, Abstracts of the 2011 Spring Annual Meeting of KWJS, 105-105 (in Korean)
  4. Mok-Young Lee : A Multi Kilowatts CW Fiber Laser Welding, Journal of KWJS, 26-4 (2008), 8-13 (in Korean)
  5. Yousuke KAWAHITO, Masami MIZUTANI and Seiji KATAYAMA : Defect Formation Mechanism and Reduction Procedure in 10 kW High Power Fiber Laser Welding of Stainless Steel, Quarterly journal of the Japan Welding Society, 26-3 (2008), 203-209 https://doi.org/10.2207/qjjws.26.203
  6. LIU Zhongjie, XU Guojian and KUTSUNA Muneharu : Laser-MAG hybrid welding of high strength steel using fiber laser and $CO_{2}$ laser, Quarterly journal of the Japan Welding Society, 25-2 (2007), 254-260 https://doi.org/10.2207/qjjws.25.254
  7. SHIN Minhyo, MURAKAMI Takahiro and NAKATA Kazuhiro : Parametric Study on One Pass Fully- Penetrated Weld Bead Formation in Horizontal Fillet Weld T-Joint by Fiber Laser-MAG Arc Hybrid Welding for Thick Steel Plate, Quarterly journal of the Japan Welding Society, 29-3 (2011), 174-180 https://doi.org/10.2207/qjjws.29.174
  8. SHIN Minhyo and NAKATA Kazuhiro : Study on Weld Bead Formation with Square-Groove Butt Joint by 10 kW Class Fiber Laser-MAG Arc Hybrid Welding, Quarterly journal of the Japan Welding Society, 29-3 (2011), 181-186 https://doi.org/10.2207/qjjws.29.181
  9. Jong-Do KIM, Chang-Je, Mok-Young LEE: Characteristics of Plasma Emission Signals in Fiber Laser Welding for API Steel (I), Journal of KWJS, 28-6 (2010), 51-57 (in Korean)
  10. Jong-Do KIM and Hyun-Joon Park : The Weld - ability of $6mm^{t}$ Primer-coated Steel for Ship - building by $CO_{2}$ Laser(I), Journal of KWJS, 23-3 (2005), 76-82 (in Korean)
  11. Jong-Do KIM and Chang-Je LEE : The Weld - ability of Laminated Stator Core for Motor by Pulsed Nd:YAG Laser [I], Journal of KSME, 30-7 (2006), 629-635 (in Korean)

Cited by

  1. Characteristics of Plasma Emission Signals in Fiber Laser Welding of API Steel (III) -The Effect on Plasma Emission Signals by Shield Gas- vol.31, pp.3, 2013, https://doi.org/10.5781/KWJS.2013.31.3.60
  2. Weldability of SUS304 and Ti Dissimilar Welds with Various Welding Speed using Single Mode Fiber Laser vol.31, pp.5, 2013, https://doi.org/10.5781/KWJS.2013.31.5.64