Welding in the World

, Volume 55, Issue 7–8, pp 83–89 | Cite as

Real-Time Monitoring of Weld Pool during GTAW using Infra-Red Thermography and analysis of Infra-Red thermal images

  • M. Vasudevan
  • N. Chandrasekhar
  • V. Maduraimuthu
  • A. K. Bhaduri
  • B. Raj
Peer-Reviewed Section


Real-time monitoring of the weld pool using infra-red (IR) thermography during gas tungsten arc (GTA) welding is gaining importance due to the requirements for on-line monitoring and control of the welding process. To facilitate real-time monitoring of the weld pool, a computer-controlled GTA welding machine with sensing of the weld pool using IR camera has been developed. The IR camera, mounted on the torch assembly, monitors the molten pool and the surface temperature distribution surrounding the weld pool during GTA welding. Temperature profiles were measured on the plates using thermocouples in combination with IR thermography to determine the emissivity of the plate surface. GTA welding was carried out on 3 mm-thick 316LN stainless steel (SS) plates under different welding conditions. IR thermal images were acquired on-line and analysed. A linear relationship was obtained between the thermal bead width, determined by line-scan analysis technique, and the actual bead width, measured by cross-sectional optical microscopy. The computed macroscopic temperature gradient and the actual of weld bead depth of penetration showed an inverse relationship. Full-frame analysis was carried out to estimate the surface temperature distribution for square-butt weld joints. For 1316LN SS weld joints, IR thermal signatures were acquired for various weld defects, such as lack of fusion, lack of penetration and tungsten inclusions, for use as reference signatures for on-line monitoring during GTA welding.

IIW-Thesaurus keywords

Defects Imaging Infrared Lack of fusion Penetration defects Thermography Visual inspection Welded joints 


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  1. [1]
    Chandrasekhar N. and Vasudevan M.: Computer based operation, monitor and control of GTA welding machine and temperature measurements during welding, International Conference on Advance Manufacturing Technology, Indian National Academy of Engineering, Chennai (6–8 February 2008).Google Scholar
  2. [2]
    Nagarajan S., Chen W.H. and Chin B.A.: Infrared sensing for adaptive arc welding, Welding Journal, 1989, vol. 68, no. 11, pp. 462s–466s.Google Scholar
  3. [3]
    Chen W.H. and Chin B.A.: Monitoring joint penetration using infrared sensing techniques, Welding Journal, 1990, vol. 69, no. 4, pp. 181s–185s.Google Scholar
  4. [4]
    Smith J.S. and Lucas W.: Vision based systems for controlling the arc welding operation and inspecting the weld bead profile, Welding in the World, 1999, vol. 43, Supplementary Issue, pp. 103–115.Google Scholar
  5. [5]
    Banerjee P., Govardhan S., Wikle H.C., Liu J.Y. and Chin B.A.: Infrared sensing for on-line weld geometry monitoring and control, Journal of Engineering for Industry, 1995, vol. 117, no. 3, pp. 323–330.CrossRefGoogle Scholar
  6. [6]
    Menaka M., Vasudevan M., Venkataraman B. and Raj B.: Estimating bead width and depth of penetration during welding by infra-red thermal imaging, Insight, 2005, vol. 47, no. 9, pp. 564–568.CrossRefGoogle Scholar
  7. [7]
    Ghanty P., Vasudevan M., Mukherjee D.P., Pal N.R., Chandrasekhar N., Maduraimuthu V., Bhaduri A.K., Barat P. and Raj B.: Artificial neural network approach for estimating weld bead width and depth of penetration from infrared thermal image of weld pool, Science and Technology of Welding and Joining, 2008, vol. 13, no. 4, pp. 395–401.CrossRefGoogle Scholar
  8. [8]
    Balfour C., Smith J.S. and Al-Shammma A.I.: Novel edge feature correlation algorithm for real-time computer vision-based molten weld pool measurements, Welding Journal, 2006, vol. 86, no. 1, pp. 1s–8s.Google Scholar
  9. [9]
    Al-Habaibeh A. and Parking R.: An autonomous low-cost infrared system for the on-line monitoring of manufacturing processes using novelty detection, International Journal of Advanced Manufacturing Technology, 2003, vol. 22, no. 3–4, pp. 249–258.CrossRefGoogle Scholar
  10. [10]
    Huang R.S., Liu L.M. and Song G.: Infrared temperature measurement and interference analysis of magnesium alloy in hybrid laser-GTA welding process, Materials Science and Engineering A, 2007, vol. 447, no. 1–2, pp. 239–243. onCrossRefGoogle Scholar
  11. [11]
    Bicknell A., Smith J.S. and Lucas J.: Infrared sensor for top face monitoring of weld pools, Measurement Science and Technology, 1994, vol. 5, no. 4, pp. 371–378.CrossRefGoogle Scholar
  12. [12]
    Farson D., Richardson R. and Li X.: Infrared measurement of base metal temperature in gas tungsten arc welding, Welding Journal, 1998, vol.77, no. 9, pp. 396–401.Google Scholar

Copyright information

© International Institute of Welding 2011

Authors and Affiliations

  • M. Vasudevan
    • 1
  • N. Chandrasekhar
    • 1
  • V. Maduraimuthu
    • 1
  • A. K. Bhaduri
    • 1
  • B. Raj
    • 1
  1. 1.Indira Gandhi Centre for Atomic ResearchKaipakkamIndia

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