Defect Detection in Weld Joints by Infrared Thermography

Lahiri, B B and Bagavathiappan, S and Saravanan, T and Rajkumar, K V and Kumar, Anish and Philip, John and Jayakumar, T (2011) Defect Detection in Weld Joints by Infrared Thermography. In: Proceedings of the International Conference on Non Destructive Evaluation for Steel and Allied Industries - NDESAI 2011, Dec. 2-3, 2011, SNTI Auditorium Jamshedpur, India.



The objective of this present paper is to evaluate the effectiveness of infrared thermography (IRT) as a non-contact, fast and reliable non-destructive evaluation procedure for detection and quantification of defects in weld joints. In the present work, a friction stir welded (FSW) joint of two aluminum plates and three 316 LN stain-less steel (SS) weld-joints with lack of penetration (LOP), lack of fusion (LOF) and tungsten inclusion (TI) defects respectively, were inspected using IRT and digital radio-graphy (DRG). Using active thermography methods, a sub-surface tunnel defect along the weld line was successfully detected in the FSW joint and its length and width were estimated by suitable pixel calibration. Using lock-in thermography, optimum frequencies were determined for each of the specimens and defect-depths were estimated. Tempe-rature fall of the defect region and defect-free region were monitored as a function of time and it was found that the rate of temperature fall in the former case is slower than that in the latter one. Results from both the tech-niques, i.e., IRT and DRG were found to be in good agree-ment with each other in all the cases. Advantage of IRT is that it provides depth information also.

Item Type:Conference or Workshop Item (Paper)
Official URL/DOI:
Uncontrolled Keywords:Defect Detection; Weld joints; Infrared Thermography
Divisions:Material Science and Technology
ID Code:4621
Deposited By:Sahu A K
Deposited On:17 Jan 2012 16:58
Last Modified:17 Jan 2012 16:58
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