Abstract
Weld quality evaluation was conducted on laser welded thin sectsions (2 mm) of hot-rolled (HR) low-carbon steel coils during cold rolling process. The analysis revealed that the poor welds consisting of the weld defects like incomplete fusion, cluster of porosity, and large difference in hardness between the weld zone and base metal were responsible for the weld failures. Experiments were conducted by varying the welding parameters; laser power and welding speed to optimize the parameters for minimizing the weld defects. The optimized weld process parameters have helped elimination of weld defects and the results are verified with microscopy and microhardness measurements. As destructive evaluation techniques are time consuming and not always permitted in industrial applications, attempts have been made in the present investigation for the utilization of suitable non-destructive techniques for the evaluation of weld quality. Non-destructive magnetic techniques of magnetic hysteresis loop and magnetic Barkhausen emissions were used in the present investigation to establish possible correlations of magnetic properties across the weld seam with the mechanical property (microhardness) for evaluation of weld quality. It is inferred that the magnetic properties of coercivity and inverse of root mean square voltage can be effectively utilized to determine weld quality in HR steel coils.
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References
J. Xie and A. Kar, Laser Welding of Thin Sheet Steel with Surface Oxidation, Welding Research Suppliments, 1999, p 343-348
D. Iordachescu, M. Blasco, R. Lopez, A. Cuesta, M. Iordachescu, and J.L. Ocana, Recent Achievements and Trends in Laser Welding of Thin Plates, J. Optoelectron. Adv. Mater., 2011, 13, p 1-4
M.I. Khan, S.K. Panda, and Y. Zhou, Effects of Welding Parameters on the Mechanical Performance of Laser Welded Nitinol, Mat. Trans., 2008, 49(11), p 2702-2708
B. Raj and T. Jaykumar, NDE Methodologies for Characterization of Defects, Stresses and Microstructures in Pressure Vessels and Pipes, Int. J. Pres. Ves. Pip., 1997, 73, p 133-146
J.N. Mohapatra, A.K. Panda, M.K. Gunjan, N.R. Bandyopadhyay, A. Mitra, and R.N. Ghosh, Ageing Behavior Study of 5Cr-0.5Mo Steel by Magnetic Barkhausen Emissions and Magnetic Hysteresis Loop Techniques, NDT. E Int., 2007, 40, p 173-178
A. Mitra, J.N. Mohapatra, J. Swaminathan, M. Ghosh, A.K. Panda, and R.N. Ghosh, Magnetic Evaluation of Creep in Modified 9Cr-1Mo Steel, Scripta Mater., 2007, 57, p 813-816
J.W. Byeon and S.I. Kwun, Magnetic Evaluation of Microstructures and Strength of Eutectoid Steel, Mater. Trans., 2003, 44(10), p 2184-2190
D.K. Bhattacharya, Non-Destructive Techniques for Microstructural and Structural Characterisation, Recent Trends in Structural Integrity Assessment, V.R. Ranganath, S. Tarafder, and A. Bahadur, Ed., National Metallurgical Laboratory, Jamshedpur, 2001, p 185-202
M. R. Neyra Astudillo, N. Nunez, I. L. Pumarega, D. N. Torres, J. Ruzzante, Magneto-Acoustic Emission and Barkhausen Noise in A508 Class II Steel, 30th European Conference on Acoustic Emission Testing & 7th International Conference on Acoustic Emission, University of Granada, 12-15 Sept., 2012.
J.W. Byeon, S.I. Kwun, S.-J. Hong, C.-K. Lee, K.-M. Kang, and Y. Sohn, Correlation of Magnetic Barkhausen Emission Profile with Strength of Thermally Degraded 2.25Chromium-1Molybdenum Steel, Mater. Trans., 2005, 46(12), p 3089-3091
M.M. Blaow and B.A. Shaw, Characterization of Welding Induced Anisotropy in Steel by Magnetic Barkhausen Noise, J. Mech. Eng. Autom., 2013, 3, p 756-763
V. Moorthy, B.A. Shaw, and J.T. Evans, Evaluation of Tempering Induced Changes in the Hardness Profile of Casecarburised EN36 Steel Using Magnetic Barkhausen Noise Analysis, NDT&E Int., 2003, 36, p 43-49
D. Anand, D.L. Chen, S.D. Bhole, P. Andreychuk, and G. Boudreau, Fatigue Behavior of Tailor (Laser)-Welded Blanks for Automotive Applications, Mater. Sci. Eng. A, 2006, 420, p 199-207
D.C. Jiles, Introduction to Magnetism and Magnetic Materials, 2nd ed., Chapman and Hall, New York, 1991, p 179-191
Acknowledgments
The magnetic study was carried out using MagStar. The authors would like to thank Dr. A. Mitra, Chief Scientist, CSIR-NML Jamshedpur for his support in this work.
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Mohapatra, J.N., Chakradhar, I., Rao, K.R.C. et al. Non-destructive Magnetic Evaluation of Laser Weld Quality in Hot Rolled Coils. J. of Materi Eng and Perform 24, 2319–2326 (2015). https://doi.org/10.1007/s11665-015-1514-1
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DOI: https://doi.org/10.1007/s11665-015-1514-1