Abstract
The mechanical properties of welded joints in resistance spot welding of DP780 steel were tested, and three different types of welding cracks in welded joints were investigated by optical microscopy, scanning electron microscopy and electron back-scattered diffraction. Finally, the failure mode of the welded joints in shear tensile test was discussed. It is found the shear tensile strength of welded joints can be greatly improved by adding preheating current or tempering current. The surface crack in welded joint is intergranular fracture, while the inner crack in welded joint is transgranular fracture, and the surface crack on the edge of the electrode imprint can be improved by adding preheating current or tempering current. The traditional failure mode criterion advised by American Welding Society is no longer suitable for DP780 spot welds and the critical nugget size suggested by Pouranvari is overestimated.
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References
F. Hayat, J. Iron Steel Res. Int. 18 (2011) No. 9, 70–78.
L. Zhou, B. Jiang, T. Cui, J. Iron Steel Res. Int. 21 (2014) No. 12, 1111–1115.
F. Hayat, H. Uzun, J. Iron Steel Res. Int. 18 (2011) No. 8, 65–72.
X. Wan, Y. Wang, P. Zhang, ISIJ Int. 54 (2014) 2375–2379.
J. Liang, H. Zhang, X. Qiu, ISIJ Int. 55 (2015) 2002–2007.
M. Pouranvari, H. R. Asgari, S. M. Mosavizadch, Sci. Technol. Weld. Join. 12 (2007) No. 3, 217–225.
X. Wan, Y. Wang, C. Fang, ISIJ Int. 54 (2014) 1883–1889.
X. Sun, P. Dong, Weld. J. 79 (2000) No. 8, 215–221.
D. Sun, B. Lang, D. Sun, Mater. Sci. Eng. A 460 (2007) 494–198.
M. Marya, X. Gayden, Weld. J. 84 (2005) No. 11, 172–182.
Test Methods for Evaluating the Resistance Spot Welding Behavior of Automotive Sheet Steel Materials, ANSI/AWS D8. 9M, American Welding Society, Miami, 2012.
F. Nikoosohbat, S. Kheirandish, M. Goodarzi, Mater. Sci. Technol. 26 (2010) 738–744.
Y. Chao, Sci. Technol. Weld. Join. 8 (2003) 133–137.
M. Pouranvari, S. Marashi, Mater. Sci. Eng. A 528 (2011) 8337–8343.
X. Sun, E.V. Stephens, R. W. Davies, M. A. Khaleel, D.J. Spinella, Weld. J. 83 (2004) No. 11, 308–318.
M. Pouranvari, S. Marashi, D. Safanama, Mater. Sci. Eng. A 528 (2011) 8344–8352.
D. Safanama, S. Marashi, M. Pouranvari, Sci. Technol. Weld. Join. 17 (2012) 288–294.
V. H. B. Hernandez, S. K. Panda, Y. Okita, J. Mater. Sci. 45 (2010) 1638–1647.
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Wang, Xp., Zhang, Yq., Ju, Jb. et al. Characteristics of Welding Crack Defects and Failure Mode in Resistance Spot Welding of DP780 Steel. J. Iron Steel Res. Int. 23, 1104–1110 (2016). https://doi.org/10.1016/S1006-706X(16)30163-7
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DOI: https://doi.org/10.1016/S1006-706X(16)30163-7