Improving austenitic stainless steel resistance spot weld quality using external magnetic field |
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| Authors: | Y. B. Li Q. X. Zhang L. Qi S. A. David |
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| Affiliation: | 1. Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, Shanghai Jiao Tong University, Shanghai, People’s Republic of China;2. State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, People’s Republic of China;3. Oak Ridge National Laboratory, Oak Ridge, TN, USA |
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| Abstract: | A ring-shaped permanent magnet is applied in resistance spot welding to improve the weld quality of austenitic stainless steel. Under the action of an external magnetic field, the profile of the weld nugget became peanut-shaped instead of ellipsoidal. The crystal orientation near the faying surface was less directional, and equiaxed grains were formed in weld nugget centre. Moreover, the shrinkage cavities tendency in traditional resistance spot welds was reduced. The relatively slow cooling speed could cause element segregation and thus change solidification mode and significantly affect weld microstructures. The mechanical performance of the welds was finally improved by the applied external magnetic field in terms of microhardness and lap-shear strength. |
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| Keywords: | Electromagnetic stirring resistance spot welding austenitic stainless steel external magnetic field ferrite number |
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