1. Effect of Inserted Strips on Electrode Degradation in Resistance Spot Welding.
- Author
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ZHAO, Y. Y., ZHANG, Y. S., LAI, X. M., and PEI-CHUNG WANG
- Subjects
AUTOMOBILE industry ,FABRICATION (Manufacturing) ,ELECTRODES ,SPOT welding ,SHEET steel ,GALVANIZED steel ,HEAT transfer - Abstract
Recent trends toward economically fabricating lightweight vehicle structures while ensuring structural performance have led to the implementation of thin sheet steels in the automotive industry. However, one of the main challenges in resistance spot welding of ultrathin steel (e.g., < 0.6 mm) is the extraordinarily short electrode life caused by the elevated electrode tip temperature. A method of inserting flexible strips between the electrode and workpiece has been proposed to reduce the electrode tip temperature, and consequently to prolong the electrode life. In the present investigation, resistance spot welding of 0.4-mm-thick galvanized lowcarbon steel with various inserted strips was experimentally investigated with a particular emphasis on the influence of inserted strips on the electrode degradation. Test results showed that by inserting metal strips between the electrode and workpiece, the electrode life was prolonged by about 300%. The electrode face diameter was no longer an effective indicator for the electrode degradation in resistance spot welding with inserted strips. Surface alloying and recrystallization of the material near the electrode face formed and played significant roles. Furthermore, the effects of the electrothermal properties and compositions of the inserted strips on the electrode tip temperature and degree of surface alloying were also evaluated. Among all the strips investigated in this study, 0.12-mm-thick Cu55Ni45 metal strip exhibited the most promising results in alleviating the electrode degradation. [ABSTRACT FROM AUTHOR]
- Published
- 2014