<![CDATA[Resistance spot welding (RSW) is widely used in the automotive industry because of its high productivity and ability to produce reliable sheet-metal joints. However, electrode-tip degradation during galvanized-steel welding can reduce weld nugget diameter and compromise joint quality. This study investigates the effect of electrode dressing on nugget diameter and estimates electrode life during RSW of 1.1 mm JAC270DN-45/45 galvanized-steel sheets. Weld quality was evaluated using ultrasonic non-destructive testing at four weld counts (1, 150, 250, and 400) with a dressed electrode and seven weld counts (1, 50, 100, 150, 200, 250, and 400) without dressing. Nugget diameters were assessed against the 4.5 mm minimum requirement specified in JIS Z 3140 for the investigated sheet thickness. With electrode dressing, nugget diameters remained between 9.4 and 8.7 mm, and all measured welds met the acceptance criterion. Without dressing, nugget diameter decreased with increasing weld count and reached 4.15 mm at the 400th weld, below the required minimum. Regression analysis estimated a usable electrode life of approximately 339 welds without dressing. These results indicate that electrode dressing helps maintain nugget diameter and weld quality during galvanized-steel spot welding. The estimated electrode life is specific to the tested material and welding conditions.]]>
Copyrights © 2026
