Yes, seam welding wheels wear just as spot welding electrodes and they need to be machined back or maintained at their original face contour. This can be done by trading out with a second set of wheels and dressing on a lathe or dress continuously on the seam welder. Some machines employ knurled small wheels which ride on the perimeter of the seam welding wheel. These smaller wheels are designed to skive the wheel surface a little each revolution to maintain the working face of the wheel at a given shape and dimension.
Seam Welder with Knurled drive Wheels
These small wheels also turn the seam welding wheels. This type of drive system provides a constant linear speed for the part as the wheel diameter gets smaller. With a hub driven welder as the wheel size decreases so does the linear speed. This has to be compensated for in order to maintain proper weld spacing.
Reference: RWMA – Resistance Welding Manual Section 4