When making a continuous seam welds sometimes warpage becomes an issue. A lot of welds and heat are going into the material and distortion can be created. The best method is flood cooling. Another method that is sometimes practical is to weld a modest length. Then skip a similar length. Weld another length and skip another length. Repeat till you reach the end then go back and pick up the skipped welds. This has proven successful in some applications. The best method to reduce warpage is flood cooling.
In flood cooling usually four water tubes are directed fore and aft of the weld on both sides of the wheel to flood the area. Another option is to submerge the part but this is usually not practical.
Continous Seam Weld
Reference: RWMA – Resistance Welding Manual Section 4