Through welding adverse residual tensile stresses are usually induced into the material. As long access exists, it is possible to treat weld seams by deep rolling. Trials were carried out on laser welded and friction stirred samples. The tracking system is able to compensate uneveness caused by the seam.

Deep rolling the friction-stir welded pistons of a mechanical excavator, by which the piston and piston rod are joined by friction welding, is already a successful application.