Mass finishing
A barrel finishing process for deburring and surface refinement of components in a rotating drum containing abrasive media. It homogenizes edge profiles and relieves machining stresses.
Trowalizing is basically barrel finishing. You put the parts in a drum with abrasive media and let it rotate, which breaks edges and smooths and compacts the surface. In welding, it's mainly interesting as preparation or post-treatment because it removes scale and impurities from the surface and introduces compressive residual stresses that counteract crack formation. But if you do it sloppily or use the wrong media, you can also remove material unevenly and create notches that cause problems later in service. Just set the drum so that the parts slide through cleanly and don't bump into each other too hard, and let it run until the surface looks uniform.