Oxynitriding of Component Surfaces
Combined process of nitriding and subsequent targeted oxidation to produce a corrosion-protecting and friction-minimizing top layer.
Oxynitriding is a case hardening process you do after welding. First treat with nitrogen, then oxidize. That gives a hard, wear-resistant surface with good corrosion protection. When welding, you have to watch out: If the weld is porous or has slag in it, the layer won't build up properly there. The surface must be clean and metallically bright, otherwise oxynitriding won't hold. The treatment itself is not for the welder; that's done by a commercial heat treater. You just need to know: After welding and before oxynitriding, the part must be stress-relief annealed, otherwise it will distort. And the weld should be as smooth and finished as possible, because the layer doesn't get thicker; it only hardens the existing surface.