AbstractSurface engineering of steels has been carried out using plasma inlmersion ion implantation (PI3) and related innovative techniques including plasma immersion ion beam enhanced deposition (PIIBED) of titanium and plasma immersion ion beam mixing (PIIBM) of nitrogen and titanium. Auger concentration profiles indicate that PI3of nitrogen produces a smooth implantation profile in the surface layer of the steel. The formation of a thin layer of TiN on the surface of the specimens treated by PIIBED of titanium and by PIIBM of nitrogen and titanium was confirmed by X-ray photoelectron spectroscopy. It has been demonstrated that the surface hardness and wear resistance of all the treated specimens were greatly improved.