Surface treatment of nitriding steel 34CrAlNi7: a comparison between pulsed plasma nitriding and plasma immersion ion implantation

A study of the response of the nitriding steel, 34CrAlNi7, to two different nitriding techniques revealed remarkable differences. The techniques used were pulsed plasma nitriding and plasma immersion ion implantation over a range of temperatures from 300 to 500°C. The surface produced by the pulsed plasma nitriding consisted of a nitride layer whose thickness varied with temperature, with an underlying diffusion zone. Plasma immersion ion implantation treatment, however, formed nitrides only at the lowest temperature, with most of the nitrogen in solid solution. Although quite different surface structures resulted from the two treatments, similar improvements in wear performance were obtained.