Wear behaviour of coloured stainless steel

Interference film is an attractive alternative for the formation of coloure d protective layers on the surface of stainless steel for various applicati ons. The process involves the growth of an oxide film (chromium and iron ox ide), by chemical or electrochemical methods, on the surface of the stainle ss steel imparting a colour, which changes from blue to green depending on the thickness of the film. The aim of the present investigation was to asse ss the wear sliding behaviour of coloured stainless steel, produced by a pu lsed electrochemical process. The specimens were obtained by using anodic c olouring coupled with cathodic hardening, and some specimens were post-heat treated at 250 degreesC for 200h. Sliding wear tests were conducted in air without lubrication using a pin on disc tribometer for 100 m. AISI 1086 pi ns were used as the counterpart. It was determined that the heat treated sp ecimens have a better sliding resistance compared with both untreated speci mens and the substrate. Wear scar morphologies and wear mechanisms were det ermined using SEM. There was clear evidence of material transfer from the p in to the coloured steel specimen in every test. The pins presented a mixed abrasion-adhesion mechanism, where the adhesive wear was predominant.