Influence of a WC/aC:H Coating on Micropitting Wear of Bearing Steel

In this study, the capabilities of a WC/aC:H coating to affect the onset of micropitting in SAE 52100 bearing steel is examined. Experiments are conducted in which two pairs of contacts (steel on steel, and steel on WC/a-C:H) and three sliding-to-rolling ratios of -10%, 0% and +10% are tested at high contact stress and in a low h regime. Results reveal that the WC/a-C:H coating can dramatically increase the micropitting resistance of the coated part, achieving a much higher number of contact cycles and higher levels of contact stress than the steel-on-steel contact.

Keywords: Micropitting, Diamond like carbon, Abrasive wear, Bearing steel