Effect of sliding speed on wear behaviour of nitrided martensitic stainless steel under boric acid and MoS <inf>2</inf> lubrication

Sliding counter bodies frequently undergo boundary lubrication at lubricant starved areas with dominated surface interaction under dry sliding condition. The effect of sliding speed (1.0- 2.5 m s -1) on the friction and wear performance of nitrided martensitic stainless steel in the presence of dry lubricants like boric acid and MoS 2 has been investigated, and the results are presented in this work. Under dry condition, wear loss increases and friction coefficient decreases with sliding speeds. The lubricant coated samples show minimal wear loss at all sliding speeds (2.5 m s -1). The friction coefficient shows a decreasing trend for the MoS2 coated sample, while the boric acid coated sample shows an increasing trend. This is possibly due to the temperature induced conversion of boric acid to boric oxide. The fine debris mixture formed during sliding may also pin the lamellar shearing of solid lubricants to increase friction. © 2012 Institute of Materials, Minerals and Mining.