Friction, wear and microstructure of unlubricated austenitic stainless steels

The friction and wear characteristics of types 304, 316 and Nitronic 60 stainless steel sliding against 440C have been compared. The studies involved a wide range of experimental techniques to characterize the wear specimens and the debris particles including optical metallography, microhardness tests, X-ray diffraction, scanning electron microscopy, microprobe analysis and transmission electron diffraction. These complementary techniques reveal that strain-induced ϵ and α' martensite phases are formed during sliding. The friction, wear and galling characteristics of these alloys depend on the stability of the austenite phase, the hardness of the α' phase and the hardness gradient.