Mechanical, electrochemical and tribological properties of nano-crystalline surface of 304 stainless steel

This paper reports our recent studies on the tribological behavior and related properties of a nano-crystalline surface of 304 stainless steel (304SS) produced by a sandblasting and annealing process. The grain size of the nano-crystalline surface layer was in the range of 20 nm, determined using transmission electron microscopy (TEM). Mechanical behavior, electrochemical properties, electron work function (EWF), wear and corrosive wear of the nano-crystalline surface were investigated using micro- and nano-mechanical probes, a scanning Kelvin probe, an electrochemical system and a tribometer, respectively. It was demonstrated that the mechanical behavior of 304SS surface was markedly improved when its grain size was reduced to nano-scale. The nano-crystalline surface caused by the sandblasting and annealing treatment exhibited considerably higher resistance to corrosion, wear and corrosive wear, compared to those of regularly grained and only sandblasted 304SS specimens. Mechanisms responsible for the improvement in mechanical, electrochemical and tribological properties of 304SS by the sandblasting and annealing treatment are discussed.