Effect of sigma phase on the wear behavior of a super duplex stainless steel

The effect of sigma phase on the sliding wear behavior of a commercial super duplex stainless steel (sDSS) was investigated. The material was heat treated at temperatures from 875 to 975 °C in order to promote the formation of sigma phase. Wear tests were carried out using ball on disc technique at constant velocity and different sliding conditions. Results show that the volume fraction of sigma phase increases the wear resistance under both dry and corrosive media although its detrimental consequences on corrosion resistance. The analysis of wear rate demonstrated that hardness introduced by sigma phase particles reduces significantly the plowing wear mechanism, typical of ductile abrasive wear, and plastic deformation in the subsurface leading to lower fatigue wear.