Enhancement of wear resistance by sand blasting-assisted rapid plasma nitriding for 304 austenitic stainless steel

In this study, a pretreatment of sand blasting (SB) was carried out prior to plasma nitriding to enhance the nitriding efficiency and improve the wear resistance for 304 austenitic stainless steel. The surface morphology, microstructure, phase constituents and wear resistance were systematically investigated by means of scanning electron microscopy, optical microscopy, Vickers hardness tester, X-ray diffraction and pin-on-disk tribotester, etc. The results showed that SB had significant enhancement effect on nitriding efficiency and wear resistance. Meanwhile, the enhancement effect is duration dependent; the optimal wear resistance is obtained at SB duration of 15 min, which is mainly ascribed to the excellent protection from the thicker and denser compound layer.