A Study on the Tribological Properties of Sulfide Layer Produced by Ion Sulphurization

Sulfide layers were made on the surface of AISI 1045 and SAE 52100 steels by means of low temperature ion sulphurization process. The tribological properties of the sulfide layers were investigated on an SRV reciprocating tester under dry and paraffin oil lubricated conditions. SEM equipped with EDAX and XRD were adopted to analyze the morphology and structure of the sulfide layers. The morphologies and composition of the wear scars were also analyzed. The results show that the sulfide layers were porous and composed of FeS, FeS 2 and substrate phases. Under both dry and paraffin oil lubricated conditions, the sulfide layers showed remarkable friction reducing effects and improved wear resistance to a certain extent. With the increase of the layer thickness, its antiwear life was prolonged, but the thickness and substrate did not affect the friction coefficient greatly. Under the same experimental conditions, the antiwear life of the sulfide layers on SAE 52100 steel was longer than that on AISI 1045 steel, and the wear resistance of the former was better.