Tribological behaviours of an ion sulphurisation layer on steels

A sulphide layer with a certain thickness was made on the surface of 1045 and 52100 steels by means of a low temperature ion sulphurisation process. Tribological behaviours of the sulphide layers were investigated on a SRV reciprocating wear tester under dry and paraffin oil lubrication conditions. SEM equipped with EDX was used to analyse the morphologies and compositions of wear scars and wear debris. Sulphide layers showed remarkable friction-reducing effects and obvious wear-resistance. With the increase in thickness of the sulphide layer, its operational period was extended, but its friction coefficient was unchanged greatly. Under the same experimental conditions, the operational period of the sulphide layer on 52100 steel was longer than that on 1045 steel, and the wear-resistance of the former was better. The wear mechanism of the sulphurised surface is discussed.