Abstract :
Sulphide layers were produced on 1045 steel substrates of five different states: as quenched, quenched and tempered at
different temperature, and annealed, respectively, by low temperature ion sulphurization technology. The effect of substrate
hardness on the microstructure and tribological properties of sulphide layer was studied by SEM equipped with EDX, XRD
and a reciprocating wear tester. Increasing defect density of substrate could probably result in thicker layer, but the surface
morphology, composition, and structure of sulphide layer were unchanged greatly. No transition layer was found between
the sulphide layer and substrate. The sulphide layer showed an obviously friction-reducing effect. The friction coefficient of
sulphide layer was independent of the substrate, but its endurance life could be extended on a harder substrate. The
wear-resistance of sulphurized surface was improved because the sulphide layer could effectively protect it from adhesion
and strain fatigue. However, the decomposition and regeneration of iron sulphide due to friction heat in the friction process
could have a certain corrosive effect on the surface. The wear volume of sulphurized surface was increased on the contrary if
the sulphide layer was thicker and its endurance life was longer. q2000 Elsevier Science B.V. All rights reserved
