Tribological Study of Borocarburizing/Sulfurizing Composite Coatings on 2Cr13 Stainless Steel

The aim of this work was to investigate the mechanical properties and wear characteristics of 2Cr13 stainless steel coated with borocarburized and sulfurized layers using pack cementation. The microstructure and phase composition of the composite coatings were analyzed using scanning electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray diffraction. The tribological properties under dry sliding against a ZrO 2 ceramic ball were evaluated using a ball-on-disk friction tester at different loads, and the wear mechanism was proposed. The sulfurized layer mainly consisted of FeS and Fe 2 S, with the FeS phase acting as a solid lubricant for the coating. The borocarburized layer was mainly composed of FeB, Fe 3 C, and Fe 2 B, with a maximum hardness of approximately 1200 HV. The borocarburizing/sulfurizing treatment significantly decreased the friction coefficient and improved the wear resistance of the 2Cr13 steel. In addition, the composite coating exhibited excellent antifriction and wear resistance under slight adhesive and oxidation wear in high-load conditions.