Friction and wear behavior of boron permeated layer on mild carbon steel under oil-lubricated condition

AISI-1045 steel was modified by means of chemical boron permeation. The friction and wear behavior of the boron permeated carbon steel under the lubrication of liquid paraffin containing additive was investigated with an SRV test rig. The microstructure and chemical composition of the boron permeated layer and of the worn steel surface were analyzed by means of X-ray diffraction and X-ray photoelectron spectrometry. As the results, boron-permeation contributed to improve the friction and wear behavior of the steel greatly, and the friction and wear behavior was further improved under the lubrication of liquid paraffin containing boron-doped oleo-glyceride. This was attributed to the combined function of both the boron permeation modification and the tribochemical action of the B-containing organic additive. The surface-modified layer was mainly composed of B₂O₃ and Fe₂B which were beneficial to improving the friction and wear behavior. A boundary lubricating film composed of B₂O₃ helped to further improve the antiwear and load-carrying properties of the surface-modified steel.