Fretting Behaviors of Steel Wires as Hoisting Ropes for Coal Mine in Corrosive Media

The main failure modes of steel wire as hoisting ropes used in coal mine were rust, wear and break of steel wires. The fretting wear tests of steel wires as hoisting ropes in corrosive media were conducted on a self-made fretting wear test rig using the 6×19 point contact rope as speciemen. The fretting behaviors of steel wires under dry condition and three media (the main component was trickling water in mine) were reviewed. The fretting wear losses were caculated and damage mechanisms of steel wires were analyzed by using optical microscopy (OM), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The results showed that corrosive media had impact on the fretting regime, i.e. mixed fretting regime in air and neutral corrosive medium while slip fretting regime in acid and alkaline corrosive media. The friction coefficients were reduced significantly due to the lubrication of corrosive media and the lowest was about 0.39 in acid corrosive medium. Interaction between corrosion and wear accelerated the loss of material, and wear depth in acid corrosive medium was the highest. The main fretting damage mechanisms of steel wires were the combination of plastic deformation, adhesion and smear, and tribo-oxidation under dry condition. Abrasive wear and corrosion were the main fretting damage mechanisms in corrosive media.