Fretting friction and wear of steel wires in tension-torsion and helical contact form

Abstract

Fretting wear among steel wires under coupled tension-torsion force would aggravate the fatigue damage of wire rope, decrease the rope's service life, and ultimately threaten the safety of mine hoist. To explore the friction and wear behaviors of steel wires under coupled tension-torsion force and helical contact form, different fretting tests of steel wires were performed on a self-made test rig. The results show that the coefficient of friction (COF) decreases with increasing contact load and increases with the increase of sliding amplitude. When the contact load and sliding amplitude increase simultaneously, the COF is the maximum value of 0.23 for the convex contact pair, while it is 0.42 for the concave contact pair. The energy loss for the concave contact pair is faster than that for the convex contact pair. Furthermore, the wear depth and wear volume of wear scars increase with increasing contact load, sliding amplitude and their combination, respectively. The effect of the sliding amplitude on the friction and wear characteristics among steel wires is greater than that of the contact load. The common wear mechanisms of steel wires for the convex contact pair are abrasive wear and fatigue wear, while that for the concave contact pair is delamination wear. Additionally, the surfaces of wear scars for the convex contact pair are smooth, while that for the concave contact pair are rough.