As the key component of mine hoisting system, hoisting wire rope is responsible for lifting coal, gangue, personnel and equipment. In the working process, the fretting wear between steel wires will aggravate the fatigue damage of hoisting wire rope, reduce the service life of wire rope, and seriously threaten the safety of the mine hoisting. In order to study the influence of strand structure on the fretting friction and wear characteristics of spiral contact steel wires, the fretting wear tests of steel wires under tension-torsion coupling force were carried out on a self-made test rig. The micro wear characteristics of steel wire surface were observed by the scanning electron microscope (SEM), and the fretting wear mechanism and fracture failure behavior of spiral contact steel wires under different strand structures were revealed. The results show that with the increase of contact force, the frictional coefficient between steel wires under the same diameter contact pairs decreases from 0.748 to 0.646, while that under different diameter contact pairs decreases from 0.941 to 0.911. The friction degree between steel wires under different diameter contact pairs is obviously greater than that under the same diameter contact pairs. In addition, in the stable stage, the friction coefficient between steel wires under the same diameter contact pairs presents a horizontal change trend, while that under different diameter contact pairs shows a slight upward trend. Under different working conditions, the depth and width of wear scars increase with increasing the contact force. For the same contact force, the wear depth of steel wires under the convex contact pairs is significantly greater than that under the concave contact pairs, and the greater the contact force is, the more obvious the difference of wear depth of steel wires under different contact forms is. Whether the diameter of the loading wire and the fatigue wire is the same or not, the wear coefficient of steel wires under different contact forms decreases with the increase of the contact force. The wear depth and coefficient of steel wires under different diameter contact pairs are significantly greater than that under the same diameter contact pairs. For the microscopic wear characteristics of steel wires, compared with the same diameter contact pairs, the worn surface of steel wires under the different diameters contact pairs presents more serious wear characteristics, and the worn surface of steel wires under the concave contact pairs is rougher than that under the convex contact pairs. Furthermore, there are a lot of wear characteristics on the surface of worn steel wire, such as wear debris, material adhesion, plastic deformation, fine scratches, material delamination, micro cracks and furrows. Therefore, the main wear mechanisms between steel wires are abrasive wear, adhesive wear and fatigue wear, and the fatigue wear of steel wires under different diameter contact pairs are more serious, which is caused by the "cutting" effect between thin steel wire and thick steel wire. As the contact force increases, the fatigue life of steel wires under different strand structures decreases gradually. And for the same contact force, the fatigue life of steel wires under different diameter contact pairs is obviously smaller than that under the same diameter contact pairs. The fracture surface of steel wires is obviously divided into fatigue source region, crack propagation region and final fracture region. Abundant secondary cracks and dimples exist in the final fracture region, and the fatigue fracture failure mechanism of steel wires is mainly ductile fracture. © 2023 Science Press. All rights reserved.
