Fretting wear behavior and strength degradation of helical contact steel wire in wire rope under different corrosive media and time-varying conditions

Corrosion and fretting wear are the two main reasons for the performance degradation and failure of wire rope. They typically appear in an alternating manner and influence each other. In this study, to explore the friction and wear characteristics of spiral contact steel wires after time-varying corrosion of different corrosion types (alkali, acid and seawater), a self-made fretting wear test device was used to perform fretting wear tests on steel wires under different corrosion conditions under specific parameters. The fracture tensile test of the corroded and worn steel wire was carried out. The degradation behavior of its mechanical strength was discussed. The results show that the corrosion type and corrosion time have a great influence on the coefficient of friction (COF) and fretting state evolution between steel wires. In addition, corrosion reduces the wear resistance. With the change of corrosion medium (acidic to seawater to alkaline) and the increase of corrosion time, the maximum wear depth, wear volume and wear coefficient all showed an upward trend. In addition, the main wear mechanisms after corrosion in non-corrosive and alkaline media are abrasive and tribochemical reactions. After corrosion in acidic medium and seawater, the main wear mechanisms are abrasive wear, surface fatigue and tribochemical reactions. Furthermore, compared with the damage under the action of single factor, the degradation of mechanical properties increased from 1.5 % - 3.6 %-5.7 %, 10.3 % and 8.9 % respectively after alkali, acid and seawater corrosion compounded the wear damage. With the increase of corrosion degree, the fracture mechanism gradually changes from ductile fracture to brittle fracture.