Steel wire ropes are critical components in many industrial applications, where they are subjected to severe operating conditions that accelerate fatigue and wear. Lubrication plays a fundamental role in reducing friction, mitigating fretting, and protecting against corrosion, but its effectiveness decreases over time as grease is lost during service. This study systematically investigates the effect of re-lubrication on the bending fatigue life of steel wire ropes through controlled rotating bending tests on 6×25F-IWRC and 6×36WS-IWRC specimens. Reference, degreased, and re-lubricated conditions were compared under different re-lubrication strategies, frequencies, and lubricant types. Results show that grease removal significantly reduces fatigue life, while re-lubrication can partially restore performance depending on its timing and formulation. Recovery appears to be independent of the frequency of relubrication and is instead primarily associated with the timeliness of the relubrication following the lubricant-loss event. However, re-lubrication does not extend fatigue life beyond the original level provided by manufacturing lubrication, except in the case of advanced additives, which yielded modest improvements. The findings highlight that the critical factor is not re-lubrication frequency but the promptness of intervention after lubricant loss. Overall, re-lubrication preserves performance under severe conditions but cannot replace the benefits of factory-applied lubrication within the strands.
Pietro et al. (Sun,) studied this question.