Mechanism and Mitigation of Local Rolling Contact Fatigue in Metro Wheels

When trains were braked while negotiating curves-particularly at stations located on such curves-the resulting low-adhesion conditions induced localized RCF on the wheels on the high-rail side. Additionally, the decreased adhesion on the high-rail side caused increased tread wear on the wheels of the low-rail side, which further promoted fatigue damage initiation at the flange root. The higher incidence of RCF on trailer wheels was attributed to two primary factors.

First, as the leading wheelset, the trailer wheels were the first to contact the oil-contaminated rail, thereby experiencing the most severe adhesion degradation. Second, motor wheels generally exhibited higher tread wear rates, which helped to remove incipient surface cracks before they could develop into macroscopic RCF damage. By implementing a regimen of regular cleaning to remove oil contamination from both rail surfaces and wheel flanges, the wheel-rail adhesion conditions were substantially improved.

This intervention effectively suppressed the occurrence of the localized rolling contact fatigue problem.