13/09/2026
That is not what I used to think. Everyday a school day.
Steel wheels will wear much faster on aluminium than on steel rail.
Why:
The hardness difference is extreme. Steel wheel treads are typically ~250–350 HB (Brinell hardness).
Aluminium alloys, even strong ones like 6000‑ or 7000‑series, are only ~60–120 HB.
This means:
Aluminium deforms under the high contact pressure of a steel wheel.The wheel sinks microscopically into the aluminium surface, creating abrasive wear particles. Those particles act like grinding paste between wheel and rail.
The aluminium oxide layer (Al₂O₃) is very hard, but it is thin and breaks up immediately under rolling contact, becoming more abrasive.
Steel-on-steel contact is a matched hardness pair designed for rolling contact fatigue, not abrasive wear.
Result:
Steel wheels on aluminium rail → high wheel wear, rapid rail damage, severe galling, high friction, and material transfer.
Steel wheels on steel rail → lowest wear, predictable rolling contact fatigue behaviour.
