Causes and Prevention of Rail Spalling
What is rail spalling/scraping?
Rail spalling/scraping refers to the phenomenon of metal flakes or chunks peeling off or detaching from the rail head surface. It is mainly caused by contact fatigue, stress concentration, and material defects, and is a typical surface fatigue damage of rails.
In which sections does rail spalling/scraping mainly occur?
It mainly occurs on small-radius curves, heavy-load lines, braking sections, turnout areas, and locations with high wheel-rail contact stress. In these sections, repeated wheel-rail compression and slippage easily lead to surface fatigue cracks.
What are the main causes of spalling/scraping?
Excessive wheel-rail contact stress, initial defects on the rail surface, insufficient lubrication, uneven rail surface, uneven material hardness, and long-term fatigue can all cause cracks to gradually expand and form spalling/scraping.
What are the hazards of spalling/scraping to train operation?
It exacerbates wheel-rail impact, increases vibration and noise, and in severe cases, causes abrupt changes in the rail surface, affecting train stability. The spalling debris can also accelerate wear on components and even affect train operation safety.
How to prevent and control rail spalling/scraping? High-strength wear-resistant steel rails are selected, wheel-rail matching is improved, curve lubrication is enhanced, track smoothness is improved, preventive rail grinding is implemented, and regular flaw detection is carried out to promptly detect and treat early fatigue cracks.