The high rail, having been in track for 22 years and ground only once exhibits well known 'normal' head checks, severe head checks with large depth and additional horizontal cracks. These horizontal cracks are visible at the gauge face beneath the head-check-zone. In this case it is impossible to remove the cracks economically. The only remaining solution is the renewal of the affected rails as realised here. Only a good grinding strategy founded on scientific investigations under operational conditions - grinding intervals, correctly defined metal removal and appropriate production tolerances - can prevent such a damage or prolong the service life of rails respectively. Then it would also be possible to predict lifetime and respective Life Cycle Cost (LCC) based on existing limits for wear at both places the middle of the running surface and the gauge corner. The measured wear proves the well known experience that wear of uphill tracks is smaller than that of downhill tracks. The analysis of damage shows that both kind of cracks affect one another. These investigations are basically necessary to idealize the cracks for following fracture mechanical analysis. Than it is possible to derive crack growth rates and scientific founded grinding strategies. The condition for this is - the damage of the rail is not in such a severe stage as described before. Any confusion of these severe head checks combined with horizontal cracks with another kind of fatigue damages such as squats is easily possible. But squats have another origin, position and appearance at the surface - they can also grow into a vertical fatigue break.
Head checks - and further damages
2003
6 Seiten, 14 Bilder, 3 Quellen
Conference paper
English
Head checks - and further damages
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