Study on early stage of rolling contact fatigue of rails using real time X-ray imaging with SOI detector

It is known that railroad rails get tired due to rolling contact with wheels, and it is desired to improve railroad safety and maintenance technology. The current countermeasures are mainly measures to suppress fatigue by grinding and removing the fatigue layer, and finding and managing cracks caused by fatigue by ultrasonic technology. However, since it requires a great deal of labor, improvement technology is required. This research is to develop the technology to improve this problem by using the strain (residual stress) and the diffraction ring by the latest X-ray diffraction technology. In this study, in collaboration with JR, we proposed a method of collecting and analyzing detailed X-ray measurement data using actual rails as samples to find signs of crack formation.