X-ray tri-axial stress analysis system using two monolithic SOI pixel detectors

Abstract

A fundamental study was conducted on the effectiveness of a silicon-on-insulator (SOI) pixel detector for industrial applications. In this study, we developed a measurement system for X-ray tri-axial stress analysis by using an INTPIX4, an integrated SOI pixel detector developed by Arai et al. This system measured the diffraction ring diffracted backward from the polycrystalline sample by using a CrKα characteristic X-ray, and performed a tri-axial residual stress analysis by applying the generalised cosα method. To verify this measurement system, we measured the residual stress of a rail used in service and examined the state of rolling contact fatigue due to contact with wheels. In this measurement, diffraction rings generated from 211 diffraction lines of the ferrite phase in the rail steel were measured. The results of this system were compared with those obtained from a commercial device using an image plate (IP). As a result, this measurement system was found to be able to effectively measure the tri-axial residual stress component 30 times faster than the commercial device, and proved to be promising for rail inspection.