Development of a transmission geometry X-ray diffraction system for measuring the austenite to martensite phase transformation in 304 L stainless steel

A bench-top energy dispersive X-ray diffraction (EDXRD) system, utilising the polychromatic bremsstrahlung continuum of a conventional industrial X-ray tube in conjunction with a HPGe detector, has been developed to measure stress-induced changes in lattice spacings in samples of 304 L austenitic stainless steel. The system has been used for mapping the austenite to martensite phase transformation that occurs with cryogenic cooling of samples of the same 304 L steel that are suitably pre-loaded compressively to induce a residual stress field. This is compared with a model produced with the Abaqus Finite Element (FE) analysis software, originally used for work on similar samples at the ESRF.