Neutron-diffraction study of martensitic- transformation in austenitic stainless-steel under low-cycling tensile- compressive loading

The fatigue behaviour of austenitic stainless steel, in which a martensitic phase is formed due to plastic deformation, is of some interest for practical reasons. Earlier, we reported the results of the first stage of the in situ stress-rig experiment on the ENGIN instrument at the ISIS facility, with samples from steel X6CrNiTi1810 subjected to different tensile-compressive loading cycles at a frequency of 5 Hz. This paper describes the results of the second stage of the experiment in which a series of samples subjected to 0.5 Hz was studied. Information about the mechanical properties of the austenitic matrix and the martensitic precipitates is obtained from the experimental mechanical and neutron-diffraction data.