Austenitic-ferritic duplex stainless steel has a high strength and an excellent corrosion resistance. Therefore it is
used, for example, in offshore systems, where the material experiences cyclic loading of high stress amplitudes
which may cause failure after long periodic operation. Laboratory experiment in very high cycle fatigue (VHCF)
regime (up to 109
cycles) may help to evaluate the defect evolution as function of load cycles and to predict possible
origins of crack formation [1]. Besides macroscopic probes TEM and X-ray techniques are important because with