Dual Beam and TEM characterisation of deformation structures in fatigued austenitic stainless steel

Thermal fatigue cracking is a damaging mode of austenitic stainless steels, particularly in the mixing zone of the Residual Heat Removal system (RHR system) of Pressure Water Reactor (PWR). The aim of this research project is to study and compare the deformation microstructures, at crack-tips and in the bulk, observed on a pulled out structural component made of AISI 304L stainless steel and those developed during cyclic deformation, on low cycle fatigue standard specimens. Such a comparison of the deformation microstructures could give key indicators of the real magnitude of the mechanical solicitation undergone by the pulled out structural component.