Due to their good mechanical properties and good corrosion resistance, AISI type 316L austenitic stainless steels (ASS) are used in a wide variety of industrial fields. Several components of the primary circuit of pressurized water nuclear reactors are made of 316L ASS. However, the susceptibility of these steels to stress corrosion cracking in this environment is an important issue. Innovative manufacturing processes to obtain better properties, more complex geometries or to reduce supply times and costs are currently in development. Hot isostatic pressing of metal powders is one of them. The objective of the thesis is precisely to evaluate the resistance to stress corrosion cracking of an ASS obtained by this innovative process and to establish the relations between its microstructure and its properties.
The process requires enclosing the powder in a container before compaction treatment and heat treatment. The surface is then machined to eliminate the container and the affected material. Given the local strain resulting from this machining and the primary importance of the pre-strain level on the resistance of 316L ASS obtained by conventional means to stress corrosion cracking, particular attention will be paid to the effect of this parameter on the resistance to stress corrosion of the studied material.
This thesis constitutes for the candidate the opportunity to address a problem of durability of metallic materials in their environment following a multidisciplinary scientific approach combining metallurgy, mechanics and physico-chemistry and based on the use of various cutting-edge techniques available at the CEA and at the Ecole des Mines. The skills that he will thus acquire can therefore be valued during the rest of his career in the industry (including non-nuclear) or in academic institutions.