Aciers ferritiques/martensitiques renforcés par nano-particules pour application à haute température en conditions extrêmes. – AXTREM

To meet the need for materials with very high performances and low cost for various applications (high temperature exchangers, turbines, cladding tubes for nuclear fuel…), companies NITRUVID, SOTEP, EDF and AREVA NP, laboratories CEA, INPG, GPM and LLB join together into a partnership to conceive and demonstrate the feasibility of a new alloys class usable at high temperatures (up to 1100°C ) in extreme conditions. These new materials, with a mode of reinforcement similar to that of the ODS (Oxide Dispersion Strengthened), will be also worked out by powders metallurgy, but without passing by the expensive and intricate stage of the mechanical alloying. Within a multistage approach, going from the production of new materials to the modelling of their creep behaviour and their mechanical and micro structural characterization at an atomic scale, the project has the ambition to understand where the good behaviour of nano-structured materials comes from. The final technical purpose of this project is to demonstrate the feasibility of steel nuances with very high performances (up to 1100°C), which could be industrialized quickly and present controlled nano-reinforcements distributions. The technologies and the modelling used for this project could be naturally transferred to other alloy families. Whereas commercial competition with the American and Japanese industrialists is extreme, it is essential that Europe preserves its technological dynamism on innovating materials. The development of new steel nuances in partnership with the European leader in nitruration treatment is a part of this strategy. With new steel nuances, twice less expensive than ODS steels, offering improved workability and properties, new markets on a larger scale could be supplied. For instance, we can quote high temperature exchangers, nuts and bolts in high output power plants, parts of catalytic pipes or fuel assemblies for generation IV nuclear reactors. This project and its applications will allow on the one hand company NITRUVID to consolidate its technological advance and to forecast the rise of new materials with very high added value, and on the other hand the French nuclear industry to position on the future market of fuel assemblies for fast reactors. It is also possible that the project gives the definition of new and less expensive powerful materials for the aircraft industry or that of new generation power plants. This project participates to the improvement of power plants output and the fight against emission of pollution by proposing on the market new materials usable at high temperatures, with better lifespan and a less energy content.