FRAMATOME, France
Nicolas Sallez
Biography
Dr. Nicolas Sallez is a metallurgical engineer specializing in materials characterization, welding metallurgy, and heat treatment processes. He began his career with a focus on Materials for Nuclear Energy, completing a PhD in partnership between Areva, EDF and CEA on optimizing powder metallurgy routes for stainless‑steel cladding materials for the ASTRID Gen-IV project. In 2015, he joined Solo Swiss SA as a metallurgist, where he developed advanced heat‑treatment processes and established an in‑house metallurgy laboratory dedicated to feasibility studies, failure analysis, process development, and training.
Since 2021, he has been part of the FRAMATOME Saint‑Marcel Technical Center, expanding his expertise to welding and forging metallurgy and supporting the growing involvement of FRAMATOME in metal additive manufacturing. As technical manager of a laboratory operating under NF EN ISO 17025, he contributes to technical expertise, knowledge transfer, and formal training. He also collaborates with numerical modeling teams on fracture mechanics, welding simulation, and phase transformation, while actively participating in several FRAMATOME Task Forces and in the metallurgy community to strengthen metallurgical cooperation across the organization.
Conferences
Room |
Date |
Hour |
Subject |
|---|---|---|---|
| Room 9 |
26-03-2026 |
10:55 am – 11:15 am |
68 Heat treatment of 316LSi made by Wire Arc Additive Manufacturing for Nuclear Components |
Conferences Details
68 Heat treatment of 316LSi made by Wire Arc Additive Manufacturing for Nuclear Components
Wire Arc Additive Manufacturing (WAAM) is emerging as an innovative technology that enables the direct production or repair of dense and complex metallic components, while seeking for costs and lead times competitiveness. Compared to traditional processes such as casting or forging, WAAM offers notable technological advantages, with the possibility to manufacture small and large parts, the creation of complex geometries, reduced machining operations, serial high-quality production. These benefits make WAAM particularly suitable to produce components for sovereign and strategical applications, such as in the civil nuclear sector. Framatome has been developing and operating this technology to meet the stringent requirements of this field, utilizing gas metal arc welding (GMAW) processes to deposit molten metal wire layer by layer from digital models.
However, despite its advantages, WAAM still presents challenges, particularly in microstructure control, which is essential to ensure mechanical properties and corrosion resistance, especially for austenitic stainless steels used in nuclear applications. This work focused on the stainless-steel
material obtained by WAAM from a 316LSi filler material submitted to a solution annealing heat treatment. This work investigates the influence of the soaking time on the mechanical and microstructural properties. It highlights two main phenomena during heat treatment: the rapid dissolution of
ferrite at 1080°C, leading to a decrease in mechanical properties, and the recrystallization of elongated grains. The combination of these effects results in moderate softening and a gradual reduction of anisotropy, thus enabling WAAMmanufactured 316LSi parts to meet the requirements for nuclear applications while exhibiting isotropic behavior.
Keywords: generative design; WAAM, Stainless Steel
