Investigation of processing routes, microstructures and mechanical properties of reduced activation ferritic/martensitic steels for nuclear fusion applications
Author: Puype, A.
Subject: Investigation of processing routes, microstructures and mechanical properties of reduced activation ferritic/martensitic steels for nuclear fusion applications
Promotor: Petrov, R.
SCK CEN Mentor: Malerba, L.
In this work, several reduced activation ferritic/martensitic (RAFM) alloys were developed and different heat treatments were designed and explored with the intention of optimizing the mechanical properties in comparison with the reference European RAFM material, EU97-2. The goal of this research is to design the chemical compositions and processing routes for RAFM steels for applications in future fusion reactors. In order to enable an effective design of the materials, this study investigates the microstructure, processing routes and mechanical properties of RAFM steels in order to gain a more fundamental understanding of the correlation between the different features, ultimately leading to a more suitable candidate for the application as structural material in the demonstration fusion reactor (DEMO). The main properties of importance are the ductile-to-brittle transition temperature (DBTT) and the strength of the materials at room and, especially at elevated temperatures.
The main objectives of this project are:
- to understand the relationship between the microstructure and the mechanical properties in RAFM steels;
- to produce RAFM grades with lower DBTT values than EU97-2, and/or materials that are less prone to harden under irradiation, for low temperature fusion application;
- to produce RAFM grades with improved creep resistance with respect to EU97-2 for high temperature fusion application.
A thorough understanding of the effect of alloying elements and processing parameters on the microstructures of the RAFM steels will eventually lead to a more efficient processing route and improved mechanical properties in comparison with EU97-2.