| Abstract Scope |
Alumina-forming austenitic steels (AFA) are a family of stainless steels with superior corrosion and creep resistance than conventional chromium-oxide-forming stainless steels, making them adequate contestants to replace them. AFA steels present a problem: their inherent FCC structure is vulnerable to irradiation swelling, making them unsuitable for use in nuclear reactors. A novel material class, alumina-forming ferritic-martensitic steels, is proposed, combining the excellent corrosion resistance from the Al2O3 and the swelling resistance from a BCC matrix. Starting with pre-alloyed atomized powders, advanced fabrication processes such as field-assisted sintering and selective laser-melting are being investigated to generate different microstructures. These microstructures were examined using SEM, SEM-EBSD and TEM, while the mechanical behavior was evaluated using small-punch tests at temperatures up to 700°C, among other techniques. Finally, corrosion experiments were conducted at 800°C and 1200°C for 500 and 8 hours, respectively. |