Annealing behavior of ferritic–martensitic 9%Cr–ODS–Eurofer steel

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 527; no. 15; pp. 3602 - 3608
• Main Authors: Sandim, H.R.Z., Renzetti, R.A., Padilha, A.F., Raabe, D., Klimenkov, M., Lindau, R., Möslang, A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.06.2010; Elsevier
• Subjects: Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defects and impurities in crystals; microstructure; EBSD; Exact sciences and technology; Grain and twin boundaries; Materials science; Other heat and thermomechanical treatments; Physics; Recrystallization; Steel; Structure of solids and liquids; crystallography; Thermal expansion; thermomechanical effects and density; Thermal properties of condensed matter; Thermal properties of crystalline solids; Thermomechanical processing; Treatment of materials and its effects on microstructure and properties; Steel; Thermomechanical processing; EBSD; Recrystallization; Ferritic martensitic steel; Grain boundaries; Temperature dependence; Scanning electron microscopy; Crystal defects; Annealing; Electron backscattering; Creep strength; Dispersions; Thermal stability; Cold rolling; Thermal properties; Chromium steels; Hardening; Oxidation resistance; Transmission electron microscopy; Thermomechanical treatments; Microstructure; Recovery (properties)
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2010.02.051

Oxide dispersion strengthened ferritic–martensitic steels are potential candidates for applications in future fusion power plants. High creep resistance, good oxidation resistance, reduced neutron activation and microstructural long-term stability at temperatures of about 650–700 °C are required in this context. In order to evaluate its thermal stability in the ferritic phase field, samples of the reduced activation ferritic–martensitic 9%Cr–ODS–Eurofer steel were cold rolled to 50% and 80% reductions and further annealed in vacuum from 300 to 800 °C for 1 h. The characterization in the annealed state was performed by scanning electron microscopy in the backscattered electron mode, high-resolution electron backscatter diffraction and transmission electron microscopy. Results show that the fine dispersion of Y-based particles (about 10 nm in size) is effective to prevent recrystallization. The low recrystallized volume fraction (<0.1) is associated to the nuclei found at prior grain boundaries and around large M 23C 6 particles. Static recovery was found to be the predominant softening mechanism of this steel in the investigated temperature range.