Irradiation effects on the performance of the alumina scale formed in FeCrAl ODS ferritic steels

2019 Fiscal Year Final Research Report

• Project/Area Number: 19K21029
• Project/Area Number (Other): 18H05839 (2018)
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund (2019); Single-year Grants (2018)
• Review Section: 0202:Condensed matter physics, plasma science, nuclear engineering, earth resources engineering, energy engineering, and related fields
• Research Institution: Tohoku University
• Principal Investigator: Yu Hao 東北大学, 金属材料研究所, 助教 (10825871)
• Project Period (FY): 2018-08-24 – 2020-03-31
• Keywords: ODS / oxidation / alumina / microstructure / irradiation

Outline of Final Research Achievements

In order to develop a robust alumina scale dispersed with nano-oxide particles for ODS FeCrAl ferritic alloys, the oxidation behavior of FeCrAl ODS ferritic alloys with zirconium and Ex. O additions was investigated at 900 oC, 1000 oC and 1100 oC in air. Microstructure characterization focused on the distribution of Y-Zr oxide particles inside alumina scales was conducted. By adjusting the contents of Zr and Ex. O additions, a distribution with dense Y-Zr oxide particles inside the alumina scale was obtained, which is expected to enhance the stability of the alumina scale during service at elevated temperatures in nuclear applications. A heavy Fe-ion simulation bombardment technique was conducted for the irradiation-processing of pre-oxidized alloys with alumina scales formation. High stability of the Y-Zr oxide particles dispersed alumina scales was confirmed during irradiation.

Free Research Field

Nuclear Materials

Academic Significance and Societal Importance of the Research Achievements

本研究では、酸化物分散強化フェライト鋼に形成されたアルミナ酸化皮膜の組織、及び剥離挙動・耐酸化性に及ぼす照射効果を調べた。本成果は、将来の高温原子炉で使用されるアルミナスケール形成ODS超合金の設計・開発のための貴重な情報となりうる。