Radiation integrity of strengthening factor in steels

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K22152
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 31:Nuclear engineering, earth resources engineering, energy engineering, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: ABE Hiroaki 東京大学, 大学院工学系研究科(工学部), 教授 (40343925)
• Project Period (FY): 2019-06-28 – 2023-03-31
• Keywords: 析出物 / 鉄鋼材料 / ジルコニウム合金 / 二層界面 / 照射効果

Outline of Final Research Achievements

This project aims to elucidate a new irradiation-induced solid-state reaction phenomenon at the metal/precipitate (oxide, carbide, intermetallic compound) bilayer interface. The objective was to develop an experimental method to deepen a more precise and quantitative understanding, especially to establish a quantitative evaluation method from the viewpoint of microstructure. Irradiation-induced destabilization of oxide particles and M23C6-type carbides in steel was investigated by ion irradiation and electron microscopy. Furthermore, we developed a new experimental method for irradiation-induced interfacial solid-state reactions. We also clarified that the mechanism of this phenomenon is that materials are exchanged at the grain interface mediated by irradiation defects in the matrix, and the constituent atoms of the grain diffuse into the matrix.

Free Research Field

原子力材料

Academic Significance and Societal Importance of the Research Achievements

鉄鋼材料やZr合金中の析出物（炭化物、酸化物、金属間化合物）は、材料強化因子として機能するが、これらが原子炉環境に特有な照射下において不安定化することを明らかにした。この現象は原子炉の構成要素（構造材料、被覆管）の強度低下につながるものである。本研究成果はこの機構論を明らかにし、さらに定量調査を可能とする新しい実験方法を提案するものである。