Transformation super plasticity deformation of reduced activation ferritic / martensitic steel

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K18306
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Nuclear fusion studies
• Research Institution: National Institute for Fusion Science
• Principal Investigator: Noto Hiroyuki 核融合科学研究所, ヘリカル研究部, 助教 (50733739)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 変態超塑性 / 低放射化フェライト鋼

Outline of Final Research Achievements

Reduced Activation Ferritic/Martensitic (RAFM) steel is a promising candidate for the blanket structural materials of fusion reactors. One of the key issues in the use of RAFM for the blanket is its low workability. As a solution of this issue, innovative processing technology based on the transformation super plasticity (TSP) was proposed. In general, TSP is known as high temperature creep deformation which is induced by phase transformation. In this study, tensile tests under constant load were carried out with cyclic temperature variation for a RAFM steel to investigate the effect of cyclic temperature variations on elongation. The result of the tensile test under constant load for the RAFM steel with cyclic temperature variations exhibited a macro-elongation to 172 %. The results of the tensile tests with varying loads showed the possibility of reducing the necessary time and enhancing the controllability for the formation of RAFM steel products using TSP.

Free Research Field

金属材料

Academic Significance and Societal Importance of the Research Achievements

今回得られたJLF-1鋼による巨視的な伸びの成果は、新しく開発された低放射化フェライト鋼という先進材料においても変態超塑性が発現することを確かめた知見である。また、本研究は、これまで結びつきの少なかった「核融合・原子力材料分野」と「超塑性分野」を融合させたものであり、核融合炉・原子炉用エネルギー材料研究の発展に貢献できたと考えている。