Role of interface between Fe2Nb Laves phase and gamm-Fe matrix in the strength of austenitic heat resistant steels

2015 Fiscal Year Final Research Report

• Project/Area Number: 25709065
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Structural/Functional materials
• Research Institution: Nagoya University (2015); Tokyo Institute of Technology
• Principal Investigator: Takata Naoki 名古屋大学, 工学(系)研究科(研究院), 准教授 (70432523)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: オーステナイト系耐熱鋼 / 金属間化合物 / Ｌａｖｅｓ相 / 結晶粒界 / 異相界面

Outline of Final Research Achievements

In order to understand a role of the interface between γ-Fe matrix and Fe2Nb-Laves phase in the deformation of the austenitic heat resistant steels at ambient temperature, the compression response of γ-Fe bicrystal micropillars with diameters of 3～5　micrometer prepared from the γ-Fe single phase steel with a composition of Fe-20Cr-30Ni (at.%) and the two-phase steel (γ-Fe + Fe2Nb Laves phase) with a with a composition of Fe-20Cr-30Ni-2Nb-0.03B (at.%) was examined using the nanoindenter equipped with a flat punch with a size of 20 micrometer. The present study demonstrate that the interface between γ-Fe matrix and Fe2Nb-Laves phase substantially enhances the local strain hardening in γ-Fe matrix close to the grain boundary, which is likely due to its strong resistance to slip transfer at ambient temperature.

Free Research Field

材料組織学