Design principle of optimal surface texture for improving steam oxidation behavior of heat-resisting materials

• Project/Area Number: 26870186
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Material processing/Microstructural control engineering; Structural/Functional materials
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: UEDA MITSUTOSHI 東京工業大学, 物質理工学院, 准教授 (90376939)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2016: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 耐熱金属材料 / 水蒸気酸化 / 保護性酸化皮膜 / 結晶方位

Outline of Final Research Achievements

This research focuses on effect of crystallographic orientation of the substrate on microstructure development of the oxide scale formed on heat resistant steels during steam oxidation. Fe-Cr-Ni alloys was used as a model system of austenitic steels for the various oxidation tests. Before steam oxidation, crystallographic orientation of the substrate was determined by electron backscatter diffraction. After steam oxidation, microstructure of the oxide scale formed on each crystal grain of the substrate was observed and categolozed based on crystallographic orientation. As a result, crystal grain of Fe-Cr-Ni alloys, which has (111) plane on the surface, has good oxidation resistance due to the formation of protective oxide scale.