Difference in thermodynamics between ferrite and martensite in the Fe-Ni system

SCRIPTA MATERIALIA

卷:138

Article

Nakada, Nobuo¹  Kusunoki, Naoki^1,3  Kajihara, Masanori¹  Hamada, Junichi² 

[1] Tokyo Inst Technol, Dept Mat Sci & Engn, Midori Ku, 4259 Nagatsuta Cho, Yokohama, Kanagawa 2268503, Japan

[2] Nippon Steel & Sumikin Stainless Steel Corp, 3434 Shimada, Yamaguchi 7438550, Japan

[3] Isuzu Motors Ltd, Tokyo, Japan

关键词: Iron nickel;    Martensite;    Ferrite;    Elastic strain energy;    Recrystallization;   

DOI  :  10.1016/j.scriptamat.2017.05.050

来源: Elsevier

【 摘 要 】

Very fine duplex microstructure composed of recrystallized-ferrite and reversed-austenite was developed by prior cold rolling and subsequent intercritical annealing in binary Fe-Ni alloys. The equilibrium austenite fraction in the recrystallized-ferrite matrix was much smaller than that in the tempered-martensite matrix, which demonstrates that martensite is less stable than ferrite even though they have the same crystal structure of body-centered cubic. The difference in molar Gibbs energy between ferrite and martensite attributed to elastic strain energy in the martensite but not to lattice defects caused by lattice invariant deformation was evaluated to be 10(3) J/mol at 773 K. (C) 2017 Acta Materialia Inc Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free