The exploration for effects of rare earth (RE)on phase transformation of Fe-based alloy is significant in the development process of advanced high strength steel containing RE. In the paper,the effects of La and Ce on martensite phase transformation of steel are studied from such two aspects as driving force and minimum energy path (MEP)using first principles calculations. The calculations of formation energy revealed that the stability of fcc-Fe was increased and stabili-ty of bcc-Fe was decreased through substitution of RE for part of Fe atom so that the driving force of martensite phase transformation was decreased. Meanwhile,the analysis on generalized solid-state nudged elastic band method indicated that there would be an additional energy barrier when phase transformation went on to the FM state with ratio c/a of 1.14 a-long Bain transformation path in the system containing RE,which was related to the sudden decrease of magnetic moment caused by the hybridization between atomic orbital of RE and nearby atomic orbital of Fe.
关键词
第一性原理计算/稀土/铁/广义固态微动弹性带/马氏体转变
Key words
first principles calculations/rare earth/Fe/generalized solid-state nudged elastic band/martensitic transformation
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