期刊
JOURNAL OF ALLOYS AND COMPOUNDS
卷 650, 期 -, 页码 239-247出版社
ELSEVIER SCIENCE SA
DOI: 10.1016/j.jallcom.2015.07.278
关键词
Phase transformation; Widmanstatten ferrite; Elastic energy; Phase field model
资金
- General Motors China Science Lab
- State Key Development Program for Basic Research of China (973 Programs) [2012CB619600]
- National Science Foundation of China (NSFC) [51471107, 50971090]
A phase field model accounting for anisotropic elastic energy has been formulated to investigate the morphology and growth kinetics of a Widmanstatten microstructure during the isothermal austenite to ferrite transformation in binary Fe-C. Physically realistic parameters are employed, for which the thermodynamic functions and the diffusional mobilities are from the literatures that were assessed via the Calphad technique and from experimental results respectively. The simulation results suggest that the anisotropy of elastic energy, resulting from the lattice distortion between the ferrite precipitate and the austenite matrix in the phase transformation, is sufficient to generate a plate-like Widmanstatten structure. The growth of the ferrite precipitate follows completely different dynamic laws in different directions, i.e., parabolic thickening in the direction of the plate thickness and linear lengthening in the direction toward the plate tip. The chief reason for the former is that the moving of the plate broad sides may be regarded as a migration of straight interfaces in the diffusion-controlled phase transformation; the latter is because that the plate tip can maintain a constant radius of curvature during the phase transition after a transient initial stage. Furthermore, the aspect ratio and the lengthening rate of the Widmanstatten ferrite plate simulated by our analyses are in good agreement with the experimental observations. (C) 2015 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据