Structural mechanism of reverse α → γ transformation and strengthening of Fe-Ni alloys
Structural mechanism of reverse α → γ transformation and strengthening of Fe-Ni alloys
复制标题
Fe-Ni合金逆α→γ相变强化的结构机制
DOI：
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发表时间：
2014
影响因子：
1.2
通讯作者：
M. F. Klyukina
中科院分区：
文献类型：
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作者：
V. Sagaradze;N. Kataeva;I. G. Kabanova;V. Zavalishin;A. Valiullin;M. F. Klyukina
Fe-32%Ni合金在以0.01K/min的速率缓慢加热到低于As的温度时，表现出非孪晶化，并出现了具有六方晶系（hcp）晶格和晶格参数a = 2.535，c = 4.132 μ m，c/a = 1.63的中间双晶相。缓慢加热到430-490°C导致形成富含镍的纳米晶奥氏体，这大大增加了马氏体的硬度。在Fe-32%Ni合金（其是马氏体与20-30%纳米晶奥氏体的混合物）中，在其快速加热至600°C期间，奥氏体的形成经由具有短程原子扩散的体机制发生。在这种情况下，扩散并不能消除合金在镍中的浓度微观不均匀性，而是导致γ相纳米晶的重新取向，几乎消除了位错结构，消除了相硬化强化。
Fe-32% Ni alloy subjected to slow heating to a temperature below As at a rate of 0.01 K/min demonstrates the untwinning and appearance of an intermediate ɛ phase with an hcp lattice and lattice parameters a = 2.535, c = 4.132 Å, and c/a = 1.63. Slow heating to 430–490°C leads to the formation of nanocrystalline austenite enriched in nickel, which substantially increases the hardness of martensite. The formation of austenite in the Fe-32% Ni alloy, which is a mixture of martensite with 20–30% nanocrystalline austenite, during its rapid heating to 600°C occurs via the bulk mechanism with short-range atomic diffusion. In this case, the diffusion does not eliminate the concentration micro-inhomogeneity of the alloy in nickel but leads to the reorientation of γ-phase nanocrystals, almost eliminates the dislocation structure, and removes the strengthening by phase hardening.