Danilhenko Vitaliy E
G.V. Kurdyumov Institute of Metal Physics NAS of Ukraine, Vernadsky Blvd. 36, Kiev, 03680, Ukraine.
Nanoscale Res Lett. 2017 Dec;12(1):201. doi: 10.1186/s11671-017-1975-2. Epub 2017 Mar 17.
Data about an effect of cyclic γ-α-γ martensitic transformations on the structure state of reverted austenite Fe-31.7 wt.% Ni-0.06 wt.% C alloy are presented. The effect of multiple direct γ-α and reverse α-γ martensitic transformations on fragmentation of austenitic grains has been investigated by electron microscopy and X-ray diffraction methods. An ultrafine structure has been formed by nanofragmentation inside the initial austenite grains due to the successive misorientation of their crystal lattice. Austenite was nanofragmented as a result of multiple γ-α-γ martensitic transformations. Slow heating of the nanofragmented alloy at a rate below 2 °C/s results in nanograin refinement of the structure by multiplication of the reverted γ-phase orientations. The conditions of structure refinement up to ultrafine and nanocrystalline levels as a result of both shear and diffusion mechanisms of reverse α-γ transformation are determined.
本文给出了关于循环γ-α-γ马氏体相变对Fe-31.7 wt.%Ni-0.06 wt.%C合金中回复奥氏体结构状态影响的数据。通过电子显微镜和X射线衍射方法研究了多次直接γ-α和反向α-γ马氏体相变对奥氏体晶粒破碎的影响。由于初始奥氏体晶粒晶格的连续取向错配，在其内部通过纳米破碎形成了一种超细结构。奥氏体由于多次γ-α-γ马氏体相变而发生纳米破碎。以低于2℃/s的速率对纳米破碎合金进行缓慢加热，会通过回复γ相取向的倍增使结构细化为纳米晶粒。确定了由于反向α-γ转变的剪切和扩散机制而使结构细化至超细和纳米晶水平的条件。
