Bondar Volodymyr, Danilchenko Vitalij, Dzevin Ievgenij
G.V.Kurdyumov Institute of Metal Physics, NAS of Ukraine, Vernadsky Blvd. 36, Kyiv, 03680, Ukraine.
Nanoscale Res Lett. 2016 Dec;11(1):96. doi: 10.1186/s11671-016-1313-0. Epub 2016 Feb 20.
Metallographic, X-ray diffraction and magnetometric analysis were used to study the regularities of martensitic transformation in melt-spun ribbons of a Fe - 28 wt. % Ni - 2.1 wt. % Ti - 2 wt. % Al - 0.05 wt. % C alloy. The substantial differences in volume fractions of the martensite phase in local regions of thin melt-spun ribbons of the alloy are related to the size effect of the transformation and structural inhomogeneity of the ribbons. The distribution of austenitic grain size in different local areas of melt-spun ribbons is significantly different. The principal factor for changing the completeness of the martensitic transformation is the size effect of transformation. Difference in the martensite volume fraction in local regions of a ribbon is mainly determined by the different volume fractions of ultrafine-grained (500-1000 nm) and nanosized (80-100 nm and less) initial austenite grains, in which the transformation was slowed down or completely suppressed. Other factors almost do not affect the completeness of the martensitic transformation. The strong stabilizing effect of the reverse α-γ transformation with respect to the subsequent direct γ-α transformation in the melt-spun ribbons is also related to the grain size effect.
采用金相、X射线衍射和磁分析方法研究了Fe-28 wt.%Ni-2.1 wt.%Ti-2 wt.%Al-0.05 wt.%C合金熔纺带材中马氏体转变规律。该合金薄熔纺带材局部区域马氏体相体积分数存在显著差异，这与转变的尺寸效应和带材的结构不均匀性有关。熔纺带材不同局部区域奥氏体晶粒尺寸分布存在显著差异。改变马氏体转变完整性的主要因素是转变的尺寸效应。带材局部区域马氏体体积分数的差异主要由超细晶粒（500-1000 nm）和纳米尺寸（80-100 nm及更小）的初始奥氏体晶粒的不同体积分数决定，在这些晶粒中转变减缓或完全受到抑制。其他因素几乎不影响马氏体转变的完整性。熔纺带材中逆α-γ转变对随后直接γ-α转变的强烈稳定作用也与晶粒尺寸效应有关。
