Effects of transformation temperature on VC interphase precipitation and resultant hardness in low-carbon steels
Effects of transformation temperature on VC interphase precipitation and resultant hardness in low-carbon steels
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DOI：
10.1016/j.actamat.2014.10.049
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发表时间：
2015-02-01
期刊：
影响因子：
9.4
通讯作者：
Tsuzaki, K.
中科院分区：
文献类型：
--
作者：
Zhang, Y. -J.;Miyamoto, G.;Tsuzaki, K.
采用Fe-0.1C-1.5Mn-0.4V-0.05Si（质量分数）合金，在不同温度下等温转变，研究了相变温度对低碳钢中VC相间析出的影响。采用电子背散射衍射、三维原子探针和纳米压痕等方法研究了铁素体和奥氏体的晶体学关系、析出相和硬度。结果表明，当相变温度从993 K降低到923 K时，非K-S（Kurdjumov-Sachs）界面处片状相间析出的数量密度显著增加，而当相变温度进一步降低到873 K时，片状相间析出的数量密度变化不大。铁素体晶粒的纳米硬度与VC数密度的变化趋势一致。从VC形核驱动力的角度讨论了相变温度对VC相间析出的影响。另一方面，宏观硬度的温度依赖性并不同意，由于事实上，持有附近的K-S取向关系与奥氏体的铁素体的分数随相变温度的变化显着的纳米硬度。(C)2014 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The effects of transformation temperature on VC interphase precipitation in low-carbon steels were investigated mainly by using an Fe-0.1C-1.5Mn-0.4V-0.05Si (mass%) alloy isothermally transformed at different temperatures. The crystallographic relationship between ferrite and austenite as well as the precipitates and resultant hardness were characterized by combining electron backscatter diffraction, three-dimensional atom probe and nanoindentation measurements in the same ferrite grains. It was found that the number density of sheet-like interphase precipitation at non-K-S (Kurdjumov-Sachs) interfaces is significantly increased by decreasing the transformation temperature from 993 K to 923 K, while no great change can be obtained by further lowering the temperature to 873 K. The nanohardness of ferrite grains shows the same trend as that of VC number density. The effects of transformation temperature on VC interphase precipitation are discussed in terms of the driving force for VC nucleation. On the other hand, the temperature dependence of macroscopic hardness does not agree with that for nanohardness due to the fact that fraction of ferrite holding near the K-S orientation relationship with austenite changes substantially with transformation temperature. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.