High Angular Resolution Electron Backscatter Diffraction Studies of Tetragonality in Fe-C Martensitic Steels
High Angular Resolution Electron Backscatter Diffraction Studies of Tetragonality in Fe-C Martensitic Steels
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Fe-C 马氏体钢中四方性的高角分辨率电子背散射衍射研究
DOI：
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发表时间：
2018
影响因子：
2.8
通讯作者：
A. Wilkinson
中科院分区：
文献类型：
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作者：
Tomohito Tanaka;A. Wilkinson
高（角）分辨率 EBSD (HR-EBSD) 旨在测量微观结构尺度上弹性晶格应变的空间变化，应变灵敏度约为 10-4 [1]。然而，测量结果是相对于获得参考图案的点处的应变状态而言的。在某些情况下，该基线参考应变状态是众所周知的，但在一般情况下却并非如此；所谓的参考模式问题。解决该问题并从而实现绝对应变测量的一种可能途径是使用模拟 EBSD 图案作为参考图案 [2]。在这里，我们探索了技术开发中实现这一目标的最新步骤，并通过映射马氏体钢中四方性的局部变化这一重要的材料科学挑战。在低碳到中碳钢中形成的板条和板状马氏体结构具有工业意义。从高温面心立方奥氏体到体心四方马氏体的马氏体相变导致复杂的分级微观结构，平衡晶格应变和界面对能量的贡献。随着碳含量的增加，X 射线衍射研究表明，马氏体的平均 c/a 比率增加，而显微镜显示微观结构长度尺度的细化。然而，人们对四方性的微观变化缺乏了解。我们使用高分辨率电子背散射衍射 (HR-EBSD) 进行一些仔细的测量来解决这一知识差距。
High (Angular) Resolution EBSD (HR-EBSD) was developed to measure the spatial variation in elastic lattice strain at the microstructural scale with strain sensitivity of ~10-4 [1]. However, the measurements are relative to the strain state at the point from which the reference pattern is obtained. In some cases, this baseline reference strain state is well-known but in the general case it is not; the so-called reference pattern problem. One possible route to solving this problem and thus achieving absolute strain measurement is to use a simulated EBSD pattern as the reference pattern [2]. Here we explore recent steps towards this goal in technique development and through an important materials science challenge of mapping local variations in tetragonality within martensitic steels. Lath and plate martensite structures formed in lowto medium-carbon steels are of industrial significance. Martensitic phase transformation from the high temperature face centre cubic austenite to the body centre tetragonal martensite leads to complex hierarchical microstructures which balances lattice strain and interfacial contributions to energy. As the carbon content is increased X-ray diffraction studies have shown that the average c/a ratio of the martensite increases, while microscopy shows a refinement in microstructural lengthscale. There is, however, a lack of knowledge concerning the microscopic variation in tetragonality. We address this knowledge gap using some careful measurements using high resolution electron backscatter diffraction (HR-EBSD).
影响因子：
2.2
作者：
Britton, T. B.;Maurice, C.;Wilkinson, A. J.
通讯作者：
Wilkinson, A. J.