Al Rafi Araf, Santillana Begoña, Feng Renfei, Thomas Brian G, Phillion André B
Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario, Canada.
Tata Steel, R&D, IJmuiden, the Netherlands.
J Microsc. 2024 Sep;295(3):266-277. doi: 10.1111/jmi.13310. Epub 2024 Apr 27.
The accurate characterisation of centreline segregation requires precise measurements of composition variations over large length scales (10 ) across the centreline of the cast product, while having high resolution, sufficient to quantify the significant composition variations between dendrites due to microsegregation at very small length scales (10 ). This study investigates the potential of a novel microscopy technique, named Synchrotron Micro X-ray Flurorescence (SMXRF), to generate large-scale high-resolution segregation maps from a steel sample taken from a thin slab caster. Two methods, Point Analysis and Regression Analysis, are proposed for SMXRF data calibration. By comparing with the traditional Laser-Induced Breakdown Spectroscopy (LIBS), and Electron Probe Micro Analyser (EPMA) techniques, we show that SMXRF is successful in quantitative characterisation of centreline segregation. Over large areas (e.g. 12 16 ) and at high resolution (10-50 pixel size) various techniques yield comparable outcomes in terms of composition maps and solute profiles. The findings also highlight the importance of both high spatial resolution and large field of view to have a quantitative, accurate, and efficient measurement tool to investigate segregation phenomena.
准确表征中心线偏析需要精确测量铸坯产品中心线大长度尺度（10 ）上的成分变化，同时要具备高分辨率，足以量化由于非常小长度尺度（10 ）上的微观偏析导致的枝晶间显著成分变化。本研究调查了一种名为同步辐射微X射线荧光光谱（SMXRF）的新型显微镜技术从薄板坯连铸机取出的钢样生成大规模高分辨率偏析图的潜力。针对SMXRF数据校准提出了两种方法，即点分析和回归分析。通过与传统的激光诱导击穿光谱（LIBS）和电子探针微分析仪（EPMA）技术进行比较，我们表明SMXRF在中心线偏析的定量表征方面是成功的。在大面积（例如12 16 ）和高分辨率（10 - 50 像素尺寸）下，各种技术在成分图和溶质分布方面产生了可比的结果。研究结果还强调了高空间分辨率和大视场对于拥有定量、准确和高效的测量工具来研究偏析现象的重要性。
