Tracing the recrystallization of warm temper-rolled Fe–6.5 wt% Si non-oriented electrical steel using a quasi in situ EBSD technique
Tracing the recrystallization of warm temper-rolled Fe–6.5 wt% Si non-oriented electrical steel using a quasi in situ EBSD technique
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DOI：
10.1007/s10853-020-05168-3
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发表时间：
2020-09
影响因子：
4.5
通讯作者：
Haijie Xu;Yunbo Xu;Youliang He;S. Yue;Jian-ping Li
中科院分区：
文献类型：
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作者：
Haijie Xu;Yunbo Xu;Youliang He;S. Yue;Jian-ping Li
Fe-6.5wt%Si无取向电工钢是一种优良的软磁材料，这是由于在高频下的低铁损和接近零的磁致伸缩。在这项研究中，Fe-6.5wt%Si无取向电工钢的加工热轧，温斜轧，中间退火，温平整和最终退火。利用准原位EBSD技术研究了最终退火过程中显微组织和织构的演变。温态平整后，在ND-RD（法向-轧制方向）横截面上的一个区域被显微硬度压痕所标记，当退火时间增加时，EBSD追踪到该区域内单个晶粒的再结晶。由于温态平整后组织、织构和储能的差异，表层和中心区域表现出不同的再结晶行为。表面区域的再结晶基本上是由具有比其相邻区域更低的储存能量的现有微晶的生长（基本上没有成核）引发的，而中心区域在退火期间显示成核和晶粒生长。单个晶粒的生长速率相对于相邻晶粒的数量进行评估，并且它们近似地遵循晶粒生长的冯诺依曼-穆林斯定律。表面区域显示出比中心区域快得多的生长速率。由于<111><113>这些晶粒的优先生长，最终织构在表面和中心区域均由//ND和//ND主导。
Fe–6.5 wt% Si non-oriented electrical steel is an excellent soft magnetic material due to the low core losses at high frequencies and near-zero magnetostriction. In this study, an Fe–6.5 wt% Si non-oriented electrical steel was processed by hot rolling, warm cross rolling, intermediate annealing, warm temper rolling and final annealing. The evolution of microstructure and microtexture during final annealing was investigated using aquasiin situ EBSD (electron backscatter diffraction) technique. After warm temper rolling, an area on the ND–RD (normal direction–rolling direction) cross section was marked by micro-hardness indents, and the recrystallization of individual grains in this area was traced under EBSD when the annealing time was increased. Due to the differences in the microstructure, texture and stored energy after warm temper rolling, the surface and center regions showed different recrystallization behaviors. The recrystallization of the surface region was essentially initiated by the growth of existing crystallites having lower stored energy than their neighboring areas (essentially no nucleation), while the center region showed both nucleation and grain growth during annealing. The growth rates of individual grains were evaluated with respect to the number of neighboring grains, and they approximately followed the von Neumann–Mullins law of grain growth. The surface region showed a much faster growth rate than the center region. The final texture was dominated by <111>//ND and <113>//ND in both the surface and center regions, due to the preferred growth of these grains.