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利用局域取向差衡量变形金属中的位错密度,对不同变形程度的退火铁素体钢样品做电子背散射衍射(EBSD)面扫描,取得取向数据进行局域取向差分析。结果表明,在相同的测量和计算条件下,局域取向差可以表征出塑性变形的金属中位错墙和显微带等亚结构。局域取向差还可以用来比较不同样品的位错密度平均水平,特别是能够区分状态接近的微区中位错密度的相对大小。利用局域取向差分析证实了具有相同成分的铁素体+马氏体(F-M)双相钢与铁素体+珠光体(F-P)钢中,前者铁素体的位错密度高于后者。局域取向差分布图表明在冷轧板中部组织中,位错墙集中分布于晶界附近;而在边部组织中,位错墙则是分散分布并相互缠结。边部组织中的位错密度显著高于中部组织,是导致局部塑性差容易开裂的一个原因。
The local dislocation density was used to measure the dislocation density in the deformed metal, and the electron backscattered diffraction (EBSD) surface scanning was performed on the annealed ferritic steel samples with different deformation degrees to obtain the orientation data for the local orientation difference analysis. The results show that under the same measurement and calculation conditions, the local misorientation can characterize the plastic deformation of metal dislocation walls and microstructures. Localized orientation differences can also be used to compare the average dislocation density for different samples, especially to distinguish the relative sizes of dislocation densities in the approaching micro-domains. Dislocation density of the former ferrite is higher than that of the latter in the ferrite + martensite (FM) duplex steel and the ferrite + pearlite (FP) steel with the same composition . In the central part of the cold-rolled plate, the dislocation walls are distributed concentratedly near the grain boundaries. In the dislocations, the dislocation walls are scattered and intertwined with each other. Dislocation density in the edge tissue was significantly higher than that in the middle, which was one of the reasons that the local plasticity was easy to crack.