论文部分内容阅读
采用基于薄板坯连铸连轧(CSP)工艺条件下的低碳钢板作为冷轧基料,在实验室模拟现场工艺进行了冷轧和罩式退火,利用X射线衍射和电子背散射衍射(EBSD)分析了退火过程中的织构和微区取向的变化,并对CSP条件冷轧板再结晶织构的形成机制进行了讨论。结果表明:γ取向线在再结晶发生后增加比较明显,但在晶粒长大阶段却略有降低。形变亚晶在再结晶过程中发生合并长大,这些具有大角度晶界的亚晶将是再结晶形核的基础。以较小的晶内平均取向差和较大的晶粒间取向差为判据,利用EBSD技术选取了最有可能成为再结晶晶核的亚晶,这些亚晶存在着以{111}<112>取向为主的择优取向。再结晶晶粒的生长速度在随后的整个退火过程中存在较大差异,{111}再结晶新晶粒的生长速度在晶粒长大阶段受到抑制,可能是其最终成品γ取向线取向分布密度下降的原因。再结晶初期晶核的择优取向与其生长速度的差异共同作用决定了再结晶的最终织构。
The cold rolled and shell annealed in the laboratory were simulated by low carbon steel plate based on the thin slab continuous casting and tandem rolling (CSP) process. The microstructure of the steel was characterized by X - ray diffraction and electron backscatter diffraction (EBSD) ) Were used to analyze the changes of texture and micro-orientation during annealing. The formation mechanism of recrystallization texture of CSP cold-rolled sheet was also discussed. The results show that the γ orientation line increases more obviously after recrystallization, but slightly decreases in the grain growth stage. Deformable subgrains merge and grow during recrystallization. These subgrains with large-angle grain boundaries will form the basis of recrystallization nucleation. Based on the smaller in-plane average orientation difference and larger intergranular orientation difference, the most likely subgrains of recrystallized nuclei were selected by EBSD technique. These subgrains exist as {111} <112 > Orientation-based preferred orientation. The growth rate of recrystallized grains is greatly different in the whole subsequent annealing process. The growth rate of {111} recrystallized new grains is restrained in the grain growth stage, which may be the orientation distribution density of γ orientations of the final product The reason for the decline. The combined effect of the preferred orientation of the nuclei and the difference in their growth rate at the beginning of recrystallization determines the final texture of recrystallization.