CSP冷轧低碳钢板的再结晶织构

Recrystallization texture in low-carbon steel sheet based on CSP technology

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。

Low carbon steel hot sheets produced by compact strip production（CSP） technology were cold rolled and batch annealed in laboratory.The texture and micro-orientation during recrystallization were investigated by X-ray diffraction and electron backscatter diffraction（EBSD）.Moreover,the mechanism of recrystallization texture was discussed.The γ-fiber textures were increased remarkably since the beginning of recrystallization,but there was a slight decrease in the grain coarsening stage.Coalescence and growth of deformation subgrains took place during the early stage of recrystallization.Subgrains,which were most likely to be recrystallization nuclei,were selected based on the lower internal average misorientation and higher grain boundaries from the deformed matrices by EBSD,they had the preferred orientation near γ-fiber especially {111}112.Meanwhile,various growth rates of the new recrystallization grains were observed in the annealing process.The growth of {111} new grains was inhibited in the grain coarsening stage.It maybe the reason that attributes to the decrease of γ-fiber in the latter stage of recrystallization.Recrystallization texture is determined by the interaction of the preferred orientation distribution and different growth rates of the nuclei.