摘要
为了研究冷轧工艺对IF钢显微组织的影响.本文借助电子背散射衍射技术,研究了20%到75%冷轧压下率的IF钢退火后的微观结构、晶界特征分布和晶界连通性.结果表明:随着冷轧压下率的增加,冷轧态晶粒逐渐由等轴状变为纤维状,退火态晶粒逐渐细化并变得均匀,小角晶界的出现频率呈下降趋势;随机晶界的出现频率呈明显上升趋势,且随机晶界占绝对优势;而CSL晶界在冷轧压下率40%以下时,变化较小,40%以上时,含量明显增加.大变形量轧制后的IF钢CSL晶界主要由Σ3晶界组成,而小变形量轧制后主要是Σ3和Σ13b晶界.对于75%压下率,还含有较多的Σ7,Σ9和Σ11等CSL晶界.通过增加冷轧压下率,0-CSL三叉晶界的含量减少,1-CSL三叉晶界的含量增加.因此,通过改变冷轧工艺,可以优化IF钢板的晶界特征分布及连通性.
With the aim of investigating effect of cold rolling on the microstructure of interstitial-free steel, microstructure, grain boundary character distribution and grain boundary connectivity were studied by means of electron back-scatter diffraction technology. The results showed that the fibrous grains were changed into equiaxed ones in the microstructure of the IF steel after cold rolled with reduction ranged from 20% to 75%. Furthermore, the higher the cold rolling reduction, the finer and more uniform grains of steel were observed after annealed. The amount of low-angle grain boundaries decreased, whereas the frequency of random grain boundaries increased sharply with the increasing of cold reduction from 20%to 75%. However, the proportion of CSL grain boundaries increased with increasing cold reduction, but there was a negligible fluctuation in the cold reduction of 40%. The majority of grain boundaries were random grain boundaries. CSL grain boundaries of IF steel were mainly compose of Σ3 grain boundaries with severe cold deformation, while CSL grain boundaries were constitute of Σ3 and Σ13b grain boundaries with weak cold deformation. Also, the amount of Σ7,Σ9 andΣ11 grain boundaries were high after 75% cold rolled. The partial substitution of 1-CSL triple junctions for 0-CSL be obtained by increasing the cold deformation. Hence, grain boundary character distribution and grain boundary connectivity of interstitial-free steel can be optimized by tailoring cold rolling reduction.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2014年第4期30-35,共6页
Materials Science and Technology
基金
国家自然科学基金资助项目(50901054
51101114)
关键词
冷轧压下率
高强IF钢
晶界特征分布
电子背散射衍射技术
high strength interstitial free steel
cold-rolled reduction
grain boundary character distribution
electron back-scatter diffraction
