基于GTN模型的冷轧硅钢边部裂纹扩展研究

针对硅钢板容易在冷轧过程中形成边部裂纹,使用Gurson-Tvergaard-Needleman(GTN)微观损伤模型对带有边部微小缺口的硅钢板在冷轧过程中损伤分布以及裂纹的萌生和扩展进行研究。通过拉伸试验和扫描电镜观察分析得到材料的损伤参数f0、fc和fF,进而通过有限元软件ABAQUS模拟得到各轧制工艺参数对缺口尖端区域损伤分布及微裂纹萌生与扩展的影响,仿真与试验结果表明,在缺口尖端形成两条损伤带,最大损伤值随着压下率的增大而增大,同时裂纹长度随着压下率的增大而迅速增加;当工作辊半径较小时更加容易出现裂纹;沿着轧制方向缺口前侧的比后侧更容易产生裂纹,两侧的裂纹长度都随着摩擦因数的增大而增大;裂纹长度会随着张力的增大而明显增大。研究结果为轧制工艺参数的选择提供理论依据和参考。

Analysis for the Propagation of Edge Crack of Silicon Steel during Cold Rolling Process Based on GTN Damage Model

Edge crack is a kind of defects in the cold rolling process of silicon steel,causes rupture of the steel in the rolling mill and need to be removd.Hence,it is necessary to understand the formation of edge cracks The damage distribution,as well as the initiation and propagation of edge cracks around the tips of the precut notches during cold rolling process are investigated by using GTN damage model.The damage parameters f0,fc and fF are determined by tensile tests and scanning electron microscope(SEM) observation.The influence of various rolling parameters on damage distribution and crack length is studied by numerical simulation.The numerical results show that the GTN damage model is available to prediction the initiation and propagation of edge cracks during rolling process.Parametric study carry out in present work reveals that it is more possible to occur edge cracks at larger reduction,higher friction coefficient,smaller roll radius and stronger unit tension.The simulation and experimental results have a good agreement.