有高温相变的电工钢热轧起浪的有限元分析

Finite element analysis of edge wave for non-oriented electrical strip with high temperature phase transition

针对电工钢自由规程轧制过程起浪问题,开展电工钢不同冷却条件下的连续冷却相变转变温度分析测定和Gleeble热模拟实验,发现电工钢在975~875℃的奥氏体-铁素体两相区,随着轧制温度降低,变形抗力反而减小;电工钢大量同宽自由规程轧制下的工作辊出现严重的不均匀的箱型磨损和明显的热胀,综合辊形变化显著.考虑电工钢两相区变形抗力差异和综合辊形变化,建立电工钢热轧过程轧辊轧件的三维弹塑性耦合有限元模型,仿真分析轧制力、弯辊与窜辊对承载辊缝形状的影响,研究摩擦系数、压下量与轧制速度对带钢宽度方向内应力变化规律的影响,采用Shohet板形判据确定电工钢比例凸度残差变化路径,明确电工钢在“平坦死区”较大的上游机架出现“异常起浪”的生成过程.该方法为电工钢热轧板形的浪形控制提供了依据.

For an edge wave problem of electrical steel in and the Gleeble thermal stress-stain simulator are analyzed as temperature is lowered in the austenite-ferrite region （ SFR （schedule-free rolling） process, the CCT curves for electrical steel. The deformation resistance decreases 975- 875℃）. The significant roll wear contours and thermal behaviors characteristics of SFR are obtained by the measured data of industrial mills. Considering the difference of deformation resistance with double phases and the actual roll contours, a 3D elastic-plastic finite element coupling model of roll stacks and strip is established for the effect of roll force, roll bending and shifting system on the loaded roll gap profile, and the influence of friction coefficient, strip thickness and rolling speed on strip internal stress distribution. The change path of ratio crown difference by Shohet criteria are attained to explain the formation process of irregular edge wave in upstream stands of hot rolling mills with larger flatness dead zones, which provides evidences for flatness control of electrical strip in hot rolling.