基于非圆弧理论的精密极薄带轧制力快速预测

Rapid prediction of rolling force of precision thin strip based on non circular arc theory

精密不锈钢极薄带是微电子、微成型等高端领域的重要工业原料,高精度钢带一般使用多辊轧机进行轧制生产。轧制力模型对极薄带的轧制过程控制起着决定性的作用,而轧制力模型的精度主要受到变形抗力和摩擦因数这2个参数的影响。轧制过程中极薄带与轧辊接触变形区的弧长一般远大于轧件厚度,轧辊辊型被压扁为非圆弧形轮廓,将轧辊以圆弧轮廓为假设前提的传统轧制力模型不再适用。针对以上问题,以非圆弧理论为基础,通过推导基于Fleck理论的解析方程,结合计算机编程开发出应用于304不锈钢极薄带的轧制力模型。为优化轧制参数提高轧制力模型的计算精度,考虑到极薄带轧制过程工艺特点是采用较大张力轧制,通过轧制-拉伸试验确定轧件的屈服强度变化并拟合得到相应的变形抗力模型。设计了基于Fleck轧制力模型的摩擦因数计算程序,结合现场采集的轧制过程中的数据,反向计算并拟合关于轧制速度变化的摩擦因数模型。数据显示了在极薄带的轧制过程中,一定范围内摩擦因数随着轧制速度的增大而变小,这是因为随着轧制速度的提升,润滑液更容易被带入到变形区,使得变形区的油膜润滑效果增强。通过计算验证表明,模型的计算值与实测值之间的误差为-10%~10%,可以满足生产过程中高效率控制需求。

Precision stainless steel ultra-thin strip is an important industrial raw material in high-end fields such as microelectronics and micro-forming,High-precision steel strips are generally rolled by multi-roll mills.The rolling force model plays a decisive role in the rolling process control of ultra-thin strip,and the accuracy of the rolling force model is mainly affected by the two parameters of deformation resistance and friction coefficient.In the rolling process,the arc length of the contact deformation zone between the extremely thin strip and the roll is generally much larger than the thickness of the rolled piece.The roll profile is flattened into a non-circular arc profile,and the traditional rolling force model based on the assumption of the arc profile is no longer applicable.In view of the above problems,based on the non circular arc theory,the rolling force model applied to 304 stainless steel strip is developed by deducing the analytical equation based on Fleck theory and computer programming.In order to optimize the rolling parameters and improve the calculation accuracy of the rolling force model,considering that the process characteristics of the ultra-thin strip rolling process are large tension rolling,the yield strength change of the rolled piece is determined by the rolling-tensile experiment and the corresponding deformation resistance model is fitted.The friction coefficient calculation program based on Fleck rolling force model is designed.Combined with the data collected in the rolling process,the friction coefficient model about the change of rolling speed is calculated and fitted in reverse.The data show that during the rolling process of the ultra-thin strip,the friction coefficient decreases with the increase of the rolling speed within a certain range.This is because as the rolling speed increases,the lubricant is more easily brought into the deformation zone,making the oil film lubrication effect in the deformation zone enhanced.The calculation and verification show that the error between the calculated value and the measured value of the model is-10%-10%,which can meet the high efficiency control requirements in the production process.