七机架热连轧机组轧制温度综合优化技术

Comprehensive optimization technology of rolling temperature for seven stand hot strip mill

热连轧轧制过程中的轧制温度会影响带钢变形抗力以及轧制力的大小,进而改变带钢的出口厚度以及出口板形分布,因此,当轧制温度设定不合理时,会导致带钢的出口厚度精度变低、出口板形质量变差。充分考虑到热连轧机组的设备特点及其轧制工艺特点,首先,通过对变形抗力模型、出口厚度模型、宽展量模型以及出口板形模型的研究,定量分析了轧制温度对变形抗力、出口厚度、带钢宽展量以及出口板形的影响效果及其影响过程。然后,针对由于轧制温度设定不合理而导致的出口板形质量较差的问题,以板形分布的极值差值程度以及波动程度为约束条件建立了带钢板形横向控制目标函数与纵向控制目标函数,进而建立了带钢板形综合控制目标函数,针对由于轧制温度设定不合理而导致的出口厚度精度较低的问题,以出口厚度偏差的标准差以及出口厚度偏差的平均值为约束条件建立了带钢厚度偏差综合控制目标函数,并在此基础上以出口板形最优以及出口厚度偏差最小为目标,以7个机架的极限轧制力、宽展量以及轧制温度变化范围为约束条件建立了七机架热连轧机组轧制温度综合优化设定目标函数,实现了七机架热连轧机组轧制温度设定值的综合优化,将该优化技术应用到了国内某热连轧机组的带钢生产中后使得带钢出口板形质量得到改善,出口厚度控制精度得到提高。

The rolling temperature during hot rolling will affect the deformation resistance and rolling force of the strip steel.Then the exit thickness and the exit shape distribution of the strip steel are changed.Therefore,the out-let thickness accuracy of strip steel will become lower and the outlet shape quality will become worse when the roll-ing temperature is set unreasonably.Fully consider the equipment characteristics and rolling process characteristics of the hot strip mill.Firstly,deformation resistance model and outlet thickness model and width model and outlet shape model are studied to solve these problems.The influence of rolling temperature on deformation resistance and exit thickness and strip width and exit shape is analyzed quantitatively.Aiming at the problem of poor exit shape quality caused by unreasonable rolling temperature setting.The horizontal control objective function and the longitu-dinal control objective function of strip shape are established with the extreme difference degree and fluctuation de-gree of strip shape distribution as constraints.And then,the shape synthesis control objective function is estab-lished.Aiming at the problem of low outlet thickness accuracy caused by unreasonable rolling temperature setting.Taking the standard deviation of the exit thickness deviation and the average value of the exit thickness deviation as constraints,the comprehensive control objective function of the strip thickness deviation was established.The com-prehensive control objective function of the strip thickness deviation was established taking the standard deviation of the exit thickness deviation and the average value of the exit thickness deviation as constraints.On this basis,the best shape of the exit and the minimum deviation of the exit thickness are set as the goals.The limit rolling force and the spread and the range of rolling temperature of the seven stands are taken as constraints.The objective function of rolling temperature optimization for seven stand hot strip mill was established.The comprehensive optimization of the rolling temperature setting value of the seven-stand hot strip mill is realized.After the optimization technology is applied to the strip production of a domestic hot strip mill,the quality of strip shape at the exit is improved,and the accuracy of strip thickness control at the exit is improved.