工艺参数对热轧机振动固有特性影响分析

 某钢厂热连轧生产线F2机架在轧制薄规格产品时发生了强烈的振动现象。为了更好地识别轧机振动的类型,抑制轧机振动,需对轧机系统的固有特性进行全面分析。考虑水平、扭转和垂直系统的振动,并考虑带钢和轧机系统的耦合作用建立热轧机11自由度振动模型,分析轧机系统在无带钢下的固有特性,并分析各阶模态对惯性参数和弹性参数的灵敏度。同时分析带钢和轧机耦合作用下前后张力、入口厚度、出口厚度、摩擦因数、变形抗力等工艺参数对轧机系统固有特性的影响。研究结果表明,带钢和轧机相耦合成一种变结构系统,系统固有特性随着工艺参数的变化而变化,工艺参数主要通过改变第4阶模态和第10阶模态来影响系统固有特性。不同的工艺参数对轧机系统固有特性的影响程度不同,入口厚度影响最为显著,可以通过改变工艺参数来改善系统固有频率。可以为轧机振动类型的识别和振动的抑制提供指导。

Influence of process parameters on vibration natural characteristics of hot rolling mill

The vibration problem of rolling mill is the main cause of strip thickness difference,surface scratch or vibration pattern. In addition,vibration can cause fatigue damage of equipment parts,and even cause instability vibration due to process reasons,which will endanger the production safety of the system. It is very important to master and understand the natural frequency and vibration characteristics of rolling mill system,which is the basic condition of vibration analysis. Strong vibration occurred on F2 stand of hot continuous rolling line in a steel plant when rolling thin products. In order to better identify the type of mill vibration and suppress the mill vibration,it is necessary to conduct a comprehensive analysis on the natural modal characteristics of the rolling mill system. Considering the vibration of horizontal,torsional and vertical system,and considering the coupling effect of strip and rolling mill system,an 11 degree of freedom vibration model of hot rolling mill is established. The natural modal characteristics of the rolling mill system without strip steel are analyzed,and the sensitivity of inertia parameters and elastic parameters to the natural modal characteristics of the rolling mill system is analyzed. At the same time,the influence of process parameters,such as front and back tension,inlet thickness,exit thickness,friction coefficient and deformation resistance on the natural characteristics of the rolling mill system is analyzed. The results show that the strip and rolling mill are coupled to form a variable structure system. The natural characteristics of the system vary with different process parameters. The process parameters mainly affect the natural characteristics of the system by changing the 4th and 10th modes. The influence of different process parameters on the natural characteristics of rolling mill system is different,and the influence of inlet thickness is the most significant. The system natural frequency can be improved by changing process parameters. The guidance for the identification of rolling mill vibration types and vibration suppression was provided.