Research On The Roll Wear And The Precision Profile Control For Silicon Steel In Hot Rolling

The size accuracy of the silicon steel cold-rolled strip is strictly required.The thickness difference of the strip usually need be within 7?m,and even up to 5?m for some customers.At present,1580mm hot continuous rolling is commonly used in the production of the silicon steel strip,and there are many types of cold rolling equipment.Based on the hot rolling and cold rolling production lines of Ma Steel Company for silicon steel strip,and taking the size accuracy as the target,this paper studied the roll wear mechanism,work roll contour for edge-drop control,work roll shifting strategy and the thickness difference prediction model of the cold-rolled strip.The specific research results are as follows:(1)A fast and integrated calculation model for strip rolling is established which combines the three-dimensional deformation model of the strip with the deformation model of the roll system.According to the wear characteristics of the work roll in hot rolling,the roll wear model based on the spherical asperity model and asperity distribution statistical model is established.The wear prediction model in hot rolling was established based on the roll-strip couple calculation model.(2)A kind of edge shape optimized work roll used in the downstream stand of hot continuous rolling is designed,which can be used for the high-precision strip such as silicon steel to improve the strip profile combined with the work roll free shifting.A particle swarm optimization algorithm was used to optimize the roll contour to ensure the stability of crown control and maximize the effect of the work roll's free shifting.Abaqus finite element software was used to analyze the profile control characteristics of the work roll on the strip.Combined with the industrial test,it is proved that the curve has a significant effect on improving the profile of the silicon steel strip,especially the edge drop.(3)The shifting strategy applied to the profile control of the silicon steel strip is designed for the work roll with free shifting function in the downstream of hot continuous rolling.The three-population optimization algorithm is used to optimize the shifting strategy for a single stand and the Multi-stand collaboration.While ensuring the wear uniformity of the work roll,it also ensures the stable control of the strip crown.(4)The hot-rolled strip shape calculation model and the thickness difference prediction model of the cold-rolled strip based on BP neural networks model are established,and the prediction accuracy of the model is calculated according to the reliability interval method.The established model connects the hot and cold rolling processes of the silicon steel strip,which can guide the optimization of hot rolling process parameters,evaluate the size grade of the hot rolling silicon steel strip and flexibly adjust the downstream process according to the requirements of finished products.