Investigation On Rolling Stability Of Hot Rolled Strip

Plate and strip plays an important role in the development of national economy,and it is widely used in industry,agriculture,national defence and civil products.In particular,hot-rolled steel strip,not only can be used as a sheet and plate can be used directly,but also as cold-rolled plate,welded pipe and cold rolled steel production of raw materials.With the development of science and technology,especially the rapid development of modern industrial sectors such as automotive,aerospace and electronics industries,iron and steel production capacity of the overall rising demand of the strip has increased dramatically,meanwhile,puts forward more strict requirements for high quality products and high quality performance of strip quality,size precision,surface quality and performance.With the increasing competition in the steel market,the profit space of the enterprise is getting smaller and smaller.In order to improve the competitiveness of the product market,the major manufacturers will increase the production of thin steel strip.Short production cycle,high cost advantage to the steel strip products,is being more and more attention,but because of thin strip production of high speed rolling,temperature drop fast,rolling force is large,easily lead to instability of strip rolling,a stack of steel,swing and rolling break accidents such as increased size and it is also difficult to control the shape accuracy.Therefore,to improve the stability of hot strip rolling to reduce the cost per ton of steel,improve the proportion of thin,reduce production accidents and equipment accidents play a crucial role.Based on the Feng 1450 Hot rolling production line as the research object,systematic analysis of various factors affecting the stability of the rolling mill production line process,and combining with the actual situation and make appropriate improvement measures,so as to improve the rolling rhythm.The main achievements of this paper are as follows:(1)According to the calibration curve,the unstable condition of the rolling mill is analyzed.The larger the deviation of the calibration force and the deviation of the calibration position,the more uncertain the volume is,and the worse the open rolling stability is.(2)By using laser cladding technology to repair the skateboard of roughing mill,improve the rigidity and maintain rate of rolling mill,reduce the stiffness difference between sides,and improve the accuracy of shape and cross section dimension of intermediate billet.(3)Through improving the measuring method of the channeling roll,the state of the equipment is analyzed and improved,the axial accuracy of the rolling mill is improved and the axial force is reduced.(4)Through the analysis and groping of the two level model long and short inheritance control law,reduce the wear and tear of the phenomenon.(5)By improving the calculation program of the two stage speed model,the problem of too large setting speed of thin gauge rolling is reduced.(6)Through the analysis of the causes of the folding head,the corresponding routine maintenance procedures are formulated to improve the stability of the rolled steel.