Discussion And Research On The Flatness Control Technology For Hot Strip Rolling

In recent years,people's demand for hot rolling steel strip increased gradually as well as the quality requirements,since 2005,the market demand of hot rolled thin strip steel has gradually increased,especially represented by the container plate,tinplate hot-rolled products with thin specifications,and the hot rolled sheet with high strength substituting cold-rolled sheet.With a surge of the capacity,plate shape problem of thin strip is particularly prominent in the actual production.The most direct performance is that the amount of quality problem customer proposed such as wave shape and compensation showed a trend of rising.How to further improve the strip shape of hot rolled products,particularly for the thin specifications,and prevent quality accidents are the most high-profile research for each iron and steel enterprise.Steel rolling technology developed rapidly in recent ten years.The control system of hot rolled strip during production process gradually developed from thickness control,temperature control,width control and flatness control to the mechanical properties control,from basic automation,process automation to production management control automation,forming a complete multistage system including control and information management.Strip shape control system is an important constituent of continuous multistage control system in hot rolling machine.This paper began with the concepts,theory and the detection means of flatness control,then briefly introduced the key control process in shape control system in Shougang Jingtang2250 hot rolling plant and analyzed the problems and difficulties in the process of plate shape control,looking for reasonable optimized methods and measures including subsequent remedial measures such as research on heating uniformity of slab in the furnace;to carry out the temperature uniformity of the slab,the research work on the stability of thin gauge rolling;through the reasonable design of roll and roll changing system,effectively reduce the middle wave,edge wave and other phenomena;the finishing area flatness operation means actual control research and using the flat line to perfect hot rolled strip shape control technology,studying and forming a complete set of quality control system to improve product quality of strip shape as well as the market competitiveness.