Study On Width Control For 1750 Hot Rolling And Its Application In Bayi Steel

The strip width accuracy is a significant indicator of the quality of hot rolled strip products.The good width accuracy can not only improve the rate of finished products,but also can supply better production conditions to hot-rolled users and posterior processes.Mainly based on 1750 large-scale hot rolled strip production line of independence integration construction in Bayi steel,this paper firstly analyzes various factors of affecting plate width comprehensively and thoroughly.Then,it parses width-spread model in VoestAlpine control model and explores control mechanism of plate width combing with hot rolled production line,and optimizes the curves of vertical roll short stroke and slab temperature compensation.At the same time,aiming at the problems of applying width control technique,different styles of width off-tolerance and its formation reason are concluded and analyzed in the production process of hot rolled stipe by means of technical data summarized from actual production,which is used to guide the practical production.Studies on width control shows that natural lateral spread of different plate width increases with the increase of plate width under the circumstance of invariant rolling reduction of thickness of plating,then it increases with the increase of thickness of plating.The variation of lateral spread becomes smaller if width-to-thickness ratio has the rising trend.Following the temperature change,spread has no change instead that exists a peak value at a certain temperature range.For example,the maximum value of that is at 1200?.Study of head and tail shape indicates that:dog bone height gets large along with the increase of rolling reduction and plate width.When only horizontal roller rolls,the plate's head and tail metal lateral spread enlarges,whose shape is liguliform of head and tail broadening.With only vertical roller rolling,there is distinct width reduction phenomenon at the plate's head and tail.Rolling with vertical and horizontal rollers simultaneously,the shape of rolled piece head and tail is becoming liguliform and fishtail while the ratio of lateral pressure amount to vertical rolling reduction is relatively low and high,respectively.The analysis of influence factors for the width accuracy reveal the influence rules of various disturbances on width control,and summarize the basic measures for width off-tolerance reduction.That provides a theoretical basis for improving the AWC and SSC functions of 1750 hot rolling production line.Thus it effectively enhances the width control level and the rate of finished products and reduces production costs.