热轧带钢高速钢复合轧辊非稳态温度场的数值模拟

在考虑轧辊空转、周向传热、摩擦热、变形热、轧辊和轧件之间传热系数的变化、轧辊物性参数随温度的变化以及轧件在轧制过程中的温降等因素基础上,对1 700 mm热轧带钢R3和F3机架工作辊的非稳态温度场进行数值模拟。研究结果表明:辊内温度变化剧烈区域的深度仅几mm,随深度的增加,温度的变化幅度迅速减小,极值出现的位置逐渐后移;轧辊中心横截面上的温度外高内低,工作层的径向温度梯度远大于辊芯的径向温度梯度;随轧钢数量的增加,温度曲线逐渐上移;沿辊身长度方向,中间温度高,两头温度低;在纯轧阶段,R3机架工作辊的吸热量和散热量比F3机架的小,而间隙阶段的散热量比F3机架的大。

Numerical simulation on unsteady state temperature field of high speed steel composite roll during continuous hot slab rolling

The unsteady state temperature field in work-rolls of the R3 and F3 mill of 1 700 mm continuous hot slab during rolling was simulated considering some influence factors,such as idling work-roll revolutions,heat conduction in peripheral direction,friction-heat,deformation-heat,variable interface heat transfer coefficient at deformation zone,temperature-depended thermo-physical properties of material and temperature decreasing of rolled metal during rolling.The results show that the depth of temperature severe change zone in the work-rolls is only several millimeters.The change range of temperature in peripheral direction deceases very quickly and the position of peak temperature gradually moves to back with the increase of the depth.The temperature in the centre section changes from high to low in radial direction.The temperature gradient in radial direction of work layer is greater than that of core and the temperature curves gradually move up with the increase of rolled slab number,and the temperature of work-roll middle zone is higher than that of end zone.The absorbed or lost heat of work-roll in R3 mill is less than that of F3 mill in the rolling period,but the lost heat of work-roll in R3 mill is more than that of F3 mill in the idle period.