热轧带钢均匀化冷却问题分析与控制措施

Analysis and control measures on uniform cooling for hot rolling strip steel

利用有限元模拟软件ABAQUS对带钢轧后冷却内应力生成机理及其变化过程进行分析,热轧带钢冷却后出现边浪是由于横向冷却速率和横向温度分布不均导致的;研究了超快冷喷嘴、U形层冷集管、侧喷水对带钢横向温度分布的影响。结果表明:冷却集管喷嘴长期处于高温环境,存在喷嘴锈蚀、老化、变形、堵塞问题,同时层冷水沿带钢宽度方向存在流量差异,导致带钢横向温度分布不均匀;侧喷的吹扫能力与侧喷角度、侧喷喷嘴磨损量、侧喷压力等有关,若侧喷吹扫不净,带钢上表面残余冷却水聚集,则会造成带钢宽度方向不均匀冷却。通过优化冷却集管流量分布的均匀性、调整侧喷水嘴的角度、优化侧喷吹扫效果,可以提高层冷区域带钢冷却的均匀性。

The generation mechanism and change process of internal stress for strip steel after rolling in the cooling were analyzed by finite element simulation software ABAQUS,and the edge wave of hot rolling strip steel after cooling was caused by the uneven transverse cool-ing rate and transverse temperature distribution.Then,the influences of ultra-fast cooling nozzles,U-shaped layered cooling headers and side spray water on the transverse temperature distribution of strip steel were analyzed.The results show that the nozzle of cooling header has been in a high temperature environment for a long time,which leads to the problems of corrosion,aging,deformation and blockage for nozzle.At the same time,the difference in the flow of layered cold water along the width direction of strip steel results in uneven transverse temperature distribution of strip steel.In addition,the blowing ability of side spray is related to the angle of side spray,the wear amount of side spray nozzle,the pressure of side spray,etc.If the side spray is not clean,the residual cooling water on the upper surface of strip steel accumulates to cause uneven cooling of strip steel along the width direction.Thus,the uniformity of strip steel cooling in the layered cooling zone is enhanced by optimizing the uniformity of the flow distribution for the cooling header,adjusting the angle of the side spray nozzle and optimizing the effect of side spray.