热轧层流冷却对带钢板形的影响仿真分析

Simulated Analysis of the Influence of Laminar Cooling Process for Strip Flatness in Hot Rolling

为分析某热连轧生产线在开卷后出现的拱背或纵切分条后出现的翘曲问题,建立ANSYS有限元仿真分析模型,分析层流冷却过程的带钢温度分布和内应力情况。在确定边界条件时,采用FLUENT软件对带钢水冷换热过程进行了数值仿真分析,得到换热系数。利用ANSYS模型仿真分析了层流冷却上下水比、前段和后段主冷模式以及初始横向温度分布对带钢内应力分布的影响,并根据分析结果,采取了改变上下水比、后段主冷模式,改善精轧横向温度不均匀分布等措施,使得拱背和纵切翘曲导致的板形缺陷改判率由4.2%降低到1.05%。

In order to analyze the strip C-shape wrap problem after uncoiling and buckling problem after length cutting,an ANSYS finite element model was established to calculate the strip temperature and internal stress distribution after laminar cooling. For giving an accurate boundary condition,the heat transfer coefficient in water cooling was calculated by a FLUENT model of strip water cooling process. Then the influence of the ratio of upper and lower water flow,the front or end section main cooling mode,the original temperature distribution on the strip internal stress were analyzed by the ANSYS model. Based on the analyzing result,the ratio of upper and lower water flow was changed,the end section main cooling mode was come into service,and the original temperature distribution was improved,then the strip defect rate of C-shape wrap problem and buckling problem was drop from 4. 2% to1. 05%.