板带热轧中间坯厚度分布规律研究

Research on thickness distribution rule of intermediate slab during hot strip rolling

在热连轧生产过程中,受测量环境和测量手段的限制,尚未实现对中间坯厚度的实时在线精确测量,对产品最终的厚度精度和精轧区穿带过程稳定性造成影响。为解决此问题,采用轧制特性法分析中间坯厚度产生偏差的原因;为进一步研究各因素对厚度偏差影响的规律,通过影响系数法计算中间坯长度方向上温度和厚度分布,建立热力耦合有限元模型,并将有限元结果与计算结果进行比较。研究结果表明:随着轧制过程的进行,在轧制方向上,中间坯温度逐渐降低,头、尾温度的平均偏差约为22℃,头、尾最大温度偏差达到32℃;由于温度偏差导致中间坯厚度呈变大趋势,中间坯头尾厚度偏差为0.20 mm,长度方向最大厚度偏差达0.53 mm;本文得到的中间坯厚度和温度的分布能够为后续精轧过程提供前提条件,为高精度控制成品轧件的厚度以及维持穿带稳定性提供依据。

Due to the restriction of environment and the measuring methods,the real-time online accurate measurement of the thickness of intermediate billet has not been realized,which affects the final thickness accuracy and the stability of strip penetration in finishing zone.To solve this problem,the reason for thickness deviation of intermediate billet was discussed by means of rolling characteristic analysis during hot rolling.In order to describe the influence of various factors on the thickness deviation,the temperature and thickness distribution along the length direction of the intermediate billet was calculated by the influence coefficient method,a three-dimensional dynamic thermo-mechanical coupling finite element model was established,and the finite element results were compared with the calculated results.The results show that as the rolling process progresses,the temperature of intermediate billet decreases gradually along the rolling length direction,and the average deviation of the temperature of head and tail is about 22℃,and the maximum temperature deviation of head and tail is 32℃.Due to the temperature deviation,the thickness of the intermediate billet tends to be thicker.The thickness deviation of the intermediate billet head and tail is 0.200 mm,and the maximum thickness deviation of the length direction is 0.53 mm.The obtained thickness and temperature distribution of the intermediate billet can provide the premise for the subsequent fine rolling process and provide basis for the high precision thickness control and the stability of the strip penetration.