WANG Xiao-dong
,
LI Fei
,
JIANG Zheng-yi
钢铁研究学报(英文版)
Non-uniformity of temperature distribution across strip width direction is the ultimate reason why the flatness defect occurs on the strip after cooling process although the strip is flat at the exit of finishing mill. One thermal, microstructural and mechanical coupling analysis model for predicting flatness change of steel strip during the run-out table cooling process was established using ABAQUS finite element software. K Esaka phase transformation kinetics model was employed to calculate the phase transformation, and coupled with temperature calculation using the user subroutine program HETVAL. Elasto-plasticity constitutive equations of steel material, in which conventional elastic and plastic strains, thermal strain, phase transformation strain and transformation induced plastic strain were considered, were derived and programmed in the user subroutine program UMAT. The conclusion that flatness of steel strip will develop to edge wave defect under the functions of the differential thermal and microstructural behaviors across strip width during the run-out table cooling procedure was acquired through the analysis results of this model. Calculation results of this analysis model agree well with the actual measurements and observation.
关键词:
hot rolled strip
,
internal stress
,
phase transformation
,
run-out table cooling
,
flatness
王晓东，李飞，李本海，李彬，王秋娜，张宝辉
钢铁
首钢迁钢2250mm热连轧生产线在达产初期出现了带钢凸度控制稳定性差的问题，甚至出现负凸度现象。对此热轧生产线的生产数据进行了分析，同时对轧辊温度与辊形进行了实际测量。究其原因为CVC辊形对热凸度和磨损辊形较为敏感，工作辊冷却水能力不足引起的轧辊热凸度过大破坏了CVC辊形曲线的板形控制能力。由于改造轧辊冷却水系统费用较高，需要停产，为了解决凸度控制稳定性问题，采用了辊形优化设计的方法。对精轧机组的CVC工作辊辊形进行了优化，空载辊缝凸度调控范围从［－0.7mm，0.7mm］增大到［－1.2mm，12mm］。同时，为了改善CVC工作辊与支撑辊辊间接触状态，设计并应用了CVC支撑辊辊形。此CVC辊形配置解决了首钢迁钢2250mm热轧线凸度控制稳定性差的问题，板形控制精度由原来的67%提高到了93％以上。
关键词:
热轧带钢
,
crown control
,
CVC
,
roll contour configuration
,
thermal crown
