超高强钢镀层均匀性研究及优化控制

Study on coating uniformity of ultra-high strength steel and optimization control

针对超高强钢在生产过程中容易出现沿带钢宽度方向镀层不均的问题,通过数值模拟仿真,研究了气刀位置带钢板形对镀层均匀性的影响,分析了气刀位置带钢板形随工艺参数的变化趋势,并提出相应优化措施,有效改善了超高强钢镀层横向均匀性。结果表明:带钢上下表面镀层沿宽度方向呈现对称的“C”形分布,镀层偏厚位置的镀层重量与镀层偏薄位置可相差1倍以上;带钢在锌锅内部经过沉没辊时,带钢上下表面产生的不对称变形使带钢在气刀位置形成C形翘曲,导致带钢上下表面与气刀距离产生显著差异,形成横向镀层不均;不同纠正辊进给量及冷却塔段张力对气刀位置带钢板形产生显著影响,随着纠正辊进给量的增加,气刀位置的带钢板形会发生显著变化,经历了“C”形、平直、“W”形,反“C”形4种状态。通过优化纠正辊进给量与冷却塔张力,可实现超高强钢镀层横向均匀性的良好控制。

In order to solve the problem of uneven coating along the width direction of the strip in the production process of ultra-high strength steel,numerical simulation was conducted to study the influence of the strip shape at the air knife position on the uniformity of the coating.The trend of the strip shape at the air knife position with process parameters was analyzed,and corresponding optimization measures were proposed to effectively improve the transverse uniformity of the coating on ultra-high strength steel.The results show that the coating on the upper and lower surfaces of the strip exhibits a symmetrical"C"shape distribution along the width direction,and the weight of the coating at the thicker position can differ by more than one time from that at the thinner position.When the strip passes through the sink roll inside the zinc pot,the asymmetric deformation on the upper and lower surfaces of the strip causes a C-shaped warp at the position of the air knife,resulting in a significant difference in the distance between the upper and lower surfaces of the strip and the air knife,resulting in uneven transresrse coating.The feed rate of different correction rollers and the tension of the cooling tower section have a significant impact on the strip shape at the air knife position.As the feed rate of the correction roller increases,the strip shape at the air knife position will undergo transverse changes,experiencing four states of"C"shape,straight,“W”shape,and anti“C”shape.By optimizing and correcting the matching between the feed rate of the roll and the tension of the cooling tower,good control of the transverse uniformity of the ultra-high strength steel coating can be achieved.