AG700L高强度热轧宽带钢板形缺陷分析与工艺改进

对高强热轧宽带钢AG700L开平后的板形缺陷进行了详细分析,讨论了精轧出口带钢板形和温度均匀性对开平板形的影响,分析了层流冷却系统中水比、侧喷、冷却模式、边部遮蔽对开平板形的影响以及优化措施。结果表明:带钢经过层流冷却时边部温降过快造成的边部压应力在开平后得到释放,是造成开平后板形缺陷的主要原因;通过优化水比为1:1.35、优化侧喷角度并提高压力至2.0 MPa、改进冷却模式、使用边部遮蔽可以提高层流均匀化冷却效果并解决开平后的板形缺陷问题。

Analysis and Process Improvement of Flatness Defects of High Strength Hot Rolled Wide Strip Steel AG700L

The flatness defects of high strength hot rolled wide strip steel AG700L after uncoiling are analyzed in detail. The influences of strip shape and temperature distribution after finishing rolling are discussed, and the influences of the ratio of upper and lower water flow, side spray, cooling methods, edge masking on uncoiling plate and optimization measures are also analyzed. The results show that the main reason of the flatness defects after uncoiling is due to release of the compressive stress caused by the temperature drop of strip edge. The flatness defects could be effectively controlled by optimizing the ratio of upper and lower water flow to 1 ： 1.35 and the angle of side spray, increasing the pressure of side spray to 2.0 MPa, improving the type of cooling and using the edge masking.