中厚板氧化铁皮对冷却过程的影响

The effect of oxide scales on cooling process of plate

热轧钢板在轧制时除鳞方式不同,即使采用相同的控冷工艺参数,其终冷温度差异较大,这是由于钢板表面氧化铁皮的厚度和形态不同导致的。为此,研究了氧化铁皮对钢板冷却过程的影响。结果表明：较厚的氧化铁皮使钢板表面粗糙增大,使传热过程中的流动边界层发生变化并对冷却过程中核态沸腾汽泡的产生具有较大影响,从而提高了冷却强度且使钢板冷却不均,出现浪形。同时分析得出：钢板表面麻点缺陷、氧化铁皮破碎、FeO的结构易使其表面粗糙度增大。因此,通过调整加热及热轧过程工艺参数,减少氧化铁皮的形成或避免产生粗糙表面都可以有效避免对钢板造成不均匀冷却,使板形得到明显改善。

The finishing cooling temperature different was great of plate by different descaling model, even with the same cooling process parameters. This was due to the different thickness and shape of the oxide on the surface of plate. Therefore, the effect of the oxidized on the cooling process of plate was studied. The results show that the thicker oxide increases the surface roughness of the plate, which changes the flow boundary layer during the heat transfer process and has a great influence on the nucleation boil- ing bubbles in the cooling process, thus increasing the cooling strength , and making the plate cooling inhomogeneous and forming wave defect. At the same time, it is found that the dent defects on the surface of the plate, the oxidation broken, and the FeO structure easy to increase the surface roughness. Therefore, by adjusting the process parameters of heating and hot rolling, reduc- ing the formation of the oxide or avoiding the rough surface could effectively avoid the uneven cooling of the plate.