热轧板结疤缺陷成因分析

Analysis of Scar Defect of Hot Rolled Strip

对热轧板结疤缺陷和冷轧板成串孔洞缺陷进行取样,金相分析认为具有黑色纤维状组织的疤皮部分是钢基受撞后的分离物。现场观察发现了钢板撞击精轧机组侧导板现象。移植结疤缺陷进行热、冷轧模拟轧制实验,再现了结疤缺陷的生成、演变过程。分析认为钢板撞击精轧机组侧导板是产生结疤缺陷的原因,而冷轧板成串孔洞则是结疤缺陷的遗传产物。避免钢板撞击精轧机组侧导板是消除结疤缺陷提高热轧板材质量关键因素之一。

The samples of hot rolled strip with surface scars and cold rolled sheet with porosity cluster were investigated by microscopy. And it was found that the scars of black fibrous structure are separated from the base metal due to collision. The collision of steel strip with flipper guide was observed on finish rolling unit. Formation and evolution of scars were studied by hot rolling and cold rolling simulation. The collision of steel strip with flipper guide on finish rolling unit is the reason of scar defect. Porosity cluster of cold rolled sheet is transformed from scars, and it is critical to avoid collision for improving the surface quality of hot rolled strip.