IF钢热轧薄板边部翘皮缺陷的产生原因及机制

 观察了IF钢热轧薄板边部翘皮缺陷的微观组织与晶界状态，分析了其形成原因和内在机制。结果表明，边部翘皮缺陷具有以下几个特征：在横截面上，翘皮表现为深度约40μm的微裂缝；裂缝附近组织具有混晶、形变的特征；裂缝内存在氧化铁皮，附近存在Al2O3-MnO-TiO2的复合氧化质点。微观组织分析与工业验证试验均表明，IF钢热轧薄板边部翘皮缺陷主要是由于中间坯边角部温度过低、热轧过程中发生不均匀变形导致。

Origination Mechanism of the Edge Shell Defect on the Hot-Rolled IF Steel Strip

The microstructure and grain boundary near the edge shell of IF hot rolled thin strip were investigated with SEM,and the origination mechanism of the edge shell of IF steel was also discussed.The results show that there are three characters for the edge shell defect: on the cross section,the shell behaves as tiny crack with the depth of about 40 μm;the microstructure near the edge shell is of characteristic of mixed crystal and deformation;there is scale in the crack,and Al2O3-MnO-TiO2 oxidation particles are also found in the microstructure near the edge shell.Both the SEM analysis and the industrial test show that the reasons of the edge shell are the low edge temperature of the transfer bar and the subsequent nonuniform deformation of the transfer bar edge in the course of hot rolling.