高强IF钢热轧卷板边部细线缺陷形成机理研究

Research on the Formation Mechanism of High Strength IF Steel Edge Thin-Line Defects

针对高强IF钢热轧卷板频发的边部细线缺陷进行微观分析和数据统计，确定边部细线缺陷产生的机理并提出相应的改善措施。微观分析发现热卷边部细线缺陷的微观特点为表面沿轧向裂口组成，截面可见裂纹双向延展性，表层组织有混晶形貌，距离边部位置在15mm左右，具有明显的冷轧遗传性，冷轧后表现为沿轧向凹坑和掉肉形貌。生产过程统计对比发现，边部细线缺陷的产生与边部减宽量和立辊使用周期关系密切，由此制定相应的优化工艺。通过采用新的工艺，高强IF钢边部细线缺陷得到明显的抑制，工业生产下可控制细线缺陷发生位置在距边部10mm以内。

The article researched on the high strength IF steel edge thin-line defects, by the way of microscopic analysis and data statistics, the formation mechanism of the defects was determined and improvement measures were presented. The defects contained lots of crack along the rolling direction on surface, cross section observation showed the two-way ductility of the crack, there were mixed crystal morphology on the surface of the crack. The defects were located about 15 mm from the edge, after the cold rolling, the appearance of pits and hole along the rolling direction was presented. Statistical comparison of production process found that, the defects was closely related to width reduction and the life cycle of the vertical roller. Accordingly, the corresponding optimization process was formulated. Through the adoption of optimization process, the defects were found to be significantly suppressed, and the position of the defects could be controlled within 10 mm from the edge.