耐候H型钢圆角翘皮缺陷的成因分析与改进措施

针对马鞍山钢铁股份有限公司大H型钢分厂生产的Q345NQR2耐候H型钢圆角翘皮缺陷问题,采用金相显微镜和扫描电镜分析的方法,分析了缺陷形成原因。结果表明,翘皮缺陷与基体存在明显分层,为热轧工序孔型不合理,万能轧制时轧辊圆角对轧件圆角切肉,轧制过程中把金属压入轧件所致。通过优化开坯机孔型、调整万能轧机水平度等措施,有效减少了此类翘皮缺陷的发生,显著提升了产品质量和经济效益。

Cause analysis and improvement measures for scar defect at round corner of weathering H-beam

In view of the scar defect at round corner of Q345NQR2 weathering H-beam produced by Maanshan Iron and Steel Co., Ltd., the causes of the defect formation were analyzed by means of metallographic microscope and scanning electron microscope.The results show that there are obvious delamination between the scar defect and the matrix, which is caused by the unreasonable pass shape in the hot rolling process, the corner of the roll cutting the flesh of the piece during universal rolling, and the metal is pressed into the piece during the rolling process.By optimizing the pass of universal rolling of the cogging mill and adjusting the levelness of the universal rolling mill, the occurrence of scar defects was effectively reduced, and the product quality and economic benefits were significantly improved.