Q355B热轧钢卷边直发纹缺陷原因与控制

Causes and Control of Q355B Hot Rolled Steel Coil Straight Line Defects

针对Q355B热轧钢卷边部直态发纹缺陷取样分析,通过电镜微观检验,并结合现场工艺确定了该类直态发纹形成原因为铸坯角部在减宽轧制时翻至上表形成的折叠类缺陷,距离边部8~30 mm,深度80~300μm。针对缺陷原因制定对应控制措施,钢卷边部直态发纹得到较好控制。

According to the sampling analysis of the straight hairline defects on the edge of Q355B hot-rolled steel,it was determined through the microscopic examination of electron microscope and combined with the field technology that the cause of the straight hairline formation was the folding defects formed when the corner of the casting blank was turned over to the table above during the width reduction rolling.The distance from the edge was 8~30 mm and the depth was 80~300μm.According to the causes of defects,the corresponding control measures are made,and the straight hairline on the edge of the steel coil is well controlled.