高碳SPHC带钢冷轧边裂缺陷机理分析

Research on Edge Crack Forming Mechanism of High Carbon SPHC Cold Rolled Strip

针对首钢迁安钢铁有限责任公司高碳SPHC冷轧板带出现边裂的问题,分析了冷硬卷边裂缺陷的宏观形貌、微观组织,以及热轧原板的微观组织,认为带钢边部晶粒粗大、铁素体拉长形态明显、带状碳化物析出严重是造成边裂的主要原因。采用低温出炉、高温终轧、低温卷取、前部密集冷却并对磨损、堵塞等质量下降的喷嘴给予维修及更换,保证全宽方向上温度的均匀性,大大减少了板带的边裂缺陷。

Based on the microstructure observation of high carbon SPHC strip,the causes of strip edge crack were ananlyzed.It was revealed that coarsening grain on the edge of the coil,deformed ferrite with elongated morphology,banded carbide precipitate were the mainly factors inducing edge crack.Several effective methods were proposed to reduce the occurrence of edge crack,such as lower heating furnace tapping temperature,higher hot rolling finishing temperature,lower coiling temperature,high cooling intensity on the earlier rolling stage,timely maintenance of the spray nozzles to guarantee the temperature homogenization on the width direction,etc.