短流程工艺低碳钢氧化铁皮缺陷成因分析

Analysis on cause of iron oxide scale defect for low carbon steel in short process process

针对短流程工艺低碳钢氧化铁皮缺陷问题,从宏观表现和微观特征方面进行系统研究,并结合产线关键设备与该钢种工艺特点,分析了氧化铁皮缺陷产生的原因,具体为:隧道炉和感应加热过程中钢板表面温度急剧上升,氧化速率迅速增加,使得铁皮应力上升;钢中的C含量较高,高温气化引起铁皮起泡,起泡位置内部生成二次铁皮,造成精轧过程压入,形成氧化铁皮缺陷。通过在钢中添加0.10%~0.15%的Si元素,同时优化隧道炉内气氛和感应加热出口温度,最终有效地减少了氧化铁皮缺陷。

Aiming at the problem of iron oxide scale defect of low carbon steel in short process process,a systematic study was carried out from the macro and micro characteristics,and the causes of iron oxide scale defect were analyzed by combining with the key equipment of production line and the process characteristics of steel.The results show that the surface temperature of steel plate rises sharply in the process of tunnel furnace and induction heating process,and the oxidation rate increases rapidly,resulting in the increasing of scale stress.The content of C element in the steel is relatively high,the high-temperature gasification causes iron scale to blister,and the secondary iron scale is formed inside the blistering position,resulting in pressing in during the finishing rolling process and forming iron oxide scale defect.By adding 0.10%-0.15%Si element to the steel and optimizing the atmosphere in the tunnel furnace and the outlet temperature of induction heating at the same time,the occurrence of iron oxide scale defects is finally effectively reduced.