防止Q195L热轧窄带钢边裂的工艺实践

2 mm窄带钢Q195L (/%: ≤0.08C、0.05～0.10Si、0.30～0.40Mn、≤0.035P、≤0.035S)的生产流程为80 t转炉-钢包合金化和软吹氩-150 mm×150 mm方坯连铸-窄带轧制工艺。金相、扫描电镜、能谱仪等对窄带钢边裂分析表明,边裂处存在FeO和网状裂纹。通过控制钢水氧含量从原≤80×10^-6 降至≤60×10^-6 ,吹氩时间从≥3min增至≥5 min,中间包钢水过热度从原25～35℃降至15～25℃,加热炉两侧温差≤40℃,减小冷却水嘴间距,增加一次立轧压下量2～5 mm等工艺措施,防止了该钢边裂发生,取得了良好的生产效果。

Process Practice to Avoid Edge Crack of Hot-Rolled Ribbon Steel Q195L

The flow sheet for production of 2 mm ribbon steel Q195L (/%, ：≤0. 08C, 0.05 ~ 0.10Si, 0.30 ~ 0.40Mn, ≤0. 035P, ≤0.035S) is 80 t converter-ladle alloying and soft argon blowing-150 mm x 150 mm billet casting ribbon steel rolling process. Analysis on edge crack ribbon steel results by using optical, scanning electron microscope and energy dispersive spectrometer show that there are FeO and reticular cracks at crack region. With the process measures including controlling the oxygen content in liquid decreasing io ≤60 x 10^-6 from original ≤80 x 10^-6, increasing argon blowing time from ≥ 3 min to ≥ 5 min, decreasing overheating extent of liquid in tundish to 15-25 ℃ from original 25 ~ 35℃ difference in temperature of both side of heating furnace ≤40 °C , decreasing distance between water cooling -nozzle and increasing reduction of first pass edging rolling by 2 ~ 5 mm, the occurrence of the edge cracks of hot-rolled ribbon steel are avoided to get nice production effect.