摘要
针对高强汽车钢的轧制过程中,带钢表面频繁出现翘皮缺陷导致的产品降级、经济利益损失大的问题,进行了现场跟踪与验证性研究。通过对铸坯缺陷试样酸侵检验、金相显微镜和扫描电子显微镜的微观结构分析,确认了“翘皮”缺陷的主要成因是铸坯角部存在着不易察觉的微裂纹。为了进一步挖掘问题根源,对连铸工艺控制情况进行了全流程的深度剖析,发现在浇注过程中,化学成分控制不精准,结晶器振动参数和SEN插入深度的设定不合理,同时还暴露出设备方面的问题,如设备精度不符,加剧了铸坯角部裂纹的形成。基于以上分析,通过收窄裂纹敏感性元素控制水平;将结晶器负滑脱时间从0.15 s降低到0.13~0.14 s;采用析晶能力强的保护渣;降低SEN的插入深度和中包过热度;同时生产高强钢前对扇形段的对弧和辊缝精度进行跟踪确认,保证设备精度合格率100%等一系列控制措施,高强汽车钢翘皮缺陷率由原来的2.02%降至0.36%。
In the rolling process of high strength automobile steel,the surface defects of the strip frequently lead to product degradation and large economic losses.By means of acid attack test,metallographic microscope and microstructure analysis of the scanning electron microscope,it is confirmed that the main cause of the defect is the subtle microcracks in the corner of the billet.In order to further dig into the root of the problem,the whole process of continuous casting process control was deeply analyzed,the setting of mould vibration parameters and SEN insertion depth is not reasonable,and the equipment problems are also exposed,such as the inaccuracy of the equipment,which aggravates the formation of corner cracks.Based on the above analysis,by narrowing the crack-sensitive element control level,the mold negative slip time is reduced from 0.15 s to 0.13~0.14 s,and the mold powder with strong crystallization ability is adopted A series of control measures such as reducing SEN insertion depth and tundish overheat,tracing and confirming arc and roll gap accuracy of sector section before producing high strength steel,ensuring 100%accuracy of equipment,etc.,the defect rate of high strength automobile steel skin was reduced from 2.02%to 0.36%.
作者
牟海鹏
Mu Haipeng(HBIS Group Tangsteel Company,Tangshan 063000,Hebei;Hebei High Quality Steel Continuous Casting Technology Innovation Center,Tangshan 063000,Hebei)
出处
《河北冶金》
2024年第3期51-56,共6页
Hebei Metallurgy
关键词
高强汽车钢
翘皮
角裂
结晶器
保护渣
过热度
high strength automotive steel
warping
angle crack
mold
powder
superheat
