摘要
利用光学显微镜、扫描电镜等方法分析了矩形连铸坯表面角部纵裂纹形貌及其缝内夹杂物成分,并从钢水过热度、保护渣性能、液面波动、结晶器进水温度、结晶器与扇形段对中等方面对裂纹成因进行了研究。结果表明,在裂纹缝隙间填充着含Na、Ca、Si、Al、O元素的夹杂物,其组成与保护渣的化学组成基本相同,说明裂纹主要产生于结晶器内,其主要产生原因是开浇前结晶器进水温度偏低及结晶器与扇形段弧度不对中。通过提高连铸开浇水温至20℃以上、调整结晶器与扇形段对中精度、定期更换过度磨损的结晶器等措施,矩形连铸坯表面角部纵裂缺陷发生率降低了98%,板坯质量得到明显改善。
The morphology and inclusion of longitudinal corner cracks of rectangular continuous casting billet were analyzed by means of optical microscopy and scanning electron microscopy.And the crack cause of were studied from the aspects of molten steel superheat,powder properties,liquid level fluctuation,water inlet temperature of mould,alignment of mould and sector.The results show that the inclusions containing Na,Ca,Si,Al and O elements are filled in the crack gap.The chemical composition of inclusions is basically the same as mould powder,which shows that the crack is mainly formed in mould.The main reasons are the low temperature of water inlet in mould before casting and the misalignment of mould and the sector arc.The incidence of longitudinal corner cracks on the surface of rectangular continuous casting slab is reduced by 98%and the quality is improved obviously by increasing the opening water temperature of continuous casting to above 20℃,adjusting the alignment accuracy between mould and sector section,and regularly replacing the over-worn mould.
作者
靳国兵
程鹏飞
肖国华
刘斌
Jin Guobing;Cheng Pengfei;Xiao Guohua;Liu Bin(Technical Center of HBIS Group Hansteel Company,Handan,Hebei056015)
出处
《河北冶金》
2019年第8期35-39,共5页
Hebei Metallurgy
关键词
矩形铸坯
角裂
纵裂纹
结晶器
夹杂物
对中
rectangular billet
corner crack
longitudinal crack
crystallizer
inclusion
alignment
