保护渣对含硫易切钢连铸坯表面质量的影响  

Effect of Mould Fluxes on Surface Quality of Continuously Cast Strand of Sulfur Contained Free Cutting Steel

作　　者：王谦[1] 谢兵[1] 迟景灏[1] 王雨[1] 冯仲渝 王小红 阎俊生 

机构地区：[1]重庆大学材料科学与工程学院 [2]重庆钢铁集团特钢公司,重庆400084

出　　处：《钢铁》2004年第11期23-25,63,共4页Iron and Steel

基　　金：国家自然科学基金资助项目 ( 5 990 40 0 8)

摘　　要：含硫易切钢中硫含量高达 0 .2 5 %～ 0 .35 % ,氧含量高达 (15 0～ 30 0 )× 10 - 6 ,结晶器内钢水弯月面处硫、氧含量更高 ,使得保护渣容易形成熔化不良的“絮状”渣团 ,导致铸坯出现严重的夹渣、横裂纹、皮下裂纹和气孔缺陷。针对该问题 ,研究了保护渣对增大结晶器弯月面处钢渣界面张力的作用途径和效果。工业化试验表明 ,在保护渣中添加金属还原剂和提高粗石墨含量 ,可有效抑制“絮状”渣团及其引起的铸坯缺陷 ,以获得表面质量优良的铸坯。工业化生产中含硫易切钢铸坯合格率达到 99.87%As sulfur contained free cutting steel with the contents of [S]=0.25 %～0.35 % and [O]= (150~300)×10 -6 continuously cast, the melting of mould fluxes was worsen and the “cotton ball” shape slag scum was formed in the mould.Such slag scum tends to increase the slag inclusion, transverse crack, subsurface crack and pinhole defects on casting strand.In order to hinder the occurrence of these defects, the effects and mechanism of mould fluxes on promoting the interfacial tension between molten slag and steel at the meniscus region were probed in detail.The results of a plant trial revealed that the addition of coarse graphite and metal powder into fluxes could effectively decrease the creation of the “cotton ball” shape slag scum and the relating strand defects.As a result, a good surface quality of bloom was realized.The comprehensive qualified ratio of cast strand of sulfur contained free cutting steel reaches at 99.87 %.

关 键 词：易切钢 保护渣 界面张力 

分 类 号：TF777.2[冶金工程—钢铁冶金]