摘要:
对ASP流程生产IF钢时T[O]、[N]和显微夹杂物的演变行为以及铸坯中大型夹杂物进行系统研究。结果表明,铸坯平均T[O]为29×10-6,平均[N]为35.7×10-6,増氮主要发生在钙处理环节。RH加铝1 min后钢中生成块状、棒状氧化铝夹杂,并且夹杂物之间发生初步聚集,随后的1~2 min内松散聚合团烧结转变为大尺寸的致密簇状夹杂物。加入钛铁后,钢中主要为Al-Ti-O系夹杂物,并且随着循环时间的延长逐渐球化。钙处理后钢中77%的夹杂物成分介于CaO·2Al2O3~CaO·6Al2O3之间。铸坯中除球状Ca-Al-Ti-O-S系复合夹杂外,还存在凝固过程中析出的方形或多齿状TiN类夹杂,大型夹杂物则主要来源于水口内壁沉积物、钢包引流砂和结晶器保护渣等。
Abstract:
The total oxygen content,nitrogen content as well as evolution behavior of the inclusions during RH refining and continuous casting in IF steel production were investigated.The following results were found.Firstly,the average total oxygen content and nitrogen content in the slab were 29×10-6 and 35.7×10-6 respectively,and calcium treatment were responsible for nitrogen pick-up.Lumpy,bar-like single alumina inclusions and loose groups were observed in steel bath the first minute after Al addition,and the fluid flow enhanced the formation and densification of clusters within the next 1~2 min.The addition of Ti resulted in the formation of Al-Ti-O complex inclusions which were changed into sphere as time passed.77% of the inclusions were between CaO·2Al2O3 and CaO·6Al2O3 after the calcium treatment.In addition to spherical Ca-Al-Ti-O-S complex inclusions,rectangular or multi-dentate TiN inclusions precipitated during solidification were found in the slab.Ultimately,the macro-inclusions were mainly from entrapment of SEN deposits,ladle drainage sand,mold powder and so on.
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