摘要
采用光学显微镜、扫描电子显微镜等对薄板坯连铸连轧(CSP)工艺生产的加稀土和不加稀土的连铸坯横断面试样的微观组织变化、夹杂物的形态以及成分进行了分析,结果表明:加入稀土改变了铸态组织,利用Image Tool软件进行测量,发现稀土使铸坯表层细晶粒区由400μm扩大到630μm;通过Image Tool软件测量加稀土和不加稀土铸坯的枝晶间距,并对测量数据进行F检验分析,分析表明加入稀土对CSP连铸坯的一次枝晶间距无显著影响,对二次枝晶间距影响特别显著,使二次枝晶间距平均值由41.22μm降低到14.21μm,可靠性99%以上;加入稀土,连铸坯中的夹杂物由钙铝酸盐夹杂物或硫化物变成了球形的稀土复合夹杂物,并且降低了夹杂物的最大尺寸,使得最大尺寸由15μm左右降低到7μm左右。
The microstructure and non-metallic inclusions of thin slab produced by CSP with and without adding RE were examined by optical and scanning electron microscopy,respectively.The results showed that the cast structure of thin slab was improved by RE.The area of fine grain was measured with Image Tool software and the area of fine grain on the surface layer was expanded from 400 μm to 630 μm by adding RE.The dendrite arm spacing（both primary and secondary） was measured with Image Tool software and the measurement data were analyzed by F test.The test results showed that： the primary dendrite arm spacing of thin slab produced by CSP was not affected by RE significantly.However,the secondary arm spacing of thin slab produced by CSP was affected by RE obviously.The average value of the secondary arm spacing was reduced from 41.22 to 14.21 μm,and the reliability was 99%.The inclusions in the thin slab were changed from calcium aluminate inclusions or sulfide to rare earth compound inclusions.And the maximum size of non-metallic inclusions were reduced from about 15 μm to about 7 μm.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2010年第5期601-606,共6页
Journal of the Chinese Society of Rare Earths
基金
内蒙古自治区科技引导项目(20071911)资助
关键词
CSP
凝固组织
枝晶间距
夹杂物
稀土
CSP
solidification
dendrite arm spacing
inclusions
rare earths
