钛脱氧钢中超细夹杂物内部结构和物相组成研究

来源期刊：钢铁2010年第5期

论文作者：齐江华 薛正良 吴杰 程常桂 周利刚

文章页码：33 - 37

关键词：氧化物冶金； 钛脱氧； 内部结构； 夹杂物物相

Key words：oxide metallurgy； Ti-deoxidized； inner structure； inclusion phase

摘    要：在真空感应炉中采用了真空碳脱氧再加钛终脱氧的脱氧工艺冶炼出了与高级别管线钢成分接近的试样钢,对钛脱氧钢中超细夹杂物的外部形貌、尺寸、内部结构和物相组成等进行了研究。在扫描电镜下通过对金相试样和电解提取的夹杂物的研究表明,钢中夹杂物是Ti-O-Mn-S形成的尺寸为1~3μm的球形复合夹杂物。通过离子减薄后观察了夹杂物的内部结构,中心是Ti-O化合物,外围是Mn-S化合物;通过电子背散射衍射(EBSD)对夹杂物物相组成的分析表明,该复合夹杂物是有利于针状铁素体(IGF)形核的Ti₂O₃和在凝固过程中以Ti₂O₃为核心形核的MnS。

Abstract: High grade pipeline steels were prepared using vacuum carbon deoxidization process followed by a final Ti-deoxidation method in vacuum induction furnace.The external shape,size,inner structure and phase compositions of superfine inclusions were researched in Ti-deoxidized steel.Through the observation of metallographic specimen and the inclusions through electrolyzation under SEM,it is indicated that the Ti-deoxidized products are globular compound inclusions(Ti-O-Mn-S) with the size of 1-3μm.With the technical of ion beam thinner the inner structure of these inclusions can be observed,whose core is Ti-O and outer is Mn-S.Based on EBSD the phase composition was analyzed and it indicated that these globular compound inclusions are Ti₂O₃ and MnS,it is also found that Ti₂O₃ which can prompt to nucleate IGF may act as nucleus in the formation of MnS during solidification process.