首秦X70管线钢夹杂物成分研究

THE STUDY ON THE NONMETALLIC INCLUSION CHEMICAL COMPOSITIONS FROM X70 PIPELINE STEEL IN SHOUQIN COMPANY

根据ASTME45-2005标准中对非金属夹杂物的分类方法，使用扫描电子显微镜和能谱仪对首秦公司生产的13．7mm厚X70管线钢中典型夹杂物的化学成分进行定量检测，并做出元素的面分布图。确认了X70中的A类夹杂物是单纯的MnS；B类夹杂物是CaO—Al2O3复合氧化物，伴随少量的MgO和CaS；D类夹杂物是MgO-Al2O3颗粒被CaO—Al2O3包裹形成的，表面有一个CaS外壳；析出物是以Ti、Nb的氮化物为主。并讨论了各种夹杂物的控制措施。

In this paper, the typical inclusion chemical compositions from X70 pipeline steel with 13.7 mm thick, which are product by Shouqin Company, are detected by using scanning electron microscope and energy dispersive spectrometer according to the classification of the nonmetallic inclusion in ASTM E45-2005 standard. Furthermore, the surface distribution diagrams of the related elements are also studied. The results show that the A type inclusion is MnS; B type inclusion is CaO-A1203 with small amount of MgO and Ca.S; D type inclusion is MgO-A1203 cluster wrapped by CaO-A1203 and the surface has a CaS shell; the precipitate is the combination of TiN, NbN and Nb（CN） . The control methods on the nonmetallic inclusion are discussed.