碳锰洁净钢中镧和铈在晶界的行为  

Behavior of Lanthanum and Cerium on Grain Boundaries in Carbon Manganese Clean Steel

作　　者：林勤[1] 郭锋[2] 朱兴元[3] 

机构地区：[1]北京科技大学物理化学系,北京100083 [2]内蒙古工业大学材料科学与工程学院,内蒙古呼和浩特010062 [3]武汉理工大学材料科学与工程学院,湖北武汉430070

出　　处：《中国稀土学报》2006年第6期729-733,共5页Journal of the Chinese Society of Rare Earths

基　　金：国家"十五"科技攻关项目(2002BA315A-5)资助项目

摘　　要：应用高分辨TEM,SEM和XRD研究碳锰洁净钢中镧和铈的存在形式、分布以及在晶界的行为。研究结果表明,镧和铈在洁净钢中存在固溶态、稀土夹杂物和稀土第二相。固溶稀土偏析在晶界,洁净钢中稀土仍有净化钢液和变质夹杂的作用。适量稀土能减少S和P在晶界的偏析,净化晶界提高钢的冲击韧性。过量稀土在晶界产生有害的稀土第二相,导致性能显著降低。In carbon manganese clean steel, the behaviors of La and Ce on grain boundaries were investigated by high-resolution transmission electron microscopy （HRTEM）, SEM, EDS and XRD analysis. The existent phases of RE have solid solution La or Ce, RE inclusion and RE second phases （RE-Fe-P, Fe- La, Fe-La eutectic and Fe-Ce phase） in clean steel. The dissolved La or Ce segregates in the grain boundaries, which reduces the segregation of both S and P on grain boundaries at suitable RE content. It improves the strength of grain boundaries and enhances the impact toughness of steel obviously. La and Ce still have purifying effect in molten steel and modify inclusion in clean steel. While excess La or Ce, La- Fe-P, La-P and Fe-La eutectic or Ce-Fe-P and Fe-Ce intermetaUic compound can form along grain boundaries. It leads to decrease of the impact energy of steel significantly.

关 键 词：镧 铈 晶界 碳锰洁净钢 稀土 

分 类 号：TG142.1[一般工业技术—材料科学与工程]