稀土处理钢中夹杂物对晶内针状铁素体形成的影响  

Effect of inclusions on the formation of intra-granular acicular ferrite in steels containing rare earth elements

作　　者：邓小旋[1] 王新华[1] 姜敏[1] 胡志勇[1] 邵肖静[1] 王万军[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083

出　　处：《北京科技大学学报》2012年第5期535-540,共6页Journal of University of Science and Technology Beijing

摘　　要：分析了稀土处理钢中夹杂物的特征(夹杂物种类、尺寸分布和体积分数)对微观组织中针状铁素体形成的影响.结果表明,钢中夹杂物种类和体积分数对针状铁素体组织的形成非常重要.稀土氧化物(包含稀土氧硫化物)与铁素体具有低至1.9%的错配度降低针状铁素体在夹杂物表面的形核能垒,从而促使它在稀土氧化物上形核.反之,稀土硫化物与铁素体具有高达42.5%的错配度不能诱导生成针状铁素体组织.此外,微观组织中针状铁素体的体积分数随着夹杂物体积分数的增加而增大,当钢中夹杂物体积分数是9.5×10-4时其体积分数达到53%.The effects of inclusion characteristics, such as type, size distribution and volume fraction on the formation of intra- granular acicular ferrite （IAF） in steels containing rare earth （RE） elements were investigated by optical microscopy, scanning elec- tron microscopy and the point counting method, It is shown that the type and volume fraction of inclusions both play a critical role in IAF formation. A low mismatch value of 1.9% between ferrite and RE-oxides （ including RE-oxysulfide） decreases the energy barrier on the inclusion surface for IAF nucleation and accelerates the nucleation on RE oxides. But RE-sulfides which have a high mismatch value of 42.5% with ferrite cannot induce IAF. The volume fraction of IAF increases with the volume fraction of inclusions increasing. When the volume fraction of inclusions reaches 9.5×10^-4, the volume fraction of IAF is 53%.

关 键 词：精炼 稀土元素 针状铁素体 夹杂物 微观组织 

分 类 号：TF703.5[冶金工程—钢铁冶金]