稀土铈对钛微合金钢中TiC和Ti（C，N）析出的影响

摘要：采用扫描电镜对不同稀土含量钢中的稀土碳化物复合相进行观察,随着稀土含量的增加,在晶界析出的稀土夹杂物数量不断增加,抑制了在晶界连续析出的TiC,降低了大尺寸TiC,Ti(C,N)的数量。稀土与碳化物主要复合相变化顺序为CeAlO3-TiC→Ce2O2S-TiC/CeS-TiC→CeP-TiC;其中CeAlO3、Ce2O2S和CeS复合相主要为5μm以下的球形、近球形;CeP复合相主要为大于5μm的条状。采用OTS夹杂物统计软件对不同稀土含量的实验钢进行统计,随着稀土含量的上升,2μm以下的TiC、Ti(C,N)数量先上升后下降,在稀土质量分数为130×10-6时达到最佳;10μm以上的大尺寸TiC、Ti(C,N)呈下降趋势。TiC、Ti(C,N)颗粒的平均尺寸在降低。但是当稀土质量分数达到190×10-6时,小尺寸TiC、Ti(C,N)的数量下降;颗粒平均尺寸上升。

Effect of rare earth cerium on precipitation of TiC and Ti(C,N) in titanium microalloyed steel

Abstract： Using scanning electron microscope observed the composite phases of rare earth carbides with different rare earth contents, with the increase of rare earth content, the number of rare earth inclusions precipitated at the grain boundaries continuously increases, which suppresses the continuous precipitation of TiC at the grain boundaries, and reduces the large-size TiC and Ti(C,N) quantity. The main composite phase change sequence of rare earth and carbide is CeAlO3-TiC→Ce2O2S-TiC/CeS-TiC→CeP-TiC; the CeAlO3, Ce2O2S and CeS composite phases are mainly spherical and nearly spherical below 5μm; the CeP composite phases are mainly strip larger than 5μm. The OTS inclusion statistics software is used to count the test steels with different rare earth contents. As the rare earth content increases, the amount of TiC and Ti(C,N) below 2μm increases first and then decreases, reaching the best when the Ce content is 130×10-6; for those above 10μm, the sizes of TiC and Ti(C,N) show a downward trend. The average size of TiC and Ti(C,N) particles is decreasing. But when the rare earth reaches 190×10-6, the amount of small-sized TiC and Ti(C,N) decreases; the average particle size increases.