ODS钢中纳米氧化物颗粒成分与结构研究

The research of nano-scale particles in the oxide dispersion strengthened steels

采用透射电镜和层析原子探针（APT）分析了9Cr-ODS钢中纳米氧化物颗粒成分和结构。研究发现,氧化物颗粒成分与其大小有一定的关系,可将其归纳为3类：（1）氧化物〈5nm,m（Y）∶m（Ti）〈1,可能是非整比化合物;（2）5-10 nm〈氧化物尺寸〈40nm,m（Y）∶m（Ti）≈1,可能是Y2Ti2O7;（3）氧化物〉40 nm,为TiO2。Cr在氧化物周围偏析形成壳状结构。

The composition and the size of nanoparticles in the 9CR-ODS has been investigated by STEM-EDS and atom probe tomography.According to the correlation between m （Y）∶m （Ti）ratio and nanoparticles size in 9Cr-ODS steel,three types of nanoparticles were observed including：（1 ）small sized nanoparticles less than 5 nm,m （Y）∶m （Ti）〉 1,indicating non-stoichiometric nanoparticles,（2 ）intermediate sized nanoparticles, ranging from 5-40 nm,m （Y）∶m （Ti）≈ 1.0,indicating Y2 Ti2 O 7 ,（3）large sized nanoparticles more than 40 nm,indicating TiO 2 .The nanoparticles was measured by proximity histogram （proxigram）method,exhibiting core shell structure with a Y-Ti-O core and a Cr shell.