【摘要】 为研究铁素体不锈钢中铜析出相的析出过程和晶体结构演化规律,采用原子探针层析技术(APT)和高分辨透射电子显微镜(HRTEM)观察了铜析出相的长大过程。结果显示:随着时效时间的延长,富铜相尺寸增大,数量密度降低,析出相形状由最初的球状转化为椭球状,最后成为杆状。析出相长大曲线可以拟合为■,符合Ostwald熟化规律。9R结构与基体的取向关系为■。本实验钢含铜相析出序列为bcc→9R→3R→fcc。更多还原

【Abstract】 In order to study the precipitation process and crystal structure evolution of copper precipitate in ferritic stainless steel, the growth process of copper precipitate was observed by atomic probe tomography(APT) and high resolution transmission electron microscopy(HRTEM). As a result, the size of copper precipitate increases and the quantity density decreases with the prolonging of annealing time. And the shape of the precipitated phase changes from the initial spheroid to ellipsoid, and finally to rod. The growth curve of the copper precipitate can be fitted into a formular■, which is consistent with Ostwald ripening rule. The orientation relationship between 9 R structure and matrix is■. The precipitation sequence of copper precipitate in the ultrapure ferritic stainless steel is bcc→9 R→3 R→ fcc.更多还原