贝氏体精细结构的透射电镜观察

TEM OBSERVATION OF THE FINE STRUCTURE OF BAINITE

使用TEM研究了钢中DI氏体的精细结构、碳化物形貌及分布和Cu－Zn－Al合金中贝氏体的形貌采用HREM观察了Cu－Zn－Al合金的界面结构台阶和界面晶格像。结果表明：加入微量元素可以使贝氏体铁素体组织明显细化贝氏体铁素体由亚单元或亚块组成、碳化物形貌不一，分布在条间、片内和亚块边界贝氏体铁素体内有大量的精细组织。Cu－Zn－Al合金初生贝氏体有台阶存在，界面结构台阶高度3—40nm，相当于15—200个原子层高度.

Fine structure of bainite, morphology and distribution of carbide in steels and morphology of bainite in Cu-Zn-Al alloy have been investigated with TEM. Interfacial structure ledges and interfacial lattice images of Cu-Zn-Al alloy have also been observed with HREM. Addition of minor alloying elements can fine the structure of bainitic ferrite markedly. The bainitic ferrite is composed of subunits or subchunks. The carbides with different morphologies are distributed between the laths. inside the plates and at the boundaries of subunits. There are abundant fine structures in bainitic ferrite. In the primary bainite of Cu-Zn-Al alloy there are interfacial structure ledges. whose heights are within 3-40 nm.corresponding to 15-200 atomic layers. The phase reaction mechanism of bainite is discussed in this article.