ODS-316奥氏体钢显微结构及弥散相的TEM研究  

TEM CHARACTERIZATION OF DISPERSOIDS AND MICROSTRUCTURE OF ODS-316 AUSTENITIC STEEL

作　　者：王曼[1] 周张健[1] 闫志刚[2] 于鹏飞[2] 孙红英[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]燕山大学亚稳材料制备技术与科学国家重点实验室,秦皇岛066004

出　　处：《金属学报》2013年第2期153-158,共6页Acta Metallurgica Sinica

基　　金：国家重点基础研究发展计划资助项目2007CB209801~~

摘　　要：采用机械合金化和热等静压方法制备了ODS-316奥氏体钢(316L+0.35%Y_2O_3+0.3%Ti,质量分数).由于应变诱导发生相变,机械合金化后的粉末存在α(FeCr)和γ(Fe,Ni)两相.热等静压后的ODS钢基本为奥氏体单相,这是由于在致密化过程中消除了应变.通过对块体样品进行TEM观察和电子衍射谱标定,观察到3类弥散颗粒:立方晶系的Y_2Ti_2O_7和TiN及正交晶系的Y_2TiO_5颗粒,其中富Y,Ti和O的弥散粒子分布较多.ODS-316奥氏体钢的抗拉强度达到726 MPa,较普通316不锈钢有显著提高.Super-critical water-cooled reactor （SCWR） has been selected to be one of the most potential advanced nuclear reactors due to its simplification and high efficiency. Oxide dispersion strengthened （ODS） austenitic steels are promising candidate materials for SCWR, which combine the advantages of both austenitic stainless steels and ODS steels. In this work, ODS-316 austenitic steel （316L＋0.35%Y203＋0.3%Ti, mass fraction） was fabricated by the process of mechanical alloying （MA） and hot isostatic pressing （HIP）. The microstructural evolution after milling and hipping were studied by XRD. Morphologies and electron diffraction patterns of dispersed particles were characterized by TEM. Tensile properties of ODS austenitic steel were measured at room temperature. It was found that there were two phases of a （FeCr） and Y（Fe, Ni） in the powders after mechanical alloying, which was resulted from strain induced transformation. ODS-316 austenitic steel was single austenitic phase, since the strain disappeared during the consolidation of HIP. According to the observation and characterization of TEM, three kinds of dispersoids were found in samples： cubic Y2Ti207 and TiN and orthorhombic Y2TiO5. However, most of the dispersoids were round particles that enriched in Y, Ti and O. The tensile strength of ODS-316 austenitic steel was improved significantly, and its UTS reached 726 MPa.

关 键 词：机械合金化 ODS奥氏体钢 弥散颗粒 

分 类 号：TL341[核科学技术—核技术及应用]