The origin of different morphology of internal oxide precipitates in ferritic and austenitic steels  

作　　者：Zhao Shen Xiaoqin Zeng Shengchuan Wu Hongbing Yu Benjamin M.Jenkins Phani Karamched Michael P.Moody Jianqiang Zhang You Wang Sergio Lozano-Perez 

机构地区：[1]National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China [2]State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu 610031,China [3]Department of Engineering Science,University of Oxford,Parks Road,OX13PJ Oxford,UK [4]Department of Materials,University of Oxford,Parks Road,OX13PH Oxford,UK [5]School of Materials Science and Engineering,University of New South Wales,Sydney,NSW 2052,Australia [6]School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China

出　　处：《Journal of Materials Science & Technology》2023年第30期88-100,共13页材料科学技术（英文版）

基　　金：This work was financially supported by National Key Re-search and Development Program of China(No.2018YFE0116200);Shanghai Pujiang Program(No.21PJ1406400);EPSRC(Nos.EP/K040375/1,EP/N010868/1,and EP/R009392/1);Prof.Lefu Zhang is acknowledged for providing the samples used in this study.In-strumental Analysis Center of SJTU is also gratefully acknowledged.The atom probe facilities at the University of Oxford are funded by the EPSRC(No.EP/M022803/1).

摘　　要：The internal oxide precipitates were supposed to be spherical in Wagner’s original theory,while the fol-lowing research demonstrated that this assumption is an exception rather than the truth,which caused deviations in the application of this theory.In this study,the internal oxide precipitates have a needle-like and a near-spherical morphology in a Fe-9Cr ferritic and a Fe-17Cr-9Ni austenitic steels after expo-sure to 600℃ deaerated steam for 600 h,respectively.The nano-to-atomic scale characterization shows that the morphology of the internal oxide precipitates is controlled by the structure of the interfaces be-tween the metal matrix and the internal oxide,while the interface structure is mainly affected by the crystallographic structure of the two phases and their orientation relationship.In addition,the internal oxide precipitation-induced volume expansion and the outward Fe diffusion-induced volume shrink oc-cur simultaneously during the oxidation process.The stress status in the internal oxidation zone(IOZ)is the competing result of the two factors,which could dynamically affect the high-temperature oxidation.The results obtained in this study suggest that there is potential to control the distribution,morphology,and interface structure of the internal oxide precipitates by selecting appropriate base metal and internal oxide-forming element,in order to obtain better high-temperature oxidation-resistant materials.

关 键 词：Austenitic steel Ferritic steel Oxide precipitates Phase boundary Orientation relationship 

分 类 号：TG1[金属学及工艺—金属学]