Mn Diffusion at Early Stage of Intercritical Annealing of 5Mn Steel  

作　　者：Xi-nan LUO Xiao-yan ZHONG Hai-wen LUO Hui-hua ZHOU Cun-yu WANG Jie SHI 

机构地区：[1]Beijing National Center for Electron Microscopy, Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University [2]School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing [3]Central Iron and Steel Research Institute

出　　处：《Journal of Iron and Steel Research International》2015年第11期1015-1019,共5页

基　　金：Item Sponsored by National Basic Research Program of China(2010CB630800,2015CB921700);National Natural Science Foundation of China(51001064,51471096);Specialized Research Fund for the Doctoral Program of Higher Education of China(20100002120047);Tsinghua University Initiative Scientific Research Program(20141081200)

摘　　要：Mn distribution and austenite morphology at the early stage of intercritical annealing of 5Mn steel were investigated. It was experimentally demonstrated that a newly formed 20 nm-thick austenite was formed without the partitioning of Mn. The elemental analysis confirmed that the growth of austenite should be controlled by the diffusion of C prior to the diffusion of Mn at a low heating rate. The austenite growth started under negligible-partitioning local equilibrium mode and then switched to partitioning local equilibrium mode. Mn segregation at the γ/α interface suggested that the collector plate mechanism was the essential way of Mn partitioning at the early stage of austenite growth.Mn distribution and austenite morphology at the early stage of intercritical annealing of 5Mn steel were investigated. It was experimentally demonstrated that a newly formed 20 nm-thick austenite was formed without the partitioning of Mn. The elemental analysis confirmed that the growth of austenite should be controlled by the diffusion of C prior to the diffusion of Mn at a low heating rate. The austenite growth started under negligible-partitioning local equilibrium mode and then switched to partitioning local equilibrium mode. Mn segregation at the γ/α interface suggested that the collector plate mechanism was the essential way of Mn partitioning at the early stage of austenite growth.

关 键 词：Mn diffusion austenite nucleation intercritical annealing negligible-partitioning local equilibrium diffusion mechanism 

分 类 号：U465.11[一般工业技术—材料科学与工程] TG161[机械工程—车辆工程]