In-situ microstructural evolutions of 5Mn steel at elevated temperature in a transmission electron microscope  

作　　者：Han-bo Jiang Xi-nan Luo Xiao-yan Zhong Hui-hua Zhou Cun-yu Wang Jie Shi Han Dong 

机构地区：[1]National Center for Electron Microscopy in Beijing,Key Laboratory of Advanced Materials(MOE),State Key Laboratory of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China [2]Central Iron and Steel Research Institute,Beijing 100081,China

出　　处：《Journal of Iron and Steel Research International》2017年第11期1109-1114,共6页

基　　金：funded by National Basic Research Program of China(2010CB630800,2015CB921700);National Natural Science Foundation of China(51671112,51471096,51390471,11374174);National Key Research and Development Program(2016YFB0700402);National Key Scientific Instruments and Equipment Development Project(2013YQ120353);Tsinghua University(20141081200)

摘　　要：The microstructural evolutions of 5Mn steel during various heat treatments have been investiga- ted by in-situ transmission electron microscopy （TEM）. The specimen of 5Mn steel was pre- pared using focused ion beam （FIB） milling, which allowed the selection of specific morphology of interest prior to the in-situ observation, The complete austenization at 800 ℃ was verified at the atomic scale by minimizing thermal expansion and sample drift in a heating holder based on micro-electro-mechanical-systems. During annealing at 650 ℃, the formation of reverted austen- ite was dynamically observed, while the morphologies of austenite laths of 5Mn steel after in-situ heating were quite similar to that after ex-situ intereritical annealing. During annealing at 500 ℃, the morphological evolution of cementite and associated Mn diffusion were investigated. It was demonstrated that a combination of FIB sampling and high temperature in-situ TEM enables us to probe the morphological evolution and elemental diffusion of specific areas of interest in steel at high spatial resolution.The microstructural evolutions of 5Mn steel during various heat treatments have been investiga- ted by in-situ transmission electron microscopy （TEM）. The specimen of 5Mn steel was pre- pared using focused ion beam （FIB） milling, which allowed the selection of specific morphology of interest prior to the in-situ observation, The complete austenization at 800 ℃ was verified at the atomic scale by minimizing thermal expansion and sample drift in a heating holder based on micro-electro-mechanical-systems. During annealing at 650 ℃, the formation of reverted austen- ite was dynamically observed, while the morphologies of austenite laths of 5Mn steel after in-situ heating were quite similar to that after ex-situ intereritical annealing. During annealing at 500 ℃, the morphological evolution of cementite and associated Mn diffusion were investigated. It was demonstrated that a combination of FIB sampling and high temperature in-situ TEM enables us to probe the morphological evolution and elemental diffusion of specific areas of interest in steel at high spatial resolution.

关 键 词：5Mn steel Focused ion beam milling In-situ observation Microstructural evolution Austenite Cementite 

分 类 号：TG142.1[一般工业技术—材料科学与工程]