G115钢中变形机制的原位透射电镜研究  

In⁃situ TEM study of deformation mechanism in G115 steel

作　　者：宋雅婧 田力男 余倩 SONG Ya-jing;TIAN Li-nan;YU Qian(Center of Electron Microscopy,State Key Laboratory of Silicon Materials,and Department of Material Science and Engineering,Hangzhou Zhejiang 310027;Huadian Electric Power Research Institute Co.Ltd.,Hangzhou Zhejiang 310030,China)

机构地区：[1]浙江大学材料科学与工程学院,硅材料国家重点实验室,电子显微镜中心,浙江杭州310027 [2]华电电力科学研究院有限公司,浙江杭州310030

出　　处：《电子显微学报》2023年第4期417-423,共7页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.51671168);高等学校学科创新引智计划(No.B16042);国家基础研究重点项目(No.2017YFA0208200).

摘　　要：新型马氏体耐热钢⁃G115钢以其优异的性能成为我国650℃超超临界火电机组厚壁部件的候选钢种。本文采用透射电镜中的原位拉伸力学实验,研究了G115钢室温变形条件下的位错行为和塑性变形机制。研究发现,位错间的相互反应、位错墙-位错的相互作用及多尺寸颗粒-位错的交互作用是材料塑性变形的主要机制。位错墙所构成的亚晶界不仅可以阻碍位错的运动,也可以选择性地传输位错。同时,析出相与位错之间的反应非常丰富。晶内随机分布的几十纳米左右粒径的富铜相可以有效钉扎位错并促进颗粒周围的位错增殖,而几百纳米左右粒径的M_(23)C_(6)颗粒则会强烈地阻碍位错滑移,形成位错的塞积和缠结。这些机制对材料的均匀塑性变形均有促进作用。The novel martensitic heat resistant steel G115 is a candidate steel for thick⁃walled parts of ultra⁃supercritical units at temperature of 650℃in our country due to its excellent performance.The dislocation behavior and plastic deformation mechanism of G115 steel under deformation conditions at room temperature were investigated by in⁃situ tensile mechanics experiments in transmission electron microscopy.It is found that the interaction between dislocations,dislocation wall⁃dislocation interaction and multi⁃size particle⁃dislocation interaction are the main mechanisms of plastic deformation.The subgrain boundaries formed by dislocation walls can not only hinder the movement of dislocations,but also selectively transport dislocations.At the same time,the reactions between precipitations and dislocations are very abundant.The copper⁃rich phase with a particle size of about tens of nanometers randomly distributed in the grain can effectively pin dislocations and promote dislocations proliferation of around the particles.While the M23 C6 phase of a few hundred nanometers can strongly hinder dislocation slip and form dislocation pile⁃up and tangle.These mechanisms all contribute to the uniform plastic deformation of the material.

关 键 词：G115钢 原位拉伸 位错行为 

分 类 号：TG142.1[一般工业技术—材料科学与工程] O772[金属学及工艺—金属材料] TG115.215.3[金属学及工艺—金属学]