电化学渗氮对不锈钢表面结构的影响  

Effect of Electrochemical Nitriding on the Surface Structure of Stainless Steel

作　　者：陈真勇[1,2] 魏欣欣 徐妍婷 张波 马秀良 CHEN Zhenyong;WEI Xinxin;XU Yanting;ZHANG Bo;MA Xiuliang(School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang National Laboratory for Materials Science,Shenyang 110016,China;Songshan Lake Materials Laboratory,Bay Area Center for Electron Microscopy,Dongguan 523830,China;Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]中国科学技术大学材料科学与工程学院,沈阳110016 [2]中国科学院金属研究所沈阳材料科学国家研究中心,沈阳110016 [3]松山湖材料实验室大湾区显微科学与技术研究中心,东莞523830 [4]中国科学院物理研究所,北京100190

出　　处：《材料研究学报》2024年第3期161-167,共7页Chinese Journal of Materials Research

基　　金：国家自然科学基金(51971228,51771212)。

摘　　要：使用原子力显微技术和透射电子显微技术等手段,研究了电化学渗氮的304L不锈钢多尺度下表面结构的演变。结果表明,在电化学渗氮电位下304L不锈钢表面发生了钝化膜的局部阴极还原、金属基体的微区阳极溶解以及溶解的金属阳离子再沉积,从而形成了起伏幅度为几十纳米的微观粗糙表面。在扫描透射成像模式下进行的超级能谱分析结果表明,表面沉积物的主要组成是Fe的氧化物,进一步佐证了在渗氮过程中发生了Fe的微区阳极溶解和Fe阳离子的再沉积过程。Nitrogen is well known as a beneficial alloying element which entitles stainless steels an enhanced corrosion resistance against chloride attack.The introduction of N into the surface of stainless steel can be achieved by electrochemical nitriding.The role that Nitrogen plays in pitting resistance has long been discussed focusing on the distribution and incorporation form of N as well as the modification to the local corrosive circumstance induced by the N-participated electrode reactions.For electrochemical nitriding,stainless steel surface,as the place on which involved electrode reactions occur,is expected to undergo structural evolution.This,to some extent,would influence the corrosion property of nitrided stainless steel.Detecting the structural evolution occurring in the electrochemical nitriding is of great significance for deciphering the involved electrode reactions and thus optimizing the nitriding parameters.In this work,using atomic force microscopy as well as transmission electron microscopy,we have clarified the concomitant localized reductive dissolution of passive film,anodic dissolution of metal matrix at micro-anodic sites,as well as re-deposition of the dissolved metal cations,which roughens the surface by forming the undulations at surface with undulation amplitude in the range of a few tens of nanometers.Element mapping analysis by Super EDS technique reveals that the re-deposited product is mainly comprised of iron oxide,which indicates iron is dissolved and the resultant iron cations occurs re-deposition.

关 键 词：材料表面与界面 表面结构演变 电化学渗氮 透射电子显微技术 原子力显微技术 304L不锈钢 

分 类 号：TG174.4[金属学及工艺—金属表面处理]