摘要
利用高温高压反应釜模拟空气压缩机叶片腐蚀环境条件,在FV(520)B不锈钢表面制备H2S腐蚀产物膜,利用XPS、SEM、XRD等分析技术分析硫化膜成分、结构,以研究硫化膜形成和生长机理。结果表明,初始阶段,硫化膜主要为Fe7S8、Fe(1-x)S,其中有较多的二价阳离子空位,硫化膜的不断生长是依靠金属阳离子通过晶格中大量空位向外迁移至气固界面并与离解的S离子反应;随硫化时间的延长膜厚不断增加,最终出现分层:外层成分为Fe7S8、Fe(1-x)S、Ni(1-x)S等,内层成分为少量Fe7S8、Fe(1-x)S、Ni(1-x)S和Cr2S3;内层中Cr2S3抑制Fe、Ni离子向外迁移,但硫化初期阶段Cr2S3的含量很少,这种抑制作用不明显,随着Cr硫化膜层的不断生长,整体硫化膜的生长速度被强烈抑制。
H2S corrosion film formed on FV( 520) B stainless steel in the simulated corrosion environment of air compressor blade service conditions in an autoclave was investigated. The composition and structure of the film were analyzed by using X-ray photoelectron spectroscopy,scanning electron microscopy,X-ray diffraction and EDS analysis to speculate the formation and growth mechanism of the sulfide film. The results show that the film is mainly composed of Fe7S8 and Fe( 1-x)S in the initial stage. There are many divalent cation vacancies in it,through which the metal cations migrate outwardly to the gas-solid interfaces to react with the dissociated S-ion. With the increasing of the sulfidation time,the thickness of the film increases and it is divided into two layers ultimately. The outer layer is composed of Fe7S8,Fe( 1-x)S,Ni( 1-x)S,and the inner layer is composed of Cr2S3 and a small amount of Fe7S8,Fe( 1-x)S,Ni( 1-x)S.The Cr2S3 in inner layer can constrain the outward diffusion of Fe,Ni ion. This effect is not obvious due to the lack of Cr2S3 in sulfide film in the primary stage of sulfidation,and it is more obvious with the continuous growth of Cr sulfide film,thus inhibiting the growth rate of the overall sulfide film strongly.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2015年第6期211-215,共5页
Transactions of Materials and Heat Treatment
基金
国家重点基础研究发展计划(2011CB013402)
安徽省教育厅产学研合作重点项目(KJ2012A232)
关键词
金属腐蚀
压缩机
阳离子空位缺陷
硫化腐蚀
corrosion of metals
compressor
cation vacancy defect
sulfide corrosion
