摘要
为了探讨HR3C耐SO_2腐蚀机制,应用XRD,SEM(EDS)和EMPA等分析方法对预涂覆碱金属硫酸盐的HR3C在不同温度与含量SO_2气氛中腐蚀行为进行研究。结果表明:腐蚀动力学曲线呈现"抛物线"趋势;腐蚀产物主要由(Fe,Cr)氧化物、少量尖晶石结构的复杂氧化物以及(Fe,Ni)硫化物组成;SO_2浓度的提高导致氧化膜明显增厚,劣化氧化膜与基体的结合;此外,腐蚀影响区的孔隙率增加,且在氧化物-腐蚀影响区界面处生成硫化物带。分析认为HR3C在SO_2气氛中的腐蚀是由合金元素的氧化与硫化所致;而且,金属氧化物的硫酸盐化与三元共晶复合盐的形成以及合金元素Fe在熔盐中的溶解也对HR3C合金腐蚀产生作用。
The corrosion behaviors of HR3C pre-coated alkali metal sulphate in SO2 atmosphere at dif-ferent temperatures were investigated by means of XRD, SEM （EDS） and EMPA in order to discuss the corrosion resistance mechanism to SO2 of HR3C. The results show that the corrosion kinetic curves follow parabolic law. The corrosion products are mainly composed of （Fe,Cr） oxides, minor compound oxides with spinel structure as well as （Fe,Ni） sulfides. The increment in SO2 content in-creases significantly the oxide films in thickness, and deteriorates the adhesion to the oxide scale and matrix. In addition, the porosities in the corrosion affected zone （the interface between the oxide films and the matrix） increase and a CrS belt exits in the interface between the oxide layer and the corrosion affected zone. The analysis shows that the corrosion of HR3C in SO2 environment is resulted from the oxidation, sulfidation of the al loy, moreover,the sulfation of metallic oxides and the formation of ter-nary composed alkali metal sulfate as well as the dissolution of Fe in melted salt also contribute to the corrosion.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2017年第1期43-51,共9页
Journal of Materials Engineering
基金
国家自然科学基金项目(51134013
51171037)
2016NSFC山西煤基低碳联合基金重点项目(U1610256)
关键词
超超临界发电
烟侧腐蚀
碱金属硫酸盐
热腐蚀
硫酸盐化
ultra supercritical power generation
fireside corrosion
alkali metal sulfate
hot-corrosion
sulfation
