亚临界/超临界水条件下镍基合金(Incoloy800,825,625)的硫化腐蚀特性研究  

Sulfidation Corrosion Behavior of Nickel-based Alloys(Incoloy800, 825 and 625) in Sub/supercritical Water

作　　者：张洁[1] 曲积钰 卢金玲[1] 刘倩[1] 罗兴锜[1] ZHANG Jie;QU Jiyu;LU Jinling;LIU Qian;LUO Xingqi(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China,Xi'an University of Technology,Xi'an 710048,China)

机构地区：[1]西安理工大学西北旱区生态水利国家重点实验室,西安710048

出　　处：《中国腐蚀与防护学报》2021年第6期892-898,共7页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(22078260和51879216)。

摘　　要：采用间歇式超临界反应釜进行了亚临界/超临界水体系中硫化物作用下,3种镍基合金(Incoloy800、825和625)的硫化腐蚀特性研究,通过分析腐蚀后合金表面形貌、腐蚀层结构及其物相组成,揭示该体系下镍基合金的硫化腐蚀机制,探究不同合金间的腐蚀行为差异,揭示腐蚀温度及合金组成元素的作用规律。结果表明,Ni/Cr含量比越低,合金在含硫超临界水中的耐腐蚀性能越好。对于Ni/Cr比为1.5的Incoloy800合金,其Ni、Cr主要用于形成致密的尖晶石相NiCrO_(4)膜而可有效地保护基体;对于Ni/Cr分别为2和3的Incoloy825,Incoloy625和Incoloy825合金在超临界条件下腐蚀膜厚约4.26μm,而Inconel625合金表面形成的是外层金属硫化物、内层金属氧化物的双层膜结构,过剩的Ni生成了疏松多孔的NiS相,导致二者合金较严重的硫化腐蚀。The corrosion characteristics of nickel-based alloys(Incoloy800, 825 and 625) in sub/supercritical water systems with the presence of sulfides were investigated using supercritical batch reactor.The surface morphology, structure and phase composition of corrosion products were characterized. The difference in corrosion behavior for the three alloys were assessed in terms of the effect of temperature and elemental composition of alloys. It is found that the nickel-based alloy with lower Ni/Cr ratio had better corrosion resistance. For Incoloy 800 alloy with Ni/Cr ratio of 1.5, the Ni and Cr mainly converted into dense spinel phase NiCrO_(4) which could protect the substrate from corrosion. With regarding to Incoloy 825 and 625 alloys, whose Ni/Cr ratios respectively were 2 and 3, the corrosion scale of Incoloy 825 alloy in supercritical water was 4.26 μm in thickness, while duplex scales with outer portion of metal sulfide and inner portion of metal oxides were formed for Inconel625 alloy. However, surplus Ni generated loose NiS phase, giving rise to significant corrosion for these two alloys.

关 键 词：超临界水 亚临界水 镍基合金 腐蚀 

分 类 号：TG174[金属学及工艺—金属表面处理]