氧控条件下T91钢在热对流铅铋合金中的氧化腐蚀行为  

Oxidation Corrosion Behavior of T91 Steel in Heat Convection Lead-bismuth Alloy with Oxygen Control

作　　者：秦博[1,2] 刘思涵 张洁 付晓刚 龙斌[1,2] QIN Bo;LIU Sihan;ZHANG Jie;FU Xiaogang;LONG Bin(Reactor Engineering Technology Research Institute,China Institute of Atomic Energy,Beijing 102413,China;Innovation Center of Nuclear Materials,China Atomic Energy Authority,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院反应堆工程技术研究所,北京102413 [2]国家原子能机构核材料创新中心,北京102413

出　　处：《材料开发与应用》2024年第6期90-97,共8页Development and Application of Materials

基　　金：中核集团集中研发“创新2030”项目(FA202412000620);基础科研项目“基于铅铋固相氧控的PbO微观截面及质量迁移特性研究”。

摘　　要：铅铋合金具有优异的核性能、高导热、高沸点和化学惰性等特性,以其作为冷却剂的铅铋快中子增殖反应堆是具有发展前景的第四代反应堆的六种堆型之一,同时,反应堆结构材料易受到铅铋合金冷却剂的腐蚀,因此,其在铅铋合金冷却剂冷中的腐蚀行为是该领域的研究热点之一。为了揭示T91钢(9Cr铁素体/马氏体钢)在低流速铅铋合金冷却剂中的腐蚀行为特性,本研究利用铅铋热对流腐蚀试验回路,开展了T91钢在低流速氧控铅铋环境下的腐蚀试验,并分析了腐蚀后T91钢的表面及截面形貌,腐蚀层的物相、成分及厚度的变化。结果表明,在330~550℃、氧含量(质量分数)为1.0×10^(-8)~5.0×10^(-8)的流动铅铋合金冷却剂中,T91钢表面形成了氧化层,该氧化层的厚度随着温度的升高和时间的增加而增厚;氧化层具有双层结构,外层为疏松Fe_(3)O_(4),内层为致密Fe(Fe_(x)Cr_(1-x))_(2)O_(4);致密的Fe(Fe_(x)Cr_(1-x))_(2)O_(4)氧化层抑制基体材料在铅铋合金冷却剂中的溶解腐蚀。Due to the excellent nuclear property,high thermal conductivity,high boiling point and chemical inertness of lead-bismuth(Pb-Bi)alloy,the Pb-Bi fast breeder reactor,which uses Pb-Bi as the coolant,is one of the six reactor types for the Generation IV reactor.Meanwhile,the reactor structural materials are tend to be corroded by the Pb-Bi alloy coolant,therefore,the corrosion behavior of the reactor structural materials is one of the research hotspots in this field.In order to reveal the corrosion behavior of T91 steel(9Cr ferritic/martensitic steel,F/M steel)Pb-Bi alloy coolant with low flow rate,the corrosion experiment of T91 under oxygen controlled Pb-Bi alloy coolant environment is carried out by using the Pb-Bi thermal convection test loop.The surface and cross-section morphologies of T91 steel,and the phase,chemical compositions and thickness of the corrosion layer are characterized.The results show that an oxide film is formed on the surface of T91 steel when the oxygen con-tent(mass fraction)in the flowing Pb-Bi alloy coolant is controlled within 1.0×10^(-8)-5.0×10^(-8) at 330-550℃,and that the oxide film increases with the increase of experimental temperature and time.The oxide film consists of two layers,with the loose Fe_(3)O_(4) in the outer layer and dense Fe(Fe_(x)Cr_(1-x))_(2)O_(4) in the inner layer.The dense Fe(Fe_(x)Cr_(1-x))_(2)O_(4) layer can inhibit the dissolution corrosion of the T91 steel in the Pb-Bi alloy coolant.

关 键 词：铅铋合金 氧化腐蚀 T91钢 氧控 热对流 

分 类 号：TG172[金属学及工艺—金属表面处理]