Inconel 617合金在非纯氦气环境中的高温腐蚀行为研究  

High Temperature Corrosion Behavior of Inconel 617 in Environment of Impure Helium

作　　者：郑伟 何学东[1] 银华强[1] 杜斌 李昊翔 马涛[1] 蒲洋 王尚军 ZHENG Wei;HE Xuedong;YIN Huaqiang;DU Bin;LI Haoxiang;MA Tao;PU Yang;WANG Shangjun(Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China;Chinergy Co.,Ltd.,Beijing 100080,China)

机构地区：[1]清华大学核能与新能源技术研究院,北京100084 [2]中核能源科技有限公司,北京100080

出　　处：《原子能科学技术》2024年第1期189-197,共9页Atomic Energy Science and Technology

基　　金：国家重点研发项目(2020YFB1901600);国家科技重大专项(ZX06901);模块化HTGR超临界发电技术合作项目(ZHJTJZYFGWD2020);清华大学实验室创新基金。

摘　　要：Inconel 617合金是高温气冷堆蒸汽发生器的候选材料,在反应堆超高温运行时可能会受到氦气中痕量杂质的腐蚀。为探究合金在高温堆环境中的腐蚀机理,本研究开展了Inconel 617合金在980℃的非纯氦气中的腐蚀实验,对气相以及腐蚀行为进行了分析。通过化学热力学和动力学计算,阐明了合金脱碳的机理,并建立了碳迁移判定模型和脱碳反应预测模型,与实验数据有良好的一致性。在此基础上,研究了预氧化和温度对脱碳反应的影响。研究结果表明,即使杂质含量极低,也会诱发相关的腐蚀行为。降低运行温度可以有效避免合金脱碳,但预氧化的抗脱碳效果不理想。因此,极低杂质含量并非高温堆一回路净化目标,应该根据模型预测和实验分析来选择更加合理的杂质控制方案。The helium coolant in the primary circuit of the high-temperature gas-cooled reactor(HTGR)contains trace of impurities such as CO,H 2,H 2O,and CH 4,which have an adverse effect on the structural materials at elevated temperature.Mainly,the corrosion behaviors include oxidation,decarburization,and carburization,depending on the impurity composition and corrosion temperature.Inconel 617 is the reference candidate material for steam generators of HTGR,which may be corroded by trace impurities in helium at high temperature.In order to explore the corrosion mechanism of the superalloy in impure helium and establish a prediction model of decarbonization phenomenon,the corrosion experiments of Inconel 617 were carried out at 980℃in the impure helium.The gas phase data and corrosion behaviors of the alloy were analyzed by gas chromatograph(GC),field emission scanning electron microscopy(FESEM)with energy-dispersive X-ray spectroscopy(EDS)system,and X-ray diffraction(XRD).The mechanism of decarbonization is elucidated by chemical thermodynamics,which indicates that the driving force of carbon transfer is the carbon potential difference between alloy and environment,and more specifically,the carbon activity difference.Then,the prediction model of the decarbonization reaction was established.The critical temperature(T A)at which the corrosion behavior occurs can be obtained by thermodynamic calculation,and it is a function of the partial pressure of carbon monoxide.This model is in good agreement with the experimental data in this study and previous works with different contents of carbon monoxide.The results show that even if the impurity level is very low,it can still induce corrosion behavior.On this basis,the effects of pre-oxidation and corrosion temperature on the decarbonization reaction of alloy were investigated.When the temperature is reduced,there is no more obvious decarbonization phenomenon of the alloy,which indicates that it is an effective way to avoid decarbonization.However,after the pre-oxidation in the

关 键 词：高温合金 非纯氦气 高温气冷堆 腐蚀 脱碳 

分 类 号：TL341[核科学技术—核技术及应用]