高温镍基合金烟气侧腐蚀机理研究  

Study on Flue Gas Side Corrosion Mechanism of High Temperature Nickel-based Alloy

作　　者：薛俊杰 刘静逸 卓建坤[2] 王晓东 刘长瑞 吕海洋 董长青[1] XUE Junjie;LIU Jingyi;ZHUO Jiankun;WANG Xiaodong;LIU Changrui;L Haiyang;DONG Changqing(School of New Energy,North China Electric Power University,Beijing 102206,China;School of Energy and Power Engineering,Tsinghua University,Beijing 100080,China;Guoneng Biological Power Generation Group Co.,Ltd.,Beijing 100052,China)

机构地区：[1]华北电力大学新能源学院,北京102206 [2]清华大学能源与动力工程学院,北京100080 [3]国能生物发电集团有限公司,北京100052

出　　处：《华北电力大学学报（自然科学版）》2022年第6期109-117,共9页Journal of North China Electric Power University：Natural Science Edition

基　　金：中央高校基本科研业务费资助项目(2019MS029);国家自然科学基金资助项目(51776070);国家重点研发计划项目(2019YFE0100100);国家电网有限公司科技资助项目(SGGNSW00YWJS2100024).

摘　　要：Inconel 740H合金作为700℃级超超临界锅炉管材的主要候选材料,对其耐腐蚀性能进行研究具有重要意义。为探究合金烟气侧腐蚀机理,本研究首先利用Fluent软件,采用非结构化网格,RNG k-ε湍流模型,对所用的气体混合器以及管式炉内的气体流动进行了模拟,研究发现N_(2)和CO_(2)在下、O_(2)和SO_(2)在上的进气方式气体混合更加均匀,对于管式炉内的石英舟,将垂直石英管方向上的两个壁面去掉,气流可与合金试样充分接触。基于模拟结果条件,本研究进一步采用涂盐法与失重法进行实验,绘制腐蚀动力学曲线分析腐蚀速率,使用XRD、EDS分析实验样品。结果表明,涂灰组合金在实验中出现了显著的腐蚀失重,而不涂灰组合金则是轻微的腐蚀增重,涂抹的合成煤灰对合金的热腐蚀具有明显的加速作用,合金表面生成的Fe_(2)O_(3)、Cr_(2)O_(3)对腐蚀有抑制作用,而涂盐组所含有的Na_(2)SO_(4)以及NaCl等物质能够破坏表面致密的氧化物层,使得合金内部进一步发生腐蚀。Inconel 740H alloy is the main candidate material for 700℃ultra-supercritical boiler pipe,and it is of great significance to study its corrosion resistance.In order to explore the mechanism of alloy flue gas side corrosion,the flow of gas in the gas mixer and tube furnace was simulated by Fluent,using unstructured grid and RNG k-εturbulence model.It was found that the gas mixing was better while N_(2) and CO_(2)came from the bottom and O_(2) and SO_(2)at the top.For the quartz boat in the tubular furnace,the airflow can fully contact with the alloy sample while the two walls in the direction of the vertical quartz tube were removed.Based on the simulation results,salt coating method and weight loss method were further used in this study to draw the corrosion kinetics curve to analyze the corrosion rat.And XRD and EDS were used to analyze the experimental samples.The results show that the coated gold has significant corrosion weight loss,while the uncoated gold has slight corrosion weight gain.The coated synthetic coal ash has a significant acceleration effect on the alloy’s thermal corrosion,and the Fe_(2)O_(3)and Cr_(2)O_(3)generated on the alloy surface have inhibitory effect on corrosion.However,Na_(2)SO_(4)and NaCl in the salt-coated group can destroy the dense oxide layer on the surface,leading to further corrosion in the alloy.

关 键 词：Inconel 740 H 镍基合金 腐蚀 烟气 超超临界锅炉 Fe_(2)O_(3) Cr_(2)O_(3) 

分 类 号：TG172[金属学及工艺—金属表面处理]