缓蚀剂对HT700T合金在氯化物熔盐中腐蚀行为的影响  

Effect of corrosion inhibitor on corrosion behavor of HT700T alloy in chloride molten salts

作　　者：易寒 朱明[1] 张欣 鲁金涛[2] 黄春林 周永莉[2] 黄锦阳[2] YI Han;ZHU Ming;ZHANG Xin;LU Jingtao;HUANG Chunlin;ZHOU Yongli;HUANG Jinyang(College of Materials Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;State Key Laboratory of Coal-Based Clean Energy,Xi’an Thermal Power Research Institute Co.,Ltd.,Xi’an 710054,China)

机构地区：[1]西安科技大学材料科学与工程学院,陕西西安710054 [2]西安热工研究院有限公司清洁低碳热力发电系统集成及运维国家工程研究中心,陕西西安710054

出　　处：《热力发电》2022年第9期155-161,共7页Thermal Power Generation

基　　金：陕西省自然科学基础研究计划项目(2020JM-716);中国华能集团有限公司总部科技项目(HNKJ20-H43)。

摘　　要：采用浸泡法研究了镍铁基高温合金HT700T在800℃下添加不同剂量Al粉缓蚀剂的NaCl/KCl/MgCl_(2)氯化物熔盐中的腐蚀行为,浸泡时间分别为200、300、400 h。采用X射线衍射(XRD)和配备能谱仪的扫描电子显微镜(SEM/EDS)对腐蚀产物的组成、形貌和元素分布进行了研究,分析了缓蚀剂对HT700T合金腐蚀行为的影响。结果表明:HT700T合金在800℃下腐蚀后,添加Al粉缓蚀剂可在样品表面生成具有面心立方结构的Ni_(3)Al相;当Al粉缓蚀剂添加量为2%(质量分数)时,可在合金表面形成致密的Al_(2)O_(3)膜;当Al粉缓蚀剂添加量为10%(质量分数)时,Al向内扩散导致合金内部元素发生变化,形成由Al_(2)O_(3)、Al-Ni-Fe、Ni-Fe、Ni-Al、Ni-Al-Fe+Cr_(2)O_(3)组成的防护层,其深度随时间变化分别为185.8μm(200 h)、145.66μm(300 h)、166.02μm(400 h),可有效降低800℃下氯化物熔盐的腐蚀速率。By immersion method,the corrosion behavior of HT700T alloy in NaCl-KCl-MgCl_(2) molten salts with different doses of Al powder inhibitor at 800 ℃ was studied,with immersion time of 200 h,300 h and 400 h.The morphologies and phase composition of the HT700T alloy after corrosion tests were determined by X-ray diffraction(XRD) and scanning electron microscopy(SEM) equipped with energy dispersive spectroscopy(EDS),and the effect of corrosion inhibitor on corrosion behavior of the HT700T alloy was analyzed.The results showed that,Ni_(3)Al with face-centred cubic(FCC) structure could be formed on the sample surface by adding Al powder inhibitor after immersion at 800 ℃.When the addition mass fraction of the Al powder inhibitor was 2%,a dense and stable Al_(2)O_(3) film could be formed on the alloy surface.When the addition mass fraction was 10%,the Al diffused inward,resulting in the change of internal elements of the alloy and the formation of protective layer(composed of Al_(2)O_(3),Al-Ni-Fe,Ni-Fe,Ni-Al,Ni-Al-Fe+Cr_(2)O_(3)),of which the depth changed with time(185.8 μm(200 h),145.66 μm (300 h),166.02 μm(400 h)),indicating the inhibitor could effectively reduce the corrosion rate of chloride molten salts at 800 ℃.

关 键 词：HT700T合金 氯化物熔盐 缓蚀 太阳能热发电 

分 类 号：TG174[金属学及工艺—金属表面处理]