600 MW超超临界机组S30432钢内壁氧化膜变化规律及水蒸气氧化动力学  

Variation law of oxide film on inner wall of S30432 steel and vapor oxidation kinetics of 600 MW ultra supercritical unit

作　　者：胡锋涛 王晨 王志武[2] 江宝世 黄有强 高立行 HU Fengtao;WANG Chen;WANG Zhiwu;JIANG Baoshi;HUANG Youqiang;GAO Lixing(Rundian Energy Science and Technology Co.,Ltd,Zhengzhou 450000,China;School of Power and Mechanical Engineering,Wuhan University,Wuhan 430000,China;China Resources Power Heze Co.,Ltd.,Heze 274000,Shandong China)

机构地区：[1]润电能源科学技术有限公司,郑州450000 [2]武汉大学动力与机械学院,武汉430000 [3]华润电力菏泽有限公司,山东菏泽274000

出　　处：《中南民族大学学报(自然科学版)》2025年第2期170-177,共8页Journal of South-Central Minzu University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51071113)。

摘　　要：通过SEM对某600 MW超超临界机组运行80000 h后的S30432钢高温再热器管内壁氧化膜进行氧化膜形貌和膜层结构分析,再用EDS、XRD对氧化物中成分测定,并分析氧化膜形成.依据氧化膜厚度评估其脱落风险.测定在640、670、700℃下S30432钢水蒸气的氧化膜厚度和时间的动力学曲线,确定炉管的运行温度和对氧化的影响.结果表明:氧化膜在形成和变化中,存在晶粒变化和成分变化.晶粒变化主要是由融合状的纳米级晶粒长大为颗粒状或碗状微米级晶粒,由表及里,晶粒越来越细小.依氧化膜厚度推算的运行温度为670℃,处于超温运行状态;S30432钢产生氧化膜脱落的厚度为39.81μm,初生氧化膜厚度远大于39.81μm,处于随时脱落状态,再运行8552 h后次生氧化膜会达到脱落阈值厚度,管内存在氧化膜大量脱落并堵塞弯管引起爆管的巨大风险.The morphology and structure of the oxide films on the inner wall of the high temperature reheater S30432 steel tube of a 600 MW ultra-supercritical unit after operating for 800000 hours were analyzed by SEM,then by using EDS and XRD the compositions of the oxide were determined,and the oxide film formation was analyzed.The risk of peeling off of the oxide films was assessed according to the film thickness.The kinetics of oxide film growth and time of vapor oxidation of steel S30432 at 640,670 and 700℃were measured to determine the operating temperature of the furnace tube and its effect on oxidation.The results showed that there were grain size changes and composition changes during film formation and evolution.The change of grain size was mainly caused by the growth of fused nanocrystals to granular or bowl-shaped micrometer sized grains,with the grains becoming smaller and smaller from the outside to the inside.The operating temperature of the tube furnace calculated according to the oxide film thickness was 670℃,suggesting an overtemperature operation.The thickness for the oxide film to start peeling off from S30432 steel surface was 39.81μm,and the thickness of primary oxide film was much greater than that,which was in danger of peeling off at any time.After running for 8552 hours,the secondary oxide film will reach the threshold thickness for peeling off.There was a great risk that a large number of oxide films would fall off and block the tube bending,which might cause explosion.

关 键 词：S30432钢 高温再热器管 氧化膜 水蒸气氧化 组织结构 

分 类 号：TU457[建筑科学—岩土工程]