STBA24钢管蒸汽氧化的微观特征研究  

Microstructure Features of Steam Oxidation Scales on STBA24 Steel Tubes

作　　者：李婷[1] 赵钦新[1] 王云刚[1] 张知翔[1] 邓翔[1] 

机构地区：[1]西安交通大学能源与动力工程学院,热能工程系,西安710049

出　　处：《动力工程学报》2010年第4期293-297,303,共6页Journal of Chinese Society of Power Engineering

基　　金：国家“十一五”科技支撑计划课题资助项目(2006BAK02B03)

摘　　要：利用宏观检查、金相检验、电镜观察、能谱分析和X射线衍射仪等方法,对某热电厂过热器和再热器管内壁氧化皮的化学成分和组织结构进行了试验研究,探讨了STBA24钢高温蒸汽氧化的微观特征和氧化机理.结果表明:STBA24钢管在运行中,当管壁温度超过材料的许用温度时,易发生高温水蒸汽氧化;腐蚀产物分内外2层,外层以Fe2O3、Fe3O4为主,易剥落,内层为致密的保护性氧化物,具有长期抗氧化能力.金属材料的蒸汽氧化和剥落会增大管壁应力,造成管壁破裂或爆管.Chemical composition and microstructure of oxide scales on inner surface of STBA24 reheater and superheater tubes in a certain thermal power plant were studied systematically using macro,metallographic,scanning electron microscope（SEM）,energy dispersive spectrum（EDS） and X-ray diffractometer（XRD） method,so as to find the microstructure features and formation mechanism of the steam oxidation scales.Results show that high-temperature steam oxidation will occur if actual working temperature of tube wall exceeds its allowable value during service period of STBA24 steel tubes.The oxidation scale can be divided into 2 layers： the outer layer is mainly made up of Fe_2O_3 and Fe_3O_4,easy to exfoliate,while the sublayer consists of a dense oxide film,with strong resistance to steam oxidation.Steam oxidation and oxide scale exfoliation may raise the stress of tube wall and result in tube burst failures.

关 键 词：STBA24钢 过热器管 再热器管 高温蒸汽氧化 微观特征 

分 类 号：TK224.94[动力工程及工程热物理—动力机械及工程]