高温运行后T91钢过热器管蒸汽侧氧化膜微观结构与形成机理  

MICROSTRUCTURE AND FORMATION MECHANISM OF OXIDE FILM ON THE STEAM SIDE OF T91 STEEL AFTER HIGH TEMPERATURE OPERATION

作　　者：钟万里[1] 李正刚[2] 王伟[1] 杨兵[2] 

机构地区：[1]广东电网公司电力科学研究院,广东广州510080 [2]武汉大学动力与机械学院,湖北武汉430072

出　　处：《热力发电》2012年第6期28-31,共4页Thermal Power Generation

基　　金：广东省科技攻关资助项目(2010B010900034)

摘　　要：对运行85 000h后的T91钢过热器管内壁氧化膜的组织结构和微区成分等特征进行了分析,并讨论其形成机理。分析表明,氧化膜与金属基体间存在一过渡区,过渡区内Cr元素被O氧化,Fe元素向外层扩散而流失,造成该区域Fe浓度下降而Cr浓度相对升高;氧化膜为双层结构,其分界面为原金属表面,外氧化层富含Fe元素而不含Cr元素,主要成分为Fe3O4,内氧化层则由(Fe,Cr)3O4组成。The features of microstructure and micro - elements in oxide film appeared on inner surface of T91 steel superheater tubes after operation of 85 000 h have been analysed,and the formation mecha- nism of oxide film being discussed. Analysis shows that a transition zone exists between the oxide film and the metal matrix,in the said zone,Cr is oxidized, and Fe diffuses to the outer layer, leading to re- duction of Fe concentration,and relatively increasing the Cr concentration. The oxide film has a struc- ture of two layers,whose boundary surface is the original metal surOface. The outer oxide layer is Fe - rich,and Cr isn＇t contained,its main composition being Fe3O4 ,while the inner oxide layer is composed of （Fe,Cr）3 O4.

关 键 词：T91钢 过热器 蒸汽氧化 氧化膜 微观结构 

分 类 号：TK223.3[动力工程及工程热物理—动力机械及工程]