超(超)临界流体环境中形成的TP347H氧化层化学成分与微观结构分析

Analysis of chemical composition and microstructure for TP347H oxide layer formed in ultra-supercritical fluid environment

对不锈钢TP347H在超(超)临界流体环境中运行10 000 h后的氧化行为进行分析。采用扫描电镜和能谱仪对TP347H钢的氧化皮截面形貌、元素分布和内壁氧化皮微观形貌进行分析。结果表明:TP347H钢的氧化层由内、外两层组成,外层疏松有孔洞,内层致密。晶界是氧化的活性位置,细化晶粒可促进铬的快速扩散,可起到改善蒸汽抗氧化性能的作用。尖晶石结构在内层氧化层形成。

The oxidation behavior of stainless steel TP347H in ultra-supercritical fluid environment is analyzed after running for 10,000 hours. Scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) are used to analyze the cross-section morphology, element distribution and micro-morphology of oxide scale on the inner wall of TP347H steel. The results show that the oxide layer of TP347H steel consists of inner and outer layers, the outer layer is porous and the inner layer is dense. Grain boundary is the active site of oxidation. Refining grain can promote the rapid diffusion of chromium and improve the oxidation resistance of steam. Spinel structure is formed in the inner oxide layer.