【摘要】 将经表面喷丸处理和未处理的TP304H钢管安装于锅炉再热器的高温段运行7474 h后,对内壁氧化膜进行形貌观察、能谱分析和X射线衍射分析。结果表明,喷丸处理可大幅度提高TP304H钢的抗水蒸汽氧化性能,氧化膜的生长速率显著降低且氧化膜的粘附性提高。显微分析表明,氧化膜由双层结构转变为单一高Cr氧化膜层,外层Fe的氧化层消失。分析认为喷丸在管子内壁产生的剧烈形变引起晶粒细化和马氏体相变,在高温下促进了Cr向表面扩散及生成富Cr的氧化层。更多还原

【Abstract】 The inner surfaces of TP304H reheater tubes with and without shot peening were examined using scanning electron microscope(SEM),energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD) after 7474 h service at high temperature.The results showed that the shot peening treatment greatly increased the oxidation resistance of the TP304H tubes by dramatically decreasing the growth rate while increasing the adhesion of the oxide scale formed.The microstructural characterization also indicated that the shot peening treatment converted the oxide scale formed on the tubes from double layers being composed of an outer layer of iron oxides into single Cr-rich layer.It is proposed that the shot peening induces severe deformation of the tube inner surface and leads to grain refinement and martensite generation of the steel,both of which promotes Cr diffusivity to the surface and thus the formation of the Cr-rich oxide layer during the exposure of the tubes at high temperature.更多还原