【摘要】 在自制的水蒸气氧化装置中,对两种具有不同晶粒度的P91钢进行了水蒸气等温氧化试验,对表面氧化膜进行了形貌观察、能谱分析和X射线衍射分析。结果表明:两种P91钢的氧化动力学曲线均具有抛物线特征,在650℃氧化300 h后,粗晶粒钢的氧化质量增加明显高于细晶粒钢的;两种钢氧化结果的差异是由于细晶粒P91钢在氧化初期(30 h内)能更快地形成富铬的氧化层,阻碍了铁离子的向外扩散,从而有效地降低了氧化速率。更多还原

【Abstract】 Isothermal oxidation test was carried out for two P91 steels with different grain sizes in water vapor by using a self-designed tubular device.The oxidation film was studied by means of SEM,XRD and EDS.The results show that oxidation kinetic curves obeyed the parabolic law.P91 steel with coarse grain exhibited more weight gain than that of with fine grain at 650 ℃ in water vapor for 300 h.A Cr-rich oxide layer formed sooner on fine grain P91 steel at the initial stage(<30 h),the outward diffusion of iron ion was retarded by this layer and so the oxidation rate was decreased.更多还原