F55双相不锈钢在800~1000℃纯氧气中的高温氧化行为

High Temperature Oxidation Behavior of F55 Super Duplex Stainless Steel at 800-1000o C in 1.013×10^(5) Pa O_(2)

研究了F55双相不锈钢在800、900、1000℃下1.013×10^(5) Pa纯氧中的氧化行为。采用光学显微镜、扫描电镜(SEM)、X射线衍射(XRD)等方法分析了合金中氧化膜结构和相组成。结果表明:在不同实验温度下氧化膜主要由Cr_(2)O_(3)和Cr、Mn氧化物组成。氧化动力学曲线均遵循抛物线规律,合金的氧化增重随着温度的升高而增大。合金近表层的α相中的Cr易于向外扩散发生氧化,α相转变为γ相。在氧化过程中,合金内部的α相发生共析生成σ+γ相,σ相中的Cr优先扩散至合金表面发生氧化反应。

The oxidation behavior of F55 duplex stainless steel in 1.013×10^(5) Pa pure oxygen at 800,900,1000℃has been studied by means of thermal gravimetric analyzer,optical microscope,scanning electron microscope(SEM)and X-ray diffraction(XRD).The results show that the oxide scales are mainly composed of Cr_(2)O_(3) and Cr-Mn oxides at the designed temperatures.The oxidation kinetics curves follow parabolic law,and the oxidation mass gain increases with the increase of temperature.During the oxidation process,theαphase on the surface of the alloy changes intoγphase due to the outward diffusion of Cr,while theαphase in the matrix undergoes eutectoid reaction to formσ+γand other phases.Cr in theσphase generated by the eutectoid reaction preferentially diffuses to the surface of the alloy to participate in the oxidation reaction.