Fe-Cr钢在空气中的氧化行为

Oxidation behavior of Fe-Cr steel in air

为了测定不同质量分数的铬元素对钢高温氧化行为的影响,采用热重法对Fe-5Cr钢与Fe-10Cr钢在800~1200℃下进行高温氧化研究。建立了两钢种的氧化动力学模型,计算出了两钢种的激活能。利用金相显微镜和X射线衍射对两钢种氧化后的断面形貌和物相进行了分析。结果表明,两钢种的高温氧化动力学曲线遵循抛物线规律,Fe-5Cr钢的激活能小于Fe-10Cr钢。800℃下,Fe-5Cr钢生成不连续的氧化铁皮,Fe-10Cr钢氧化铁皮极少部分形核。900~1200℃下,氧化铁皮结构由外向里依次为Fe2O3、Fe3O4和Cr2O3。由于Cr2O3的阻碍作用,氧化铁皮中没有发现FeO。由于高温和高氧分压,Cr2O3失效,导致两钢种在1000~1200℃下具有相似的氧化速率。

In order to determine the effects of different mass percent of Cr on the oxidation behavior of steel at high temperature,the high temperature oxidation of Fe-5 Cr steel and Fe-10 Cr steel at 800-1200℃were studied by thermogravimetric method.The oxidation kinetics model of the two steels was established,and the activation energies of the two steels were calculated.The cross section morphology and phase of the two steels after oxidation were analyzed by metallographic microscope and XRD.The results show that the kinetics curve of oxidation at high temperature of two steels follow parabolic law,and the activation energy of Fe-5 Cr steel is less than that of Fe-10 Cr steel.At800℃,Fe-5 Cr steel generates a discontinuous scale,and very few oxide scale of Fe-10 Cr steel is nucleated.At 900-1200℃,the scale structures from the outside to the inside are Fe2O3,Fe3O4 and Cr2O3.Due to the barrier of Cr2O3,no FeO is found in the scale.Because of the high temperature and oxygen partial pressure,the failure of Cr2O3 leads to the similar oxidation rate of the two steels at 1000-1200℃.