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通过对低铬(409L)和中铬(439)含钛铁素体不锈钢在900℃下空气中开展恒温氧化试验,获得了两种钢的氧化动力学曲线,并结合EPMA、SEM和XRD等方法对氧化皮的结构进行了分析.结果表明,409L和439氧化动力学曲线均遵从抛物线规律,但409L抛物线速度常数远高于439;409L氧化80 h后氧化层结构由外侧Fe2O3和内侧(Fe,Cr,Mn)3O4复合尖晶石组成;439氧化80 h后氧化层外侧则由Cr2O3和(Cr,Mn)3O4尖晶石组成,内侧为一层SiO2,基体内还伴有钛的内氧化;较高的铬含量能保证TiO2内氧化颗粒稳定存在,而TiO2内氧化颗粒阻止离子迁移,显著降低氧化速度.“,”The isothermal oxidation tests of the low chromium(409L)and medium chromium(439)titanium stainless steel were carried out at 900 ℃.The oxidation kinetic curves of the two steels were obtained and the structure of oxide scale was analyzed by EPMA,SEM and XRD.The results indicated that the curves of the 409L and 439 stainless steel both followed the parabolic curve.But the parabolic velocity constant for 409L stainless steel was much higher than that for 439 stainless steel.The oxide layer of 409L stainless steel was formed by (Fe,Cr,Mn)3O4 and Fe2O3 after oxidation of 80 h.The outside layer of the oxide layer of 439 stainless steel was formed by Cr2O3 and (Cr,Mn)3O4,the inner layer of the oxide layer was SiO2 and the internal oxidation of Ti was accompanied in the matrix.The higher content of Cr can ensure the stable existence of the oxide particles in the TiO2,and the TiO2 oxidation particles can prevent the ion migration and reduce the oxidation rate significantly.