A Study Of High Temperature Oxidation Of Fe-1Cr Steel

In this paper,Fe-1Cr Steel were used as experimental material.Measured the law of oxidation weight gain over time and calculated oxidation activation energy from oxidation kinetics experiments by thermogravimetric analyzer?TGA?,then discussed the oxidation time and temperature with the influence of the experimental steel's oxide thickness and structure from the high temperature oxidation experiments with tube type heating furnace.The oxidation of iron internal organization and analysis were observed by opticalic microscope?OM?,scanning electron microscope?SEM?and electron microprobe?EPMA?,and getted specific phase composition from X-ray diffraction analysis?XRD?.The experimental conclusion is as follows:The oxidation kinetics experiment shows that Fe-1Cr steel's mass gain of per unit are less than Fe-0Cr steel after 120 min high temperature oxidation.At 700?,Fe₃O₄ grow in the surface,and form hematite up to the Fe₃O₄ with the highly temperature.Hematite develops as whiskers and grains that controlled with oxidation temperature.With the extension of oxidation time,Fe-1Cr steel's mass gain of per unit and time from the linear relations to parabola relationship.After 30 min different oxidation temperature oxidation,it can be found: that when the oxidation temperature higher than 700 ?,specimen surfaces generated by the oxidation products in addition to Fe oxides,include Fe₂SiO₄ and FeCr₂O₄,and they are mainly distributed in the oxidation product close to the position of the substrate.When the temperature higher than 900 ?,the oxide scale will obvious stratification.Fe₂SiO₄ and FeCr₂O₄ at above 1000 ? can protect substrate by prevent the spread of the Fe ion.After different time oxidation at same temperature,it can be found that in the process of high temperature oxidation,FeCr₂O₄ than Fe₂SiO₄ generated much earlier.The thickness of the oxide scale relate to the dense of lower degree and ion diffusion velocity,and it mainly depends on oxidation temperature whether oxide scale can be formed to prevent oxidation continuation.