高Al低密度钢的高温氧化行为

为观察Fe-Mn-Al-C系高Al低密度钢在高温下的抗氧化性能,采用氧化增重法测定了4种合金在950~1 100℃下的氧化动力学曲线。通过SEM观察氧化层形貌特征,利用线扫描能谱分析氧化后合金元素的变化,分析了28Mn-10Al合金氧化膜发生膨胀破裂的原因。结果表明,Al元素提高钢的抗氧化性,而Mn元素则降低Al的抗氧化性。抗氧化性较好的28Mn-12Al、20Mn-10Al合金表层未发现Fe的氧化,而氧化严重的28Mn-8Al合金氧化层Fe元素含量较高。28Mn-12Al合金抗氧化性最好,氧化膜的连续性及致密性优于其他3种合金,氧化物连续且晶粒细小,在氧化过程中具有一定的防护作用。

High-temperature oxidation behavior of low density steel with high Al content

The oxidation kinetic curves of four Fe-Mn-Al-C low density steels were measured by weight-increase method under 950-1100?? to analyze their oxidation behaviors at high temperature. The morphology of the oxide layer was examined by scanning electron microscope and variations of elements after oxidation were obtained with line scanning spectroscopy to analyzed the reason for bulging and fracture of oxide layer of 28Mn-10Al steel. The results show that Al improves oxidation resistances of the steels while Mn weakens it. 28Mn-12Al and 20Mn-10Al alloys have good inoxidizability and there is not oxidation of Fe in the surfaces of alloys, while there is oxidation of a certain amount of Fe in the surface of 28Mn-8Al alloy which is oxidized seriously. 28Mn-12Al alloy has the best inoxidizability and the continuity and compactness of its oxide film are the best. The oxides of 28Mn-12Al alloy are continuous and their grains are fine, which prevents further oxidation.