Applications at elevated temperature require alloys that can form a protective oxide layer, and Cr and Si are known to form these layers, allowing FeCrSi alloys to be oxidation resistant. However, few studies have considered Si content higher than 2 wt.%. The objective here was to analyze the cyclic oxidation resistance of innovative FeSiCrNi alloys with different Si and Cr contents (around 5 wt.% of both). Cyclic oxidation tests were performed on three alloys at 950 °C in still air. The microstructure of the cast and heat-treated alloys and the oxide scales formed were analyzed by scanning electron microscope and energy-dispersive X-ray spectroscopy. Oxide layers were also characterized by X-ray diffraction. Comparing silicon contents of 4.65 and 5.9 wt.% in two different alloys containing around 4 wt.% chromium and 0.8 wt.% carbon, it was demonstrated that the lower silicon content was not enough to avoid iron oxides formation and continuous spallation. On the other hand, the higher silicon alloy exhibited low mass gains and a protective oxide layer composed of Cr₂O₃ and MnCr₂O₄, with some enrichment of silicon at metal/oxide interface. A third alloy, containing 2.7 wt.% carbon and, thus, graphite in its microstructure suffered decarburization in some regions, although in other regions it formed a protective oxide even in an alloy containing 3.25 wt% Cr and 6.6 wt.% Si. These results demonstrate that it is possible to have a high-temperature resistant alloy with low Cr content relative to conventional alloys by using high Si additions.

在高温下的应用需要能够形成保护性氧化层的合金，已知 Cr 和 Si 可以形成这些层，从而使 FeCrSi 合金具有抗氧化性。然而，很少有研究认为 Si 含量高于 2 wt.%。此处的目的是分析具有不同 Si 和 Cr 含量（两者的重量百分比约为 5%）的新型 FeSiCrNi 合金的抗循环氧化性。在静止空气中在 950°C 下对三种合金进行循环氧化试验。通过扫描电子显微镜和能量色散 X 射线光谱分析铸造和热处理合金的微观结构和形成的氧化皮。氧化层也通过X射线衍射表征。比较 4.65 和 5.9 wt.% 的硅含量 在含有约 4 wt.% 铬和 0.8 wt.% 碳的两种不同合金中，结果表明，较低的硅含量不足以避免氧化铁的形成和连续散裂。另一方面，高硅合金表现出低质量增益和由 Cr 组成的保护性氧化层₂ O ₃和MnCr ₂ O ₄，在金属/氧化物界面有一些硅富集。第三种合金含有 2.7 wt.% 的碳，因此其微观结构中的石墨在某些区域发生脱碳，但在其他区域，即使在含有 3.25 wt.% Cr 和 6.6 wt.% Si 的合金中，它也会形成保护性氧化物。这些结果表明，通过使用高硅添加量，有可能获得相对于常规合金具有低 Cr 含量的耐高温合金。