High-Temperature Oxidation of Fe- Si Alloys in the Temperature Range 900-1250°C
High-Temperature Oxidation of Fe- Si Alloys in the Temperature Range 900-1250°C
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DOI：
10.4028/www.scientific.net/ddf.273-276.661
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发表时间：
2008-01
影响因子：
--
通讯作者：
L. Suárez;J. Schneider;Y. Houbaert
中科院分区：
文献类型：
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作者：
L. Suárez;J. Schneider;Y. Houbaert
金属和合金暴露在高温下会导致氧化皮的形成，对表面质量有很大影响。氧化层的最重要特征是其厚度、成分、结构、粘附性和连贯性。温度、时间、气氛和化学成分决定了氧化层的生长。本文从氧化物生长机理、动力学和相形态等方面讨论了Fe-Si合金高温氧化性能的特点。研究了不同Fe-Si合金钢在900-1250°C空气中的氧化动力学、氧化膜结构和成分。在空气中进行氧化实验，以分析氧化过程。实验在电炉中在900至1250°C的温度下进行，时间在16至7200秒之间。因此，处理后的标本的特点是金相和他们的规模厚度测量的光学显微镜。通过EDS（能量色散谱）和EBSD（电子背散射衍射）分析研究了垢的形态并确认了垢的组成。结果表明，硅合金高温氧化呈现典型的三层氧化膜结构.在氧化皮的晶界上发现了铁硅酸盐，观察表明在氧化皮-金属界面处有硅的富集。这种富集以混合的浮氏体-铁硅酸盐（铁橄榄石）相FeO-Fe 2SiO 4的形式存在。当钢的表面存在液相时，由于存在浮氏体-铁橄榄石共晶，会发生非常快速的氧化物积聚。
Exposure of metals and alloys to high temperatures leads to the formation of oxide scales, with a large impact on surface quality. The most important features of the oxide layer are its thickness, composition, structure, adherence and coherence. Temperature, time, gas atmosphere and chemical composition determine the growth of oxide layers. In this paper, the characteristics of the high temperature oxidation properties of Fe-Si alloys are discussed in terms of oxide growth mechanism, kinetics and phase morphology. The oxidation kinetics of different Fe-Si alloy steels in air, its scale structure and composition were investigated over the temperature range 900-1250°C. Oxidation experiments were performed in air, to analyse the oxidation process. Experiments were carried out in an electric furnace at temperatures ranging from 900 to 1250°C, for times between 16 and 7200s. Thus treated specimens were characterised by metallography and their scale thickness was measured by optical microscopy. Scale morphology was studied and scale composition confirmed by EDS (Energy Dispersive Spectroscopy) and EBSD (Electron Backscattered Diffraction) analysis. Results show that high temperature oxidation of Si- alloys presents the classic three layered oxide scale. On the grain boundaries in the scale, iron-silicate was found. Observations show a Sienrichment at the scale –metal interface. This enrichment is present in the form a mixed wustite-iron silicate (fayalite) phase, FeO-Fe2SiO4. A very rapid build-up of oxide occurs when a liquid phase, due to the wustite-fayalite eutectic, is present in the surface of the steel.