Microstructural evolution of intermetallic layer in hot-dipped aluminide mild steel with silicon addition
Microstructural evolution of intermetallic layer in hot-dipped aluminide mild steel with silicon addition
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DOI：
10.1016/j.surfcoat.2011.04.061
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发表时间：
2011-06-25
影响因子：
5.4
通讯作者：
Wang, Chaur-Jeng
中科院分区：
文献类型：
--
作者：
Cheng, Wei-Jen;Wang, Chaur-Jeng
采用热浸镀方法在纯铝、Al-0.5Si、Al-2.5Si、Al-5Si和Al-10 Si（wt.%）熔体中对低碳钢进行了表面涂层在700摄氏度下浸泡180秒。利用光学显微镜、扫描电子显微镜和X射线能谱仪、X射线衍射仪和电子背散射衍射仪对渗层的显微结构和相组成进行了表征。此外，金属间化合物层的厚度和钢基体的金属损失进行了测量，以研究低碳钢和铝浴之间的相互作用。结果表明，硅的加入导致Al 7 Fe 2Si和Al 2Fe 3Si 3相分别形成在FeAl 3层之上和Fe 2Al 5层之中。随着铝浴中硅含量的增加，金属间化合物层的厚度减小，金属间化合物层/钢基体界面由不规则形态转变为平坦形态。金属间化合物层厚度的减小主要归因于Al 7 Fe 2Si层从金属间化合物层脱离到铝浴中。平整的金属间化合物层/低碳钢基体界面是由于锯齿状钢基体与含固溶硅的Fe 2Al 5层反应在Fe 2Al 5层中形成了Al 2Fe 3Si 3沉淀物。(C)2011爱思唯尔有限公司版权所有。
Mild steel was coated by hot-dipping into molten pure aluminum, Al-0.5 Si, Al-2.5 Si, Al-5 Si and Al-10 Si (wt.%) baths at 700 degrees C for 180 seconds. The microstructure and phase constitution of the aluminide layers were characterized by means of optical microscope, scanning electron microscope with energy dispersive X-ray spectroscopy, X-ray diffraction and electron backscatter diffraction. Also, the thicknesses of the intermetallic layers and the metal losses of the steel substrate were measured to investigate the interaction between mild steel and aluminum baths. The results revealed that the additions of silicon to the aluminum baths caused Al7Fe2Si and Al2Fe3Si3 phases to form above the FeAl3 layer and in the Fe2Al5 layer, respectively. As the silicon content in the aluminum bath increased, the thickness of the intermetallic layer decreased, and the intermetallic layer/steel substrate interface transformed from an irregular morphology into a flat morphology. The decrease of the thickness of the intermetallic layer was principally attributed to the detachment of the Al7Fe2Si layer from the intermetallic layer into the aluminum bath. The flattened intermetallic layer/mild steel substrate interface was due to the formation of Al2Fe3Si3 precipitates in the Fe2Al5 layer by the serration-like steel substrate reacting with the Fe2Al5 layer containing solid-solute silicon. (C) 2011 Elsevier B.V. All rights reserved.