Investigation of corrosion resistance of solid silicon- molybdenumizing layers against zinc

• Main Authors: Xin ZHANG, Huiling LIU, Xiufeng LI, Lei MAO
• Format: Article
• Language: zho
• Published: Hebei University of Science and Technology 2017-06-01
• Series: Journal of Hebei University of Science and Technology
• Subjects: material failure and protection; silicon-molybdenumizing; infiltration layer structure; corrosion resistance; molten zinc
• Online Access: http://xuebao.hebust.edu.cn/hbkjdx/ch/reader/create_pdf.aspx?file_no=b201703011&flag=1&journal_

In order to improve the corrosion resisting property of ferrous metals in molten zinc, siliconizing, molybdenumizing and silicon-molybdenumizing are carried out on the Q235 steel surface by solid powder method. The infiltration layers’ morphology, compactness degree, microhardness, component and phase structure are analyzed. Moreover, the samples are soaked in the molten zinc bath at 470 ℃ for 26 h, and their corrosion rate is measured. The results show that the intermetallic compounds (Fe3Si, Fe3Mo, MoSi2 and Mo5Si3) with good corrosion resisting property are produced in infiltration layers. The addition of Mo element can promote the penetration of Si element in the infiltration agents, thus increasing the compact density of infiltration layers. The comparative results also prove that the silicon-molybdenumizing layers are more compact, especially for the sample with m(Si)∶m(Mo)=2∶1. Its corrosion rate decreases almost two orders of magnitude compared with that of the substrate, showing better corrosion resisting property. However, the existence of defects (such as holes) in the infiltration layers leads to the decrease of compact density, and the corrosion resisting property in molten zinc is also affected. Therefore, in the future studies much attention should be paid to the improvement of the compact density of solid infiltration layers, so as to further increase the corrosion resisting property.