• Corrosion Science and Technology
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• 제23권5호
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• pp.425-436
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• 2024

In this study, corrosion properties of galfan-coated carbon steel were compared and analyzed after applying trivalent chromium chemical conversion treatment and polymer coating techniques. Potentiodynamic polarization and galvanostatic corrosion experiments were performed to compare corrosion resistance of galfan-coated carbon steel with different coatings. Results of the potentiodynamic polarization test demonstrated that the specimen treated with both trivalent chromium chemical conversion and polymer coating exhibited superior corrosion resistance to other specimens, showing the lowest corrosion current density of 0.058 µA/cm². In contrast, the specimen coated only with galfan presented the highest corrosion current density of 0.118 µA/cm², indicating the lowest corrosion resistance. These results were further validated through additional analyses, including galvanostatic corrosion experiment, 3D microscopy, scanning electron microscopy, and energy-dispersive spectroscopy. Results of this investigation confirmed that trivalent chromium chemical conversion treatment along with polymer coatings could effectively enhance corrosion resistance of carbon steel, offering a promising and environmentally friendly anti-corrosion technology.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2009년 추계학술발표대회
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• pp.95-95
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• 2009

Zinc coatings provide the most effective and economical way of protecting steel against corrosion. There are three types of galvanizing lines typically used in production line in galvanizing industries,Galvanize (GI) coating (Zn-0.1-0.3%Al), Galfan coating (Zn-5%Al), Galvalume(GL) coating (45%Zn-Al). In continuous Galvanizing lines, the immersed bath hardware (e.g. bearings, sink, stabilizer, and corrector rolls, and also support roll arms and snout tip) are subjected to corrosion and wear failure. Understanding the reaction of these materials with the molten Zn alloy is becomes scientific and commercial interest. To investigate the reaction with molten Zn alloys, static immersion test performed for 4, 8, 16, and 24 Hr. Two different baths used for the static immersion, which are molten Zn and molten Zn-55%Al. Microstructures characterization of each of the materials and intermetallic layer formed in the reaction zone was performed using optical microscope, SEM and EDS. The thickness of the reaction layer is examined using image analysis to determine the kinetics of the reaction. The phase dominated by two distinct phase which are eutectic carbide and matrix. The morphology of the intermetallic phase formed by molten Zn is discrete phase showing high dissolution of the material, and the intermetallic phase formed by Zn-55wt%Al is continuous. Aluminum reacts readily with the materials compare to Zinc, forming iron aluminide intermetallic layer ($Fe_2Al_5$) at the interface and leaving zinc behind.