Structure and characterization of hot dip galvanized coatings in acidic medium in low carbon steel.
Abstract
In the present work, the structural and microstructural characterization and mechanical properties analysis of hot-dip galvanized coatings on steel sheets was carried out, sometimes at different temperatures of a liquid Zn bath and different immersion times, with the intention to determine the ideal conditions of adherence and mechanical properties. Cleaning of the low-content steel sheets was carried out using a 1 M concentration of HCL. Likewise, an instrumental analysis was performed by X-ray diffraction (XRD), Zn was identified with PDF [96-230-0115] BCC with 4.51% crystallinity and 1Å of crystallite size, and PDF [96-901- 0309] FCC with 21.21% crystallinity and 2Å; Jarosite was identified which shows that an immersion in an acid medium causes a hydrolysis of iron and extraction of phosphorus and sulfur from the steel matrix. Furthermore, by scanning electron microscopy (MEB-EDS), the size of the coating layers of the compounds formed on these layers was determined. From what is concluded, that the cleaning with HCL after sandblast cleaning and a hot dip galvanizing temperature of 473 ° C, one minute of heating the sheet before immersion and two minutes of immersion in the liquid bath Zn are the best conditions for a good adhesion of coating on a steel coating.
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References
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