Caracterización del recubrimiento de zinc sobre acero a-36, al variar la calidad superficial y ser tratado térmicamente.

Abstract

This investigation characterized the zinc coating on A-36 steel, modifying its surface quality and generating temperature changes. Initially, milling and grinding processes were used to obtain test specimens, which were hot dip galvanized. Using the methodology, the specimens were subjected to different tests, such as: metallography, micro-hardness, chemical composition, roughness, wear, temperature adherence, salt spray corrosion and pull-off. In the first instance the results showed that the specimens with grinding surface conserved a long useful life, greater resistance to corrosion and less detachment of the coating due to wear, compared to the milled specimens, based on the degree of roughness that each one of these processes originated. All this added the percentage of silicon in the substrate, the immersion time of the zinc bath and the structures formed in the zeta phase (ζ), which depending on their shape, size and distribution, provide greater roughness on the surface of the test specimens in the same way will determine the hardness of the coating. On the other hand, test specimens with milled surface show an improvement compared to the grinded specimens related to the parameters of adhesion by detachment and temperature, improvement properties of hardness, surface roughness and corrosion resistance, due to formation of a protective layer between the substrate-coating interface caused by the diffusion of zinc, when these are heat treated with a temperature of 300 °C and 400 °C.