Study on the Atmospheric Corrosion of Galvanized Steel in the Anhui Province Power Grid and Its Influence Law#br# #br#

Abstract

In order to evaluate the corrosion state of power grid galvanized steel components in the atmospheric environment of Anhui Province, galvanized steel samples, which were naturally exposed for 1 and 3 a, respectively, were analyzed using scanning electron microscopy(SEM), energy-dispersive X-ray spectroscopy(EDX) and X-ray diffractometer(XRD) to investigate the compositions and morphologies of the corrosion products, thereby revealing their atmospheric corrosion mechanisms. Meanwhile, the corrosion rates of the galvanized steel samples were determined using the weight-loss method, combined with grey correlation analysis, to ascertain the influence law of major environmental factors on the atmospheric corrosion rate of the galvanized steel samples. Results showed that the atmospheric corrosion products of the galvanized steel samples consisted of ZnO and minor amounts of Zn5(OH)6(CO3)2 and Zn4(OH)6SO4. The surface of the corrosion layer featured cellular protrusions composed of flaky Zn5(OH)6(CO3)2 and Zn4(OH)6SO4, forming chrysanthemum-like patterns. The structure of the corrosion layer was dense and closely bonded to the galvanized layer, providing effective protection, and thus, the corrosion degree of the galvanized steel was low. The major environmental factors affecting the atmospheric corrosion rate of the galvanized steel samples in Anhui Province were ranked as follows: temperature > relative humidity > O3 > NO2 > PM2.5 > PM10 > SO2. Temperature and atmospheric relative humidity had a more significant impact, whereas the influence of SO2 was minimal.

Keywords

• power grid equipment; galvanized steel; atmospheric corrosion; gray relation analysis; environmental factor