Atmospheric corrosion of galvanized steel and precipitation runoff from zinc in a marine environment

Abstract

Este estudo focaliza o comportamento do aço galvanizado em um ambiente marinho corrosivo e no processo de escoamento superficial para o mesmo material que ocorrem em Valparaíso, Chile. O potencial de corrosão e a taxa de corrosão avaliados através de perda de massa foram utilizados para determinar os danos da corrosão para o aço galvanizado. As composições dos produtos de corrosão foram determinadas utilizando difratometria de raios X (XRD) e sua morfologia através da microscopia eletrônica de varredura (SEM). As soluções de escoamento coletadas após as chuvas foram analisadas para determinar o valor de pH e das concentrações dos íons Cl-, SO4 2e Zn 2+. Os resultados após 15 meses mostram que o potencial de corrosão do aço galvanizado aumenta ao longo do tempo, indicando a formação de uma película protetora que consiste em produtos de corrosão de zinco. Estes produtos foram identificados como zincita e simoncoleita. Os valores de pH obtidos para as soluções de escoamento são semelhantes das amostras de água da chuva de referência, e as concentrações de cloreto das soluções de escoamento são aproximadamente duas vezes as da água de chuva This study focuses on the behavior of galvanized steel in a corrosive marine environment and on the runoff process for the same material occurring in Valparaiso, Chile. The corrosion potential and corrosion rate evaluated via mass loss were used to determine the corrosion damage to the galvanized steel. The compositions of the corrosion products were determined using X-ray diffractometry (XRD), and their morphology through scanning electron microscopy (SEM). The runoff solutions collected after rainfall were analyzed to determine the pH value, and Cl-, SO 4 2and Zn 2+ ion concentrations. The results after 15 months show that the corrosion potential of the galvanized steel increases over time, indicating the formation of a protective film that consists of zinc corrosion products. These products were identified as zincite and simonkolleite. The pH values obtained for the runoff solutions are similar to those of the reference rainwater samples, and the chloride concentrations of the runoff solutions are approximately twice those of the rainwater.

Atmospheric corrosion patterns of electrogalvanized mild steel at east southern coastal areas of CPEC

“…Results obtained from the current study are in agreement with the findings of Syed et al and Volovitch et al Findings are also consistent with the results reported by Vera, et al and Natesan et al…”

“…This could be due to higher humidity and closeness to the sea. [13] Results obtained from the current study are in agreement with the findings of Syed et al [2,4] and Volovitch et al [32] Findings are also consistent with the results reported by Vera, et al [24,33] and Natesan et al [23,[25][26]…”

“…[4][5][6][7][8]27] Comparison of the results with the reported studies on different marine stations world-wide showed that the environment of NIO and KPT was very harsh especially concerning sulphur dioxide concentration. [23][24][25][26][27] The concentration of chloride in the present study was also higher than the values reported for marine sites in Saudi Arabia, Abu Dhabi, Colombia, India, Mexico, Brazil, and Spain. [4][5][6][7]10,25,31] 3.2 | Visual Study of Corroded…”

“…Corrosivity of marine test sites has been studied worldwide, and the environmental parameters are reported …”

“…Corrosivity of marine test sites has been studied worldwide, and the environmental parameters are reported. [3][4][5][6][7][8][9][10][11][23][24][25][26][27][28][29][30] . It is a well-recognized fact that the process of atmospheric corrosion depends on environmental parameters that include relative humidity (RH), temperature (T), sunlight, period and amount of precipitation and direction of the wind.…”