Corrosion Failure Analysis of Hot-Dip Galvanized Steel in a Room Environment

Castaño

et al. 2018

The primary goal of the study was to establish corrosivity category in accordance with ISO 9223 norm of the two test stations located at National Institute of Oceanography (NIO) and Karachi Port Trust (KPT) along the east southern coastal route of China Pakistan Economic Corridor (CPEC) project in Pakistan. Electrogalvanized mild steel test coupons were exposed for a period of 12 months from May 2014 to May 2015. Results indicated that for both NIO and KPT test stations the corrosivity category in term of corrosion rate (C5+) was not in agreement with the corrosivity category (C5) established by using the pollution category and time of wetness. Corrosion kinetic parameters n and correlation coefficient (R2) obtained for NIO were 1.58 and 0.98 and for KPT 1.43 and 0.95 respectively. Scanning electron microscopy/energy dispersive X‐ray spectroscopy (SEM/EDS) showed the presence of simonkolleite at NIO while zincite and hydrozincite at KPT. Fourier transform infrared (FTIR) spectroscopy showed that the typical corrosion products formed on both test stations were simonkolleite and hydrozincite. XRD showed the presence of zincite at both test stations and hydrozincite only at KPT.

Section: Corrosion Rates and Kinetic Parameters For Electrogalvanizmentioning

confidence: 99%

Section: Corrosion Rates and Kinetic Parameters For Electrogalvanizmentioning

confidence: 99%

Section: Corrosion Rates and Kinetic Parameters For Electrogalvanizmentioning

confidence: 99%

See 1 more Smart Citation

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

Jamil

Castaño

et al. 2018

“…This coincides well with the common corrosion products reported by various researchers for marine test stations worldwide. [35,36] Figure 7 depicted XRD spectra of the corrosion products formed on electrogalvanized mild steel test coupons after a 24-month exposure at the NIO and KPT atmospheric corrosion stations. Results showed that hydrozincite, zinc oxide, zinc hydroxychloride, and zinc were the major corrosion products found at NIO, whereas simonkolleite, zinc oxide, and zinc were detected at KPT.…”

Section: Characterization Of Corrosion Productsmentioning

confidence: 99%

Atmospheric corrosion kinetics and dynamics of electrogalvanized mild steel in southeastern coastal area of China–Pakistan Economic Corridor

Jamil

Castaño

et al. 2020

This study aims to examine atmospheric corrosivity, corrodants, and corrosion products of southeastern coastal area of China–Pakistan Economic Corridor as per ISO protocols 9223 and 9225, and ASTM standards G1, G50, G140‐02, D4458‐94, and D2010. Test sites are located at National Institute of Oceanography (NIO) and Karachi Port Trust (KPT) at the banks of the Arabian Sea. Electrogalvanized mild steel test coupons were exposed, and levels of corrodants (sulfur dioxide, chloride, and time of wetness) were measured for a period of 24 months, from May 2014 to May 2016. Corrosivity category C5+ is established in terms of the corrosion rate for both NIO and KPT test stations, which does not coincide with the corrosivity category C5 ascertained by employing environmental characteristics and atmospheric corrodants. Corrosion kinetic parameter “n” and correlation coefficient (R2) are 0.71 and 0.97 for NIO and 0.96 and 0.97 for KPT, respectively. Scanning electron microscopy/energy‐dispersive spectroscopy, Fourier‐transform infrared spectroscopy, and X‐ray diffraction spectroscopy have corroborated the presence of simonkolleite and hydrozincite, zinc oxide, zinc hydroxychloride, and zinc in corrosion products at both test sites.

“…The adsorption or reaction of oxygen and carbon dioxide in the corrosion products is the possible reason for the increase in the mass-% of carbon and oxygen content. [24,35,38] F I G U R E 6 SEM images of the galvanized steel after 12 months of exposure at the urban test sites (T 1 -T 5 ) located in Karachi coastal city. SEM, scanning electron microscopy Numerous investigations have reported the characterization of the corrosion products on galvanized steel upon exposure to the atmosphere.…”

Section: Scanning Electron Microscopy/ Energy-dispersive X-ray Specmentioning

confidence: 99%

Physicochemical studies of galvanized steel corrosion in urban, industrial, and marine environments, and corrosion mapping of Karachi city: An important coastal city of the 21st‐century modern maritime silk route

Zafar

Mahmood

et al. 2020

The coastal city of Karachi is an imperative part of China-Pakistan Economic Corridor, which is integrated with the modern maritime silk route of the 21st century. This paper presents the corrosion mapping and physicochemical studies of galvanized steel corrosion exposed at the urban, industrial, and marine test sites located in the Karachi coastal city from July 2018 to June 2019. Tests have been performed to determine chloride, sulfur dioxide, time of wetness (TOW), and corrosion rates as per ISO protocols 9223 and 9225, and ASTM standards G1, G50, G140-02, D4458-94, and D2010. All test sites have been assigned the C5+ corrosivity category, based on corrosion rates of the galvanized steel, which is not completely in line with the corrosivity category derived from atmospheric pollutants and TOW values for these test sites. SEM/EDS, XRD, and FTIR have characterized the presence of simonkolleite, hydrozincite, and zincite at nearly all the test sites, whereas gordaite is only detected at the marine test sites. Zinc(I) chlorohydroxysulfate is also observed at an urban test site. This study has furnished a novel product of a galvanized steel corrosion map for Karachi, Pakistan.