Tropical/non‐tropical marine environments impact on the behaviour of carbon steel and galvanised steel

Abstract

The aim of this study is to assess the main factors that affect the behaviour of carbon steel and galvanised steel in tropical and non‐tropical marine environments, identifying those factors that directly affect the behaviour. The results from the INNOVA (Chile) and MICAT/PATINA (Venezuela) projects will be used. These projects evaluated metals exposed to different marine environments using procedures outlined in ISO 9223/9226. The results show that temperature has no significant effect on the behaviour of the materials at the study sites in question (Venezuela being 10 °C warmer than Chile), independent of the tropical nature of the exposure environment, while it is precipitation (>600 mm) and chloride and SO2 content in the environment that mainly influence the behaviour of the carbon steel and the galvanised steel. In addition, an artificial neural network was generated to evaluate the corrosion rate of the studied metals, using meteoro‐chemical variables. The neural network for the carbon and galvanised steel was more precise for the exposure sites located in Chile.

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…”

“…Present study agreed well with the findings of Almarshad, et al and Vera et al who also found that for galvanized mild steel the mass loss increases with exposure time. They also found that for some test stations corrosion rates were far much higher than the C5 category . Corrosion category for test stations in the present study was close to the values reported for Jeddah and Wajah test stations in Saudi Arabia, Las Torres, Venezuela and Quintero, Chile .…”

“…Current studies agreed well with the findings of Cole, et al who reported the corrosion behavior of zinc in five different countries with different marine environments and concluded with the help of regression analysis that the corrosion rate of zinc is primarily controlled by the time of wetness (TOW) . Findings are also consistent with Vera et al who reported that high SO 2 content of the atmosphere was responsible for high corrosion rate …”

“…Comparison of the corrosion rates of electrogalvanized mild steel in NIO and KPT test stations with the corrosion rates reported for Mangalore, Mumbai, and Surat situated along the Arabian Sea coast in India showed that atmosphere in Karachi is very corrosive . Present study agreed well with the findings of Almarshad, et al and Vera et al who also found that for galvanized mild steel the mass loss increases with exposure time. They also found that for some test stations corrosion rates were far much higher than the C5 category .…”

“…They also found that for some test stations corrosion rates were far much higher than the C5 category . Corrosion category for test stations in the present study was close to the values reported for Jeddah and Wajah test stations in Saudi Arabia, Las Torres, Venezuela and Quintero, Chile . Comparison of the results also indicated that NIO and KPT test stations of Karachi, Pakistan has more corrosive atmospheres as compared to the marine test stations of Abu Dhabi, Spain, Panama, Mexico, Chile and Brazil .…”