Seawater Corrosivity Around the World: Results from Three Years of Testing

Abstract

A world-wide test program was undertaken by Task Group G 1.09.02.03 to assess the relative corrosivity of seawater at 14 test sites. Aluminum alloy A95086, copper-nickel alloy C70600, and carbon steel alloy KOI501 specimens were prepared at one location, shipped to the various sites, and returned to the original site for final evaluations. Results obtained through three years of testing indicate that average corrosion behavior was generally within limits of previously published results. Individual site characteristics have been identified, however, that can have a profound effect on test results. Even when the ASTM standard test method was prescribed, variations affecting corrosion results became evident. In reality there is no natural seawater environment, as identified to date, in which to test materials. The final five year results are yet to be collected, but the cooperation of all program participants has contributed much toward accomplishment of the objectives. Still, more frequent and broader monitoring of sea-water variables at the exposure sites would assist in interpreting corrosion results.

The influence of macrofouling on the corrosion behaviour of API 5L X65 carbon steel

“…For carbon steel exposed in natural seawater and in the presence of a fouling community, Griffin et al (1989) calculated Influence of macrofouling on carbon steel corrosion 197 0.085 mmpy after 3 years' immersion, and Palraj and Venkatachari (2006) described a rate of 0.152 mmpy after 1 year. Kirk and Pikull (1990) reported values between 0.075 and 0.200 mmpy for carbon steel exposed in seawater for a minimum of 6 months. These authors found average values of 0.168 mmpy over 6 months and 0.172 mmpy in 1 year, decreasing to 0.117 mmpy at the end of 3 years, emphasising that there was no temporal tendency of rate increases.…”

“…It is important to interpret the uniform corrosion rates considering the aspect of oxygen concentration cells on the panel surfaces. Kirk and Pikull (1990) and Gentil (1996) suggested that the uniform corrosion rate on carbon steel is directly associated with oxygen concentration: the rate increases in the presence of oxygen and decreases in minor concentrations. The present control treatment showed the highest uniform corrosion rate.…”

“…Until now studies on the corrosive process in presence of a macrofouling community did not include ecological aspects. These studies utilised qualitative methods to analyse the community (presence or absence), insufficient replication or did not refer to the fouling community and its impact on corrosion processes (Efird, 1976;Chandler, 1979;Griffin et al 1989;Eashwar et al 1990;Kirk & Pikull, 1990;Neville & Hodgkiess, 1998;2000;Chiang & Wu, 2001;Koryakova et al 2001;Luo & Lee 2001;Palraj & Venkatachari, 2006).…”

Profiling Corrosion Rates for Offshore Wind Turbines with Depth in the North Sea

“…The question for shallow waters is how to test for corrosion in an unexploited site. There have been many experiments done but none in the literature takes a detailed approach in profiling corrosion loss with depth in the past decade from the literature [26,27]. This will require a new design to accommodate the experiment to profile the corrosion rate and loss with depth and is explained below.…”

Seawater heat pumps in China, a spatial analysis

“…The seawater salinity in China seas is 1.5 times to 2 times higher than Baltic Sea in North Europe. Researches have proved that salinity around 3% is most corrosive [46], so more corrosion precautions should be used in China compared with North European countries. Usually titanium heat exchanger is used, which can be 2 to 3 times more expensive than heat exchangers made from other metallic materials [47].…”