Corrosion behaviour of metals and alloys in the waters of the Arabian Sea (original) (raw)
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UCTEA Chamber Of Metallurgical and Materials Engineers, 2021
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Corrosion behavior of metals and alloys in marine-industrial environment
Science and Technology of Advanced Materials, 2008
This work deals with atmospheric corrosion to assess the degrading effects of air pollutants on ferrous and non-ferrous metals and alloys, which are mostly used as engineering materials. An exposure study was conducted in the Tuticorin port area located on the east coast of South India, in the Gulf of Mannar with Sri Lanka to the southeast. Common engineering materials, namely mild steel, galvanized iron, Zn, Al, Cu and Cu-Zn alloys (Cu-27Zn, Cu-30Zn and Cu-37Zn), were used in the investigation. The site was chosen where the metals are exposed to marine and industrial atmospheres. Seasonal 1 to 12 month corrosion losses of these metals and alloys were determined by a weight loss method. The weight losses showed strong corrosion of mild steel, galvanized iron, Cu and Zn and minor effect on Al and Cu-Zn alloys. Linear regression analysis was conducted to study the mechanism of corrosion. The composition of corrosion products formed on the metal surfaces was identified by x-ray diffraction and Fourier transform infrared spectroscopy.
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A number of alloys, including stainless steels, aluminum, and nickel-based alloys, are used in seawater for various applications. The localized corrosion of these materials is affected, among other factors, by temperature, microbial activity, chlorination, and fl ow rate. A predictive model, based on the calculation of repassivation and corrosion potentials, is presented and compared to fi eld experiences of these alloys in seawater systems. An empirical model is used for calculating the repassivation potential of these alloys as a function of seawater composition. A mechanistic model is used for calculating the corrosion potential as a function of oxygen and chlorine concentrations. The parameters for the corrosion potential are derived from tests in fl owing natural seawater or synthetic seawater. The model calculations agree with the relative ranking of these alloys in seawater. Limitations of the current model and improvements are suggested.
Corrosion Behavior of Cast Iron in Freely Aerated Stagnant Arabian Gulf Seawater
Materials, 2015
In this work, the results obtained from studying the corrosion of cast iron in freely aerated stagnant Arabian Gulf seawater (AGS) at room temperature were reported. The study was carried out using weight-loss (WL), cyclic potentiodynamic polarization (CPP), open-circuit potential (OCP), and electrochemical impedance spectroscopy (EIS) measurements and complemented by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) investigations. WL experiments between two and 10 days' immersion in the test electrolyte indicated that the weight-loss the cast iron increases with increasing the time of immersion. CPP measurements after 1 h and 24 h exposure period showed that the increase of time decreases the corrosion via decreasing the anodic and cathodic currents, as well as decreasing the corrosion current and corrosion rate and increasing the polarization resistance of the cast iron. EIS data confirmed the ones obtained by WL and CPP that the increase of immersion time decreases the corrosion of cast iron by increasing its polarization resistance.
Bare stainless steel type 304 and 316 alloys were exposed to atmospheric, underground and seawater splash conditions in order to evaluate their corrosion properties. The exposure was undertaken for 15 months at the coastal and industrial city of Jubail located in the Arabian Gulf. The corrosivity of the environment was determined by testing the soil, groundwater, seawater and air quality. Corrosion rate of the exposed coupons was determined by weight loss method. The experimental results indicate that the both types of stainless steels corroded moderately in this environment. Primary factors influencing the corrosion process are thought to be high degree of variation in temperature and humidity combined with high chloride and sulphate concentrations. The corrosion rate of stainless steel is also compared with those reported for other international locations.
Crevice Corrosion Performance of Some Commercial Stainless Steels in Arabian Gulf SEAWATER1
Crevice corrosion tests were carried out to evaluate the perjormance of some conven- tional and high alloy stainless steels in Arabian Gulf seawater at 25oC and 50oC using specimens having three different surface conditions namely as received wheel ground and 180 grit SiC ground. Immersion tests of 150-180 days duration and accelerated tests were employed to inves- tigate the crevice corrosion behavior. Immersion test results show that crevice corrosion of 3127 hMo, Remanit 4565, 654 SMO, and Monit 44635 initiated as surficial corrosion with virtually no measurable depth of attack; 254 SMO, Duplex 2205, Remanit 4575, 904L and 317L corroded on l-2 sites attack. Crevice corrosion attack was most pre- dominant at 50o C in 180 grit SiC finished surfaces and there was no evidence of crevice corrosion attack in as received samples at room temperature. A method based on Oldfield and Sutton9 mathematical modelling of corrosion in chloride media has been applied for determining critical crev...
Corrosion of Bare and Galvanized Mild Steel in Arabian Gulf Environment
Journal of Materials Engineering and Performance, 2010
... It is an established fact that the corrosion rate in industrial and marine areas may be several times that in rural region (Ref 5). Also, the corrosion rate in an industrial area may be hundred times greater than that in a desert or arctic region (Ref 5). Atmospheric corrosion results ...
Localized corrosion of AISI 316L S.S in Arabian Gulf seawater
Desalination, 1994
An investigation has been carried out to evaluate the localized corrosion behavior such as pitting and crevice corrosion of AISI 316L in Arabian Gulf seawater. The immersion test and electrochemical techniques were utilized to study the different factors affecting the localized corrosion. The maximum pit depth appears to be a linear function of exposed area and exposure time. An increase in temperature causes a decrease in pitting potential, and increase in corrosion rate and pitting tendency. The kinetic of passive film formation at corrosion potential of 316L stainless steel is slow, and the slow scan rate lets the film thickening to occur, therefore, the slow scan rate is most suitable to study the localized corrosion using potentiodynamic pitting test. The results show that more homogeneous is the surface, higher the pitting potential and lesser the pit depth. The immersion test was utilized to evaluate the effect of crevice formers and crevice geometry on the crevice corrosion of AISI 316L S.S. The effect of crevice formers and crevice geometry on the initiation time of crevice corrosion was studied by monitoring the corrosion potential with time. The influence of temperature on the crevice corrosion was investigated by studying the critical crevice corrosion at elevated temperatures. The mechanism of corrosion has been discussed.