Effect of state of sea on atmospheric corrosion in coastal zones

Abstract

However, the current work has shown that the wind eVect is not so clear at the T arragona B. CHICOtesting station, on the Mediterranean coast of Spain, where marine winds are generally moderate. Apparently, factors other than marine wind speed at the coast exert a significant influence on the aerosol production. In addition to wind data, the study considers data on the state of the sea in the coast close to the T arragona testing station obtained from records from an experimentation buoy. T hese latter data suggest a direct relationship between chloride aerosol deposition rate and the square of wave height. T he eVect of chloride deposition rate on atmospheric corrosion at the T arragona testing station has also been studied. Using bimetallic 'Climat' type specimens a proportionality has been revealed between corrosion and atmospheric salinity.

Environmental Conditions for Akaganeite Formation in Marine Atmosphere Mild Steel Corrosion Products and Its Characterization

“…Meteorological data were supplied by a weather station belonging to the Spanish Meteorological Agency, situated very close (25 m) to corrosion Station 3. The three atmospheric corrosion stations were equipped with the necessary instrumentation to measure atmospheric pollution in terms of SO 2 38-39 and Cl -. 40 As can be inferred from Table 1, the atmospheric SO 2 content was negligible (0.96 mg SO 2 /m 2 /d to 1.44 mg SO 2 /m 2 /d).…”

“…v TEM/SAED has been used to precisely identify the nature and structure of the cigar-shape crystals forming these aggregates. The corresponding high resolution images show d-spacing of 0.74 nm (d 101 ) and 0.28 nm (d 121 ) correspond to the akaganeite structure along [- [1][2][3][4][5][6][7][8][9][10][11] . The Fourier transform and the calculated SAED pattern along this projection clearly demonstrated that these crystals show the structural features characteristic of the hollandite structure type corresponding to akaganeite.…”

“…The corrosion rate is a function of the chloride deposition rate. [1][2][3] The higher corrosion rate of steel in marine atmospheres may also be a result of other causes: (a) being hygroscopic, chloride species (sodium chloride, magnesium chloride, etc.) promote the electrochemical corrosion process, favoring the formation of electrolytes at relative humidity (RH) values lower than 100%, and (b) the solubility of the corrosion products formed also plays an important role.…”

“…16 The oxidation process of ferrous hydroxychloride, which leads to akaganeite formation, passes through different steps. 25 In a first oxidation stage, ferrous hydroxychloride gives rise to the standard chloridecontaining green rust one GR1 (Cl -) whose simplified formula is Fe 4 (OH) 8 Cl: 2Fe 2 (OH) 3 Cl + 2H 2 O → Fe 4 (OH) 8 Cl + e -+ 2H + + Cl - (2) Because of the large chloride concentration of the solution, in a second stage the standard, GR1 (Cl -) leads to over-chlorinated compounds (GR1(Cl -)*). Finally, the oxidation process of these over-chlorinated compounds gives rise to the akaganeite formation; the increase of the chloride content of GR1(Cl -)* compounds favors the formation of akaganeite and these compounds are considered to be the precursor of akaganeite.…”

Characterization of rust phases formed on low carbon steel exposed to natural marine environment of Chennai harbour – South India

“…Similarly, corrosion of steels in the coasts of Spain, Gulf of Mexico, Bombay (India), etc. has been reported in the literature [11][12][13][14]. Several investigators have carried out the rust characterization and results were made available to the corrosion community [15][16][17].…”