Mechanics, Materials Science & Engineering, December 2016
ISSN 2412-5954
3
The Authors. Published by Magnolithe GmbH. This is an open access article under the CC BY-NC-ND license http://creativecommons.org/licenses/by-nc-nd/4.0/
MMSE Journal. Open Access www.mmse.xyz
23
Mechanics, Materials Science & Engineering, December 2016
MMSE Journal. Open Access www.mmse.xyz
24
ISSN 2412-5954
Mechanics, Materials Science & Engineering, December 2016
MMSE Journal. Open Access www.mmse.xyz
25
ISSN 2412-5954
Mechanics, Materials Science & Engineering, December 2016
-0,3 -0,4
ISSN 2412-5954
NaCl 2,0 g/L NaCl 4,0 g/L
-0,5 -0,6 -0,7 -0,8 -0,9 -8
-7
-6
-5
-4
-3
-2
-2
Log (I / A cm )
1,2 Tafel Curva CP
0,9
NaCl 2,0 g/L
0,6 0,3 0,0 -0,3 -0,6 -0,9 -8
-7
-6
-5
-4
-3
-2
Log (I / A cm )
MMSE Journal. Open Access www.mmse.xyz
26
-2
Mechanics, Materials Science & Engineering, December 2016
ISSN 2412-5954
For this type of steel, the electrochemical mechanism of corrosion process originates in the form of localized corrosion (crevice) usually associated with electrolyte stagnation conditions in microenvironments where there is hindrance or difficulty to the spread of chemical species. The solution within the crack is deoxygenated due to initial corrosion that consumes, through cathodic process, the oxygen in solution: O2 + 2H2O + 4e 4OH-. The oxygen diffusion rate into the crack is not fast enough to replenish the oxygen consumed in the cathodic process. The cathodic process moves out of the crack where oxygen is plentiful. There is separation of anodic and cathodic regions. The ferrous ions are formed within the crack (Fe Fe ++ + 2e-) and hydroxyls in oxygenated regions. The ferrous ions undergo hydrolysis (Fe ++ + H2O Fe (OH) + + H+) and decrease the pH within the crack. Due to the current flow and mass transport phenomena, aggressive ions migrate under the influence of electrostatic field into the crack, and are concentrated there, causing great changes in chemical conditions. As a result there is the iron hydroxide (II), white color, which due to the oxidation process is turned slowly into iron hydroxide (III), which has a brown-orange coloration according to the iron content (III) .When this type of coloring appears in structures (concrete and steel), it indicates that they are suffering corrosion. The oxidized iron assumes that color and begins to crumble. In the affected areas, the metal will lose density and, if the process is not contained, it can reach the full degradation.
MMSE Journal. Open Access www.mmse.xyz
27
Mechanics, Materials Science & Engineering, December 2016
MMSE Journal. Open Access www.mmse.xyz
28
ISSN 2412-5954
-50%
-100%
29
MMSE Journal. Open Access www.mmse.xyz
Mangaratiba
Engenheiro Paulo de Frontin Mendes Vassouras Miguel Pereira Areal Comendador Levy Gasparian Paraty Angra dos Reis
Sapucaia Paty do Alferes
Rio das Flores
Rio Claro
Porto Real Itatiaia Pinheiral Resende Quatis Volta Redonda Barra Mansa
Mechanics, Materials Science & Engineering, December 2016 ISSN 2412-5954
300%
250%
200%
150%
100%
50%
00%
Mechanics, Materials Science & Engineering, December 2016
MMSE Journal. Open Access www.mmse.xyz
30
ISSN 2412-5954
Mechanics, Materials Science & Engineering, December 2016
ISSN 2412-5954
0.25 0.2 0.15 0.1 0.05 0
Fig. 15. Numbers of employees in some cities in the southern state.
[9] de Macena Rezende, D. (2014). SUPER 13Cr MODIFICADO [10] Greaney, M. J., Das, S., Webber, D. H., Bradforth, S. E., & Brutchey, R. L. (2012). Improving open circuit potential in hybrid P3HT: CdSe bulk heterojunction solar cells via colloidal tertbutylthiol ligand exchange. Acs Nano, 6(5), 4222-4230. MMSE Journal. Open Access www.mmse.xyz
31
Mechanics, Materials Science & Engineering, December 2016
ISSN 2412-5954
C., Gomes, L. A. V., Nascimento, P. A. M. M., & Toledo, Novos Estudos-CEBRAP, (98), 43-67. -2011. Base de Dados. [13] Sawacha, E., Naoum, S., & Fong, D. (1999). Factors affecting safety performance on construction sites. International journal of project management, 17(5), 309-315. [14] Porter, M. (2003). The economic performance of regions. Regional studies, 37(6-7), 549-578. [15] Leiblein, M. J., Reuer, J. J., & Dalsace, F. (2002). Do make or buy decisions matter? The influence of organizational governance on technological performance. Strategic management journal, 23(9), 817-833. Cite the paper Silva (2016). Statistical Study of Corrosion Types in Constructions in South Region of Rio De Janeiro Brazil. Mechanics, Materials Science & Engineering, Vol 7. doi: 10.13140/RG.2.2.29609.60004
MMSE Journal. Open Access www.mmse.xyz
32