Atmospheric Corrosion Studies of Ductile Iron and Austenitic Stainless Steel in an Extreme Marine Environment

Olasupo Ogundare, Babaniyi Babatope, Adelana Razaq Adetunji, Samuel Olugbenga Oloruntoba Olusunle

Department of Materials Science and Engineering, ObafemiAwolowo University, Ile Ife. Nigeria.
Department of Physics, ObafemiAwolowo University, Ile Ife. Nigeria.
National Agency for Science and Engineering Infrastructure, Abuja. Nigeria.
Prototype Engineering Development Institute Ilesa Nigeria.

DOI: 10.4236/jmmce.2012.119088                

Abstract

This paper presents the corrosion characteristics and the accompanying changes in the microstructure of unalloyed duc-tile iron (DI) and austenitic stainless steel (ASS) in table salt medium representing an upper limit in an extreme marine environment. The individual corrosion rates of DI and ASS was evaluated for the maximum time period of 1200 hr. Using the immersion test technique, the corrosion rate of DI was evaluated and found to be four-orders of magnitude greater than that of ASS. The corrosion product morphologies of the DI showed that the nodular matrix was gradually covered up as immersion time progressed while the corrosion channels and volume of pits that initially formed in ASS respectively deepened and increased with increased exposure time. This work is important as a reference point for the quantification of the corrosion effectiveness of alloying DI. The microstructures of the corroded samples showed corro-sion initiation and gradual accumulation of corrosion products.

Keywords

Atmospheric Corrosion; Ductile IronL Austenitic Stainless Steel; Sodium Chloride And Microstructure

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	A. Galal, N. F. Atta and M. H. S. Al-Hassan, “Effect of Some Thiophene Derivatives on the Electrochemical Behaviour of AISI 316 Austenitic Stainless Steel in Acidic Solutions Containing Chloride Ions: I. Molecular structure and inhibition efficiency relationship,” Materials Chemistry and Physics, Vol. 89, No. 1, 2005, pp. 38-48. doi:10.1016/j.matchemphys.2004.08.019
[2]	A. I. Munoz, J. G. Anton, S. L. Nuevalos, J. L. Guinon and V. P. Herranz, “Corrosion Studies of Austenitic and Duplex Stainless Steels in Aqueous Lithium Bromide Solution at Different Temperatures,” Corrosion Science, Vol. 46, No. 12, 2004, pp. 2955-2974. doi:10.1016/j.corsci.2004.05.025
[3]	M. A. Streicher, “Stainless Steels: Past, Present and Future,” Climax Molybdenum Co., Ann Arbor, 1997.
[4]	T. Nakayama and Y. Oshida, “Identification of the Initial Oxide Films on 18-8 Stainless Steel in High Temperature Water,” Corrosion, Vol. 21, 1968, pp. 336-337.
[5]	G. Okamoto and T. Shibata, “Passivity and Breakdown of Passivity of Stainless Steel,” In: R. P. Frankenthel and J. Kruger, Eds., Passivity of Metals, Electrochemical Society, New York, 1978.
[6]	J. A. Platt, A. Guzman, A. Zuccari, D. W. Thornburg, B. F. Rhodes, Y. Ossida, D. W. Thornburg, B. F. Rhodes, Y. Ossida and B. K. Moore, “Corrosion Behavior of 2205 Duplex Stainless Steel,” American Journal of Orthodontics and Dentofacial Orthopetics, Vol. 112, 1997, pp. 69-79.
[7]	O. O. Oluwole, P. O. Atanda, O. A. Odekunbi and E. Odegbaju, “Corrosion Behavior of 18/8 Stainless Steel and Nickel-Plated Low Carbon Steel in Cassava Fluid,” Journal of Minerals and Materials Characterization and Engineering, Vol. 8, No. 10, 2009, pp. 803-811.
[8]	M. M. Amin, W. B. Wan Nik and K. Yunus, “Oxidation Behaviour of Low Carbon Steel in Natural Water,” Oriental Journal of Chemistry, Vol. 18, No. 2, 2002, pp. 183-186.
[9]	N. D. Prasanna, “Effect of Processes Variables on the Structure Mechanical Properties and Wear Characteristics of Austempered Ductile Iron,” Ph.D. Thesis, Bangalore University, Bangalore, 2000.
[10]	R. Grundy, “The Development and Introduction of Spheroidal Graphite Irons into an Established Range of Malleable Irons to Meet Current Engineering Requirements,” Transactions of Foundrymen, Vol. 72, 1979, pp. 141-151.
[11]	K. L. Gillespie, “Troubleshooting Manufacturing Processes,” 4th Edition, SME, 1988. p. 4.
[12]	C. S. Kanetkar, H. H. Cornell and D. M. Stefanescu, Transaction of American Foundrymen’s Society, Vol. 92, 1984, pp. 417-428.
[13]	O. Aponbiede and M. Okelekwe, “The Effect of Chloride Salts on the Mechanical Properties of Gray Cast Iron,” Journal of Emerging Trends in Engineering and Applied Sciences, Vol. 2, No. 2, 2011, pp. 256-259.
[14]	M. Misbahul Amin, “The CsCl-and CsNO3-Induced High Temperature Oxidation of Nimonic-90 Alloy at 1123 K,” Applied Surface Science, Vol. 115, No. 4, 1997, pp. 355-360. doi:10.1016/S0169-4332(97)00003-2
[15]	R. Mehra and A. Soni, “Cast Iron Deterioration with Time in Various Aqueous Salt Solutions,” Bulletin of Materials Science, Vol. 25, No. 1, 2002, pp. 53-58. doi:10.1007/BF02704595
[16]	Department of Geology, San Jose State University, “Salinity and Variability,” 2004 http://geosun1.sjsu.edu/~dreed/105/exped6/5.html
[17]	M. Mobin and H. Shabnam, “Corrosion Behaviour of Mild Steel and SS 304L in Presence of Dissolved Copper,” Journal of Minerals and Materials Characterization and Engineering, Vol. 9, No. 12, 2010, pp. 1113-1130.
[18]	J. R. Davila, A. Garrote, A. M. Gutierrez, P. Carnicer, L. Cobos and I. Erauskin, “New Applications of the Oxygas Rotary Furnace as a Means of Production in Melting,” Proceedings of 1995 International Gas Research Conference, Cannes, 6 November 1995, pp. 2764-2773.
[19]	ASTM G 1-90, “Standard Practice of Preparing, Cleaning and Evaluating Corrosion Test Specimens, Annual Book of ASTM Standards,” Vol. 3.02, ASTM, Philadelphia, 1993.
[20]	A. Y. Badmos, H. A. Ajimotakan and E. O. Emmanuel, “Corrosion in Petroleum Pipelines,” New York Science Journal, Vol. 2, No. 5, 2009, pp. 36-40.
[21]	S. A. Umoren, U. M. Eduok and E. E. Oguzie, “Corrosion Inhibition of Mild Steel in 1 M H2SO4 by Polyvinyl Pyrrolidone and Synergistic Iodide Additives,” Portugaliae Electrochimica Acta, Vol. 26, 2008, pp. 533-546.
[22]	N. D. Prasanna, M. K. Muralidhara, M. K. Agarwal and K. Radhakrishna, “Mechanical Properties and Corrosion Characteristics of IS400/12 Grade Ductile Iron,” Transactions of 57th International Foundrymen Congress, Osaka, 1 December 2009, pp. 89-95.