Passive Behavior and Passivity Breakdown of AISI 304 in LiBr Solutions through Scanning Electrochemical Microscopy

The passive behavior and passivity breakdown of AISI 304 stainless steel in LiBr solutions has been investigated by means of scanning electrochemical microscopy (SECM). The sample generation - tip collection (SG-TC) mode was used to operate the SECM and the tip potential was biased to detect the electroactive species. The evolution of the current at the ultramicroelectrode tip with the applied potential within the passive range was followed at different LiBr concentrations. Results show that the absolute value of the current at the tip increases with the applied potential. Additionally, SECM was also used to detect stable pits formed on the stainless steel surface in a 0.2 M LiBr solution. The results show clear evidence of the presence of high amounts of other reducible species (metal cations) apart from oxygen. Also, the dish-shape morphology of the pits observed using Confocal Laser Scanning Microscopy will be discussed in relation to the kinetics of the reactions observed using SECM. (c) 2014 The Electrochemical Society. All rights reserved.The authors would like to express their gratitude to the Generalitat Valenciana for its help in the SECM acquisition (PPC/2011/013) and in the CLSM acquisition (MY08/ISIRM/S/100) and to Dr. Asuncion Jaime for her translation assistance.Fernández Domene, RM.; Sánchez Tovar, R.; García Antón, J. (2014). Passive Behavior and Passivity Breakdown of AISI 304 in LiBr Solutions through Scanning Electrochemical Microscopy. Journal of The Electrochemical Society. 161(12):565-572. https://doi.org/10.1149/2.1051412jesS56557216112Cobb Harold M. (Ed.), Steel Products Manual: Stainless Steels, Iron & Steel Society, 1999.Schweitzer P. A. , Corrosion Engineering Handbook: Fundamentals of Metallic Corrosion, CRC Press, Boca Ratón, FL., 2007.Hakiki, N. B., Boudin, S., Rondot, B., & Da Cunha Belo, M. (1995). The electronic structure of passive films formed on stainless steels. Corrosion Science, 37(11), 1809-1822. doi:10.1016/0010-938x(95)00084-wWijesinghe, T. L. S. L., & Blackwood, D. J. (2008). Photocurrent and capacitance investigations into the nature of the passive films on austenitic stainless steels. Corrosion Science, 50(1), 23-34. doi:10.1016/j.corsci.2007.06.009Hakiki, N. E. (1998). Semiconducting Properties of Passive Films Formed on Stainless Steels. Journal of The Electrochemical Society, 145(11), 3821. doi:10.1149/1.1838880Olefjord, I. (1985). Surface Composition of Stainless Steels during Anodic Dissolution and Passivation Studied by ESCA. Journal of The Electrochemical Society, 132(12), 2854. doi:10.1149/1.2113683Lothongkum, G., Chaikittisilp, S., & Lothongkum, A. . (2003). XPS investigation of surface films on high Cr-Ni ferritic and austenitic stainless steels. Applied Surface Science, 218(1-4), 203-210. doi:10.1016/s0169-4332(03)00600-7Freire, L., Carmezim, M. J., Ferreira, M. G. S., & Montemor, M. F. (2010). The passive behaviour of AISI 316 in alkaline media and the effect of pH: A combined electrochemical and analytical study. Electrochimica Acta, 55(21), 6174-6181. doi:10.1016/j.electacta.2009.10.026Roberge P. R. , Corrosion Engineering. Principles and Practice, 1st. ed., McGraw-Hill, New York, NY, 2008.Wipf, D. O. (1994). Initiation and study of localized corrosion by scanning electrochemical microscopy. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 93, 251-261. doi:10.1016/0927-7757(94)02872-9Casillas, N. (1994). Pitting Corrosion of Titanium. Journal of The Electrochemical Society, 141(3), 636. doi:10.1149/1.2054783Basame, S. B., & White, H. S. (1995). Scanning electrochemical microscopy of native titanium oxide films. Mapping the potential dependence of spatially-localized electrochemical reactions. The Journal of Physical Chemistry, 99(44), 16430-16435. doi:10.1021/j100044a034Still, J. W. (1997). Breakdown of the Iron Passive Layer by Use of the Scanning Electrochemical Microscope. Journal of The Electrochemical Society, 144(8), 2657. doi:10.1149/1.1837879Zhu, Y. (1997). Scanning Electrochemical Microscopic Observation of a Precursor State to Pitting Corrosion of Stainless Steel. Journal of The Electrochemical Society, 144(3), L43. doi:10.1149/1.1837487Basame, S. B., & White, H. S. (1998). Scanning Electrochemical Microscopy:  Measurement of the Current Density at Microscopic Redox-Active Sites on Titanium. The Journal of Physical Chemistry B, 102(49), 9812-9819. doi:10.1021/jp982088xWilliams, D. E. (1998). Elucidation of a Trigger Mechanism for Pitting Corrosion of Stainless Steels Using Submicron Resolution Scanning Electrochemical and Photoelectrochemical Microscopy. Journal of The Electrochemical Society, 145(8), 2664. doi:10.1149/1.1838697Lister, T. E., & Pinhero, P. J. (2002). Scanning Electrochemical Microscopy Study of Corrosion Dynamics on Type 304 Stainless Steel. Electrochemical and Solid-State Letters, 5(11), B33. doi:10.1149/1.1510621Lister, T. E., & Pinhero, P. J. (2003). The effect of localized electric fields on the detection of dissolved sulfur species from Type 304 stainless steel using scanning electrochemical microscopy. Electrochimica Acta, 48(17), 2371-2378. doi:10.1016/s0013-4686(03)00228-7González-Garcı́a, Y., Burstein, G. ., González, S., & Souto, R. . (2004). Imaging metastable pits on austenitic stainless steel in situ at the open-circuit corrosion potential. Electrochemistry Communications, 6(7), 637-642. doi:10.1016/j.elecom.2004.04.018Souto, R. M., González-Garcı́a, Y., & González, S. (2005). In situ monitoring of electroactive species by using the scanning electrochemical microscope. Application to the investigation of degradation processes at defective coated metals. Corrosion Science, 47(12), 3312-3323. doi:10.1016/j.corsci.2005.07.005Völker, E., Inchauspe, C. G., & Calvo, E. J. (2006). Scanning electrochemical microscopy measurement of ferrous ion fluxes during localized corrosion of steel. Electrochemistry Communications, 8(1), 179-183. doi:10.1016/j.elecom.2005.10.003Gabrielli, C., Joiret, S., Keddam, M., Perrot, H., Portail, N., Rousseau, P., & Vivier, V. (2007). A SECM assisted EQCM study of iron pitting. Electrochimica Acta, 52(27), 7706-7714. doi:10.1016/j.electacta.2007.03.008Yin, Y., Niu, L., Lu, M., Guo, W., & Chen, S. (2009). In situ characterization of localized corrosion of stainless steel by scanning electrochemical microscope. Applied Surface Science, 255(22), 9193-9199. doi:10.1016/j.apsusc.2009.07.003Santana, J. J., González-Guzmán, J., Fernández-Mérida, L., González, S., & Souto, R. M. (2010). Visualization of local degradation processes in coated metals by means of scanning electrochemical microscopy in the redox competition mode. Electrochimica Acta, 55(15), 4488-4494. doi:10.1016/j.electacta.2010.02.091González-García, Y., Santana, J. J., González-Guzmán, J., Izquierdo, J., González, S., & Souto, R. M. (2010). Scanning electrochemical microscopy for the investigation of localized degradation processes in coated metals. Progress in Organic Coatings, 69(2), 110-117. doi:10.1016/j.porgcoat.2010.04.006Yuan, Y., Li, L., Wang, C., & Zhu, Y. (2010). Study of the effects of hydrogen on the pitting processes of X70 carbon steel with SECM. Electrochemistry Communications, 12(12), 1804-1807. doi:10.1016/j.elecom.2010.10.031Aouina, N., Balbaud-Célérier, F., Huet, F., Joiret, S., Perrot, H., Rouillard, F., & Vivier, V. (2011). Single pit initiation on 316L austenitic stainless steel using scanning electrochemical microscopy. Electrochimica Acta, 56(24), 8589-8596. doi:10.1016/j.electacta.2011.07.044Bard A. J. Mirkin M. V. (Eds.), Scanning Electrochemical Microscopy, 1st. ed., Marcel Dekker, New York, NJ, 2001.Kaneko, M., & Isaacs, H. . (2000). Pitting of stainless steel in bromide, chloride and bromide/chloride solutions. Corrosion Science, 42(1), 67-78. doi:10.1016/s0010-938x(99)00056-6Frankel, G. S. (1998). Pitting Corrosion of Metals. Journal of The Electrochemical Society, 145(6), 2186. doi:10.1149/1.1838615Kaneko, M., & Isaacs, H. S. (2002). Effects of molybdenum on the pitting of ferritic- and austenitic-stainless steels in bromide and chloride solutions. Corrosion Science, 44(8), 1825-1834. doi:10.1016/s0010-938x(02)00003-3Abd El Meguid, E. A., & Mahmoud, N. A. (2003). Inhibition of Bromide-Pitting Corrosion of Type 904L Stainless Steel. CORROSION, 59(2), 104-111. doi:10.5006/1.3277539Anderko, A., & Young, R. D. (2000). Model for Corrosion of Carbon Steel in Lithium Bromide Absorption Refrigeration Systems. CORROSION, 56(5), 543-555. doi:10.5006/1.3280559Chau, D. S., Wood, B. D., Berman, N. S., & Kim, K. J. (1993). Solubility of oxygen in aqueous lithium bromide using electrochemical technique. International Communications in Heat and Mass Transfer, 20(5), 643-652. doi:10.1016/0735-1933(93)90076-8Macdonald, D. D. (1992). The Point Defect Model for the Passive State. Journal of The Electrochemical Society, 139(12), 3434. doi:10.1149/1.2069096Paola, A. D. (1989). Semiconducting properties of passive films on stainless steels. Electrochimica Acta, 34(2), 203-210. doi:10.1016/0013-4686(89)87086-0Hakiki, N. E., Montemor, M. F., Ferreira, M. G. S., & da Cunha Belo, M. (2000). Semiconducting properties of thermally grown oxide films on AISI 304 stainless steel. Corrosion Science, 42(4), 687-702. doi:10.1016/s0010-938x(99)00082-7Carmezim, M. J., Simões, A. M., Figueiredo, M. O., & Da Cunha Belo, M. (2002). Electrochemical behaviour of thermally treated Cr-oxide films deposited on stainless steel. Corrosion Science, 44(3), 451-465. doi:10.1016/s0010-938x(01)00076-2Sharma S. K. , Green Corrosion Chemistry and Engineering: Opportunities and Challenges, Wiley-VCH Verlag GmbH & Co., First Edition, Germany, 2012.Venkatraman, M. S., Cole, I. S., & Emmanuel, B. (2011). Corrosion under a porous layer: A porous electrode model and its implications for self-repair. Electrochimica Acta, 56(24), 8192-8203. doi:10.1016/j.electacta.2011.06.020Thomas, S., Cole, I. S., Sridhar, M., & Birbilis, N. (2013). Revisiting zinc passivation in alkaline solutions. Electrochimica Acta, 97, 192-201. doi:10.1016/j.electacta.2013.03.008Gao, S., Dong, C., Luo, H., Xiao, K., Pan, X., & Li, X. (2013). Scanning electrochemical microscopy study on the electrochemical behavior of CrN film formed on 304 stainless steel by magnetron sputtering. Electrochimica Acta, 114, 233-241. doi:10.1016/j.electacta.2013.10.009Lu, G., Cooper, J. S., & McGinn, P. J. (2007). SECM imaging of electrocatalytic activity for oxygen reduction reaction on thin film materials. Electrochimica Acta, 52(16), 5172-5181. doi:10.1016/j.electacta.2007.02.022Song C. Zhang J. , Electrocatalytic Oxygen Reduction Reaction, in: J. Zhang (Ed.), PEM Fuel Cell Electrocatalysts and Catalyst Layers, Ch. 2, Springer, London, 2008, p. 89.Macdonald, D. D. (1999). Passivity–the key to our metals-based civilization. Pure and Applied Chemistry, 71(6), 951-978. doi:10.1351/pac199971060951Macdonald, D. D., Rifaie, M. A., & Engelhardt, G. R. (2001). New Rate Laws for the Growth and Reduction of Passive Films. Journal of The Electrochemical Society, 148(9), B343. doi:10.1149/1.1385818Macdonald, D. D. (2006). On the Existence of Our Metals-Based Civilization. Journal of The Electrochemical Society, 153(7), B213. doi:10.1149/1.2195877Marconnet, C., Wouters, Y., Miserque, F., Dagbert, C., Petit, J.-P., Galerie, A., & Féron, D. (2008). Chemical composition and electronic structure of the passive layer formed on stainless steels in a glucose-oxidase solution. Electrochimica Acta, 54(1), 123-132. doi:10.1016/j.electacta.2008.02.070Rhode, S., Kain, V., Raja, V. S., & Abraham, G. J. (2013). Factors affecting corrosion behavior of inclusion containing stainless steels: A scanning electrochemical microscopic study. Materials Characterization, 77, 109-115. doi:10.1016/j.matchar.2013.01.006Newman, R. C., & Franz, E. M. (1984). Growth and Repassivation of Single Corrosion Pits in Stainless Steel. CORROSION, 40(7), 325-330. doi:10.5006/1.3593930Simões, A. M., Bastos, A. C., Ferreira, M. G., González-García, Y., González, S., & Souto, R. M. (2007). Use of SVET and SECM to study the galvanic corrosion of an iron–zinc cell. Corrosion Science, 49(2), 726-739. doi:10.1016/j.corsci.2006.04.021Beck, T. R. (1979). Occurrence of Salt Films during Initiation and Growth of Corrosion Pits. Journal of The Electrochemical Society, 126(10), 1662. doi:10.1149/1.2128772Alkire, R. C., & Wong, K. P. (1988). The corrosion of single pits on stainless steel in acidic chloride solution. Corrosion Science, 28(4), 411-421. doi:10.1016/0010-938x(88)90060-1Bastos, A. C., Simões, A. M., González, S., González-García, Y., & Souto, R. M. (2004). Imaging concentration profiles of redox-active species in open-circuit corrosion processes with the scanning electrochemical microscope. Electrochemistry Communications, 6(11), 1212-1215. doi:10.1016/j.elecom.2004.09.022Böhni H. , Localized Corrosion of Passive Metals, in: Winston Revie R. (Ed.), Uhlig's Corrosion Handbook, 2nd ed., Ch. 10, Wiley Interscience, New York, 2000.Leiva-García, R., García-Antón, J., & Muñoz-Portero, M. J. (2010). Contribution to the elucidation of corrosion initiation through confocal laser scanning microscopy (CLSM). Corrosion Science, 52(6), 2133-2142. doi:10.1016/j.corsci.2010.02.034Laycock, N. J., & Newman, R. C. (1997). Localised dissolution kinetics, salt films and pitting potentials. Corrosion Science, 39(10-11), 1771-1790. doi:10.1016/s0010-938x(97)00049-8Moayed, M. H., & Newman, R. C. (2006). The Relationship Between Pit Chemistry and Pit Geometry Near the Critical Pitting Temperature. Journal of The Electrochemical Society, 153(8), B330. doi:10.1149/1.2210670Ernst, P., & Newman, R. . (2002). Pit growth studies in stainless steel foils. I. Introduction and pit growth kinetics. Corrosion Science, 44(5), 927-941. doi:10.1016/s0010-938x(01)00133-0Ernst, P., Laycock, N. J., Moayed, M. H., & Newman, R. C. (1997). The mechanism of lacy cover formation in pitting. Corrosion Science, 39(6), 1133-1136. doi:10.1016/s0010-938x(97)00043-7Sun, D., Jiang, Y., Tang, Y., Xiang, Q., Zhong, C., Liao, J., & Li, J. (2009). Pitting corrosion behavior of stainless steel in ultrasonic cell. Electrochimica Acta, 54(5), 1558-1563. doi:10.1016/j.electacta.2008.09.056Ren, J., & Zuo, Y. (2005). The growth mechanism of pits in NaCl solution under anodic films on aluminum. Surface and Coatings Technology, 191(2-3), 311-316. doi:10.1016/j.surfcoat.2004.04.05

Study of the sensitisation process of a duplex stainless steel (UNS 1.4462) by means of confocal microscopy and localised electrochemical techniques

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