http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Mon, 25 Feb 2013 08:02:20 +0000 http://www.hindawi.com/journals/ijc/2013/805167/ Corrosion occurs in many engineering structures such as bridges, pipelines, and refineries and leads to the destruction of materials in a gradual manner and thus shortening their lifespan. It is therefore crucial to assess the structural integrity of engineering structures which are approaching or exceeding their designed lifespan in order to ensure their correct functioning, for example, carrying ability and safety. An understanding of corrosion and an ability to predict corrosion rate of a material in a particular environment plays a vital role in evaluating the residual life of the material. In this paper we investigate the use of genetic programming and genetic algorithms in the derivation of corrosion-rate expressions for steel and zinc. Genetic programming is used to automatically evolve corrosion-rate expressions while a genetic algorithm is used to evolve the parameters of an already engineered corrosion-rate expression. We show that both evolutionary techniques yield corrosion-rate expressions that have good accuracy. Amine Marref, Saleh Basalamah, and Rami Al-Ghamdi Copyright © 2013 Amine Marref et al. All rights reserved. Sun, 30 Dec 2012 18:34:24 +0000 http://www.hindawi.com/journals/ijc/2012/496960/ Polymer components for liquid sealing applications are employed in a variety of potentially corrosive environments, such as seawater. Frequently, corrosion of the metal is found at or adjacent to the rubber-metal interface rather than at a noncontact area. The corrosion of different metal alloys (titanium, bronze, nickel, aluminum, 316 stainless steel, and 4130 steel) in combination with rubber O-rings (Buna-N and EPDM) of varying internal diameters and cross-sectional shapes in seawater over a period of four years is described herein. The corrosion of some metals (i.e., 4130 stainless steel) was found to be accelerated through interaction with Buna-N rubber O-rings. Theories to account for corrosion at the polymer-metal interface, especially with respect to polymer composition and O-ring size and shape, are discussed. Amelia M. Anderson-Wile, Bradley M. Wile, Qiang Wen, and Hui Shen Copyright © 2012 Amelia M. Anderson-Wile et al. All rights reserved. Tue, 11 Dec 2012 10:04:08 +0000 http://www.hindawi.com/journals/ijc/2012/925958/ This work presents the electrochemical evaluation of a proposed copper corrosion protection hybrid coating acting as a smart corrosion protection system. This consists of an alkyd varnish, painted over electrospun nylon fibers acting as a secondary diffusion barrier and also as a benzotriazole (BTAH) inhibitor nanocontainer. Submicron diameter electrospun nylon 6-6 fiber nanocontainers were prepared from a polymeric solution containing BTAH at different concentrations, and Cu samples were coated with the electrospun fibers and painted over with an alkyd varnish by the drop method. Functional groups in fibers were determined through FTIR spectroscopy. Optical and SEM microscopies were used to characterize the nanocontainer fibers. Samples were evaluated using electrochemical impedance and noise, during six weeks of immersion, in a chloride-ammonium sulfate solution. Excellent response was obtained for the smart inhibitor coating system. For long periods of immersion good corrosion protection performance was observed. The results presented demonstrate the good barrier properties of the hybrid coating, obstructing the diffusion of aggressive species, through the electrospun structure. Furthermore the nanocontainer functionality to store and liberate the corrosion inhibitor, only when it is needed, was also proved. C. Menchaca, I. Castañeda, A. Soto-Quintero, R. Guardián, R. Cruz, M. A. García-Sánchez, and J. Uruchurtu Copyright © 2012 C. Menchaca et al. All rights reserved. Thu, 06 Dec 2012 15:28:05 +0000 http://www.hindawi.com/journals/ijc/2012/452631/ Corrosion behaviour of AZ and ZA magnesium alloys in untreated, aerated, and deaerated chloride media was investigated. The influence of impurity, alloying element, and oxygen on corrosion potential, rate, and pitting was examined in alkaline media saturated with Mg(OH)2 at pH 9 and 25°C. After 8 h immersion, slightly less active corrosion potentials were generally observed in deaerated than oxygen containing solutions. AZ91D and ZA104 alloys recorded much lower corrosion rates in deaerated medium as compared to AZ91E, ZAC 10403 (0.3Ca), and ZACS1040305 (0.3Ca+ 0.5Sr). Generally, ZAC alloy showed the highest corrosion rate, followed by ZACS alloy, and both showed a constant value in the three media with or without oxygen. The effect of oxygen is then dependent on the alloy properties and is not a simple acceleration of the cathodic reaction but could cause also inhibition and/or passivation. Pit depth and distribution were influenced by alloy composition. The pits were found deeper and more localized on AZ and more uniformly dispersed on ZA alloy surfaces. Mustafa Ö. Öteyaka, Edward Ghali, and Réal Tremblay Copyright © 2012 Mustafa Ö. Öteyaka et al. All rights reserved. Wed, 05 Dec 2012 10:24:40 +0000 http://www.hindawi.com/journals/ijc/2012/986186/ Facundo Almeraya, José Maria Bastidas, Andres A. Torres Acosta, and Citlalli Gaona Tiburcio Copyright © 2012 Facundo Almeraya et al. All rights reserved. Tue, 13 Nov 2012 13:55:40 +0000 http://www.hindawi.com/journals/ijc/2012/478508/ In the present study as in our previous studies (Arikan and Doruk, 2008 and Arikan et al., 2012), similar specimens taken from a hot rolled cylindrical duplex stainless steel (DSS) bar with 22% Cr grade were solution annealed at 1050°C and then aged at 800∘C from 100 to 31622 min for sensitization treatment. Double loop electrochemical potentiodynamic reactivation and standard weight loss immersion acid tests were conducted. The solution annealed samples were found unsensitized. The samples aged for 100 min were less sensitized whereas samples aged for 316 min and more time were sensitized. The degree of sensitization (DOS) can be attributed to higher contribution of chromium and molybdenum depleted areas that result from intermetallic phases. However, especially the samples aged from 3162 to 31622 min have revealed chromium replenishment. Consequently, the degree of sensitization was lowered in comparison to the results obtained in previous studies. Mehmet Emin Arıkan, Rafet Arıkan, and Mustafa Doruk Copyright © 2012 Mehmet Emin Arıkan et al. All rights reserved. Wed, 07 Nov 2012 10:19:23 +0000 http://www.hindawi.com/journals/ijc/2012/924283/ The aims of this study, firstly, to obtain high degree of clay exfoliation in the epoxy matrix by three dispersion methods such as normal mixing, shear mixing, and high-speed mixing and, secondly, to investigate corrosion behavior of epoxy/organoclay nanocomposite, immersion test, weight change, and penetration behavior were conducted. From the three mixing methods, the high-speed mixing method showed larger clay interlayer distance, smaller clay aggregate, and more homogeneity and expectedly resulted in high anticorrosive properties. Penetration depths of these nanocomposites showed a small difference; however, the most noticeable improvements in anticorrosion performance for epoxy/organoclay nanocomposites under high-speed mixing method were found to reduce penetration and weight uptake which are described via the model of nanoparticulate-filled structure and discussed in corrosion protection mechanism against environmental liquid penetration. Wiwat Keyoonwong, Yi Guo, Masatoshi Kubouchi, Saiko Aoki, and Tetsuya Sakai Copyright © 2012 Wiwat Keyoonwong et al. All rights reserved. Wed, 19 Sep 2012 16:18:31 +0000 http://www.hindawi.com/journals/ijc/2012/479761/ A study on the corrosion behavior of a series of experimental high-chromium (18.53–30.48 wt.%), high-carbon (3.82–5.17%) cast irons in NaCl-KCl (1 : 1 M) at 670°C has been evaluated by using weight loss technique and compared with a 304-type stainless steel. It was found that all castings had a higher corrosion rate than conventional 304SS and that the addition of Cr increased the degradation rate of the cast irons. Additionally, corrosion rate increased by increasing the C contents up to 4.29%, but it decreased with a further increase in its contents. Results are discussed in terms of consumption of the Cr2O3 layer by the melt. S. Vuelvas-Rayo, J. G. Gonzalez-Rodriguez, J. Porcayo-Calderon, V. M. Salinas-Bravo, and S. I. Maldonado-Ruiz Copyright © 2012 S. Vuelvas-Rayo et al. All rights reserved. Tue, 11 Sep 2012 09:44:19 +0000 http://www.hindawi.com/journals/ijc/2012/760284/ Cerium-based conversion coatings were deposited on as-cast aluminum alloy 380 substrates by a spontaneous immersion process. In this study, the effects of rinsing temperature prior to immersion in the coating deposition solution were studied with respect to the surface morphology, electrochemical response, and corrosion resistance of the coatings. Panels rinsed at 25∘C prior to coating had large cracks and holes in the coating. In contrast, panels rinsed at 100∘C prior to coating had a uniform coating morphology with fewer, smaller cracks. Electrochemical testing revealed that coatings deposited on substrates rinsed at 100∘C had higher impedance (~80 kΩ·cm2) and lower corrosion current (~0.34 𝜇A/cm2) compared to coatings deposited on substrates rinsed at 25∘C, which had 10 kΩ·cm2 impedance and 2.7 𝜇A/cm2 corrosion current. Finally, ASTM B117 salt spray testing showed that rinsing at 100∘C prior to coating resulted in cerium-based conversion coatings that could resist the formation of salt tails for at least 8 days. Ci Lin, Surender Maddela, William G. Fahrenholtz, and Matthew J. O'Keefe Copyright © 2012 Ci Lin et al. All rights reserved. Mon, 03 Sep 2012 17:55:16 +0000 http://www.hindawi.com/journals/ijc/2012/162729/ A low-carbon steel A-36 and two conventional weathering steels A-588 and COR-420 exposed at four atmospheric test stations located in (i) Tocumen, an urban site near the Pacific Ocean, (ii) Sherman-Open, (iii) Sherman-Coastal, and (iv) Sherman-Breakwater on the Caribbean coast of Panama. Kinetics of the short-term atmospheric corrosion process and the relationship with exposure time and environmental characteristics of each site were investigated. The atmospheric exposure conditions, particularly the time of wetness, deposition of chloride, and the washing effect of contaminants on the metal surface by rain are of upmost importance in determining the corrosion behaviour and composition of rust. The corrosion products were mainly identified using room temperature and low temperature (80 K) Mössbauer spectroscopy, FTIR, and X-ray powder diffraction. In all samples, γ-FeOOH and α-FeOOH were the main constituents. Maghemite (γ-Fe2O3), magnetite (Fe3O4), and Akaganeite (β-FeOOH) were also identified. Juan A. Jaén, Josefina Iglesias, and Cecilio Hernández Copyright © 2012 Juan A. Jaén et al. All rights reserved. Wed, 29 Aug 2012 15:47:36 +0000 http://www.hindawi.com/journals/ijc/2012/185842/ The hot corrosion behavior of Fe40Al intermetallic alloyed with Ag, Cu, Li, and Ni (1–5 at.%) in NaCl-KCl (1 : 1 M) at 670°C, typical of waste gasification environments, has been evaluated by using polarization curves and weight loss techniques and compared with a 304-type stainless steel. Both gravimetric and electrochemical techniques showed that all different Fe40Al-base alloys have a much higher corrosion resistance than that for stainless steel. Among the different Fe40Al-based alloys, the corrosion rate was very similar among each other, but it was evident that the addition of Li decreased their corrosion rate whereas all the other elements increased it. Results have been explained in terms of the formation and stability of an external, protective Al2O3 layer. G. Salinas, J. G. Gonzalez-Rodriguez, J. Porcayo-Calderon, V. M. Salinas-Bravo, and M. A. Espinoza-Medina Copyright © 2012 G. Salinas et al. All rights reserved. Tue, 21 Aug 2012 10:25:16 +0000 http://www.hindawi.com/journals/ijc/2012/857823/ Copper pitting corrosion can lead to premature plumbing failures, and can be caused by aggressive potable waters characterized by high pH, free chlorine residual and low alkalinity. In such waters and under continuous flow, certain inhibitors including phosphate, silica or natural organic matter may greatly reduce pitting occurrence. In the current work, 1 mg/L phosphate (as P) completely prevented initiation of pits, and 5 mg/L silica (as Si) significantly decelerated pitting. However, much lower doses of these inhibitors had little benefit and actually accelerated the rate of attack in some cases. Effects of organic matter were dependent on both the type (e.g., natural versus ozonated humic substances) and dosage. Dose-response effects of free chlorine and alkalinity were also investigated. Based on electrochemical data, pits initiated more rapidly with increased free chlorine, but even moderate levels of chlorine (~0.4 mg/L) eventually caused severe pitting. High alkalinity decreased pit propagation rates but did not prevent pit formation. Emily Sarver and Marc Edwards Copyright © 2012 Emily Sarver and Marc Edwards. All rights reserved. Tue, 14 Aug 2012 09:25:59 +0000 http://www.hindawi.com/journals/ijc/2012/286174/ Rokuro Nishimura, Tooru Tsuru, Toshiaki Ohtsuka, Nobuyoshi Hara, En-Hou Han, and Osama Alyousif Copyright © 2012 Rokuro Nishimura et al. All rights reserved. Tue, 07 Aug 2012 09:45:28 +0000 http://www.hindawi.com/journals/ijc/2012/162425/ The surfaces of AISI 316L stainless steel were laser alloyed with ruthenium powder and a mixture of ruthenium and nickel powders using a cw Nd:YAG laser set at fixed operating parameters. The microstructure, elemental composition, and corrosion characteristics of the alloyed zone were analyzed using optical and scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and corrosion potential measurements. The depth of alloyed zone was measured using the AxioVision program and found to be approximately 1.8 mm for all the alloyed specimens. Hardness profile measurements through the surface-substrate interface showed a significant increase from 160 HV for the substrate to a maximum of 247 HV for the alloyed layer. The sample laser alloyed with 80 wt% Ni-20 wt% presented the most noble corrosion potential (𝐸corr) of −0.18 V and the lowest corrosion current density (𝑖corr). M. B. Lekala, J. W. van der Merwe, and S. L. Pityana Copyright © 2012 M. B. Lekala et al. All rights reserved. Wed, 01 Aug 2012 08:54:02 +0000 http://www.hindawi.com/journals/ijc/2012/451864/ Concrete is a porous material and the ingress of water, oxygen, and aggressive ions, such as chlorides, can cause the passive layer on reinforced steel to break down. Additives, such as fly ash, microsilica, rice husk ash, and cane sugar bagasse ash, have a size breakdown that allows the reduction of concrete pore size and, consequently, may reduce the corrosion process. The objective of this work is to determine the corrosion rate of steel in reinforced concrete by the addition of 20% sugar cane bagasse ash by weight of cement. Six prismatic specimens (7×7×10 cm) with an embedded steel rod were prepared. Three contained 20% sugar cane bagasse ash by weight of cement and the other three did not. All specimens were placed in a 3.5% NaCl solution and the corrosion rate was determined using polarization resistance. The results showed that reinforced concrete containing sugar cane bagasse ash has the lowest corrosion rates in comparison to reinforced concrete without the additive. R. E. Núñez-Jaquez, J. E. Buelna-Rodríguez, C. P. Barrios-Durstewitz, C. Gaona-Tiburcio, and F. Almeraya-Calderón Copyright © 2012 R. E. Núñez-Jaquez et al. All rights reserved. Wed, 18 Jul 2012 11:21:15 +0000 http://www.hindawi.com/journals/ijc/2012/646142/ This research in progress includes results on the corrosion performance of reinforcing steel in alkaline media when two different dehydrated cacti (Opuntia ficus-indica—Nopal—and Aloe Vera) were used as additions in pH 12.5 and 13.3 solutions and in concrete. The dehydrated cactus addition was mixed at different concentrations by either solution or cement mass (0.10%, 0.25%, 0.5%, 1.0%, and 2.0%). Half-cell potentials and LPR measurements were performed at different time periods to characterize the possible corrosion inhibiting effect of the cactus additions tested in such alkaline media. Results showed good corrosion inhibiting effect of dehydrated Nopal on reinforcing steel, in all tested solutions, when chloride ions are present. Aloe Vera did show also corrosion inhibiting improvements in some extent. The addition of such cactus led to an apparent formation of a denser and more packed oxide/hydroxide surface layer on the steel surface that decreased corrosion activity. This oxide/hydroxide layer growth was confirmed by microscopic evaluation of the metal surface layer performed at the end of the research program. The preliminary findings suggest that adding Nopal at concentrations between 1% and 2%, by mass, might be suitable for durability enhancing applications in alkaline media, especially in concrete structures. A. A. Torres-Acosta, W. Martínez-Molina, and E. M. Alonso-Guzmán Copyright © 2012 A. A. Torres-Acosta et al. All rights reserved. Sun, 15 Jul 2012 08:13:01 +0000 http://www.hindawi.com/journals/ijc/2012/172394/ An experimental study on the uniaxial tensile property of concrete exposed to the acid rain environment was carried out. Acid rain with pH level of 1.0 was deposed by the mixture of sulfate and nitric acid solution in the laboratory. Dumbbell-shaped concrete specimens were immersed in the simulated acid rain completely. After being exposed to the deposed mixture for a certain period, uniaxial tensile test was performed on the concrete specimens. The results indicate that elastic modulus, tensile strength, and peak strain have a slight increase at the initial corrosion stage, and with the extension of corrosion process, elastic modulus and tensile strength decrease gradually, while the peak strain still increases. It is found that the compressive strength is more sensitive than the tensile strength in aggressive environment. Based on the experimental results, an equation was proposed to describe the ascending branch of the stress-strain curve of the concrete corroded by acid rain. Ying-zi Zhang, Ying-fang Fan, and Hong-nan Li Copyright © 2012 Ying-zi Zhang et al. All rights reserved. Tue, 10 Jul 2012 15:26:57 +0000 http://www.hindawi.com/journals/ijc/2012/749185/ Corrosion depth of concrete can reflect the damage state of the load-carrying capacity and durability of the concrete structures servicing in severe environment. Ultrasonic technology was studied to evaluate the corrosion depth quantitatively. Three acidic environments with the pH level of 3.5, 2.5, and 1.5 were simulated by the mixture of sulfate and nitric acid solutions in the laboratory. 354 prism specimens with the dimension of 150 mm × 150 mm × 300 mm were prepared. The prepared specimens were first immersed in the acidic mixture for certain periods, followed by physical, mechanical, computerized tomography (CT) and ultrasonic test. Damage depths of the concrete specimen under different corrosion states were obtained from both CT and ultrasonic test. Based on the ultrasonic test, a bilinear regression model is proposed to estimate the corrosion depth. It is shown that the results achieved by ultrasonic and CT test are in good agreement with each other. Relation between the corrosion depth of concrete specimen and the mechanical indices such as mass loss, compressive strength, and elastic modulus is discussed in detail. It can be drawn that the ultrasonic test is a reliable nondestructive way to measure the damage depth of concrete exposed to acidic environment. Fan Yingfang, Hu Zhiqiang, and Liu Jianglin Copyright © 2012 Fan Yingfang et al. All rights reserved. Sun, 08 Jul 2012 10:02:15 +0000 http://www.hindawi.com/journals/ijc/2012/923010/ Porosity has a significant effect on the mechanical response of concrete. It is essential to well understand the relation between porosity characteristics inside the concrete with the damage process of concrete exposed to the aggressive environment. To simulate the acidic environment, the acid solutions with pH level of 1.5 and 2.5 were deposed by the mixture of the sulfate and nitric acid in the laboratory. Computed tomography (CT) and scanning electron microscopy (SEM) were used to characterize the microstructures of concrete exposed to the acidic solution for the scheduled periods. Pore distribution and porosity ratio of concrete specimens suffering various damage processes are obtained. The CT digital images were analyzed by Pro-Plus software. The threshold value is suggested to identify the pore. The developments of pore structure and porosity ratio of the concrete samples are examined. The relation between the porosity characteristic and mechanical response of concrete is discussed. Y. F. Fan, H. Y. Luan, and S. Y. Zhang Copyright © 2012 Y. F. Fan et al. All rights reserved. Sun, 08 Jul 2012 09:14:51 +0000 http://www.hindawi.com/journals/ijc/2012/414156/ The stress-corrosion cracking of A516 pressure vessel steel was investigated by the use of slow strain-rate tests. The orientation of samples to the rolling direction was investigated, and it was found that samples machined longitudinal to the rolling direction showed a slightly increased sensitivity to stress corrosion. The temperature variation showed that for different gas mixtures, the maximum sensitivity to stress corrosion was in the region of 45° to 55°C for the 25% CO gas mixture, whereas with higher CO concentrations, this temperature region of maximum sensitivity moved to higher temperatures. Surface finish showed a slight increase in sensitivity to cracking with increased surface roughness. The most significant increase was found with increased total gas pressures and when samples have been exposed to the environment for an extended period. This was as a result of the inhibition of the corrosion reaction by the passivation of the carbon monoxide, which is a time-dependent process. J. W. van der Merwe Copyright © 2012 J. W. van der Merwe. All rights reserved. Thu, 05 Jul 2012 13:08:53 +0000 http://www.hindawi.com/journals/ijc/2012/894875/ The environment-induced cracking (EIC) of aluminum alloy 5052-H3 was investigated as a function of applied stress and orientation (Longitudinal rolling direction—Transverse: LT and Transverse—Longitudinal rolling direction: TL) in 0.5 M sodium chloride solution (NaCl) using a constant load method. The applied stress dependence of the three parameters (time to failure; 𝑡𝑓, steady-state elongation rate, 𝐼ss, and transition time at which a linear increase in elongation starts to deviate, 𝑡ss) obtained from the corrosion elongation curve showed that these relationships were divided into three regions, the stress-dominated region, the EIC- dominated region, and the corrosion-dominated region. Aluminum alloy 5052-H3 with both orientations showed the same EIC behavior. The value of 𝑡ss/𝑡𝑓 in the EIC-dominated region was almost constant with 0.57±0.02 independent of applied stress and orientation. The fracture mode was transgranular for 5052-H3 with both orientations in the EIC-dominated region. The relationships between log 𝐼ss and log 𝑡𝑓 for 5052-H3 in the EIC-dominated region became a good straight line with a slope of −2 independent of orientation. Osama M. Alyousif and Rokuro Nishimura Copyright © 2012 Osama M. Alyousif and Rokuro Nishimura. All rights reserved. Thu, 05 Jul 2012 09:50:11 +0000 http://www.hindawi.com/journals/ijc/2012/482730/ The beneficial effect of the removal of MnS inclusions on the pitting of stainless steels has been demonstrated in two ways. (1) High-purity Type 316L stainless steel with no inclusions was used as a specimen in the measurement of anodic polarization curves in 0.5 M NaCl and (2) commercial Type 316L stainless steel with MnS and slag-related inclusions was first polarized at different potentials for 30 min in 1 M Na2SO4 of pH 3 and then anodic polarization measurements were taken in 0.5 M NaCl. Pitting did not occur in the passive or transpassive region of the high-purity steel. The polarization treatment dissolved MnS and some oxide inclusions (CaO and SiO2) on the surface of the commercial steel. An increase in pitting potential of the commercial steel was noted after treatment at potentials above 0.2 V. At the same time, the number of current spikes due to metastable pits decreased significantly. These results are more likely due to the beneficial effect of removing MnS inclusions from the steel surface rather than the modification effect of the chemical composition of passive films on the surface. Nobuyoshi Hara, Koichi Hirabayashi, Yu Sugawara, and Izumi Muto Copyright © 2012 Nobuyoshi Hara et al. All rights reserved. Tue, 19 Jun 2012 08:05:18 +0000 http://www.hindawi.com/journals/ijc/2012/643727/ One of the main goals of the nuclear industry is to increase the nuclear safety and reliability of nuclear power plants (NPPs). As the steam generator (SG) is the most corrosion sensitive component of NPPs, it is important to analyze the corrosion process and optimize its construction materials to avoid damages like corrosion cracking. For this purpose two different kinds of SGs and its feed water distributing systems from the NPP Jaslovske Bohunice were studied by nondestructive Mössbauer spectroscopy. The samples were scraped from the surface and analyzed in transmission geometry. Magnetite and hematite were found to be the main components in the corrosion layers of both SGs. Dependant of the material the SG consisted of, and the location in the system where the samples were taken, the ratios between magnetite and hematite and the paramagnetic components were different. The obtained results can be used to improve corrosion safety of the VVER-440 secondary circuit as well as to optimize its water chemistry regime. Jarmila Degmová, Július Dekan, Vladimír Slugeň, Constanze Thees, Ivan Smieško, and Pavol Šeliga Copyright © 2012 Jarmila Degmová et al. All rights reserved. Tue, 05 Jun 2012 10:31:44 +0000 http://www.hindawi.com/journals/ijc/2012/246013/ The corrosion inhibition of mild steel in 1 M HCl solution by a synthesized compound (3-benzoylmethyl benzimidazolium hexafluoroantimonate) was investigated electrochemically and by weight loss experiments. The concentration of this inhibitor ranged from 5×10−7 M to 5×10−4 M. The effect of temperature (from 303 to 343 K) and concentrations (from 5×10−7 M to 5×10−4 M) were investigated. The percentage inhibition increased with the increase of the concentration of the inhibitor and reached about 98% at the concentration of 5×10−4 M at 303 K. The percentage inhibition decreased with the increase of temperature. The thermodynamic parameters for the adsorption of this inhibitor on the metal surface were calculated. This compound was found to be a very good corrosion inhibitor due to the presence of nitrogen in benzimidazole and phenyl ring. Ayssar Nahlé, Ideisan I. Abu-Abdoun, and Ibrahim Abdel-Rahman Copyright © 2012 Ayssar Nahlé et al. All rights reserved. Mon, 04 Jun 2012 10:12:33 +0000 http://www.hindawi.com/journals/ijc/2012/626240/ The corrosion behavior of the Ni3Al/Ni3V two-phase intermetallic compounds with and without minor elements (Nb, Co, and Cr) to be composed of L12 phase (Ni3Al) and a mixed phase of L12 (Ni3Al) and D022 (Ni3V) has been investigated by using an immersion test in 0.5 kmol/m3 HCl, H2SO4, and HNO3 solutions. The surface morphology was observed before and after the immersion test by scanning electron microscope (SEM). The results were compared to those of the L12 single-phase Ni3(Si,Ti) and austenitic stainless steel type 304. In all acidic solutions, preferential dissolution of (L12+D022) phase was found in Ni3Al/Ni3V, but no intergranular attack, whereas the attacks took place on Ni3(Si,Ti). The Ni3Al/Ni3V showed a higher corrosion resistance in HCl solution and a lower resistance in HNO3 solution than Ni3(Si,Ti) and type 304. The addition of the minor elements enhanced corrosion resistance in HNO3 solution, but not clearly in HCl and H2SO4 solutions. In HCl and H2SO4, their weight losses during the immersion test were almost the same. Gadang Priyotomo, Hideyuki Momono, Sanat Wagle, Kenji Okitsu, Akihiro Iwase, Yasuyuki Kaneno, Rokuro Nishimura, and Takayuki Takasugi Copyright © 2012 Gadang Priyotomo et al. All rights reserved. Tue, 29 May 2012 11:58:54 +0000 http://www.hindawi.com/journals/ijc/2012/915090/ The corrosion protection of steels by conducting polymer coating is reviewed. The conducting polymer such as polyaniline, polypyrrole, and polythiophen works as a strong oxidant to the steel, inducing the potential shift to the noble direction. The strongly oxidative conducting polymer facilitates the steel to be passivated. A bilayered PPy film was designed for the effective corrosion protection. It consisted of the inner layer in which phosphomolybdate ion, PMo12O3−40 (PMo), was doped and the outer layer in which dodecylsulfate ion (DoS) was doped. The inner layer stabilized the passive oxide and the outer possessed anionic perm-selectivity to inhibit the aggressive anions such as chloride from penetrating through the PPy film to the substrate steel. By the bilayered PPy film, the steel was kept passive for about 200 h in 3.5% sodium chloride solution without formation of corrosion products. Toshiaki Ohtsuka Copyright © 2012 Toshiaki Ohtsuka. All rights reserved. Thu, 17 May 2012 10:34:39 +0000 http://www.hindawi.com/journals/ijc/2012/380329/ The inhibition and the effect of temperature and concentration of trans-4-hydroxy-4′-stilbazole on the corrosion of mild steel in 1 M HCl solution was investigated by weight loss experiments at temperatures ranging from 303 to 343 K. The studied inhibitor concentrations were between 1×10−7 M and 1×10−3 M. The percentage inhibition increased with the increase of the concentration of the inhibitor. The percentage inhibition reached about 94% at the concentration of 1×10−3 M and 303 K. On the other hand, the percentage inhibition decreased with the increase of temperature. Using the Temkin adsorption isotherm, the thermodynamic parameters for the adsorption of this inhibitor on the metal surface were calculated. Trans-4-hydroxy-4′-stilbazole was found to be a potential corrosion inhibitor since it contained not only nitrogen and oxygen, but also phenyl and pyridine rings that are joined together with a double bond (–C=C–) in conjugation with these rings. Ayssar Nahlé, Ideisan I. Abu-Abdoun, and Ibrahim Abdel-Rahman Copyright © 2012 Ayssar Nahlé et al. All rights reserved. Mon, 14 May 2012 09:35:01 +0000 http://www.hindawi.com/journals/ijc/2012/204640/ Atomistic simulation is a powerful tool for probing the structure and properties of materials and the nature of chemical reactions. Corrosion is a complex process that involves chemical reactions occurring at the interface between a material and its environment and is, therefore, highly suited to study by atomistic modeling techniques. In this paper, the complex nature of corrosion processes and mechanisms is briefly reviewed. Various atomistic methods for exploring corrosion mechanisms are then described, and recent applications in the literature surveyed. Several instances of the application of atomistic modeling to corrosion science are then reviewed in detail, including studies of the metal-water interface, the reaction of water on electrified metallic interfaces, the dissolution of metal atoms from metallic surfaces, and the role of competitive adsorption in controlling the chemical nature and structure of a metallic surface. Some perspectives are then given concerning the future of atomistic modeling in the field of corrosion science. Christopher D. Taylor Copyright © 2012 Christopher D. Taylor. All rights reserved. Wed, 09 May 2012 09:33:25 +0000 http://www.hindawi.com/journals/ijc/2012/847323/ The present paper studies the corrosion behaviour of a new lower-cost type of austenitic stainless steel (SS) with a low nickel content in alkaline-saturated calcium hydroxide solution (a simulated concrete pore (SCP) solution) with sodium chloride (0.0%, 0.4%, 1.0%, 2.0%, 3.0%, and 5.0% NaCl) and embedded in alkali-activated fly ash (AAFA) mortars manufactured using two alkaline solutions, with and without chloride additions (2% and 5%), in an environment of constant 95% relative humidity. Measurements were performed at early age curing up to 180 days of experimentation. The evolution with time of electrochemical impedance spectroscopy was studied. 𝑅ct values obtained in SCP solution or in fly ash mortars were so high that low-nickel SS preserved its passivity, exhibiting high corrosion resistance M. Criado, S. Fajardo, and J. M. Bastidas Copyright © 2012 M. Criado et al. All rights reserved. Tue, 08 May 2012 13:22:06 +0000 http://www.hindawi.com/journals/ijc/2012/450854/ The effect of equal-channel angular pressing (ECAP) on the pitting corrosion of pure Al was investigated using electrochemical techniques in solutions containing 0.1 m mol·dm−3 of Na2SO4 and 8.46 mol·dm−3 of NaCl (300 ppm Cl−) and followed by surface analysis. The potential for pitting corrosion of pure Al was clearly shifted in the noble direction by the ECAP process indicating that this process improves resistance to pitting corrosion. The time dependence of corrosion potential and the anodic potential at 1 A·m−2 revealed that the rate of formation of Al oxide films increased due to a decrease in the grain size of the Al after ECAP. Since there exists a negligible amount of impurity precipitates in pure Al, the improvement in pitting corrosion resistance of pure Al by ECAP appears to be attributable to an increase in the rate of formation of Al oxide films. Injoon Son, Hiroaki Nakano, Satoshi Oue, Shigeo Kobayashi, Hisaaki Fukushima, and Zenji Horita Copyright © 2012 Injoon Son et al. All rights reserved.