• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.641-646
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• 1998

The structures exposed to marine environment do not show long-term durability due to corrosion of steel and deterioration of concrete by the attack of various salts dissolved in sea water. In this study, Partial substitution of cement with fly ash(20%) or blast furnace slag(40%) was made together with the addition of 4 different corrosion-inhibitors, as a protective measure of concrete structures against chemical attack of salts. Combined effects of mineral and corrosion-inhibiting admixtures were tested by measuring the resistance and compressive strength of concretes under the simulated tidal condition, which consists of alternating 12 hour periods of immersion in artificial sea water and drying in air. Both the strength and concrete resistance were found to decrease in following order, regardless of the corrosion inhibitors the concretes with blast furnace slag, those with fly ash and those without any mineral admixtures. The interrelation between compressive strength of concrete and resistance was investigated.

• KSBB Journal
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• v.18 no.5
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• pp.393-397
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• 2003

The effect of corrosion inhibitors on antimicrobial activity of biocides (Kathon 886 MW, Triadine 3, Triadine 10 and Grotan BK) was investigated using the Pseudomonas aeruginosa which frequency of occurrence in contaminated fluids is very high and its growth and survival is excellent. When a biocide was used with a corrosion inhibitor, the antimicrobial activity of it was affected by the corrosion inhibitor used. The antimicrobial activity of Kathon 886 MW increased when corrosion inhibitor (each of SS 510, MEA) was used. Triadine 3, Triadine 10, Grotan BK showed the similar trend of antimicrobial effect for the corrosion inhibitors used. Their antimicrobial activities increased when the corrosion inhibitor such as CP-105, CP-E-7 and MEA was used individually. The antimicrobial activity of each corrosion inhibitor was also compared. The results showed that CP-E-7 and MEA was bioresistant and the other corrosion inhibitors were biosupportive. The antimicrobial activity of biocides was in the order of Triadine 10 < Triadine 3 < Kathon 886 MW < Grotan BK.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.229-232
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• 1998

Recently it has become general to use the inhibitor with a view to protecting corrosion of rebars in concrete. As the inhibitors used in construction works are almost made in America or Japan, we immediately need to begin home production of inhibitors. In this paper, to estimate the domestic anodic inhibitor of nitrite in comparison with foreign made inhibitor we made some fundamental experiments of setting time, slump and compressive strength. Besides, we analysed the effect of corrosion protection of inhibitor on the ground of corrosion current, resistance to chloride penetration and diffusion of chloride ingress in concrete.

• Journal of the Korean Chemical Society
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• v.13 no.1
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• pp.13-15
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• 1969

This investigation is to make comparative evaluation of the corrosion inhibiting effects of quinoline, oxine and 7-nitroso 8-hydroxy quinoline (7NHQ). In case of quinoline, and oxine, since the N atom in them functions as cation, the process involved is assumed to be cathode control. On the other hand 7-NHQ was found to form a stable chelate compound with $Fe^{++}$ ion in acidic solution and shows as anode control predominantly. After plotting polarization curves, Tafel parameters were calculated in each solution involving the inhibitors, at the same time corrosion inhibiting effects were separately measured and compared from data of both corrosion current and analytical method.

• Corrosion Science and Technology
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• v.2 no.5
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• pp.233-237
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• 2003

Pickling inhibitors can be used to form an adsorbed layer on the metal surface to hinder the discharge of H^+$ and dissolution of metal ions. Nitrogen-containing inhibitors were selected as corrosion inhibitors for mild steel (MS) in pickling acid process. In this study, the addition of inhibitor, the pickling temperatures and the pickling times were the parameters to investigate the effects on the inhibition efficiency (IE) for MS by using weight loss measurement. Preliminary results show that the IE increased with the increase in pickling time from 10 minutes to 60 minutes, and the IE also increased with the increase in temperature at room temperature and $40^{\circ}C$. At the higher temperature. the IE values are higher and almost independent with the pickling time. Furthermore, the potentiodynamic polarization, open circuit corrosion potential-time and corrosion current-time studies show that nitorgen-containing inhibitor behaves predominantly as cathodic polarization. The roughness test and SEM investigation are also studied in this paper.

• Corrosion Science and Technology
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• v.6 no.4
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• pp.206-210
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• 2007

Aerospace aluminum alloys such as Al alloy 2024-T3 and 7075-T6 are subject to localized corrosion due the existence of intermetallics containing Cu, Mg or Zn. Chromate is currently widely used in the aerospace industry as the corrosion inhibitor for these alloys. However, chromate needs to be replaced due to its strong carcinogenicity. In this study, an extensive pigment screening has been performed to find replacements for chromates. Different categories of inhibitors were evaluated by immersion tests, DC polarization tests and other methods. Phosphates, zinc salts, cerium salts, vanadates and benzotriazole were found to be effective inhibitors for AA7075. Among those inhibitors, zinc phosphate was found to be the most effective in our novel, silane-based, one-step aqueous primer system. The performance of this primer is comparable to that of currently used chromate primers in accelerated corrosion tests, while it is completely chromate-free and its VOC is about 80% less than that of current primers. Studies by SEM/EDS showed that the unique structure of the superprimer accounts for the strong anti-corrosion performance of the zinc phosphate pigment. The self-assembled stratified double-layer structure of the superprimer is characterized by a less-penetrable hydrophobic layer at the top and a hydrophilic layer accommodating the inhibitors underneath. The top layer functions as the physical barrier against water ingress, while the lower layer functions as a reservoirfor the inhibitor, which is leached out only if the coating is damaged by a scratch or scribe. The presence of a silane in the primer further improves the adhesion and anti-corrosion performance of the primer.

• Journal of Advanced Marine Engineering and Technology
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• v.13 no.4
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• pp.54-62
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• 1989

When some kinds of inhibitors, i.e. $1{\times}10{-3}mol/l$ arsenic trioxide, 0.2 mol/l 2-mercaptoethanol, 0.2mol/l thiourea were added to 3% NaCl solution, there were some considererable effects to decrease corrosion current density in natural potential condition and the effect fo solution temperature increasing corrosion rate was smaller than that of no addition to 3% NaCl solution. However the susceptibility of hydrogen embrittlement due to over-protection in case of cathodic protection was much greater than that of no addition, especially was the greatest in case of addition of 2-mercaptoethanol. Therefore adding inhibitors for anti-corrosion effect, it is suggested that selection of the optimum protection potential is important from the view point of prevention against hydrogen embrittlement due to over-protection in case of cathodic protection.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.65-66
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• 2021

In this study, the optimum amount of hybrid inhibitors i.e. L-Arginine (LA) and sodium phosphate tribasic dodecahydrate (SP), applied for carbon steel rebar in simulated pore concrete (SCP) solution contaminated with 3.5 wt.% NaCl, was discovered. The corrosion inhibition performance of hybrid inhibitors was investigated by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization. The highest corrosion inhibition efficiency was found as 99.52% corresponding to 2% LA and 0.25% SP after 210 h exposure. Anodic type inhibition action was confirmed by potentiodynamic polarization study. Surface studies including scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to figure out the surface morphology of the steel rebar treated with hybrid inhibitors in order to collaborate with electrochemical studies.

• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.564-567
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• 1989

The use of some mono-substituted phenyl N-phenylcarbamates derivatives as corrosion inhibitors for nickel in 1M perchloric acid was studied by galvanostatic polarization. The inhibition appears to function through general adsorption isotherm. However, galvanostatic polarization data suggest that in the case of all seven inhibitors both anode are polarized under the influence of an external current. Electrocapillary measurements have also revealed that the tendency of the inhibitors tested to adsorb on metallic surface follows the same order of efficiency.

• Corrosion Science and Technology
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• v.17 no.5
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• pp.203-210
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• 2018

This paper compares the inhibition properties of aspartic and lactic acid salts with nitrite ions and their effect on critical chloride concentration. The tests were carried employing carbon steel specimens in saturated lime solution with varying pH in the range between13 to 13.6. The critical chloride concentration was estimated through multiple specimen potentiostatic tests at potentials in the usual range for passive rebar in the alkaline concrete of atmospheric structures. During tests, chloride salt was added every 48 h until all the specimens showed localized attacks. The cumulative distribution curves, i.e. the number of corroded specimens as a function of the chlorides concentration was obtained. Furthermore, IR spectra were recorded for the evaluation of the presence of the organic inhibitors on the passivity film. The results confirmed the inhibitory effect of 0.1M aspartate comparable with nitrite ions, at a similar concentration. Addition of calcium lactate did not result in an increase in the critical chloride concentration. However, the formation of a massive scale containing the substance that could reduce the corrosion propagation was observed.