• Journal of the Korean Electrochemical Society
• /
• v.11 no.3
• /
• pp.184-189
• /
• 2008

Inhibitive effects of chromate, phosphate, sulfate, and borate on chloride pitting corrosion of Al have been investigated using cyclic voltammetry. During the anodic oxide growth, the critical concentration of chloride for pit initiation decreased in the order: chromate > phosphate > sulfate > borate, and the maximum pitting current density increases in the reverse order: chromate < phosphate < sulfate < borate. The decreasing pitting current density was observed in the successive polarization cycles, which was attributed to the aging of Al oxides and field relaxation at oxide/solution interface.

• Journal of the Korean Electrochemical Society
• /
• v.12 no.4
• /
• pp.311-316
• /
• 2009

Inhibition effects of alanine and methionine on the corrosion of aluminum were investigated in artificial sea water. Based on the low coverage of alanine and methionine we suggested that alanine and methionine adsorption process in aluminum surface is Langmuir isotherm and the carboxyl ion of amino acids seems to be adsorbed on Al.

• Journal of Electrochemical Science and Technology
• /
• v.8 no.2
• /
• pp.115-123
• /
• 2017

Electrochemical noise signals in many cases exhibit a DC drift that should be removed prior to further data analysis. Polynomial fitting and moving average removal method have been used to remove trends of electrochemical noise (EN) in time domain. The corrosion inhibition of synthesized schiff base N,N'-bis(3,5-dihydroxyacetophenone)-2,2-dimethylpropandiimine on API-5L-X70 steel in hydrochloric acid solutions were used to study the effects of drifts removal methods on noise resistance calculation. Also, electrochemical impedance spectroscopy (EIS) was used to study the corrosion inhibition property of the inhibitor. The results showed that for the calculation of $R_n$, both methods were effective in trend removal and the polynomial with m=4 and MAR with p=40 were in agreement.

• Journal of the Korea Concrete Institute
• /
• v.26 no.4
• /
• pp.517-524
• /
• 2014

Nitrite-Type hydrocalumite (calumite) is a material that can adsorb chloride ions ($Cl^-$) that cause corrosion of reinforce bars and liberate the nitrite ions ($NO_2{^-}$) that inhibit corrosion in reinforced concrete. In this study, polymer-modified mortars using two types of epoxy resin with calumite are prepared with various polymer binder-ratios of 0, 5, 10, 15, 20% and calumite contents of 0, 5%. The specimens are tested for chloride ion penetration, carbonation, drying shrinkage and corrosion inhibition. As a result, the chloride ion penetration and carbonation depth of PMM using epoxy resin somewhat increases with increasing calumite contents, but those remarkably decreases depending on the polymer-binder ratios. The 28-d drying shrinkage shows a tendency to decrease with increasing polymer-binder ratio and calumite content. Unmodified mortars with calumite content of 5% did not satisfy quality requirement by KS. However, it was satisfied with KS requirement by the modification of epoxy resin in cement mortar. On the whole, the carbonation and chloride ion penetration depth of epoxy-modified mortars with calumite is considerably improved with an increase in the polymer-binder ratio regardless of the calumite content, and is remarkably improved over unmodified mortar. And, the replacement of the portland cement with the calumite has a marked effect in the corrosion-inhibiting property of the epoxy-modified mortars.

• Journal of Electrochemical Science and Technology
• /
• v.10 no.1
• /
• pp.29-36
• /
• 2019

Corrosion inhibition by synthesised ligand, 2-acetylpyridine 4-ethyl-3-thiosemicarbazone (HAcETSc) and its tin(IV) complex, dichlorobutyltin(IV) 2-acetylpyridine 4-ethyl-3-thiosemicarbazone ($Sn(HAcETSc)BuCl_2$) on mild steel in 1 M hydrochloric acid (HCl) was studied using weight loss measurement, potentiodynamic polarisation, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The inhibition efficiency increases by increasing the inhibitor concentrations. The polarisation study showed that both synthesised compounds were mixed type inhibitors. The electrochemical impedance study showed that the presence of inhibitors caused the charge transfer resistance to increase as the concentration of inhibitors increased. The adsorption of these compounds on mild steel surface was found to obey Langmuir's adsorption isotherm with the free energy of adsorption ${\Delta}G{^o}_{ads}$ of -3.7 kJ/mol and -7.7 kJ/mol for ligand and complex respectively, indicating physisorption interaction between the inhibitors and 1 M HCl solution.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2001.05a
• /
• pp.295.2-295
• /
• 2001

• 한국전기화학회:학술대회논문집
• /
• 2004.04a
• /
• pp.47-47
• /
• 2004

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 1999.05a
• /
• pp.18-18
• /
• 1999

• Journal of the Korean institute of surface engineering
• /
• v.31 no.2
• /
• pp.73-80
• /
• 1998

The aim of this study is to develop sintered stainless steels (SSS) with good mechanical strength, wear resistance, and corrosion resistance by nitrogen ion implantation on the Culated SSS surface. Stainless steel compacts containg Cu (2-10 wt%) were prepared by electroless Cu-pating method which results in the increased3 homogenization in alloying powder. Nitrogen ion implantation was carried out by using N2 gas as the ion source. Nitrogen ions were embedded by an acceleratol of 130keV with doese $3.0\times10^{17}\;ions/\textrm{cm}^2$ on the SSS at $25^{\circ}C$ in$2\times10^{-6}$ torr vacuum. The nitrogen ion implanted SSS obtained from anodic ploarization curves revealed higher corrosion potential than that of nitrogen ion unimplante one. And nitrogen ion implanted 316LSSS had good resistance to pitting corrosion due to the synergistic effect of Mo and N, and the inhibition of $NH_4\;^+$<\TEX>, against $CI^-$<\TEX>.

• Journal of the Korea Institute of Building Construction
• /
• v.17 no.2
• /
• pp.157-166
• /
• 2017

In general, carbonation and chlorine ions are the most harmful causes of deterioration of concrete structures. Recently, a method has been developed to control the corrosion of rebar in concrete containing chloride by impregnating a Surface coating material with a inhibitor. In this study, accelerated carbonation and differential thermogravimetric analysis (TG-DTA) and CASS tests were carried out to evaluate the characteristics of Surface coatings containing Organic Corrosion inhibitors which are excellent in corrosion inhibition and fix degradation causes $CO_2$ and $Cl^-$. As a result of the experiment, TG-DTA analysis and accelerated carbonation showed that $CO_2$ was directly reacted with amine derivative in concrete by the incorporation of Organic Corrosion inhibitor. In other words, $CO_2$ was immobilized and carbonation inhibition effect was confirmed. In addition, in the CASS test, the specimen coated with the Surface coating material containing the Organic Corrosion inhibitor with $Cl^-$ fixing property showed no corrosion until the 28th day and had excellent performance in preventing corrosion of a rebar by the chloride ion.