• Nuclear Engineering and Technology
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• v.32 no.6
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• pp.595-604
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• 2000

Flow-Accelerated Corrosion Behavior of SA106 Gr.C steel in room temperature alkaline solution simulating the CANDU primary water condition was studied using Rotating Cylinder Electrode. Systems of RCE were set up and electrochemical parameters were applied at various rotating speeds. Corrosion current density decreased up to pH 10.4 then it increased rapidly at higher pH. This is due to the increasing tendency of cathodic and anodic exchange half-cell current. Corrosion potential shifted slightly upward with rotating velocity. Passive film was formed from pH 9.8 by the mechanism of step oxidation and the subsequent precipitation of ferrous species into hydroxyl compound. Above pH 10.4, the film formation process was active and the film became stable. Corrosion current density showed increment in pH 6.98 with the rotating velocity, while it soon saturated from 1000 rpm above pH 9.8. This seems that activation process which represents formation of passive film on the bare metal surface controls the entire corrosion process

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.540-543
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• 2000

The purpose of this study is to research and develop solid polymer electrolyte(SPE) for Li polymer battery. The temperature dependence of conductivity, impedance spectroscopy and electrochemical properties of PAN/PVDF electrolytes as a function of a mixed ratio were reported for PAN/PVDF based polymer electrolyte films, which were prepared by thermal gellification method of preweighed PAN/PVDF, plasticizer and Li salt. The conductivity of PAN/PVDF electrolytes was $10^{-3}$S/cm. $PAN_{10}$$PVDF_{10}$$LiClO_4$$PC_{5}$$EC_{5}$ electrolyte has the better conductivity compared to others. The interfacial resistance behavior between the lithium electrode and PAN/PVDF based polymer electrolyte has also been investigated and compare with that between the lithium electrode and the PAN/PVDF based polymer electrolyte.

• Journal of the Korean institute of surface engineering
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• v.50 no.2
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• pp.91-97
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• 2017

The aim of this paper is to investigate the characteristics of electrochemical corrosion with the plasma ion nitriding temperature for 16Cr-10Ni-2Mo stainless steel. The corrosion behavior was analyzed by means of galvanostatic experiment in natural seawater that applied various current density with plasma ion nitriding temperature parameters. In result of galvanostatic experiment, relatively less surface damage morphology and the less damage depth was observed at a nitrided temperature of $450^{\circ}C$ that measured the thickest nitrided layer(S-phase). On the other hand, the most damage depth and unified corrosion behavior presented at a temperature of $500^{\circ}C$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.4 s.235
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• pp.477-484
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• 2005

Model fer the dynamic simulation of dynamic behaviors of a solid oxide fuel cell (SOFC) is provided. This model is based upon (1) coupled mass and heat transfer characteristics and (2) important chemical reactions such as electrochemical and reforming reactions in high temperature fuel cells such as SOFC. It is found that the thermal inertia of solid materials in SOFC plays an important role to the dynamic behavior of cell temperature. Dynamic characteristics of cell voltage, power, and chemical compositions with different levels of load change are investigated.

• Journal of the Korean institute of surface engineering
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• v.31 no.3
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• pp.157-164
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• 1998

Effects of alloying elements on the pitting behavior of Ti-Al intermetalic compounds in the electrolytic soution containing Cl- were investigated through electrochemical tets and corrosion morphologies. Corrosion potential increased in the case of Cr addition to Ti-48%Al, whereas it decreased in the case of Si and B addition. The simultaneous addition of Cr and Si increased passive current density and decrosion corrosion potential. The passive current density of N addtion was higher than that of B addition in H2SO4 solution. With the addition of alloying elements, The pitting resistance decreased in order of TiAl>TiAlSi>TiAlN>TiAlB>TiAlCr and whin siumultaneous addition, it decreased in order of TiAlCrSi>TiAlCrBN>TiAlCrrN. The surface merohology after pitting test showed that the TiAl coataining Si had for fewer pits than that containing Cr and N simultaneously.

• Journal of the Korean institute of surface engineering
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• v.29 no.3
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• pp.203-210
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• 1996

The purpose of this study is to investigate behavior of surface oxide on the cold rolled sheet used for the drum material and its phosphatability. Phosphatability is dependent of the characteristics of surface oxide on the cold-rolled sheet and can be estimated by using the electrochemical method and measuring $\tau$ value which is the time to be exposed to substrate Fe. $\tau$ value is varied with the steel composition, width direction of the sheet and SPM length. The good phosphatability and uniform surface color can be obtained by increasing SPM elongation and decreasing FCS temperature.

• Bulletin of the Korean Chemical Society
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• v.10 no.5
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• pp.414-418
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• 1989

The electrochemical behavior of cadmium(Ⅱ) in tartrate solution has been studied over the pH range of 6 to 13.6 in order to explain the phenomena of the changes in limiting current depending on the pH. The polarographic limiting current showed a constant value up to pH of 7.8, after which it decreased sharply to show a minimum at pH between 11 and 12. The limiting current, then, increased again with increasing pH. The number of peaks in cyclic voltammogram was 1 to 3 depending on the pH of the solution. Two other voltammetric peaks could be observed when the main reduction peak diminished. The decrease of limiting current at 7.5$Cd(C_4H_3O_6)^-$. The increase of limiting current at strong alkaline solution, however, was due to the complex $Cd(Tart)_2(OH)_2^{4-}$.

• Bulletin of the Korean Chemical Society
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• v.15 no.12
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• pp.1054-1058
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• 1994

Different behavior on the formation of soluble intermediate was observed depending on the substrate employed during the nucleation of lead dioxide from plumbous ion using a rotating ring-disk electrode. It was found that no soluble intermediate was formed at glassy carbon electrode, while the presence of soluble intermediate could be detected at platinum substrate. From the different anodic behavior of two substrates, the formation of a probable Pb(Ⅲ) soluble intermediate was suggested. A most probable nucleation mechanism at the platinum substrate involving a second order chemical reaction was derived on the basis of rotating disk electrode experiments.

• Journal of Fisheries and Marine Sciences Education
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• v.10 no.1
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• pp.79-86
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• 1998

In this study, the adhesive effect, blistering behavior and electrochemical polarization behavior of red lead film by the pretreatment work of sandblasting and potassium chromate($K_2CrO_4$) were investigated to prevent the corrosion of gas storage tank under marine environment. The main results obtained are as follows : 1) The adhesive effect of red lead film by the pretreatment work of sandblasting and potassium chromate is more improved than that of red lead film. 2) The blistering occurrence of red lead film by the pretreatment work of sandblasting and potassium chromate is more delayed than that of red lead film. 3) As the anodic potential is increased, corrosion current density of red lead film by the pre treatment work of sandblasting and potassium chromate is lower drained than that of red lead film.

• Korean Journal of Metals and Materials
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• v.49 no.10
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• pp.780-789
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• 2011

The effects of alloyed carbon on the pitting corrosion, the general corrosion, and the passivity behavior of Fe18Cr10Mn0.4NxC (x=0~0.38 wt%) alloys were investigated by various electrochemical methods and XPS analysis. The alloyed carbon increased the general corrosion resistance of the FeCrMnN matrix. Carbon enhanced the corrosion potential, reduced the metal dissolution rate, and accelerated the hydrogen evolution reaction rate in various acidic solutions. In addition, carbon promoted the pitting corrosion resistance of the matrix in a chloride solution. The alloyed carbon in the matrix increased the chromium content in the passive film, and thus the passive film became more protective.