Tafel Slopes and Corrosion Rates from Polarization Resistance Measurements

CORROSION ◽  
1973 ◽  
Vol 29 (10) ◽  
pp. 397-402 ◽  
Author(s):  
FLORIAN MANSFELD
Keyword(s):  
Experimental Data ◽  
Time Dependence ◽  
Polarization Resistance ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Observation Time ◽  
Least Square ◽  
Corrosion Rates ◽  
Tafel Slopes ◽  
Good Agreement

Abstract A new analysis of polarization curves in the non-Tafel region in the vicinity of the corrosion potential is described which allows calculation of the polarization resistance (Rp) and the Tafel slopes (ba and bc). From these data instantaneous corrosion rates are calculated. Experimental data for the system Fe/1N H2SO4 are analyzed by the proposed method and by computer least square analysis. The good agreement observed suggests that all important corrosion parameters (corrosion potential, corrosion current, Tafel slopes) can be obtained by the proposed analysis. These parameters are used for mechanistic considerations which explain the observation time dependence of corrosion potential and corrosion current.

Evaluation of Corrosion Rates from Polarization Measurements

CORROSION ◽  
1975 ◽  
Vol 31 (5) ◽  
pp. 173-177 ◽  
Author(s):  
RODNEY L. LeROY
Keyword(s):  
Polarization Curve ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Powerful Method ◽  
Polarization Data ◽  
Polarization Measurements ◽  
Corrosion Rates ◽  
Tafel Slopes ◽  
Tafel Constants

Abstract Polarization measurements within 5 to 20 mV of the corrosion potential offer a powerful method for determining corrosion rates. In this paper, known methods for evaluating the corrosion current from polarization data are critically examined. It is noted that calculated currents are generally in error when the anodic and cathodic Tafel slopes are precisely known, due to non-linearity of the polarization curve. A new result is derived, which allows the corrosion current to be calculated without error if the Tafel slopes are known. Diagrams are presented which show the sensitivity of calculated corrosion rates to errors in estimation of the Tafel constants.

scholarly journals An electrochemical method to investigate the effects of compound composition on gold dissolution in thiosulfate solution

2020 ◽  
Vol 9 (1) ◽  
pp. 496-502 ◽  
Author(s):  
Zhaohui Zhang ◽  
Bailong Liu ◽  
Mei Wu ◽  
Longxin Sun
Keyword(s):  
Dissolution Rate ◽  
Current Density ◽  
Polarization Resistance ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Gold Dissolution ◽  
Tafel Polarization ◽  
Edta Solution

AbstractThe electrochemical behavior of gold dissolution in the Cu2+–NH3–S2O32−–EDTA solution has been investigated in detail by deriving and analyzing the Tafel polarization curve, as this method is currently widely implemented for the electrode corrosion analysis. The dissolution rate of gold in Cu2+–NH3–S2O32−–EDTA solution was determined based on the Tafel polarization curves, and the effects of various compound compositions in a Cu2+–NH3–S2O32−–EDTA mixture on the corrosion potential and corrosion current density were analyzed. The results showed that the corrosion potential and polarization resistance decreased, whereas the corrosion current density increased for certain concentrations of S2O32−–NH3–Cu2+ and EDTA, indicating that the dissolution rate of gold had changed. The reason for promoting the dissolution of gold is also discussed.

The Corrosion of Carbon Steel and Stainless Steel in Simulated Geothermal Media

1985 ◽  
Vol 38 (8) ◽  
pp. 1133 ◽  
Author(s):  
BG Pound ◽  
MH Abdurrahman ◽  
MP Glucina ◽  
GA Wright ◽  
RM Sharp
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Stainless Steels ◽  
Polarization Resistance ◽  
Iron Sulfide ◽  
Low Carbon Steel ◽  
Passive Films ◽  
Low Carbon ◽  
Corrosion Rates ◽  
Good Agreement

The corrosion rates of low-carbon steel, and 304, 316 and 410/420 stainless steels in simulated geothermal media containing hydrogen sulfide have been measured by means of the polarization resistance technique. Good agreement was found between weight-loss and polarization resistance measurements of the corrosion rate for all the metals tested. Carbon steel formed a non-adherent film of mackinawite (Fe1 + xS). The lack of protection afforded to the steel by the film resulted in an approximately constant corrosion rate. The stainless steels also exhibited corrosion rates that were independent of time. However, the 410 and 420 alloys formed an adherent film consisting mainly of troilite ( FeS ) which provided only limited passivity. In contrast, the 304 and 316 alloys appeared to be essentially protected by a passive film which did not seem to involve an iron sulfide phase. However, all the stainless steels, particularly the 410 and 420 alloys, showed pitting, which indicated that some breakdown of the passive films occurred.

The Preparation of Coatings with Codepositon Plating on A3 Steel and its Corrosion Resistance

2010 ◽  
Vol 150-151 ◽  
pp. 1034-1038
Author(s):  
Shang Dong Chen ◽  
Ting Sun ◽  
Hong Nian
Keyword(s):  
Corrosion Resistance ◽  
Polarization Resistance ◽  
Polarization Effect ◽  
Corrosion Potential ◽  
Steel Substrate ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Plain Carbon Steel ◽  
Cathode Polarization ◽  
Electrochemical Corrosion Behavior

A new method for preparation of coatings with codeposition plating on the ordinary A3 steel and heat treatment later. Research the coatings on electrochemical corrosion behavior variation in Q-sun. Results show that corrosion potential shuffle, corrosion current density reduced nearly two number magnitudes value, polarization resistance increased, the cathode polarization effect enhanced obviously in polarization curves, and self-corrosion current reduced, impedance increased twenty times in alternating current impedance atlas than A3 steel substrate without coatings. It was indicated that the coating improve effectively the corrosion resistance of plain carbon steel.

scholarly journals Corrosion Resistance of X5CrNi18-10 Stainless Steel

2017 ◽  
Vol 62 (4) ◽  
pp. 2101-2106
Author(s):  
M. Kciuk ◽  
S. Lasok
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Polarization Resistance ◽  
Corrosion Potential ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
Eds Microanalysis ◽  
Scanning Electron

AbstractThe paper presents the influence of heat treatment on the structure and corrosion resistance of X5CrNi18-10 steel. To determine the structure which has been obtained after heat treatment the methods of light and scanning electron microscopy with EDS microanalysis were used. The electrochemical corrosion properties of the investigated steel were studied in 3.5% NaCl solution using potentiodynamic polarization tests. Basing on the registered curves, the corrosion current, polarization resistance and corrosion potential were determined. The corrosion tests were followed by fractographic researches.

Some Errors in Linear Polarization Measurements and Their Correction

CORROSION ◽  
1974 ◽  
Vol 30 (3) ◽  
pp. 92-96 ◽  
Author(s):  
FLORIAN MANSFELD
Keyword(s):  
Polarization Curve ◽  
Linear Polarization ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Potential Curve ◽  
Polarization Measurements ◽  
Tafel Slopes ◽  
The Relationship ◽  
Current Potential

Abstract The errors due to the use of the approximation Icorr′ = B′ΔI, where B′ depends on anodic and cathodic Tafel slopes, in commercial corrosion current meters is shown to be due to the nonlinearity of the current-potential curve in the vicinity of the corrosion potential. These errors are calculated for various combinations of Tafel slopes. It is proposed to use the relationship Icorr = κΔI, where κ depends on Tafel slopes, sign, and magnitude of polarization. The values of κ are tabulated for various combinations of Tafel slopes and polarization of +10 and −10 mV. The proposed procedure leads to correct values of corrosion currents independent of the degree of nonlinearity of the polarization curve.

High corrosion resistant ZrC films synthesized by ion-beamassisted deposition

1999 ◽  
Vol 14 (2) ◽  
pp. 615-618 ◽  
Author(s):  
Xiao-Ming He ◽  
Li Shu ◽  
Hai-Bo Li ◽  
Duan Weng
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Polarization Resistance ◽  
Corrosion Potential ◽  
Ion Beam ◽  
High Hardness ◽  
Corrosion Current ◽  
Experimental Results ◽  
Corrosion Resistant ◽  
Ion Beam Assisted Deposition

ZrC films with high hardness were deposited on A3 steel by ion-beam-assisted deposition and had a corrosion rate more than two orders less and a corrosion potential 0.19 V greater than those of the bare A3 steel. The corrosion current of ZrC films was 10 times less and the polarization resistance at least 7.82 times higher than those of both Teflon and ZrN films, respectively. The experimental results confirmed that ZrC films notably enhanced the corrosion resistance of steels.

scholarly journals Effect of Recrystallization Annealing on Corrosion Behavior of Ta-4%W Alloy

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 117 ◽  
Author(s):  
Guoqiang Ma ◽  
Qiongyao He ◽  
Xuan Luo ◽  
Guilin Wu ◽  
Qiang Chen
Keyword(s):  
Corrosion Resistance ◽  
Anodic Dissolution ◽  
Corrosion Behavior ◽  
Current Density ◽  
Polarization Resistance ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Recrystallization Annealing ◽  
Site Lattice

The effect of recrystallization annealing on corrosion behavior of Ta-4%W alloy was studied. It is found that the deformed sample contains high dense dislocations and dislocation boundaries. During annealing, these dislocations and dislocation boundaries are replaced by recrystallizing grains until the alloy is fully recrystallized. Both the anodic dissolution and the cathodic activity is much more blocked. The corrosion potential gradual shift towards negative values and corrosion current density decrease, while polarization resistance increases after annealing, indicating enhanced corrosion resistance of the alloy. Such an enhancement is caused by the increase of low-Σ coincide site lattice boundaries and decrease of dislocations and dislocation boundaries.

Corrosion Rates off Mild Steel in Alkaline Lithium Bromide Solutions by the Polarization Resistance Method

CORROSION ◽  
1966 ◽  
Vol 22 (2) ◽  
pp. 39-47 ◽  
Author(s):  
ARTHUR COHEN ◽  
ROBERT V. JELINEK
Keyword(s):  
Weight Loss ◽  
Mild Steel ◽  
Polarization Resistance ◽  
Anodic Polarization ◽  
Lithium Bromide ◽  
Corrosion Current ◽  
Inhibitor Concentration ◽  
Corrosion Rates ◽  
Mixed Control ◽  
Cathodic And Anodic Processes

Abstract This is an electrochemical evaluation of a chemical inhibitor on the corrosion behavior of mild steel (ASTM A-414) in solutions containing 54 percent lithium bromide and 0.2 percent lithium hydroxide at 25 C (77 F). Inhibiting effects of lithium chromate at concentrations up to 3000 ppm were studied Results are analyzed in terms of corrosion current determined from polarization resistance measurements and cathodic and anodic polarization slopes. These are compared with weight loss measurements. The system inhibited with lithium chromate behaved as expected. Corrosion current, determined from polarization resistance, decreased steadily with increasing inhibitor concentration to a limiting value above 1000 ppm. Relative corrosion rates (ratio of corrosion rate of steel in the inhibited solution to that in the uninhibited solution) agree reasonably well with weight loss measurements. Extrapolations of Tafel slopes from cathodic and anodic polarization curves to the corrosion potential suggest that in the lithium chromate inhibited system, the anodic reaction controls; whereas in the uninhibited solution, cathodic and anodic processes are equally important and lead to mixed control. Severe pitting of the steel and gel formation have been observed in a number of experiments involving lithium chromate. Hence, proper chemistry involving inhibitor concentration and alkalinity control is very critical.

Electrochemical Corrosion Behavior of Ultra-Supercritical Unit Waterwall Tube Material in Simulated Solution of Oxygenated Treatment at Room Temperature

2013 ◽  
Vol 328 ◽  
pp. 882-885
Author(s):  
Cun Ren Ma ◽  
Hai Wei Lu ◽  
Guo Hua Lu ◽  
Wei Su ◽  
Tian Sheng Chen ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Polarization Resistance ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Tube Material ◽  
Waterwall Tube ◽  
Tafel Slopes ◽  
Electrochemical Corrosion Behavior

The electrochemical corrosion behavior of ultra-supercritical unit waterwall tube material in simulated solution of oxygenated treatment (OT) with different concentration of Cl- and SO42- at room temperature was investigated by electrochemical impedance spectroscopy and Tafel slopes. The results showed that the polarization resistance Rp values decreased and corrosion current density (icorr) increased with increasing Cl-/ SO42- concentration in solution. Corrosion potentials (Ecorr) decreased with increasing Cl-/ SO42- concentration in solution.

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