scholarly journals Galvanic Corrosion between Depleted Uranium and 40Cr Steel

2012 ◽  
Vol 531-532 ◽  
pp. 220-225
Author(s):  
Zhen Pu ◽  
Qing Fu Wang ◽  
Mao Bin Shuai ◽  
Ding Mu Lang
Keyword(s):  
Current Density ◽  
Linear Polarization ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Open Circuit ◽  
Depleted Uranium ◽  
Accelerated Corrosion ◽  
Linear Polarization Resistance ◽  
Corrosion Behaviors ◽  
40Cr Steel

Individual corrosion and galvanic corrosion behaviors of depleted uranium (DU) and 40Cr steel were investigated by electrochemical analyzing technologies in 3.5w.t%NaCl solution, including open circuit potential(OCP) test, linear polarization(LP) test, potentiodynamic polarizaition(PD) test, galvanic corrosion potential and corrosion current density test. The results reveal that the OCP of DU and 40Cr steel are around -790mV and -660mV, respectively. 40Cr has a higher linear polarization resistance than DU in galvanic corrosion. The dynamic processes of galvanic corrosion goes through an conversion in the whole test period. DU acts as anode with an accelerated corrosion rate, while the 40Cr steel behaves as cathode during the process of galvanic corrosion for DU/40Cr couple. The galvanic potential and current density of the DU/40Cr couple are -780mV and 17.5μA/cm-2, respectively.

Effects of Temperature on Galvanic Corrosion Behaviors of Super 13Cr and P110 Steel Couples in NaCl Solution

2014 ◽  
Vol 1033-1034 ◽  
pp. 829-833 ◽  
Author(s):  
Xiao Fei Yao ◽  
Wei Tian ◽  
Ling Wu
Keyword(s):  
Current Density ◽  
Corrosion Current Density ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Potential Difference ◽  
Nacl Solution ◽  
P110 Steel ◽  
Corrosion Behaviors ◽  
Effects Of Temperature ◽  
Increasing Temperature

Electrochemical methods were employed to investigate galvanic corrosion behaviors of super13Cr and P110 couples in NaCl solution at different temperature. Corrosion morphologies and products of the couples were analyzed by SEM, EDS and XRD. The results showed that there were potential difference distinctly between super 13Cr and P110 steel in NaCl solution at different temperature, when its contacted, galvanic corrosion of super 13Cr-P110 steel couples will occurred. P110 was accelerated to corrode as anode and super 13Cr was protected as cathode in the coupling. Super 13Cr-P110 steel couples could not be used as P110 without any protection in NaCl solution at 20 °C to 80 °C. Corrosion current density and galvanic corrosion of super13Cr-P110 steel couples increased with increasing temperature in NaCl solution, of which corrosion products are Fe3O4.

The Galvanic Corrosion Behaviors of 13Cr-N80 Steel Couples in NaCl Solution at Different Temperature

2013 ◽  
Vol 750-752 ◽  
pp. 467-472 ◽  
Author(s):  
Ling Wu ◽  
Fa Qin Xie ◽  
Xiao Fei Yao
Keyword(s):  
Current Density ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Potential Difference ◽  
Nacl Solution ◽  
N80 Steel ◽  
Corrosion Behaviors ◽  
Increasing Temperature

Electrochemical method was employed to investigate galvanic corrosion behaviors of super13Cr and N80 couples in 5% NaCl solution at different temperature. Corrosion morphologies and products of the couples were analyzed by SEM, EDS and XRD. The results show that there existed distinct potential difference between super13Cr and N80 with different degree of corrosion in 5% NaCl solution at different temperature. N80 was accelerated to corrode as anode, however, super 13Cr was protected as cathode when their coupling. In order to avoid galvanic corrosion, the super 13Cr-N80 couples could not be used without any protection of N80 from 25°C to 80°C. Corrosion current density of the super13Cr-N80 couples increased with increasing temperature in 5% NaCl solution, as well as the more serious corrosion of N80, of which corrosion products are Fe3O4.

Galvanic Corrosion between Depleted Uranium and 45 Steel

2013 ◽  
Vol 749 ◽  
pp. 606-610 ◽  
Author(s):  
Zhen Pu ◽  
Qing Fu Wang ◽  
Mao Bin Shuai ◽  
Ding Mu Lang
Keyword(s):  
Corrosion Rate ◽  
Current Density ◽  
Energy Dispersive Spectroscopy ◽  
Galvanic Corrosion ◽  
Depleted Uranium ◽  
Corrosion Products ◽  
Energy Dispersive ◽  
Nacl Solution ◽  
Accelerated Corrosion

Self-corrosion and galvanic corrosion of depleted uranium and 45 steel were studied by electrochemical analyzing technologies. Corrosion products were analyzed by Energy-dispersive spectroscopy (EDS). The results showed that, in the 3.5wt.%NaCl solution, DU acted as anode with an accelerated corrosion rate, and 45 steel acted as cathode during the process of galvanic corrosion for DU/45 couple. The galvanic potential and current density of the DU/45 couple were around-770mV and 12.5μA/cm-2, respectively.

scholarly journals Study on Corrosion of Macroporous Silicon in Sodium Hydroxide Solution by Electrochemical Methods and Scanning Electron Microscopy

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Chuan Lai ◽  
Zhen Xiang ◽  
Changlu Liu ◽  
Chaoju Zhu ◽  
Hui Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Linear Polarization ◽  
Polarization Resistance ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Open Circuit ◽  
Macroporous Silicon ◽  
Linear Polarization Resistance ◽  
Scanning Electron

The fabricated macroporous silicon with a porosity of 26.33% corrosion in NaOH solution was systemically investigated by open circuit potential measurements, linear polarization measurements, potentiodynamic polarization measurements, and scanning electron microscopy, respectively. Results show that the potential open circuit and linear polarization resistance decreases with the NaOH concentration increasing. The corrosion potential shifts significantly to more negative potentials and corrosion current density increases with NaOH concentration increasing. Adding ethanol to 1.0 M NaOH can lead to the linear polarization resistance decrease, corrosion potentials shift in the positive direction, and corrosion current density increase. In addition, the scanning electron microscopy images demonstrate that the macroporous silicon samples are seriously damaged by 1.0 M NaOH and 1.0 M NaOH/EtOH (30%).

Numerical Modeling of Galvanic Corrosion Behaviors on Uranium Surface

2013 ◽  
Vol 702 ◽  
pp. 140-144
Author(s):  
Ping An Shi ◽  
Hong Liang Zhou
Keyword(s):  
Numerical Simulation ◽  
Current Distribution ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Electrode Kinetics ◽  
Uniform Corrosion ◽  
Corrosion Rates ◽  
Ohmic Resistance ◽  
Circular Defect ◽  
Corrosion Behaviors

The Uranium and Titanium corrosion rates are described by a Tafel’s relationship, and the cathodic protection of Uranium is a function of a Wagner number. A numerical simulation of galvanic corrosion of Uranium surface under thin layer electrolyte is presented. The model considered that the effect of a circular defect and oxygen reduction and corrosion in the Uranium surface, the effect of electrolyte thickness and conductivity and defect radius on corrosion current distribution of Uranium with is investigated. The results shows that the corrosion rate at the center is non-uniform, and it could lead to the formation of a hemispherical-shaped pit. And the effect of radius is to increase the importance of the electrode kinetics relative to ohmic resistance, and to increase the potential difference between the center and edge of the Uranium surface, resulting in non-uniform corrosion current distribution.

Effect of Nitrite Ions on Polarization Behavior of Steel Immersed in Simulated Concrete Pore Environments

2013 ◽  
Vol 368-370 ◽  
pp. 919-924
Author(s):  
Zhong Lu Cao ◽  
Makoto Hibino ◽  
Hiroki Goda
Keyword(s):  
Polarization Curve ◽  
Current Density ◽  
Linear Polarization ◽  
Anodic Polarization ◽  
Cathodic Polarization ◽  
Corrosion Current ◽  
Anodic Polarization Curve ◽  
Polarization Curves ◽  
Passive State ◽  
Nitrite Concentration

The influence of nitrite concentration on the linear polarization curves of steel, Tafel slope and Stern-Geary constant B have been investigated in three different pH environments simulating the highly alkaline environment, carbonated environment and neutral environment that really existed on the surface of steel in concrete. The results indicate that when the steel is in passive state, the presence of nitrite has little influence on anodic/cathodic polarization curves and Stern-Geary constant B; but when the steel is corroded, the presence of nitrite not only reduces the current density of anodic polarization curve but also decreases the value of Stern-Geary constant B. If this influence is not considered in practical corrosion measurement, the corrosion current will be overestimated.

Some Limitations of the Linear Polarization Techniques in Evaluating Corrosion Behavior

CORROSION ◽  
1969 ◽  
Vol 25 (11) ◽  
pp. 455-461 ◽  
Author(s):  
M. E. INDIG ◽  
C. GROOT
Keyword(s):  
Corrosion Behavior ◽  
Linear Polarization ◽  
Saturation Pressure ◽  
Reference Electrode ◽  
Corrosion Current ◽  
Open Circuit ◽  
Platinum Black ◽  
Oxidation Reactions ◽  
Current Time ◽  
Weight Losses

Abstract Current, potential, and weight losses were measured on a system consisting of a stainless steel working electrode, a platinum black reference electrode and platinum auxiliary electrode. The electrolyte was slightly alkaline lithiated water containing 3 ppm hydrogen at 288 C (550 F) and at saturation pressure. Linear polarization measurements were made in the region 0–20 millivolts from the open circuit potential. A corrosion current was calculated from these measurements, using previously cited Tafel constants. The cathodic Tafel constant was also measured directly. The cathodic Tafel slope agreed well with previous values. The corrosion current, estimated by linear extrapolation of the log current vs. voltage curve to zero applied current, agreed well with the current calculated from linear polarization. However, the descaled weight loss of the corroded electrode was only tenth of that computed from the current, time and Faraday's Law. The deviation from the expected corrosion behavior is explained by another anodic half reaction. The steady state exchange current is an equilibrium between several oxidation reactions and several reduction reactions. Only when the corrosion potential is sufficiently removed from the equilibrium potentials of the anodic and cathodic half reactions that constitute the corrosion reaction can the other competing reactions be ignored.

Effect of Laser Shock Peening on the Wear–Corrosion Synergistic Behavior of an AZ31B Magnesium Alloy

2019 ◽  
Vol 142 (4) ◽  
Author(s):  
Arpith Siddaiah ◽  
Bo Mao ◽  
Yiliang Liao ◽  
Pradeep L. Menezes
Keyword(s):  
Surface Roughness ◽  
Galvanic Corrosion ◽  
Open Circuit ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Accelerated Corrosion ◽  
Functional Behavior ◽  
Zero Resistance ◽  
Shock Peening ◽  
Synergistic Behavior

Abstract Laser shock peening (LSP) is one of the widely used surface processing techniques for tailoring functional behavior of surfaces. LSP has been used to enhance friction, wear, and mechanical properties. However, understanding of LSP-treated surfaces involving tribological contacts in electrochemically active environments is limited because the mechanism of wear–corrosion interactions (tribocorrosion) for such surfaces is still unclear. In the present study, the effect of LSP on the wear–corrosion behavior of an AZ31B Mg alloy is investigated. A zero-resistance ammeter (ZRA) method is utilized to examine the evolution of open circuit potential (OCP) during wear–corrosion analysis. The study finds that the LSP processing can decrease the corrosion potential difference between worn and unworn regions of the surface, thereby mitigating the effect of wear-accelerated corrosion during sliding. The effect of wear-accelerated corrosion is evident from the change in average surface roughness (Sa) of the unworn areas. It is found that understanding the change in surface roughness due to wear–corrosion interactions is necessary to investigate the onset and propagation of galvanic corrosion. Based on these results, the study details the mechanism of wear–corrosion interactions during sliding.

Effect of High-Intensity Pulsed Ion Beam Irradiation on the Electrochemical Corrosion Behavior of AZ31 Magnesium Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 571-574
Author(s):  
Peng Li
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Current Density ◽  
Ion Beam ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Open Circuit ◽  
Electrochemical Corrosion Behavior ◽  
Shot Number

HIPIB irradiation experiment is carried out at a specific ion current density of 1.1 J/cm2 with shot number from one to ten in order to explore the effect of shot number on electrochemical corrosion behavior of magnesium alloy. Surface morphologies, microstructure and corrosion resistance of the irradiated samples are examined by scanning electron microscopy (SEM), transmission electron microscope (TEM) and potentiodynamic polarization technique, respectively. It is found that HIPIB irradiation leads to the increase in open circuit potential, corrosion potential and breakdown potential, and the decrease in the corrosion current density and the corrosion rate as compared to the original sample. The improved corrosion resistance is mainly attributed to the grain refinement and surface purification induced by HIPIB irradiation.

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