Maximum Utilization Current Density in Cathodic Protection: Part I: Aluminum in Acid Media

CORROSION ◽  
1984 ◽  
Vol 40 (2) ◽  
pp. 88-92 ◽  
Author(s):  
J. D. Talati ◽  
G. A. Patel ◽  
D. K. Gandhi
Keyword(s):  
Current Density ◽  
Cathodic Protection ◽  
Acid Media ◽  
Maximum Utilization

scholarly journals Numerical Model for Simulation of the Cathodic Protection System with Dynamic Nonlinear Polarization Characteristics

2020 ◽  
Vol 19 ◽  
Keyword(s):  
Numerical Model ◽  
Current Density ◽  
Cathodic Protection ◽  
Electric Potential ◽  
Protection System ◽  
Nonlinear Polarization ◽  
Electrode Surfaces ◽  
Polarization Characteristics ◽  
Cathodic Protection System

Cathodic protection is defined as a method for slowing down or complete elimination of corrosion processes on underground or underwater, insulated or uninsulated metal structures. Protection by cathodic protection system is achieved by polarizing protected object to more negative value, with respect to its equilibrium potential. Design of the cathodic protection system implies determination of the electric potential and current density on the electrode surfaces after installation of the cathodic protection system. Most efficient way for determination of the electric potential and current density in the cathodic protection system is by applying numerical techniques. When modeling cathodic protection systems by numerical techniques, electrochemical reactions that occur on electrode surfaces are taken into account by polarization characteristics. Because of nature of the electrochemical reactions, polarization characteristics are nonlinear and under certain conditions can be time – varying (dynamic nonlinear polarization characteristics). This paper deals with numerical modeling of the cathodic protection system with dynamic nonlinear polarization characteristics. Numerical model presented in this paper is divided in the two parts. First part, which is based on the direct boundary element method, is used for the calculation of the distribution of electric potential and current density on the electrode surfaces in the spatial domain. Second part of the model is based on the finite difference time domain method and is used for the calculation of the electric potential and current density change over time. The use of presented numerical model is demonstrated on two simple geometrically examples.

Experimental Study on the Effect of Cathodic Protection System for Concrete Slab Specimens with Zn-Mesh Sacrificial Anode in Marine Environment

2013 ◽  
Vol 785-786 ◽  
pp. 264-272
Author(s):  
Jin A Jeong ◽  
Chung Kuk Jin
Keyword(s):  
Marine Environment ◽  
Current Density ◽  
Cathodic Protection ◽  
Concrete Slab ◽  
Reinforced Concrete Structures ◽  
Sacrificial Anode ◽  
Protection Effect ◽  
Protection Technology ◽  
Cathodic Prevention ◽  
Cathodic Protection System

This study is to acquire the confirmation data regarding the cathodic protection (CP) characteristics for slabs in marine bridges and piers exposed to hash seawater environments. It was possible to confirm the performance of CP only by the measurement of CP potentials for the slab specimens applied with zinc mesh sacrificial anode CP system. The CP current density for the cathodic protection (CProt) that CP started after a repair of corrosion was 2 times higher than that for the cathodic prevention (CPrev) that CP commenced from the beginning of experiment, and the most of protection current density (87.0-91.5%) flew to the closer top rebar in slab specimens. 4 hour depolarization potentials were higher in the CPrev system than in the CProt one, and it was confirmed that the CPrev has more protection effect with less protection current, comparing to the CProt. It was also confirmed that the CP of both CPrev and CProt by means of zinc mesh sacrificial anode for reinforced concrete structures were very effective corrosion protection technology in marine environment.

The Effect Rust and Over-Protection Voltage of Impressed Current Cathodic Protection towards LR Grade a Steel Disbondment

2016 ◽  
Vol 842 ◽  
pp. 92-98
Author(s):  
Muhammad Fitrullah ◽  
Siti Mutia Mawaddah ◽  
Wahyudin ◽  
P. Tarigan ◽  
O. Soesaptri ◽  
...  
Keyword(s):  
Corrosion Product ◽  
Current Density ◽  
Cathodic Protection ◽  
Direct Contact ◽  
Reference Electrode ◽  
Plate Surface ◽  
Artificial Defect ◽  
Impressed Current ◽  
Impressed Current Cathodic Protection

Corrosion at the bilge due to direct contact with the seawater is an issue which is necessary to be taken into account. The problem can be solved by giving combined protection such as coating and cathodic protection impressed current cathodic protection (ICCP). For broader range, there is occasionally a possibility of over-protection at certain area especially that is close to anodes. It can trigger cathodic disbondment to occur. Cathodic disbondment is a situation when the coating loses its adhesion to the steel due to the voltage originated from cathodic protection. This trial was conducted by using several samples of LR Grade A plate coated by primer coat epoxy and top coat polyurethane. The plate was then given artificial defect with the size of R2, R3 and R4 accoring to ISO 4628-3 or is equal to 0,5% ; 1% and 8% of the plate surface width. Futhermore, impressed current cathodic protection was conducted with the steel anode, Ag/AgCl reference electrode and over-protection voltage were-1,5 ; -2,0 ; -2,5 ; -3,0 ; -3,5 and-4,0 volt. Electrolyte media employed was seawater. Furthermore, the disbondment taken place was measured after 6 hours and analyzed the corrosion product produced. In the research, it could be seen that the broader the defect was, the smaller the disbondment area was. The width of disbondment area was depending on current density. The smaller the voltage (volt) was, the broader the disbondment in accordance with the increase of disbondment width taking place on the plate surface. The corrosion product produced was Fe3O4 (Magnetite).

A Study on Sacrificial Anode Cathodic Protection for Wharf Steel Pile of Tripoli Lebanon

2014 ◽  
Vol 556-562 ◽  
pp. 228-231
Author(s):  
Da Jing Fang ◽  
Jun Huang ◽  
Ya Ping Wang ◽  
Er Bu Shen ◽  
Shun Kai Li ◽  
...  
Keyword(s):  
Field Test ◽  
Current Density ◽  
Cathodic Protection ◽  
Protection System ◽  
Sacrificial Anode ◽  
Sheet Pile ◽  
Sea Mud ◽  
Current Densities ◽  
Steel Pipe Sheet Pile ◽  
Optimal Average

In this paper, the sacrificial anode protection system for steel pile of Tripoli wharf (Lebanon) was studied. Optimal average protection current densities were selected for steel pipe/sheet pile of seaside zone back filled zone and sea mud zone. Based on field test and investigation, we found that the optimal average protection current density for seaside zone is 0.060 A/m2, back filled zone 0.030 A/m2 and sea mud zone 0.025 A/m2, respectively.

Corrosion of Pipeline Steel in the Presence of Alternating Current and the New CP Recommendation

2010 ◽  
Author(s):  
A. Q. Fu ◽  
Y. F. Cheng
Keyword(s):  
Corrosion Rate ◽  
Current Density ◽  
Cathodic Protection ◽  
Pitting Corrosion ◽  
Pipeline Steel ◽  
Alternating Current ◽  
National Association ◽  
Ac Current ◽  
Ac Interference ◽  
Full Protection

The alternating current (AC)-induced corrosion of a cathodically protected X65 pipeline steel was studied in a high pH, concentrated carbonate/bicarbonate solution. Results demonstrated that the corrosion rate of the steel increases with the AC current density, and AC interference could increase the pitting corrosion of the steel. In the absence of AC interference or at a low AC current density, i.e., 20 A/m2, a cathodic protection (CP) potential of −950 mV(Cu/CuSO4 electrode, CSE), which is 100 mV more cathodic than −850 mV(CSE) recommended by National Association of Corrosion Engineers (NACE), provides a full protection over the steel. When the AC current density is higher than 20 A/m2, the NACE-recommended CP is incapable of protecting the pipeline from corrosion. A new CP standard is thus developed for recommendation to industry to avoid AC corrosion of pipelines.

Cathodic Protection of Iron In the Temperature Range 25 C-92 C★

CORROSION ◽  
1958 ◽  
Vol 14 (4) ◽  
pp. 54-56 ◽  
Author(s):  
G. R. HOEY ◽  
M. COHEN
Keyword(s):  
Current Density ◽  
Cathodic Protection ◽  
Cathodic Polarization ◽  
Open Circuit ◽  
Cathodic Current Density ◽  
Oxygen Solubility ◽  
Nacl Solution ◽  
Cathodic Current ◽  
Temperature Range ◽  
Higher Temperature

Abstract The cathodic protection of iron was studied in the temperature range 25 C to 92 C. The limiting protective current density and the open circuit cathodic current density for iron in dilute NaCl solution goes through a temperature maximum at roughly 75 C. This is explained in terms of the effect of decreasing oxygen solubility at the higher temperature on the local cathodic reaction, 2H+ + O2 + 4e = 20H- Iron corrodes under cathodic control at room temperature, whereas at the higher temperatures there is a mixed cathodic-anodic control. Cathodic polarization curves for iron in dilute NaCl solution were obtained in the temperature range 25 C to 92 C. Unsteady potentials were observed in the vicinity of the limiting protective current, whereas at higher and lower currents, steady potentials were observed. The current density at which the potential of the iron reaches —0.5 volt on the hydrogen scale gives satisfactory protection. The nature of the corrosion products of iron is unaffected by temperature in the range studied. 5.2.2

scholarly journals MODEL PENGENDALIAN KATODIK DALAM ELEKTRODE DISK PEMUTAR SISTEM KOROSI

2012 ◽  
Vol 12 (1) ◽  
pp. 65
Author(s):  
ISNI UTAMI
Keyword(s):  
Activation Energy ◽  
Flow Rate ◽  
Current Density ◽  
Cathodic Protection ◽  
Corrosion Potential ◽  
Cathodic Reaction ◽  
Interface Potential ◽  
Higher Temperature ◽  
Spinning Cylinder ◽  
Cathode Protection

The effect of fluids flow rate onto necessity of current density cathodic protection which characterized using Rotatingdisk electrode (RDE) model has been researched on an electrochemistry manner. This research was done to AISI 1018 steel as the electrode spinning cylinder-shaped inside aerated dissolvable NaCl 3.5%. using variation spinning rate 0–2000rpm and 25–75° C temperature. Current density cathodic protection necessity determined from the steel interface potential - 800mV with reference anode Ag/AgCl. Experiment result shows that the increasing of electrode rate, cathodic protection current density needs increased due to diffusion layer tare faction and also because corrosion potential become more positive. Higher temperature would increase cathode protection current density needs and makes corrosion potential more negative. Oxygen activation energy value to be diffused onto electrode surface support the corrodibility AISI 1018 toward temperature increment, because cathodic reaction controlled by transfer mass of dissolved oxygen.

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