Effects of alternating current interference on cathodic protection potential and its effectiveness for corrosion protection of pipelines

2016 ◽  
Vol 52 (1) ◽  
pp. 22-28 ◽  
Author(s):  
D. Kuang ◽  
Y. F. Cheng
Keyword(s):  
Corrosion Protection ◽  
Cathodic Protection ◽  
Alternating Current ◽  
Protection Potential

scholarly journals First principles DFT study of interstitial hydrogen and oxygen atoms in the MAX phase Ti2AlN

RSC Advances ◽  
2017 ◽  
Vol 7 (60) ◽  
pp. 37852-37857 ◽  
Author(s):  
Francesco Colonna ◽  
Christian Elsässer
Keyword(s):  
Ab Initio ◽  
Corrosion Protection ◽  
First Principles ◽  
Dft Study ◽  
Max Phase ◽  
Oxygen Absorption ◽  
Protection Potential ◽  
And Diffusion ◽  
Interstitial Hydrogen ◽  
Oxygen Atoms

We model hydrogen and oxygen absorption and diffusion in Ti2AlN via ab initio simulations to assess its corrosion protection potential.

Corrosion Protection Features Of the Hyperion Ocean Outfall★

CORROSION ◽  
1959 ◽  
Vol 15 (7) ◽  
pp. 41-46 ◽  
Author(s):  
HARRY J. KEELING
Keyword(s):  
Los Angeles ◽  
Corrosion Protection ◽  
Cathodic Protection ◽  
Current System ◽  
Coal Tar ◽  
Design Life ◽  
Impressed Current ◽  
Cathodic Protection System ◽  
Negative Buoyancy ◽  
Impressed Current Cathodic Protection

Abstract Details are presented on the planning, design and installation of corrosion protection facilities to provide 100-year design life for a 7-mile, 22-inch steel pipe sewer outfall, the outer end of which is in ocean water 340 feet deep. The outfall serves the sewerage systems of Los Angeles and 16 other adjacent municipalities. An impressed current cathodic protection system is used to protect the exterior of the pipe which is wrapped with a multiple-layer coal tar coating reinforced with glass fiber with bonded impregnated asbestos felt shield. A reinforced pneumatically applied cement mortar jacket provides negative buoyancy. Interior is protected by centrifugally-spun mortar lining with epoxy sleeves at welded tie-in joints. Because of the depth of water in which the pipe was to be placed several novel features were necessary. Cathodic protection was applied continuously during installation by the use of zinc anodes. This system was monitored to detect any serious coating holiday before the pipe was laid in deep water. Permanent test leads also were attached to the pipe so performance of the impressed current system could be checked, continuously. After 1½ years' operation there has been very little change in effective coating resistance, a pipe potential of —1.05 volts versus a copper/copper sulfate electrode being maintained with consumption of about 150 ma. 5.2.3

Fatigue-Corrosion of High Strength Steels in Synthetic Seawater under Cathodic Protection

2020 ◽  
Vol 841 ◽  
pp. 294-299
Author(s):  
Sergio Lorenzi ◽  
Cristian Testa ◽  
Marina Cabrini ◽  
Francesco Carugo ◽  
Luigi Coppola ◽  
...  
Keyword(s):  
Cathodic Protection ◽  
Fatigue Behavior ◽  
High Strength Steels ◽  
High Strength ◽  
Loading Frequency ◽  
Offshore Pipelines ◽  
Synthetic Seawater ◽  
Steel Grades ◽  
Protection Potential ◽  
Fatigue Corrosion

The paper is aimed to the study of the corrosion-fatigue behavior of high strength steels for offshore pipelines. Tests have been performed in order to study fatigue crack growth in synthetic seawater under cathodic protection. The tests have been carried out on three different steel grades from 65 to 85 ksi with tempered martensite and ferrite-bainite microstructures. The effect of stress intensity factor, cathodic protection potential and cyclic loading frequency is shown.

Cathodic protection criteria of low alloy steel in simulated deep water environment

2020 ◽  
Vol 67 (4) ◽  
pp. 427-434
Author(s):  
Haijing Sun ◽  
Weihai Xue ◽  
Jiaxin Xu ◽  
Guoliang Chen ◽  
Jie Sun
Keyword(s):  
Shallow Water ◽  
Alloy Steel ◽  
Deep Water ◽  
Cathodic Protection ◽  
Water Environment ◽  
Deep Ocean ◽  
Low Alloy Steel ◽  
Content Type ◽  
Offshore Industry ◽  
Protection Potential

Purpose The purpose of this work is to provide theoretical guidance and experimental analysis for optimized cathodic protection (CP) design of low alloy steel in deep water environments. Design/methodology/approach In the present study, the CP criteria of 10Ni5CrMoV low alloy steel were investigated in a simulated deep water environment (350 m) regarding the theoretical protection potential and measured protection potential. The influences of hydrostatic pressure (HP) and temperature were also discussed in detail. The theoretical protection potential was analyzed with the Nernst equation, and the measured minimum protection potential was derived by extrapolating the Tafel portion of anodic polarization curves. Findings The results indicate that the minimum protection potential of low alloy steel shifts to a positive value in a deep-ocean environment. This can be attributed to the combined effects of HP and the temperature. Moreover, the temperature has a stronger influence compared with HP. The results suggest that the CP potential criteria used in shallow water are still applicable in the deep ocean, which is further confirmed through the SEM and x-ray diffraction analysis of the corrosion products resulted from the potentiostatic cathodic polarization experiments at −0.85 VCSE. Originality/value In recent decades, successful applications of CP for long-term corrosion protection of the steel components applied at a subsea level have enabled the offshore industry to develop reliable and optimized CP systems for shallow water. However, differences in the seawater environment at greater depths have raised concerns regarding the applicability of the existing CP design for deeper water environments. Hence, this research focuses on the CP criteria of low alloy steel in simulated deep water environment concerning the theoretical protection potential and measured protection potential. The influences of HP and temperature were also discussed.

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