PREVENTION OF STRESS‐CORROSION CRACKING BY CATHODIC PROTECTION

1965 ◽  
Vol 12 (9) ◽  
pp. 9-12
Author(s):  
L. Fairman
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Cathodic Protection ◽  
Corrosion Cracking

Characterization of the Crack Propagation in the API X-52 and API X-65 Steels into Cathodic Protection

2009 ◽  
Vol 1242 ◽  
Author(s):  
A. Aguilar ◽  
R. Esparza ◽  
M.A. Gil ◽  
L.F. Cuahutitla ◽  
E. Rubio-Rosas ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Crack Propagation ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Cathodic Protection ◽  
Reference Electrode ◽  
Important Variable ◽  
Corrosion Cracking ◽  
High Concentrations

ABSTRACTCathodic protection has been applied for many years as the best method to prevent the corrosion in systems which transported hydrocarbon pipelines. However, it has found the presence of stress corrosion cracking (SCC) in steel pipelines with high concentrations of carbonates and bicarbonates with pH final (9 to 11). The resistance to the stress corrosion cracking of the API X-52 and API X-65 steels was evaluated on compact modified wedge opening specimens (WOL). The specimens were loaded of 95% of the yield strength. The resistance of crack propagation and the corrosion rate were evaluated with different applied potentials (-850 and -650 mV), this with respect to a saturated copper/copper sulfate reference electrode. The used electrolytes were simulated soils (carbonate-bicarbonate solution). Evidence of crack propagation of the API X-52 and API X-65 steels were carried out by scanning electron microscopy. The obtained result showed susceptibility to SCC on specimens with cathodic protection. The cathodic protection applied (-850 mV vs Cu/CuSO4 electrode) decreases considerably the corrosion rate on the evaluated steels. In this work the loaded stress showed to be a very important variable on the susceptibility to SCC.

Predicting Corrosion Under Disbonded Coating Using Modeling and Cathodic Protection Monitoring Coupon

2002 ◽  
Author(s):  
N. Sridhar ◽  
D. S. Dunn ◽  
O. Moghissi ◽  
F. King ◽  
J. Been
Keyword(s):  
Numerical Modeling ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Cathodic Protection ◽  
Corrosion Cracking ◽  
Soil Conditions ◽  
Modeling Approach ◽  
Bare Steel ◽  
Disbonded Coating

Coating defects generally take the form of either exposed bare steel or a disbondment, where a gap is formed between a relatively intact coating and bare steel. Cathodic protection can be difficult to achieve and monitor in the disbonded regions depending on the type of coating and soil conditions. Furthermore, stress corrosion cracking occurs predominantly under disbonded coatings. This paper describes a numerical modeling approach to predict the potential and chemistry under disbonded coating. In addition, the use of a monitoring coupon to simulate pipeline disbondments is demonstrated.

Stress Corrosion Cracking of Pipeline Steel in Soil Environments of Eastern China

2007 ◽  
Vol 353-358 ◽  
pp. 223-226
Author(s):  
Guang Fu Li ◽  
Chun Bo Huang ◽  
Hao Guo ◽  
Wu Yang
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Cathodic Protection ◽  
General Trend ◽  
Pipeline Steel ◽  
Eastern China ◽  
Corrosion Cracking ◽  
Electrode Potentials ◽  
Soil Solutions ◽  
Hydrogen Induced Cracking

Stress corrosion cracking (SCC) behaviors of pipeline steel X70 in various near-neutral pH soil environments with characteristics of eastern China have been studied through electrochemical measurements and slow strain rate tests (SSRT) at various electrode potentials in four solutions containing different typical soils in eastern China as well as in NS-4 solution. The SCC susceptibility in the four soil solutions was generally higher than that in NS-4 solution. There was a general trend that SCC susceptibility increased with decreasing the potential, suggesting that hydrogen induced cracking probably plays a key role in the cracking at least at low potentials and the parameters of cathodic protection in engineering should be carefully optimized to avoid SCC.

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