Synergistic Effects of Hydrogen and Stress on Corrosion of X100 Pipeline Steel in a Near-Neutral pH Solution

2009 ◽  
Vol 19 (9) ◽  
pp. 1284-1289 ◽  
Author(s):  
C. Zhang ◽  
Y. F. Cheng
Keyword(s):  
Pipeline Steel ◽  
Synergistic Effects ◽  
Neutral Ph ◽  
X100 Pipeline Steel

The Role of Electrochemical Conditions in Near-Neutral pH SCC Initiation Mechanism(s)

2010 ◽  
Author(s):  
Abdoulmajid Eslami ◽  
Mohammadhassan Marvasti ◽  
Weixing Chen ◽  
Reg Eadie ◽  
Richard Kania ◽  
...  
Keyword(s):  
Cathodic Protection ◽  
Pipeline Steel ◽  
Synergistic Effects ◽  
Co2 Concentration ◽  
Initiation Mechanism ◽  
Ph Values ◽  
Neutral Ph ◽  
Comprehensive Test ◽  
Disbonded Coating

In order to improve our understanding of near-neutral pH SCC initiation mechanism(s), a comprehensive test setup was used to study the electrochemical conditions beneath the disbonded coatings in cracking environments. In this setup the synergistic effects of cyclic loading, coating disbondment, and cathodic protection were considered. Our previous results showed that there can be a significant variation in the pH of the localized environment under the disbonded coating of pipeline steel. The pH inside the disbondment can change significantly from near-neutral to high pH values, strongly depending on the level of cathodic protection and CO2 concentration. Both of these variables affected the electrochemical conditions on the steel surface and therefore the initiation mechanisms. This work highlights the role of electrochemical conditions in near-neutral pH SCC initiation mechanisms.

scholarly journals The Pitting Susceptibility Investigation of Passive Films Formed on X70, X80, and X100 Pipeline Steels by Electrochemical Noise and Mott-Schottky Measurements

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Yang Zhao ◽  
Ping Liang ◽  
Yanhua Shi ◽  
Yunxia Zhang ◽  
Tao Yang
Keyword(s):  
Distribution Function ◽  
Electrochemical Noise ◽  
Pipeline Steel ◽  
Stochastic Theory ◽  
Gumbel Distribution ◽  
Passive Films ◽  
Initiation Rate ◽  
Pipeline Steels ◽  
X100 Pipeline Steel ◽  
Pit Initiation

The pitting susceptibility of passive films formed on X70, X80, and X100 pipeline steels was investigated by means of electrochemical noise (EN) and Mott-Schottky measurements. The EN results were analyzed according to the shot-noise theory and stochastic theory. Pit initiation process was analyzed quantitatively using the Weibull distribution function. Pit growth process was simulated by Gumbel distribution function. The experimental results of Mott-Schottky plots showed that the passive films formed on the three pipeline steels displayed an n-type semiconductor character, and the passive film for X100 pipeline steel has the lowest donor density (ND) among the three passive films. The EN results demonstrated that X100 pipeline steel had the lowest pit initiation rate and pit growth probability, which implied that the X100 pipeline steel had the lowest pitting susceptibility.

scholarly journals Influence of the ultrasonic surface rolling process on stress corrosion cracking susceptibility of high strength pipeline steel in neutral pH environment

RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 36876-36885 ◽  
Author(s):  
Bingying Wang ◽  
Yu Yin ◽  
Zhiwei Gao ◽  
Zhenbo Hou ◽  
Wenchun Jiang
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Pipeline Steel ◽  
High Strength ◽  
Rolling Process ◽  
Corrosion Cracking ◽  
X80 Pipeline Steel ◽  
Enhancement Technique ◽  
Neutral Ph ◽  
Developed Surface

A developed surface enhancement technique, USRP, was applied on X80 pipeline steel and the stress corrosion cracking susceptibility was studied.

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