The stress corrosion cracking behavior of X120 pipeline steel in a simulated acidic soil solution

2012 ◽  
Vol 59 (6) ◽  
pp. 311-316 ◽  
Author(s):  
Jing Liu ◽  
JiHao Cheng ◽  
Qian Hu ◽  
Feng Huang ◽  
JinQiao Xu ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Soil Solution ◽  
Stress Corrosion Cracking ◽  
Pipeline Steel ◽  
Corrosion Cracking ◽  
Acidic Soil ◽  
Cracking Behavior

Stress Corrosion Cracking Behavior of X60 Pipe Steel in Soil Environment

2009 ◽  
Vol 1242 ◽  
Author(s):  
Z. Velazquez ◽  
E. Guzman ◽  
M‥A. Espinosa-Medina ◽  
A. Contreras
Keyword(s):  
Strain Rate ◽  
Stress Corrosion ◽  
Soil Solution ◽  
Stress Corrosion Cracking ◽  
Room Temperature ◽  
Cathodic Polarization ◽  
Pipeline Steel ◽  
Corrosion Cracking ◽  
Time To Failure ◽  
Cracking Behavior

ABSTRACTStress corrosion cracking (SCC) susceptibility of API X60 pipeline steel in a soil solution by slow strain rate tests (SSRT), and surface fracture analysis was investigated. The SSRT were performed at strain rate of 25.4 × 10-6 mm/sec in a glass autoclave containing the soil solution called NS4 with pH of 3 and 10 at room temperature and 50°C. Both anodic and cathodic polarization potentials of 200 mV referred to Ecorr was applied. The results of ratio reduction area (RRA), time to failure ratio (TFR) and elongation plastic ratio (EPR) indicate that X60 pipeline steel was susceptible to SCC at pH 3 and cathodic polarization of -200 mV at room temperature and 50°C. Scanning electron microscopy (SEM) observations of these specimens showed a brittle type of fracture with transgranular appearance. The SCC process and mechanism of X60 steel into NS4 solution was hydrogen based mechanism. With the different applied potentials the dominance of SCC process changes. At low pH the temperature effect on SCC susceptibility is more noticeable at 20°C. However at high pH this effects changes, being the steel more susceptible to SCC at 50°C.

Effects of Environmental Factors on Stress Corrosion Cracking of Pipeline Steels

2005 ◽  
Vol 297-300 ◽  
pp. 939-944 ◽  
Author(s):  
Wu Yang ◽  
Guang Fu Li ◽  
Hao Guo ◽  
Jian Jiang Zhou ◽  
Chun Bo Huang ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Pipeline Steel ◽  
Electrochemical Measurement ◽  
Corrosion Cracking ◽  
Potential Region ◽  
Cracking Behavior ◽  
High Ph ◽  
Neutral Ph

Effects of some environmental factors on stress corrosion cracking (SCC) of pipeline steel X-70 both in near-neutral pH environments, including NS4 solution and several solutions containing main types of soil in the eastern part of China, and in high pH solution were studied by means of electrochemical measurement and slow strain rate testing (SSRT). The anodic polarization curves showed different features in near-neutral pH and high pH solutions in terms of active-passive transition behavior. In near-neutral pH solutions, the cracking mode was transgranular with the feature of quasi-cleavage, the susceptibility to SCC increased with decreasing potential, pH and temperature as well as increasing CO2, indicating a dominant mechanism of hydrogen induced cracking (HIC). In high pH solutions, the cracking behavior was similar to that in near-neutral pH solutions when the specimens were polarized at cathodic potentials, but quite different at anodic potentials. A comparison of the electrochemical behavior with the SCC potential region indicated a dominant SCC mechanism associated with anodic dissolution (AD) of X70 in high pH solution at anodic potentials. A preliminary experimental potential (E)-pH-SCC diagram has been established for X70 in near-neutral pH environments.

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