Local additional potential model for effect of strain rate on SCC of pipeline steel in an acidic soil solution

2009 ◽  
Vol 51 (12) ◽  
pp. 2863-2871 ◽  
Author(s):  
Z.Y. Liu ◽  
X.G. Li ◽  
C.W. Du ◽  
Y.F. Cheng
Keyword(s):  
Strain Rate ◽  
Soil Solution ◽  
Potential Model ◽  
Pipeline Steel ◽  
Acidic Soil

scholarly journals Effect of Sulfate-Reducing Bacteria (SRB) on the Corrosion of Buried Pipe Steel in Acidic Soil Solution

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 625
Author(s):  
Lijuan Chen ◽  
Bo Wei ◽  
Xianghong Xu
Keyword(s):  
Soil Solution ◽  
Steel Surface ◽  
Pipeline Steel ◽  
Electrochemical Techniques ◽  
Sulfate Reducing Bacteria ◽  
Acidic Soil ◽  
Microbiologically Influenced Corrosion ◽  
Soil Environment ◽  
Sulfate Reducing ◽  
Reducing Bacteria

The influence of sulfate-reducing bacteria (SRB) on the corrosion behaviors of X80 pipeline steel was investigated in a soil environment by electrochemical techniques and surface analysis. It was found that SRB grew well in the acidic soil environment and further attached to the coupon surface, resulting in microbiologically influenced corrosion (MIC) of the steel. The corrosion process of X80 steel was significantly affected by the SRB biofilm on the steel surface. Steel corrosion was inhibited by the highly bioactive SRB biofilm at the early stage of the experiment, while SRB can accelerate the corrosion of steel at the later stage of the experiment. The steel surface suffered severe pitting corrosion in the SRB-containing soil solution.

Electrochemical and Tension Tests Behavior of API 5L X60 Pipeline Steel in a Simulated Soil Solution

2013 ◽  
Vol 755 ◽  
pp. 153-161 ◽  
Author(s):  
Luis M. Quej-Aké ◽  
Ricardo Galván-Martínez ◽  
Antonio Contreras-Cuevas
Keyword(s):  
Carbon Steel ◽  
Strain Rate ◽  
Soil Solution ◽  
Electrochemical Impedance ◽  
Pipeline Steel ◽  
Failure Process ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Tension Tests ◽  
Before And After

In this work electrochemical impedance spectroscopy (EIS) and slow strain rate tests (SSRT) were used for the evaluation of API 5L X60 carbon steel in contact with a simulated soil solution called NS4. EIS monitoring before and after performing the tension tests was carried out. SSRT were carried out in NS4 solution at room temperature to simulate dilute ground water that has been found associated with stress corrosion cracking (SCC) of low carbon steel pipelines. A strain rate of 1x10-6 sec-1 was used. According to the analysis of SSRT, the X60 pipeline steel is highly resistant to SCC. In order to perform the electrochemical test, two working electrodes were considered, a complete specimen, before the SSRT and a fractured specimen after the SSRT. The analyses of results show that the electrochemical response was different in each samples. The corrosion rate (CR) obtained by the two corrosion techniques revealed that the CR of the fractured specimen was higher than the CR of the complete specimen. This behavior is attributed to the fact that the fractured specimen present a high degree of tortuosity and this condition activate the corrosion process. In addition, according to the cathodic Tafel slope, the reduction reacction was influenced by a difusion process. A combine fracture type in SSRT was observed: ductil and brittle with a transgranular appearance. Some pits and internal cracks close to the fracture zone were observed. The failure process and mechanism of X60 steel in NS4 solution are controlled by dissolution and hydrogen embrittlement.

Effect of Potentials on Stress Corrosion Cracking of X80 Pipeline Steel in Simulated Soil Solution

2011 ◽  
Vol 197-198 ◽  
pp. 1549-1554 ◽  
Author(s):  
Yuan Cheng ◽  
Hong Ying Yu ◽  
Ying Wang ◽  
Xu Meng ◽  
Li Xin Zhang ◽  
...  
Keyword(s):  
Strain Rate ◽  
Stress Corrosion ◽  
Soil Solution ◽  
Anodic Dissolution ◽  
Stress Corrosion Cracking ◽  
Fracture Mechanism ◽  
Pipeline Steel ◽  
Corrosion Cracking ◽  
X80 Pipeline Steel ◽  
X80 Steel

The stress corrosion cracking (SCC) susceptibility of X80 pipeline steel, which was used in the Second West-East Gas Pipeline, was investigated in simulated soil solution of Xinzhou in Hubei province of China. The SCC susceptibility was studied using the slow strain rate tensile (SSRT) tests in which different potentials were applied. The fracture surfaces were observed using SEM. X80 steel was susceptible to SCC in simulated solution. The SCC was not serious with the anodic potentials applied. The fracture mechanism was anodic dissolution. But the SCC was affected obviously with different cathodic potentials because of the different influence of the hydrogen.

Stress Corrosion Cracking of X70 Pipeline Steel in Near-Neutral pH Soil Solution

2004 ◽  
Author(s):  
B. Y. Fang ◽  
J. Q. Wang ◽  
E.-H. Han ◽  
Z. Y. Zhu ◽  
W. Ke
Keyword(s):  
Cyclic Loading ◽  
Strain Rate ◽  
Stress Corrosion ◽  
Soil Solution ◽  
Stress Corrosion Cracking ◽  
Pipeline Steel ◽  
Low Frequency ◽  
Chloride Ion ◽  
Corrosion Cracking ◽  
Electrochemical Tests

Stress corrosion cracking behavior of X70 pipeline steel was studied using slow strain rate tests (SSRT) and cyclic loading at high R and low frequency in a nearneutral pH soil solution saturated with 5% CO2+95% N2. The soil was from Xinjiang Uygur Autonomous Region where the Chinese West-East natural gas transmission pipeline started. Electrochemical tests including a potentiodynamic polarization technique and electrochemical impedance spectrum (EIS) were also conducted in order to analyze the effect of the concentration of bicarbonate, bubbled gas and the addition of chloride ion on the polarization behaviors. The results of SSRT showed that transgranular stress corrosion cracking (TGSCC) occurred in Xinjiang soil solution. Crack initiation was associated with pitting, inclusion and streamline of rolling. The susceptibility to SCC increased with the decrease of the applied electrochemical potential and strain rate. Cyclic loading tests with smooth specimens showed that some cracks initiated after certain cycles and cracking mode was transgranular. Under the cyclic loading of high R and low frequency, the crack propagation rate (CPR) of precracked specimens did not increase at some region of stress intensity factor range (ΔK), which showed that the crack propagation process was dominated by SCC. The results of the electrochemical tests showed that the polarization behaviors were influenced greatly by the concentration of bicarbonate, bubbled gas and the addition of chloride ion. Low concentration of chloride ion in bicarbonate could cause the elimination of passivity and SCC behavior to that in near-neutral pH soil solution.

Residual Stress Assessment and its Effect on SCC of Pipelines Steel in Acidic Soil Environment

2014 ◽  
Vol 1616 ◽  
Author(s):  
A. Contreras ◽  
L.M. Quej-Ake ◽  
R. Galvan-Martinez ◽  
O. Vega
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Soil Solution ◽  
Pipeline Steel ◽  
Acidic Soil ◽  
Soil Environment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Welding Joints ◽  
Internal Side

ABSTRACTEffect of residual stresses of multiple welding repairs on API 5L X52 pipeline steel on stress corrosion cracking (SCC) in a simulated acidic soil solution was studied. Four conditions of repairs of the girth weld were evaluated. The residual stresses were measured through X-ray diffraction (XRD) on the internal side of the pipe in longitudinal and circumferential direction. The circumferential and longitudinal residual stresses values are compressive on the inner surface of the welding joints. The highest residual stresses were measured in the hoop direction reaching values of about 98% of the yielding strength (360 MPa). It was observed that its magnitude increases as move away from weld center line. The effect of residuals stresses in the SCC susceptibility of X52 pipeline steel was evaluated through slow strain rate tests (SSRT) in a simulated acidic soil solution. Relation between mechanical properties obtained from SSRT and residual stresses on the SCC susceptibility was analyzed. Results of SCC index taking account the ratios obtained from the mechanical properties of the welding joints evaluate, showed good SCC resistance in acidic soil solution at low pH. Scanning electron microscopy (SEM) observations showed that the region with high residual stresses prior to generate cracks in the steel due to the combination of soil solution and the strain exerted, should favor pitting formation and not cracking.

Tension Tests Behavior of API 5L X60 Pipeline Steel in a Simulated Soil Solution to Evaluate SCC Susceptibility

2012 ◽  
Vol 1481 ◽  
pp. 71-80
Author(s):  
A. Contreras ◽  
S. L. Hernández ◽  
R. Galvan-Martinez ◽  
O. Vega-Becerra
Keyword(s):  
Strain Rate ◽  
Soil Solution ◽  
Room Temperature ◽  
Pipeline Steel ◽  
Failure Process ◽  
Low Carbon Steel ◽  
Fracture Type ◽  
Low Carbon ◽  
Surface Fracture ◽  
Tension Tests

ABSTRACTIn this work slow strain rate tests (SSRT) were used for the evaluation of API 5L X60 in contact with a simulated soil solution called NS4 in order to evaluate stress corrosion cracking (SCC) susceptibility. SSRT were carried out in NS4 solution at room temperature to simulate dilute ground water that has been found to be associated with SCC of low carbon steel pipelines. A strain rate of 1x10-6 sec-1 was used. According to the analysis of SSRT results, the X60 pipeline steel is highly resistant to SCC at the conditions studied. A combine fracture type it was observed: ductile and brittle with a transgranular appearance. Some pits close to the fracture zone were observed. The failure process and mechanism of X60 steel in NS4 solution are controlled by anodic dissolution and hydrogen embrittlement which was revealed with the internal cracks observed in the surface fracture. There is a relation between the strength of the steel and the SCC susceptibility, thus, increasing strength in the steel, the SCC susceptibility increases as a function of the pH solution used.

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.

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