scholarly journals Analysis of the Long-Term Corrosion Behavior of X80 Pipeline Steel in Acidic Red Soil Using Electrical Resistance Test Technique

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Shuaixing Wang ◽  
Daoxin Liu ◽  
Nan Du ◽  
Qing Zhao ◽  
Jinhua Xiao
Keyword(s):  
Corrosion Rate ◽  
Electrical Resistance ◽  
Pipeline Steel ◽  
Test System ◽  
Red Soil ◽  
X80 Pipeline Steel ◽  
Test Technique ◽  
X80 Steel

The long-term corrosion rate of X80 steel in an acidic red soil was monitored in situ by using a precise electrical resistance (ER) test system. The corrosion characteristics of X80 steel were examined via SEM, EDS, and XRD. The results indicated that the corrosion rate determined from ER test was very similar to that obtained from the mass loss test. The ER test technique made it possible to predict the long-term corrosion rate of steel in soil in situ. The corrosion rate of X80 steel in acidic red soil was about 0.0902 mm/a at 38 weeks, but the corrosion rate was dropped to 0.0226 mm/a after 5 years. The final corrosion product layer was composed mainly of FeOOH,γ-Fe2O3, and FeCO3.

scholarly journals Electrochemical Investigation of Corrosion of X80 Steel under Elastic and Plastic Tensile Stress in CO2 Environment

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 949 ◽  
Author(s):  
Wei Wu ◽  
Hailong Yin ◽  
Hao Zhang ◽  
Jia Kang ◽  
Yun Li ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Tensile Stress ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Pipeline Steel ◽  
Open Circuit ◽  
Co2 Corrosion ◽  
X80 Pipeline Steel ◽  
X80 Steel ◽  
Co2 Environment

An investigation into the electrochemical corrosion behavior of X80 pipeline steel under different elastic and plastic tensile stress in a CO2-saturated NaCl solution has been carried out by using open-circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopy, and surface analysis techniques. The results show that the corrosion rate of X80 steel first increases and then slightly decreases with the increase of elastic tensile stress, whereas the corrosion rate sharply increases with the increase of plastic tensile stress. Both elastic and plastic tensile stress can enhance steel corrosion by improving the electrochemical activity of both anodic and cathodic reactions. Moreover, compared with elastic tensile stress, plastic tensile stress has a more significant effect. Furthermore, electrochemical reactions for CO2 corrosion and mechanoelectrochemical effect are used to reasonably explain the corrosion behavior of stressed X80 steel in CO2 environment.

SEM In Situ Investigation on Fatigue Cracking Behavior of X80 Pipeline Steel with Inclusions

2011 ◽  
Vol 284-286 ◽  
pp. 1096-1100 ◽  
Author(s):  
Ke Tong ◽  
Yan Ping Zeng ◽  
Xin Li Han ◽  
Yao Rong Feng ◽  
Xiao Dong He
Keyword(s):  
Crack Initiation ◽  
Pipeline Steel ◽  
Fatigue Cracking ◽  
Fatigue Loading ◽  
In Situ Observation ◽  
X80 Pipeline Steel ◽  
Cracking Behavior ◽  
The Matrix ◽  
Extension Period

The micro-mechanical behavior of inclusions in X80 pipeline steel under fatigue loading was investigated by means of SEM in situ observation. The influence of sizes and shapes of inclusion on crack initiation and propagation was analyzed. The result shows that for large-size single-particle inclusion, cracks initiate from the interior under the fatigue loading. When a certain circulation cycles are reached, cracks initiate at the matrix near the sharp corner of the inclusion. The cracks extend at the matrix during the stable extension period and unstable extension period following the crack initiation, until fracture occurred. For chain inclusion, cracks first initiate at the interface between inclusion and matrix within the chain area, and the circulation cycles needed for initiation are far less than single inclusion. Cracks steadily extend after the initiation, and then fracture after very short circulation cycles. A chain of inclusion with the shape corners is serious harmful to the fatigue properties.

Quenching Temperature‘s Impact on the Microstructure and Mechanical Properties of X80 Pipeline Steel

2011 ◽  
Vol 308-310 ◽  
pp. 762-766
Author(s):  
Yong Jie Ma ◽  
Xi Lu Liu ◽  
Guang Liang Zhang
Keyword(s):  
Mechanical Properties ◽  
Pipeline Steel ◽  
X80 Pipeline Steel ◽  
Quenching Temperature ◽  
Austenite Grain ◽  
State Study ◽  
Lath Bainite ◽  
Small Needle ◽  
X80 Steel ◽  
Increased Strength

The state study on mechanical properties’ changes of X80 steel at different quenching temperature. The results showed that the quenching temperature is 1000 °C, X80 Austenite grain coarsening is serious, leading to the production of coarse lath bainite ferrite, resulting in increased strength of X80 steel, toughness and hardness of a serious reduction; When the quenching temperature is 930 °C, and assisted by the appropriate temperatures, can make the X80 steel the small needle-like ferrite-based organizations, to obtain good hardness, strength, ductility and toughness of the match.

Mechanical Properties and CO2 Corrosion Behavior of High Strength and Toughness X80 Pipeline Steel

2014 ◽  
Vol 1010-1012 ◽  
pp. 1709-1712
Author(s):  
Li Dong Wang ◽  
Feng Lei Liu ◽  
Hui Bin Wu
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Acicular Ferrite ◽  
Pipeline Steel ◽  
High Strength ◽  
Strengthening Mechanism ◽  
Granular Bainite ◽  
X80 Pipeline Steel ◽  
Better Than ◽  
Strength And Toughness

A type of X80 grade high strength and toughness pipeline steel was designed and researched. The strengthening mechanism of the steel was analyzed by SEM, TEM and XRD, and the CO2corrosion behavior of the steel was simulated by high-temperature and high-pressure autoclave. The result shows that the microstructure of the base metal is mainly acicular ferrite with a small amount of granular bainite. Acicular ferrite consists of laths which occlude and interweave with each other, and there are many dislocation and carbonitrides distributing in acicular ferrite, which made the pipeline steel have good strength and toughness. Under the simulation of the actual working conditions, the activity of reactants is low at 30°C, so the corrosion rate is smaller at this temperature; the maximum of corrosion rate occurs at 60°C; when the temperature increases to 90°C, the corrosion rate is lower than that of 60°C, that is because hindering corrosion effect which take by the acceleration deposit of corrosion product is better than the acceleration corrosion reactions.

Effects of Hydrogen on Electrochemical Behaviors of X80 Steel in Simulated Soil Solution

2011 ◽  
Vol 335-336 ◽  
pp. 468-473 ◽  
Author(s):  
Chuan He ◽  
Xu Chen ◽  
Yang Xu ◽  
Zhi Yong Liu
Keyword(s):  
Soil Solution ◽  
Current Density ◽  
Polarization Resistance ◽  
Pipeline Steel ◽  
Charge Transfer Resistance ◽  
X80 Pipeline Steel ◽  
Transfer Resistance ◽  
Hydrogen Charging ◽  
Charging Time ◽  
X80 Steel

X80 pipeline steel specimens were treated by electrochemical hydrogen charging under various current density and charging time. The polarization resistance and corrosion rate of X80 steel were analyzed in Yingtan simulated soil solution under the different hydrogen charging conditions. The results showed that hydrogen accelerated anodic dissolution and enhanced corrosion sensitivity. With hydrogen in the steel, the charge transfer resistance and polarization resistance decreased, double electric layer capacitor and corrosion current increased. The effects were enhanced with the increase of hydrogen charging time and current density.

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

2010 ◽  
Vol 146-147 ◽  
pp. 920-925 ◽  
Author(s):  
Yuan Cheng ◽  
Hong Ying Yu ◽  
Li Xin Zhang ◽  
Ying Wang ◽  
Xu Meng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Stress Corrosion ◽  
Soil Solution ◽  
Stress Corrosion Cracking ◽  
Pipeline Steel ◽  
Corrosion Cracking ◽  
X80 Pipeline Steel ◽  
X80 Steel ◽  
Scanning Electron

The stress corrosion cracking susceptibility of X80 pipeline steel was investigated in a simulated soil solution using slow strain rate tensile (SSRT) tests. The different potentials were applied in the tests. The fracture surfaces were observed using scanning electron microscopy (SEM). The X80 steel was susceptible to SCC in simulated solution. The SCC susceptibility had no apparent change with the anodic potentials applied. The fracture mechanism was anodic dissolution. However, the SCC susceptibility increased with the decrease of the cathodic potentials obviously. The cracking was induced by the Hydrogen diffusing into the metal.

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.

Microstructure and Texture Comparison of an Acicular Ferrite Pipeline Steel with Different Hot Rolling Process

2011 ◽  
Vol 399-401 ◽  
pp. 264-267
Author(s):  
Hai Yan Wang ◽  
Hui Ping Ren ◽  
Le Han ◽  
Zi Li Jin ◽  
Hao Sun
Keyword(s):  
Hot Rolling ◽  
Acicular Ferrite ◽  
Pipeline Steel ◽  
Orientation Distribution ◽  
Rolling Process ◽  
X80 Pipeline Steel ◽  
Hot Rolling Process ◽  
X80 Steel ◽  
Hot Rolled ◽  
Electron Back Scattered Diffraction

Microstructure of X80 pipeline steel with different hot rolling process was compared using Optical microscopy (OM), Bulk X-ray texture and micro orientation analysis was carried out by Orientation distribution function (ODF) and Electron back-scattered diffraction (EBSD), to analyze the various texture components of the pipeline steels under two different rolling processes. The results show that the final microstructures under the two schedules both present typical acicular ferrite characteristic. On the other side, the corresponding textures were found mainly comprised of two fibers in the rolling and normal direction in hot rolled X80 steel plate, there were obvious {112} , {110} , and {111} fiber, which seemed to be related with the mechanical properties anisotropy. Therefore, the influences of the microstructure and texture on the anisotropy were also discussed in this paper.

Frequency Domain Analysis and Application of Electrochemical Noise of X80 Pipeline Steel

2014 ◽  
Vol 1015 ◽  
pp. 659-662
Author(s):  
Peng Xin Feng ◽  
Wen Long Xu ◽  
Hai Tao Lai ◽  
Xun Zhu ◽  
Wen Wei Lu ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Electrochemical Noise ◽  
Pipeline Steel ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Metal Corrosion ◽  
Linear Segment ◽  
X80 Pipeline Steel ◽  
X80 Steel ◽  
Moisture Potential

In this paper, frequency domain analysis and application of electrochemical noise of X80 Pipeline Steel in Xinzhou Soil is researched. In the frequency data analysis of electrochemical noise, there are three characteristic parameters. It can be seen from experiments that X80 steel buried in Xinzhou soil with14% moisture content shows that metal corrosion is still not change much. And, it can be inferred that corrosion of X80 pipeline steel in Xinzhou soil with 18% moisture, corrosion is uniform while the morphology is not the uniform , it is the morphology that some pitting are connecting into the film. In Xinzhou soil with 22% moisture, potential PSD figure is different after corrosion happened for one day and three days. Thus, the corrosion type can be determined by high-frequency slope of the linear segment of potential PSD figure.

In situ corrosion characterization of simulated weld heat affected zone on API X80 pipeline steel

2014 ◽  
Vol 85 ◽  
pp. 401-410 ◽  
Author(s):  
L.W. Wang ◽  
Z.Y. Liu ◽  
Z.Y. Cui ◽  
C.W. Du ◽  
X.H. Wang ◽  
...  
Keyword(s):  
Heat Affected Zone ◽  
Pipeline Steel ◽  
X80 Pipeline Steel ◽  
Weld Heat
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