Role of inclusions in the pitting initiation of pipeline steel and the effect of electron irradiation in SEM

2018 ◽  
Vol 130 ◽  
pp. 252-260 ◽  
Author(s):  
Yafei Wang ◽  
Guangxu Cheng ◽  
Wei Wu ◽  
Yun Li
Keyword(s):  
Electron Irradiation ◽  
Pipeline Steel

scholarly journals On the role of grain size on slurry erosion behavior of a novel medium-carbon, low-alloy pipeline steel after induction hardening

Wear ◽  
2021 ◽  
pp. 203678
Author(s):  
Vahid Javaheri ◽  
Oskari Haiko ◽  
Saeed Sadeghpour ◽  
Kati Valtonen ◽  
Jukka Kömi ◽  
...  
Keyword(s):  
Grain Size ◽  
Pipeline Steel ◽  
Induction Hardening ◽  
Slurry Erosion ◽  
Medium Carbon ◽  
Erosion Behavior

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.

Role of Fe oxides in corrosion of pipeline steel in a red clay soil

2014 ◽  
Vol 80 ◽  
pp. 309-317 ◽  
Author(s):  
Maocheng Yan ◽  
Cheng Sun ◽  
Jin Xu ◽  
Junhua Dong ◽  
Wei Ke
Keyword(s):  
Clay Soil ◽  
Pipeline Steel ◽  
Red Clay ◽  
Fe Oxides

scholarly journals Role of Microstructure in Susceptibility of X70 Pipeline Steel to Hydrogen Embrittlement

2010 ◽  
Vol 654-656 ◽  
pp. 162-165 ◽  
Author(s):  
D. Hejazi ◽  
A.J. Haq ◽  
N. Yazdipour ◽  
D.P. Dunne ◽  
Frank J. Barbaro ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Fracture Surface ◽  
Heat Affected Zone ◽  
Pipeline Steel ◽  
Rolled Strip ◽  
Bend Tests ◽  
Point Bend ◽  
Hot Rolled ◽  
Surface Observations

In order to investigate the susceptibility of steels to hydrogen embrittlement as a function of their microstructure X70 steel was chosen in different conditions: normalized transfer bar, as-received hot rolled strip and heat affected zone (HAZ). Notched and fatigue pre-cracked samples were subjected to electrochemical hydrogen charging to achieve 2 ppm hydrogen content. Three point bend tests were conducted on as-received and hydrogen charged samples. The results showed that HAZ samples are more susceptible to hydrogen embrittlement than the others. This was supported by fracture surface observations.

scholarly journals The role of electron-stimulated desorption in focused electron beam induced deposition

2013 ◽  
Vol 4 ◽  
pp. 474-480 ◽  
Author(s):  
Willem F van Dorp ◽  
Thomas W Hansen ◽  
Jakob B Wagner ◽  
Jeff T M De Hosson
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Electron Beam ◽  
Electron Irradiation ◽  
Carbon Membrane ◽  
Average Value ◽  
Fundamental Process ◽  
Electron Stimulated Desorption ◽  
Substrate Temperatures

We present the results of our study about the deposition rate of focused electron beam induced processing (FEBIP) as a function of the substrate temperature with the substrate being an electron-transparent amorphous carbon membrane. When W(CO)6 is used as a precursor it is observed that the growth rate is lower at higher substrate temperatures. From Arrhenius plots we calculated the activation energy for desorption, E des, of W(CO)6. We found an average value for E des of 20.3 kJ or 0.21 eV, which is 2.5–3.0 times lower than literature values. This difference between estimates for E des from FEBIP experiments compared to literature values is consistent with earlier findings by other authors. The discrepancy is attributed to electron-stimulated desorption, which is known to occur during electron irradiation. The data suggest that, of the W(CO)6 molecules that are affected by the electron irradiation, the majority desorbs from the surface rather than dissociates to contribute to the deposit. It is important to take this into account during FEBIP experiments, for instance when determining fundamental process parameters such as the activation energy for desorption.

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