scholarly journals Corrosion behavior and mechanism of X80 steel in silty soil under the combined effect of salt and temperature

RSC Advances ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 129-147
Author(s):  
Xiangling Bai ◽  
Bin He ◽  
Pengju Han ◽  
Ruizhen Xie ◽  
Funan Sun ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Spectroscopic Characterization ◽  
Combined Effect ◽  
Electrochemical Measurements ◽  
Silty Soil ◽  
Characterization Techniques ◽  
X80 Steel

The combined effect of salt and temperature on the corrosion behavior of X80 steel in silty soil was studied by microscopic and spectroscopic characterization techniques and electrochemical measurements.

scholarly journals Effect of Sn Addition on Microstructure and Corrosion Behavior of As-Extruded Mg–5Zn–4Al Alloy

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2069 ◽  
Author(s):  
Jian Ding ◽  
Xin Liu ◽  
Yujiang Wang ◽  
Wei Huang ◽  
Bo Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Photoelectron Spectroscopy ◽  
Corrosion Current ◽  
Electrochemical Measurements ◽  
Corrosion Mechanism ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Average Grain Size

The effect of Sn addition on the microstructure and corrosion behavior of extruded Mg–5Zn–4Al–xSn (0, 0.5, 1, 2, and 3 wt %) alloys was investigated by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical measurements, and immersion tests. Microstructural results showed that the average grain size decreased to some degree and the amount of precipitates increased with the increasing amount of Sn. The extruded Mg–5Zn–4Al–xSn alloy mainly consisted of α-Mg, Mg32(Al,Zn)49, and Mg2Sn phases as the content of Sn was above 1 wt %. Electrochemical measurements indicated that the extruded Mg–5Zn–4Al–1Sn (ZAT541) alloy presented the best corrosion performances, with corrosion potential (Ecorr) and corrosion current density (Icorr) values of −1.3309 V and 6.707 × 10−6 A·cm−2, respectively. Furthermore, the corrosion mechanism of Sn is discussed in detail.

Optical Visualization of Carbon Nanotubes-a Unifying Linkage Between Microscopic and Spectroscopic Characterization Techniques

Small ◽  
2010 ◽  
Vol 6 (18) ◽  
pp. 1968-1973 ◽  
Author(s):  
Claudia Backes ◽  
Jan M. Englert ◽  
Nicolas Bernhard ◽  
Frank Hauke ◽  
Andreas Hirsch
Keyword(s):  
Carbon Nanotubes ◽  
Spectroscopic Characterization ◽  
Characterization Techniques ◽  
Optical Visualization

Microstructure and Galvanic Corrosion of Dissimilar Weldment Between Duplex Stainless Steel UNS 31803 and X80 Steel

2009 ◽  
Author(s):  
Xiaoyan Wang ◽  
Lei Zhang ◽  
Xianren Kuang ◽  
Minxu Lu
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Heat Affected Zone ◽  
Galvanic Corrosion ◽  
Base Material ◽  
Nacl Solution ◽  
Gas Field ◽  
X80 Steel

Kela-2 Gas Field is the main supply for the West-East Gas Pipeline which runs across China with length of 4000 kilometers. Natural gas from Kela-2 contains CO2/H2S sour components and 10% condensation water, which makes the medium present very strong corrosivity. In avoidance of corrosion failure, DSS UNS S31803 line pipes were introduced to transmit the gas from the Gas Field to gathering center and processing factory. And it is the first time DSS pipes which is totally about 13km were widely used in oil and gas pipeline around the world. As it is known, DSS UNS S31803 pipes and traditional linepipes X80 were welded together between the gathering lines and mainline. Duplex stainless steel (DSS) UNS S31803 and X80 were welded by metal inertia gas welding (MIG) with consumable ER2209, and the joints take on good mechanical properties. The type II boundary close to the fusion boundary at the carbon steel side was observed by SEM. Obvious concentration gradient of Ni and Cr was observed in the region between the two boundaries, where the hardness was much higher. The weld metal with columnar and some polygonal ferrites take on good passivation against test solution. The heat affected zone beside the X80 base material is mostly granular bainite, some polygonal ferrites and few MA, X80 base material present obvious rolling state, the microstructure of which is the same to X80 heat affected zone, but the level of crystal size reach to 11.6. The corrosion behavior of them dosen’t have any difference, but the corrosion potential of X80 HAZ is much higher than X80 BM, about 50 mv, the corrosion rate of X80 HAZ is also much higher than X80 base material. Potential curves of different weldment regions were also studied in 3.5% NaCl solution and 3.5% NaCl solution with saturated CO2. Galvanic corrosion behavior of weld metal and X80 steel was also tested and the conclusion is: The cathode reaction is controlled by oxygen diffusion, and when area ratio S (S = Ac / Aa, Ac is the area of DSS WM, Aa is the area of X80 BM) increases, corrosion current of X80 is enhanced rapidly, which is called “gathering principle”. When the weld metal and X80 coupled, cathode has much higher polarization potential and is protected completely.

scholarly journals Corrosion Behavior of X80 Pipe Steel under HVDC Interference in Sandy Soil

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 809 ◽  
Author(s):  
Runzhi Qin ◽  
Yanxia Du ◽  
Zitao Jiang ◽  
Xiuyun Wang ◽  
Anqing Fu ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Sandy Soil ◽  
Direct Current ◽  
Corrosion Mechanism ◽  
High Voltage Direct Current ◽  
Corrosion Reaction ◽  
Local Soil ◽  
X80 Steel ◽  
Remaining Time ◽  
Peak Value

With the development of high voltage direct current (HVDC) systems, some pipelines have been badly interfered. The corrosion mechanism of pipelines has not been clearly clarified. In this work, laboratory experiments were designed to study the corrosion behavior of X80 steel under HVDC interference in sandy soil. The corrosion rates were related to the change in direct current (DC) density, which experienced three stages in the interference process. As soon as high DC interference voltage was applied to the working electrode, the current density increased sharply to a peak value in a few seconds. It then decreased rapidly to a steady value over dozens of seconds. Finally, it remained steady for the remaining time. With the measurement of local soil properties, the change in DC density was attributed to the local soil temperature increment, the water content decrement, and the substantial growth in the soil spread resistance. Moreover, the parameters contribute to the corrosion reaction during the interference process. The corrosion products were characterized at different times of interference via Raman spectroscopy. Lepidocrocite was produced under high DC density and then transformed to hematite under low DC density. Based on the above, the corrosion model during HVDC interference is proposed.

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