scholarly journals Study of Corrosion Behavior of X80 Steel in Clay Soil with Different Water Contents under HVDC Interference

2020 ◽  
pp. 3935-3954
Author(s):  
Zhenchang Xu ◽  
Keyword(s):  
Corrosion Behavior ◽  
Clay Soil ◽  
X80 Steel ◽  
Water Contents

scholarly journals Study on Corrosion Behavior of X80 Steel in Guangdong Soil with Different Water Contents under HVDC Interference

2020 ◽  
Vol 88 (1) ◽  
pp. 1-7
Author(s):  
Hui ZHANG ◽  
Yanxia DU ◽  
Runzhi QIN ◽  
Zhenchang XU ◽  
Qinglin GU
Keyword(s):  
Corrosion Behavior ◽  
X80 Steel ◽  
Water Contents

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.

scholarly journals Effect of Alternating Stray Current Density on Corrosion Behavior of X80 Steel under Disbonded Coating

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Qing-Miao Ding ◽  
Yong-Xiang Qin ◽  
Tao Shen ◽  
Yu-ning Gao
Keyword(s):  
Corrosion Behavior ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Negative Deviation ◽  
Stray Current ◽  
Cathode Area ◽  
X80 Steel ◽  
Wire Beam Electrode ◽  
Disbonded Coating

In this paper, the effect of alternating stray current (AC) density on the corrosion behavior of X80 steel under disbonded coating was studied by electrochemical methods, wire beam electrode (WBE) technology, and surface observation technology. The results showed that under the interference of different AC densities, the corrosion potential of X80 steel under disbonded coating underwent negative deviation, and the degree of negative deviation increased with the increase of AC density. The corrosion current density of X80 steel under disbonded coating with the action of 0~100 A/m2 AC density had few differences. While the corrosion current density of X80 steel with the action of 200~300 A/m2 AC density increased and the corrosion current density was higher than that under low AC density. The cathode area of the wire beam electrode under disbonded coating is mainly distributed outside and the edge of the gap between disbonded coating and X80 steel, while the anode area is mainly distributed inside the gap.

scholarly journals Corrosion Behavior of API 5L X80 Steel in the Produced Water of Onshore Oil Recovery Facilities

2017 ◽  
Vol 20 (suppl 2) ◽  
pp. 432-439 ◽  
Author(s):  
Edkarlla Sousa Dantas de Oliveira ◽  
Roseana Florentino da Costa Pereira ◽  
Ivanilda Ramos de Melo ◽  
Maria Alice Gomes de Andrade Lima ◽  
Severino Lepoldino Urtiga Filho
Keyword(s):  
Corrosion Behavior ◽  
Oil Recovery ◽  
Produced Water ◽  
X80 Steel

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.

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