Corrosion of welded joints of bimetallic composite tube in simulated offshore gas field environment

2014 ◽  
Vol 61 (6) ◽  
pp. 380-386 ◽  
Author(s):  
Deng Hongda ◽  
Zeng Shunpeng
Keyword(s):  
Welded Joints ◽  
Sea Water ◽  
Galvanic Corrosion ◽  
Inconel 625 ◽  
Gas Field ◽  
Content Type ◽  
Composite Tube ◽  
Bimetallic Composite ◽  
Production Water ◽  
Welding Line

Purpose – The purpose of this investigation was to research the corrosion behavior of welded joints of bimetallic composite tube (X65/316L) welded with Inconel 625 in simulated sea water and in simulated production water, respectively. Design/methodology/approach – The different electrochemical corrosion and galvanic corrosion behaviors of different welded zones were identified using the dynamic potential scan method and galvanic corrosion technique. Findings – The heat-affected zone (HAZ) of welded joints was the most critical zone for corrosion. The closer to the welding line, more severe was the corrosion that was evident in the HAZ at room temperature. In welded joints of X65 tested in simulated seawater, tremendous corrosion occurred in the HAZ, followed by the base metal, and finally the welding line. However, there were few differences in corrosion of the different zones of welded joints in 316L in simulated production water. In such joints of 316L, corrosion comparatively attacked more easily to the HAZ. In galvanic corrosion tests, tremendous galvanic corrosion was evident on welded joints on X65, but comparatively slight gavanic corrosion appeared at welded joints in 316L. With the increased temperature, galvanic corrosion of welded joints was enhanced. Originality/value – The results can provide reference for reducing the gavalic corrosion of welded bimetallic composite tube metal in the actual operation.

scholarly journals Composite tube damage evaluation in aggressive oil-gas field

2020 ◽  
Vol 986 ◽  
pp. 012040
Author(s):  
E L Alekseeva ◽  
M K Kurakin ◽  
M A Kovalev ◽  
A A Lapechenkov ◽  
M L Shishkova ◽  
...  
Keyword(s):  
Damage Evaluation ◽  
Gas Field ◽  
Composite Tube ◽  
Oil Gas

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

Corrosion fatigue strength of ship structural steel butt welded joints in synthetic sea-water

1999 ◽  
Vol 13 (5) ◽  
pp. 385-391
Author(s):  
Y Kobayashi ◽  
Y Tanaka ◽  
H Goto ◽  
K Matsuoka ◽  
Y Motohashi
Keyword(s):  
Fatigue Strength ◽  
Structural Steel ◽  
Corrosion Fatigue ◽  
Welded Joints ◽  
Sea Water ◽  
Corrosion Fatigue Strength

scholarly journals Increasing of the Mechanical Properties of Friction Stir Welded Joints of 6061 Aluminum Alloy by Introducing Alumina Particles

2017 ◽  
Vol 17 (2) ◽  
pp. 29-40 ◽  
Author(s):  
M. A. Tashkandi ◽  
J. A. Al-Jarrah ◽  
M. Ibrahim
Keyword(s):  
Aluminum Alloy ◽  
Base Metal ◽  
Welded Joints ◽  
Volume Fraction ◽  
Welding Process ◽  
Welding Zone ◽  
6061 Aluminum Alloy ◽  
Friction Stir ◽  
Alumina Particles ◽  
Welding Line

AbstractThe main aim of this investigation is to produce a welding joint of higher strength than that of base metals. Composite welded joints were produced by friction stir welding process. 6061 aluminum alloy was used as a base metal and alumina particles added to welding zone to form metal matrix composites. The volume fraction of alumina particles incorporated in this study were 2, 4, 6, 8 and 10 vol% were added on both sides of welding line. Also, the alumina particles were pre-mixed with magnesium particles prior being added to the welding zone. Magnesium particles were used to enhance the bonding between the alumina particles and the matrix of 6061 aluminum alloy. Friction stir welded joints containing alumina particles were successfully obtained and it was observed that the strength of these joints was better than that of base metal. Experimental results showed that incorporating volume fraction of alumina particles up to 6 vol% into the welding zone led to higher strength of the composite welded joints as compared to plain welded joints.

scholarly journals Pararhodobacter marinus sp. nov., isolated from deep-sea water of the Indian Ocean

2019 ◽  
Vol 69 (4) ◽  
pp. 932-936 ◽  
Author(s):  
Qiliang Lai ◽  
Xiupian Liu ◽  
Jun Yuan ◽  
Shuchen Xie ◽  
Zongze Shao
Keyword(s):  
Indian Ocean ◽  
Deep Sea ◽  
Type Species ◽  
Sea Water ◽  
Rrna Gene ◽  
Chromosomal Dna ◽  
Content Type ◽  
Deep Sea Water ◽  
Link Type ◽  
The Indian Ocean

A taxonomic study was carried out on strain CIC4N-9T, which was isolated from deep-sea water of the Indian Ocean. The bacterium was Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and non-motile. Growth was observed at salinities of 0–9% and at temperatures of 4–41 °C. The isolate was able to degrade gelatin but not aesculin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CIC4N-9T belonged to the genus Pararhodobacter , with the highest sequence similarity to the only recognized species, Pararhodobacter aggregans D1-19T (96.9 %). The average nucleotide identity and estimated DNA–DNA hybridization values between strain CIC4N-9T and P. aggregans D1-19T were 80.4 and 23.0 %, respectively. The principal fatty acids were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C16 : 0, C18 : 1ω7c 11-methyl, C18 : 0 and C17 : 0. The G+C content of the chromosomal DNA was 66.8 mol%. The sole respiratory quinone was determined to be Q-10. Phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, two unknown phospholipids, four unknown aminolipids and one unknown polar lipid were present. The combined genotypic and phenotypic data show that strain CIC4N-9T represents a novel species within the genus Pararhodobacter , for which the name Pararhodobacter marinus sp. nov. is proposed. The type strain is CIC4N-9T (=MCCC 1A01225T=KCTC 52336T).

Confident Egypt strikes Israeli-Palestinian gas deals

2021 ◽  
Keyword(s):  
Financial Resources ◽  
East Mediterranean ◽  
Gas Field ◽  
Content Type

Significance The agreement with Israel is to construct a pipeline from the Leviathan offshore gas field; the agreement with the PA is a non-binding memorandum of understanding about investing in the Gaza Marine project. The agreements are among Egypt's higher-profile interventions in the wider East Mediterranean gas sector for several years. Impacts Egypt is unlikely to have the financial resources to undertake investment in the Gaza Marine field. Israeli obstruction and Palestinian disunity will continue to block progress on developing Gaza Marine. Egypt is more inclined to engage publicly with Israel and less concerned about a popular backlash against such engagement.

Investigation of mechanical and corrosion behavior of laser hybrid weld joint of 2205 duplex stainless steel

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chuanbo Zheng ◽  
Cheng Zhang ◽  
Xiao Yong Wang ◽  
Jie Gu
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Welded Joints ◽  
Two Phase ◽  
Content Type ◽  
2205 Duplex Stainless Steel ◽  
Laser Hybrid

Purpose Duplex stainless steel is composed of equal amounts of austenite and ferrite, which has excellent corrosion resistance and strength. However, after the metal was welded, the ratio of austenite and ferrite in the joint is unbalanced, and secondary phase precipitates are produced, which is also an important cause of pitting corrosion in the joint. Design/methodology/approach This paper aims to study the mechanical and corrosion behavior of welded joints, by adjusting the welding parameters of laser hybrid welding, dual heat sources are used to weld 2205 duplex stainless steel. The two-phase content of different parts of the welded joint is measured to study the influence of the ratio of the two-phase on the mechanical and corrosion properties of the joint. Findings The ratio of austenite and ferrite in different welded joints has an obvious difference, and from top to bottom, the austenite content decreased gradually, and the ferrite content increased gradually. The harmful phases are precipitated in the middle and lower part of the joint. The strength of welded joints is slightly lower than that of base metal. At the same time, the fracture analysis shows that some ferrite phases are affected by the precipitate in the grain and produce quasi-cleavage fracture. The corrosion results show that the corrosion resistance of the welded joints is lower than that of the base metal, and the concentration of chloride ions affects the corrosion resistance. Originality/value In this paper, the authors use the influence of different welding processes on the two-phase ratio of the joint to further study the influence of the microstructure on the corrosion resistance and mechanical properties of the weld.

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