Corrosion behavior and microstructure analysis of butt welds of Q690 high strength steel in simulated marine environment

Wei, Huanhuan; Tang, Yiqun; Chen, Chen; Xi, Peifeng

doi:10.1016/j.jobe.2024.108509

Cited by 4 publications

(1 citation statement)

References 39 publications

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“…Although many studies have been performed on the corrosion of E690 steel in marine environments, most have focused on SCC and corrosion fatigue. Due to the influence of DO, water temperature, salinity, pH, and dissolved inorganic nitrogen [20][21][22][23][24][25], the corrosion process of steel is complex in marine environments. The corrosion mass loss of steel is promoted with the increase in dissolved oxygen concentration.…”

Section: Introductionmentioning

confidence: 99%

Galvanic Corrosion of E690 Offshore Platform Steel in a Simulated Marine Thermocline

Hu,

Lin,

Deng

et al. 2024

Metals

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Marked changes in temperature, pH, dissolved oxygen (DO) content, and nutrient content typically occur in marine thermoclines, which are key factors that affect the corrosion of metals. Offshore platforms require marine metals to be exposed to deep-sea environments and thus increase their penetration into the marine thermocline. This study investigates the galvanic corrosion of E690 steel in a marine thermocline using a simulated marine thermocline (SMT). Specifically, the corrosion of E690 steel was analyzed using the wire beam electrode (WBE) technique, linear polarization (LP), corrosion morphology, and weight loss measurement. Results indicated that the SMT had a stable multilayer structure, and the variations in temperature, DO, pH, and nutrient concentration in the SMT were similar to those in the natural marine thermocline. There were two forms of E690 steel corrosion in the SMT: galvanic corrosion and seawater corrosion. The corrosion rate of seawater corrosion was influenced by the DO concentration. Galvanic corrosion occurred after the intrusion of E690 steel into the marine thermocline. The driver of galvanic corrosion was the difference values for Ecorrs of E690 steel at various depths of the marine thermocline. The Ecorr of E690 steel was influenced by the temperature, pH, and DO of the seawater, in the following order: DO >> T > pH. The continuous reduction in Ecorr with depth contributed to large-scale galvanic corrosion, and the oscillation variation in Ecorr with depth was the reason for small-scale galvanic corrosion. The primary anodic regions of galvanic corrosion were located in the area with the fastest temperature variation in the thermocline, and the position of the anodic regions rose with time. The anodic regions gradually expanded with time. The proportion of galvanic corrosion in the average corrosion rate could increase up to approximately 80% in the stable anodic region. There were many hemispherical corrosion pits on the surface of the single electrodes that were at the depths of 75 cm, 105 cm, and 135 cm. These single electrodes comprised a long-term, sustainable anodic region of galvanic corrosion.

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Section: Introductionmentioning

confidence: 99%

Galvanic Corrosion of E690 Offshore Platform Steel in a Simulated Marine Thermocline

Hu,

Lin,

Deng

et al. 2024

Metals

View full text Add to dashboard Cite

show abstract

Research and application progress of welding technology under extreme conditions

Xu,

Yin,

Chen

2024

Arch. Civ. Mech. Eng.

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Galvanic Corrosion of E690 Offshore Platform Steel in a Simulated Marine Thermocline

Hu,

Lin,

Deng

et al. 2024

Preprint

View full text Add to dashboard Cite

Marked changes in temperature, pH, dissolved oxygen (DO) content, and nutrient content typically occur in marine thermoclines, which are key factors that affect the corrosion of metals. Offshore platforms have required marine metals to be exposed to deep-sea environments and have thus increased their penetration into the marine thermocline. This study investigates the galvanic corrosion of E690 steel in a marine thermocline using a simulated marine thermocline (SMT). Specifically, the corrosion of E690 steel was analyzed using the wire beam electrode (WBE) technique, linear polarization (LP), corrosion morphology, and weight loss measurement. Results indicated that the SMT had a stable multilayer structure, and the variations of temperature, DO, pH and nutrient concentration in the SMT were similar to those in the natural marine thermocline. Galvanic corrosion occurred after the intrusion of E690 steel into the marine thermocline. The driver of galvanic corrosion was the of E690 steel at various depths of the marine thermocline. The Ecorr of E690 steel was influenced by the temperature, pH and DO of seawater, and the order was DO >> T > pH. The continuous reduction of Ecorr with depth contributed to the large-scale galvanic corrosion, and the oscillation variation of Ecorr with depth was the reason for small-scale galvanic corrosion. The primary anodic regions of galvanic corrosion were located in the area with the fastest temperature variation in the thermocline. The proportion of galvanic corrosion in the average corrosion rate could increase up to approximately 80% in the stable anodic region. There were many deep corrosion pits in the long-term and stable anodic region of galvanic corrosion.

show abstract

Corrosion behavior and microstructure analysis of butt welds of Q690 high strength steel in simulated marine environment

Cited by 4 publications

References 39 publications

Galvanic Corrosion of E690 Offshore Platform Steel in a Simulated Marine Thermocline

Galvanic Corrosion of E690 Offshore Platform Steel in a Simulated Marine Thermocline

Research and application progress of welding technology under extreme conditions

Galvanic Corrosion of E690 Offshore Platform Steel in a Simulated Marine Thermocline

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