Flow Loop Study of NaCl Concentration Effect on Erosion, Corrosion, and Erosion-Corrosion of Carbon Steel in CO2-Saturated Systems

Erosion–corrosion in flow changing devices as a result of sand transportation is a serious concern in the hydrocarbon and mineral processing industry. In this work, the flow accelerated erosion–corrosion mechanism of 90°, 60°, and 30° long radius horizontal–horizontal (H–H) carbon steel elbows with an inner diameter of 50.8 mm were investigated in an experimental closed-flow loop. For these geometrical configurations, erosion–corrosion was elucidated for erosive slug flow regimes and the extent of material degradation is reported in detail. Qualitative techniques such as multilayer paint modeling and microscopic surface imaging were used to scrutinize the flow accelerated erosion–corrosion mechanism. The 3D roughness characterization of the surface indicates that maximum roughness appears in downstream adjacent to the outlet of the 90° elbow. Microscopic surface imaging of eroded elbow surfaces disseminates the presence of corrosion pits on the exit regions of the 90° and 60° elbows, but erosion scars were formed on the entry regions of the 30° elbow. Surface characterization and mass loss results indicated that changing the elbow geometrical configuration from a small angle to wide angle significantly changed the mechanical wear mechanism of the tested elbows. Moreover, the maximum erosive location was identified at the top of the horizontally-oriented elbow for slug flow.

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The Effect of Impingement Velocity and Angle Variation on the Erosion Corrosion Performance of API 5L-X65 Carbon Steel in a Flow Loop

Metals ◽

10.3390/met8060402 ◽

2018 ◽

Vol 8 (6) ◽

pp. 402 ◽

Cited By ~ 8

Author(s):

Ihsan Toor ◽

Hafiz Irshad ◽

Hassan Badr ◽

Mohammed Samad

Keyword(s):

Carbon Steel ◽

Corrosion Performance ◽

Flow Loop ◽

Angle Variation ◽

Erosion Corrosion ◽

Impingement Velocity

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Effect of Sand Fines Concentration on the Erosion-Corrosion Mechanism of Carbon Steel 90° Elbow Pipe in Slug Flow

Materials ◽

10.3390/ma13204601 ◽

2020 ◽

Vol 13 (20) ◽

pp. 4601 ◽

Cited By ~ 1

Author(s):

Rehan Khan ◽

Hamdan H. Ya ◽

William Pao ◽

Mohd Amin Abd Majid ◽

Tauseef Ahmed ◽

...

Keyword(s):

Carbon Steel ◽

Slug Flow ◽

Corrosion Mechanism ◽

Flow Conditions ◽

Flow Loop ◽

Material Degradation ◽

Hydrocarbon Processing ◽

Erosion Corrosion ◽

Average Size ◽

Worn Surface

Erosion-corrosion of elbow configurations has recently been a momentous concern in hydrocarbon processing and transportation industries. The carbon steel 90° elbows are susceptible to the erosion-corrosion during the multiphase flow, peculiarly for erosive slug flows. This paper studies the erosion-corrosion performance of 90° elbows at slug flow conditions for impact with 2, 5, and 10 wt.% sand fines concentrations on AISI 1018 carbon steel exploiting quantitative and qualitative analyses. The worn surface analyses were effectuated by using laser confocal and scanning electron microscopy. The experiment was conducted under air and water slug flow containing sand fines of 50 µm average size circulated in the closed flow loop. The results manifest that with the increase of concentration level, the erosion-corrosion magnitude increases remarkably. Sand fines instigate the development of perforation sites in the form of circular, elongated, and coalescence pits at the elbow downstream and the corrosion attack is much more obvious with the increase of sand fines concentration. Another congruent finding is that cutting and pitting corrosion as the primitive causes of material degradation, the 10 wt.% sand fines concentration in carrier phase increases the erosion-corrosion rate of carbon steel up to 93% relative to the 2 wt.% sand fines concentration in slug flow.

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Influence of Sand Fines Transport Velocity on Erosion-Corrosion Phenomena of Carbon Steel 90-Degree Elbow

Metals ◽

10.3390/met10050626 ◽

2020 ◽

Vol 10 (5) ◽

pp. 626 ◽

Cited By ~ 1

Author(s):

Rehan Khan ◽

Hamdan H. Ya ◽

William Pao ◽

Mohamad Zaki bin Abdullah ◽

Faizul Azly Dzubir

Keyword(s):

Carbon Steel ◽

Production Systems ◽

Internal Surface ◽

Corrosion Mechanism ◽

Flow Loop ◽

Material Loss ◽

Loss Analysis ◽

Erosion Corrosion ◽

Transport Velocity ◽

Discrete Phase

Erosion-corrosion is an ineluctable flow assurance problem confronted in hydrocarbon transportation and production systems. In this work, the effect of sand fines velocity on the erosion-corrosion behavior of AISI 1018 carbon steel long radius 90° elbows was experimentally and numerically investigated for liquid-solid flow conditions. Experiments were effectuated for sand fines of mean diameter 50 µm circulated in a flow loop with three different velocities (0.5, 1 and 2 m/s). To elucidate the erosion-corrosion mechanism and degradation rate, the material loss analysis, multilayer paint modeling (MPM) and microscopic imaging technique were employed, with computational fluid dynamics (CFD) and discrete phase modeling (DPM) also capacitating to evaluate the erosion distribution. It was perceived that increasing slurry velocity significantly changes the particle-wall impaction mechanism, leading to an increase in material degradation in the elbow bottom section up to 2 times in comparison to the low transport velocity. The erosion scars and pits development at the elbows internal surface was found to govern the wear mechanism in the carbon steel and made downstream section susceptible to erosion and corrosion. The material removal mechanisms were ascertained to change from cutting to pitting and plastic deformation with an increase of sand fines transportation velocity from 0.5 m/s to 2 m/s.

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