Erosion-corrosion is an unavoidable material degradation process in flow pipelines transporting abrasive particles with carrier fluids. In this study, the multiphase flow loop apparatus is employed to assess the erosion-corrosion behavior and mechanism relative to AISI 1018 carbon steel (CS) and AISI 304L stainless steel (SS) 90° long radius elbows with the inner diameter of 50.8 mm. Fine silica sand of 50 µm average size was used as a dispersed phase and erosion-corrosion tests were conducted for slug flow conditions. The erosion-corrosion analysis of 90° elbows was determined from its surface morphologies before and after the experiment using confocal and scanning electron microscopy (SEM). The direct mass loss was measured to quantify the erosion-corrosion rate of the elbow configurations. Additionally, multilayer paint modeling experiments were performed to relate qualitative inferences on erosion distribution and location with the erosion-corrosion mechanism. It was observed that the erosion or corrosion pitting mechanism prevailed on the 1018 CS elbow surface, and the 304L SS displayed excellent erosion-corrosion resistance properties. Moreover, the erosion-corrosion rate was found to be 4.12 times more in the 1018 CS compared to the 304L SS with the maximum particle impaction identified at the exit of the horizontal-horizontal (H-H) 90° elbow for slug flow.

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.

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.

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.

Polymeric materials such as High density polyethylene(HDPE) are ductile in nature, having very low strength. In order to improve strength by non-treated rigid fillers, polymeric materials become extremely brittle. Therefore, this work focuses on achieving pseudo-ductility (high strength and ductility) by using a combination of rigid filler particles (CaCO₃ and bentonite) instead of a single non-treated rigid filler particle. The results of all tensile-tested (D638 type i) samples signify that the microstructural features and surface properties of rigid nano fillers can render the required pseudo-ductility. The maximum value of tensile strength achieved is 120% of the virgin HDPE, and the value of elongation is retained by 100%. Furthermore, the morphological and fractographic analysis revealed that surfactants are not always going to obtain polymer–filler bonding, but the synergistic effect of filler particles can carry out sufficient bonding for stress transfer. Moreover, pseudo-ductility was achieved by a combination of rigid fillers (bentonite and CaCO₃) when the content of bentonite dominated as compared to CaCO₃. Thus, the achievement of pseudo-ductility by the synergistic effect of rigid particles is the significance of this study. Secondly, this combination of filler particles acted as an alternative for the application of surfactant and compatibilizer so that adverse effect on mechanical properties can be avoided.