Particle Shape and Size Effects on Slurry Erosion of AISI 5117 Steels

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
M. A. Al-Bukhaiti ◽  
A. Abouel-Kasem ◽  
K. M. Emara ◽  
S. M. Ahmed
Keyword(s):  
Silicon Carbide ◽  
Particle Size ◽  
Aspect Ratio ◽  
Size Effects ◽  
Particle Shape ◽  
Impact Angle ◽  
Carbon Steels ◽  
Silica Sand ◽  
Slurry Erosion ◽  
Shape And Size

Solid particle shape and size effects on the slurry erosion behavior of AISI 5117 carbon steels are investigated, using whirling-arm ring for two different erodent particles, namely, silica sand (SiO2) and silicon carbide (SiC). From this work, it was found that aspect ratio and circularity factor (CF) increase for silica sand and decrease for silicon carbide with increasing size. The erosion rate increased with the increase of particle size for the two types of erodent particles and its value was greater in the case of silicon carbide particles. At the same test conditions, it has been noticed that the particle size plays the major role in the slurry erosion of 5117 steels in comparison with the aspect ratio and circularity factor. Microcutting and plowing with serrated wear tracks were observed for coarse SiC particles having irregular and angular shape. But, for coarse SiO2 particles which had a rounded shape, the main mechanism was plowing with plain and smooth wear tracks for an impact angle of 30 deg. Indentations and material extrusion prevailed for the coarse size of the two erodents for an impact angle of 90 deg.

Experimental Investigation on the Influence of Particle Size in a Submerged Slurry Jet on Erosion Rates and Patterns

2017 ◽  
Author(s):  
Soroor Karimi ◽  
Amir Mansouri ◽  
Siamack A. Shirazi ◽  
Brenton S. McLaury
Keyword(s):  
Particle Size ◽  
Erosion Rate ◽  
Erosive Wear ◽  
Impact Angle ◽  
Piping System ◽  
Slurry Erosion ◽  
Material Particle ◽  
Impact Speed ◽  
Effect Of Particle Size ◽  
Sand Particles

Sand particles entrained in fluids can cause erosive wear and damage to piping materials by impacting their surfaces which could result in failure of the piping system. Several parameters have been determined to affect the erosion behavior and mechanism of solid particle erosion. Some of these parameters include surface material, particle impact speed and angle, and particle size, shape and hardness. However, the effect of particle size on the total erosion rate and local erosion pattern has not been thoroughly investigated. It has been observed that sand particles with various sizes cause different slurry erosion patterns. Changing the particle size alters the Stokes number and consequently produces different erosion patterns and magnitudes. Thus, the effects of particle size on total erosion rate and erosion pattern in a submerged slurry jet are investigated for different impingement angles. Experiments are performed on 316 stainless steel specimens for average particles sizes of 25, 75, 150, and 300 μm. The jet angle is varied to 45, 75 and 90 degrees, and the slurry jet velocity is set to 14 m/s. The erosion pattern of the specimen is examined by obtaining the 3D microscopic profile of the eroded specimen by means of an optical profiler. It is found that the erosion profile changes as the jet angle varies. It is also observed that erosion profile is significantly different for smaller particles as compared to the larger particles. Moreover, these differences become more pronounced as the jet angle decreases. The present work discusses the differences of erosion patterns produced by both large and small particles. Computational Fluid Dynamics (CFD) is also used to study the effect of particle size on particle trajectories, impact speed, and impact angle. Also, CFD results help in explaining the differences observed in the erosion profiles caused by different particle sizes.

Stepwise Erosion as a Method for Investigating the Wear Mechanisms at Different Impact Angles in Slurry Erosion

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Y. M. Abd-Elrhman ◽  
A. Abouel-Kasem ◽  
S. M. Ahmed ◽  
K. M. Emara
Keyword(s):  
Rebound Effect ◽  
Impact Angle ◽  
Silica Sand ◽  
Slurry Erosion ◽  
Nominal Size ◽  
Erosion Mechanisms ◽  
Impact Angles ◽  
The Impact ◽  
Calculated Number ◽  
Number Of Particles

In the present work, stepwise erosion technique was carried out to investigate in detail the influence of impact angle on the erosion process of AISI 5117 steel. The number of impact sites and their morphologies at different impact angles were investigated using scanning electron microscope (SEM) examination and image analysis. The tests were carried out with particle concentration of 1 wt. %, and the impact velocity of slurry stream was 15 m/s. Silica sand—which has a nominal size range of 250–355 μm—was used as an erodent, using whirling-arm test rig. The results have shown that the number of craters, as expected, increases with the increase in the mass of erodent for all impact angles and this number decreases with the increase of the impact angle. In addition, the counted number of craters is larger than the calculated number of particles at any stage for all impact angles. This may be explained by the effect of the rebound effect of particles, the irregular shape for these particles, and particle fragmentation. The effect of impact angle based on the impact crater shape can be divided into two regions; the first region for θ ≤ 60 deg and the second region for θ ≥ 75 deg. The shape of the craters is related to the dominant erosion mechanisms of plowing and microcutting in the first region and indentation and lip extrusion in the second region. In the first region, the length of the tracks decreases with the increase of impact angle. The calculated size ranges are from few micrometers to 100 μm for the first region and to 50 μm in the second region. Chipping of the former impact sites by subsequent impact particles plays an important role in developing erosion.

Particle Size Effects on Slurry Erosion of 5117 steels

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
A. Abouel-Kasem
Keyword(s):  
Aspect Ratio ◽  
Erosion Rate ◽  
Threshold Energy ◽  
Average Diameter ◽  
Silica Sand ◽  
Water Mixture ◽  
Slurry Erosion ◽  
Shape Factors ◽  
Erosion Mechanism ◽  
Erosion Rates

The effect of particles size and shape on erosion rates and erosion mechanisms of 5117 steels are investigated using slurry whirling-arm ring. Six different sized silica sand particles are used as erodent. These particles are characterized in terms of their average diameter, aspect ratio, and circularity factor. The measured average diameter varies from 112.7 μm to 516.4 μm. The wear tests are carried out at impact velocity of 15 m/s and 30 deg and 90 deg impact angles using a sand-water mixture of 1 wt % concentration. Analysis of erosion rates shows that there exists threshold energy of impacting particles at which a transition in erosion rate is noticed for sizes of 200 μm. It is also observed that the erosion rate increases with the increase in shape factors (aspect ratio and circularity factor). The surface morphology of the eroded surface at impact of 30 deg shows that below 200 μm, the erosion mechanism is indentation and material extrusion and above 200 μm, the erosion mechanism is ploughing.

Induced pulsing in trickle beds — Particle shape and size effects on pulse characteristics

2006 ◽  
Vol 61 (22) ◽  
pp. 7448-7462 ◽  
Author(s):  
M.E. Trivizadakis ◽  
D. Giakoumakis ◽  
A.J. Karabelas
Keyword(s):  
Size Effects ◽  
Particle Shape ◽  
Trickle Beds ◽  
Pulse Characteristics ◽  
Shape And Size

A Study on Slurry Erosion Behavior of High Chromium White Cast Iron

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
M. A. Al-Bukhaiti ◽  
A. Abouel-Kasem ◽  
K. M. Emara ◽  
S. M. Ahmed
Keyword(s):  
Impact Velocity ◽  
Erosion Resistance ◽  
Normal Incidence ◽  
Impact Angle ◽  
Silica Sand ◽  
Slurry Erosion ◽  
High Chromium ◽  
Nominal Size ◽  
Plastic Indentation ◽  
Erosion Mechanisms

High chromium white irons (HCCIs) are used extensively throughout the mineral processing industry to handle erosive and corrosive slurries. This study is an investigation of the effect of impact angle and velocity on slurry erosion of HCCI. The tests were carried out using a rotating whirling-arm rig with particle concentration of 1 wt. %. Silica sand which has a nominal size range of 500–710 μm was used as an erodent. The results were obtained for angles of 30 deg, 45 deg, 60 deg, and 90 deg to the exposed surface and velocities of 5, 10, and 15 m/s. The highest erosion resistance of HCCI was at normal impact and the lowest at an angle of 30 deg, irrespective of velocity. The low erosion resistance at an oblique angle is due to large material removal by microcutting from ductile matrix and gross removal of carbides. The effect of velocity, over the studied range from 5 m/s to 15 m/s, on the increase in the erosion rate was minor. The change of impact velocity resulted in changing the slurry erosion mechanisms. At normal incidence, plastic indentation with extruded material of the ductile matrix was the dominant erosion mechanism at low impact velocity (5 m/s). With increasing impact velocity, the material was removed by the indentation of the ductile matrix and to smaller extent of carbide fracture. However, at high impact velocity (15 m/s), gross fracture and cracking of the carbides besides plastic indentation of the ductile matrix were the dominant erosion mechanisms.

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