Solid Particle Impact Erosion Research Articles

Experimental investigation of low velocity and high temperature solid particle impact erosion wear

Next generation Concentrating Solar Power (CSP) plants utilizing solid particles as the heat transfer medium (HTM) are expected to achieve greater operational efficiencies. However, the erosion from the solid particles can cause significant damage to component materials. Low particle speeds (1–2 m/s) are proposed as a means of preventing excessive damage to containment materials. Within the current investigation, solid particle erosion of three potential containment materials, stainless-steel grade 316L, a nickel alloy (Inconel 740H), and a refractory material (Tufcrete 60 M), are examined at a particle impact speed of 1.6 m/s. CarboBead-HSP 40/70 particles, a candidate HTM for CSP systems, impact the specimens at a relatively high impact angle of 60° based on containment design criteria. Experiments were conducted at ambient temperature and 800 °C to examine erosion of the materials at very low impact speeds and determine how temperature effects erosion. Initial results revealed surprising outcomes inconsistent with available literature: ambient temperature erosion of SS316L is an order of magnitude lower than IN740H, but erosion (erosion-corrosion) of SS316L at 800 °C surpasses IN740H by two orders of magnitude. Results suggest removal of oxide layers (erosion-corrosion) is responsible for the significant erosion that was observed even at these low particle speeds.

Erosion of a multistage orifice due to liquid-solid flow

Liquid-solid impact erosion represents one of the major problems affecting systems reliability in many industries including oil and gas and power generation industries. The presence of solid particles, which cannot be avoided in these systems, is the main cause of erosion failure of piping and equipment, especially downstream complex pipe fittings. The present study aims at numerically investigating the effects of flow parameters and particle size on the solid particle impact erosion in a two-stage orifice arrangement with different spacing in a carbon steel pipe. The impact erosion occurs as a result of the presence of sand particles in the water stream. Inlet flow velocity ranges from 1 to 4m/s (Re ≈ 2.5 × 104 to 105) and solid particles in the range 50–400µm are used in this study. Also, the two orifices diameter ratios ranging from 0.5 to 0.77 with a spacing of 1D and 2D are used. The numerical analysis was performed using the k-ε eddy viscosity model integrated with a discrete phase model (DPM) along with solid impact erosion correlations to predict the impact erosion features in the piping system. The results show a strong dependence of erosion rates on the orifice diameter ratio, solid particle size and bulk liquid flow velocity. The two critical erosion locations were found downstream the second orifice; namely in the recirculation and reattachment zones. The least erosion rate was found in the case of double-orifice configuration with 1D spacing. Although a high-velocity region exists in the spacing between the two orifices, very small rate of erosion was found in this region for small particles and negligible erosion for large particles Dp≥100μm. Moreover, the erosion rates were found to increase with the increase of flow velocity and with the decrease of orifice diameter ratio and solid particle size.

Erosion wear behaviour of 3 mol-% yttria-stabilised zirconia ceramics by solid particle impact at elevated temperatures

The solid particle impact erosion wear behaviour of 3 mol-% yttria-stabilised zirconia ceramics is studied at elevated temperatures. The influence of erosive temperature on the erosion wear resistance and erosion mechanism of 3 mol-% yttria-stabilised zirconia ceramic at the impact angle of 90° is investigated. The results show that material removal rate of volume erosion wear of 3 mol-% yttria-stabilised zirconia ceramics increases with rising temperature. The erosion rate increases slowly between room temperature and 600°C. The 3 mol-% increases rapidly between 800 and 1200°C. The maximum erosion rate of 0·55 mm3 g−1 is found at 1200°C. The increase of the erosion wear rate is because of the decrease of the mechanical properties at high temperatures. The erosion wear mechanism of 3 mol-% yttria-stabilised zirconia ceramics is temperature-dependent, which is mainly plastic deformation below 800°C and mainly cracking in irregular crisscross patterns leading to the flaky exfoliation of material, between 800 and 1400°C. The results provide an insight into the mechanism of material damage and failure of advanced ceramics by high temperature erosion.

Effect of temperature on solid particle impact erosion wear mechanism of 5 mol% Yttria Stabilized Zirconia ceramics

The effect of elevated temperature on solid particle impact erosion wear behavior of 5mol% Yttria Stabilized Zirconia ceramics (5YSZ) was studied using corundum sand as solid impact particles, an impact angle of 90°, and an impact speed of 50–60m/s. Moreover, the erosion wear mechanism of 5YSZ ceramics at different temperatures was discussed. The solid particle impact erosion wear rate of 5YSZ ceramics was increased from 0.10mm3/g to 0.81mm3/g when the temperature rose from room temperature to 1200°C, and then decreased to 0.64mm3/g at 1400°C. The plastic deformation erosion mechanism of 5YSZ ceramics was observed from room temperature to 1400°C, and the erosion wear mechanism of cracking in irregular crisscross patterns lead to the stepwise heightened flaky exfoliation of the material from 600°C to 1200°C, which became the main erosion wear mechanism. These results provide the theoretical base for extension of service life of 5YSZ ceramics by avoiding the conditions that lead to erosion wear mechanisms.

Study of erosion wear behavior of MgO stabilized ZrO<sub>2</sub> ceramics due to solid particles impact at elevated temperature

Erosion wear behavior of MgO stabilized ZrO2 (MgSZ) ceramics was studied at elevated temperature by a self-made solid particle impact erosion wear testing apparatus. Volume erosion wear rate of MgSZ ceramics was measured at up to 1400°C with an impact angle of 90°. The effects of erosion temperature on erosion wear behavior and mechanism for different temperature ranges have been discussed. The results indicate that volume erosion wear rate of MgSZ ceramics increased with temperature. Specifically, volume erosion wear rate increased at a rate of 1.87 × 10−4 from room temperature to 600°C, 5.99 × 10−4 from 800 to 1000°C, and tended to be constant from 1000 to 1400°C. Volume erosion wear rate reached its maximum value of 0.60 mm3/g at around 1000°C. The increase in erosion wear rate is related to the decrease in mechanical performance of MgSZ with increasing temperature. When MgSZ ceramics were impacted by corundum particles, the main material removal mechanism was found to be plastic deformation from room temperature to 600°C and crack crisscross leading to flaky exfoliation of material from 1000 to 1400°C. Between 600 and 800°C, a transition region from plastic deformation to flaky exfoliation was found.

Influence of LaMgAl11O19 On Solid Particle Impact Erosion Wear Behavior of 3YSZ Ceramic at Elevated Temperatures

To study the improvement in solid particle impact erosion wear resistances of 3 mol% yttria‐stabilized zirconia (3YSZ) ceramic at elevated temperatures up to 1400°C, 2 wt% LaMgA111O19 was added into 3YSZ to prepare LaMgA111O19‐3YSZ ceramic for erosion resistance tests with angular corundum abrasive particles. The testing results show that the volume erosion rates of 3YSZ and LaMgA111O19‐3YSZ ceramic were similar in the temperature range from room temperature to 600°C, then exhibited a sharp increase from 600°C to 1200°C, and dropped again at 1400°C. It was mainly caused by the change in material removal mechanisms from plastic deformation below 600°C to the interaction of transverse cracks in the temperature range from 600°C to 1400°C. The solid particle impact erosion wear properties of 3YSZ ceramic in the temperature range from 600°C to 1400°C were successfully improved by the addition 2 wt% LaMgA111O19 platelets. Comparing with the volume erosion rate of pure 3YSZ ceramic (0.687 mm3/g) at 1200°C, the value of LaMgA111O19‐3YSZ ceramic (0.551 mm3/g) has been decreased by 20%.

MSE法を用いたDLC膜の表面強度特性の評価

DLC (Diamond-like carbon) films attract attentions because of their excellent tribological properties. Although DLC films are applied in various fields, there are few evaluation techniques for the surface strength of DLC films. We have been proposing our original evaluation technique, namely micro slurry-jet erosion (MSE) method. It's a new type of solid particle impact erosion test, which uses 1.2μm alumina particles as erodent. A parameter of surface strength of thin hard coating or film is determined as wear rate (μm/min) in the MSE method. In this study, the MSE test was carried out for DLC films with various hydrogen contents. As a result, it was found that the wear rate of the DLC films increased exponentially with an increase of hydrogen content from 0.001μm/min (hydrogen content : 0 at.%) to 1.28μm/min (hydrogen content : 30 at.%). The worn surface roughness measured by AFM increased with an increase of hydrogen content. Therefore, it was suggested that the increase of hydrogen content causes a decrease of surface strength of DLC films. We concluded that MSE method is useful for evaluation of the surface strength of DLC films.

A numerical 3D simulation for prediction of wear caused by solid particle impact

Discrete element method has been used to simulate the behavior of particles interacting with a flat plate in order to define a relationship between shear-normal impact energy and wear rate during mechanical erosion. The analysis was performed for various collision angles, velocities and particle concentrations and, it was found that the shear impact energy of particles with the plate was maximized at collision angles near 30° where the wear rate had its maximum value. To investigate the influence of particles accumulation on the surface, a similar simulation procedure for a single particle impacting a plate was carried out and the results demonstrated the role of particles interactions on normal-shear impact energy and consequently on the erosion mechanism. Comparison of the simulation data with experimental data indicated that the shear impact energy was mainly relevant to cutting and cracking erosion mechanism while normal impact energy was related to forging and extrusion mechanisms. The results obtained suggest that this numerical simulation method may be used in a predictive way to study practical design problems and to explain some phenomena associated with solid particle impact erosion.

Solid particle impact erosion of alumina-based refractories at elevated temperatures

Solid particle erosion tests have been conducted on three different alumina-based refractories at elevated temperatures up to 1400 °C, using sharp SiC particles between 325 and 830 μm in diameter. The impact speed is 50 m/s and the impact angle is varied between 30° and 90°. The objective of this study is to ascertain the effects of temperature and impact angle on the erosion resistance of alumina refractories. The experimental results reveal that the alumina-based refractories, in general, exhibit increasing erosion resistance with increasing temperature and decreasing impact angle, with the minimum erosion rate at 1200 °C and 30° impact angle. Chrome corundum refractory brick is the most resistant to vertical erosion, due to its highest alumina content, and associated hardness and density, as well as strongly bonded aggregate and binder phase. The primary material removal mechanisms are fracture and chipping of binder phase and aggregate, as well as aggregate pull-out.

Erosion Wear Analysis of SiC Filled Glass-Epoxy Composites using Taguchi Technique

Abstract This paper describes the processing of a class of hybrid composites prepared by filling of SiC particulates in glass fiber reinforced epoxy resin. Experiments are conducted to study the solid particle erosion response of these composites. A theoretical model for the wear rate of the composites during solid particle impact erosion is proposed for predictive purpose. The validity of the theoretical model is assessed with experimental results and the influence of control factors like impingement angle, impact velocity, erodent temperature, erodent size, stand-off distance and filler content etc. on wear rate is studied. For this purpose a novel technique like Taguchi experimental design is employed. It is observed that the erodent temperature, filler content, impact velocity, impingement angle are the most significant factors effecting the erosion rate. The peak erosion rate is found to be occurring at an impingement angle of 75°. The morphology of eroded surfaces is examined by using scanning electron microscopy (SEM) and possible erosion mechanisms are discussed.

Development of a new type micro slurry‐jet erosion (MSE) tester for evaluation of wear properties of hard thin coatings

AbstractVersatile and reliable techniques for evaluation of hard thin coatings are necessary for the development and tribological assessment of new coatings. We have proposed a new type of micro slurry‐jet erosion (MSE) test, i.e. a solid particle impact erosion test for swift evaluation of wear properties of hard thin coatings. We are using a new type of MSE test apparatus (pot type tester) that makes it possible to obtain the wear loss per unit mass of erodent, which in this test was alumina particles with an average size of 1.2 µm. Its performance was evaluated by using a Si wafer plate under various test condition. In addition, the MSE tester was demonstrated by evaluating the wear resistance of TiN on high‐speed steel substrate. The new MSE test generates highly reproducible results and is very sensitive to the quality of the coatings. Copyright © 2009 John Wiley & Sons, Ltd.

Effect of bend orientation on life and puncture point location due to solid particle erosion of a high concentration flow in pneumatic conveyors

An investigation into predicting failure of pneumatic conveyor pipe bends due to hard solid particle impact erosion has been carried out on an industrial scale test rig. The bend puncture point locations may vary with many factors. However, bend orientation was suspected of being a main factor due to the biased particle distribution pattern of a high concentration flow. In this paper, puncture point locations have been studied with different pipe bend orientations and geometry (a solids loading ratio of 10 being used for the high concentration flow). Test results confirmed that the puncture point location is indeed most significantly influenced by the bend orientation (especially for a high concentration flow) due to the biased particle distribution and biased particle flux distribution.

A model to predict the solid particle erosion rate of metals and its assessment using heat-treated steels

A new predictive model for the wear rate of metals during solid particle impact erosion is presented. The model proposes that erosion rate is related to the product of toughness ( U T) and uniform strain ( ε U). Predictions for the variation of erosion rate with impact angle are also made. The validity of the model was assessed using an extensive set of new experimental data generated for heat-treated steels. Two steels were heat treated to form a total of 12 different microstructures, each having distinctly different mechanical behaviour. Erosion tests were carried out at a combination of three impact velocities and three angles of particle impingement in a rotating disc accelerator erosion tester. Fine olivine sand was used as the abrasive at one feed rate. Tensile tests were carried out on all the heat-treated steels over a range of temperatures from room temperature to 400°C. The model predictions were not satisfied by mechanical property measurements made at room temperature. However, for each given erosion test condition, a good linear relationship was found between room temperature erosion rate and 1/ U T ε U when mechanical properties were measured at elevated temperatures. The elevated temperature chosen to give the best-fit was between 200 and 300°C depending on the impact velocity. It is believed that the significance of the elevated temperature property measurements is that they account for localised heating occurring at the impacting particle during the high strain/strain-rate deformation typical of erosion. Certain heat-treatments gave a poorer fit to the relationship and explanations for this are proffered. The model was also able to account for changes in erosion rate with impact angle. Suggestions are made for improving the model and to refine its predictive capability.

The abrasion/erosion and erosion-corrosion characteristics of steels

The metal wastage which occurs on the combustion gas side of in-bed heat exchanger tubes in fluidized bed combustors (FBCs) is an important problem in this method of generating power from coal. The particle flow conditions which occur along the tube surfaces that remove material are the subject of some speculation as to whether three-body abrasion or solid particle impact erosion is causing the degradation. In this paper, evidence is presented that shows that the basic mechanism of particles degrading the surface is essentially the same for both descriptions of the active mechanism. The ability to extrapolate to long-term metal wastage rates in actual in-service FBC exposures from short-term laboratory tests that reach steady state loss rate conditions in the order of 5 h is also discussed. The concept of trading off various test conditions such as test temperature and particle size, shape, and velocity to realize similar amounts of metal wastage from balanced test conditions is presented.

Modèle mathématique pour la prédiction de la vitesse d'érosion

(1988). Mathematical model predicting cavitation erosion rate. La Houille Blanche: Vol. 74, No. 7-8, pp. 571-576.

Phenomenological model for cavitation erosion rate computation

A mathematical model incorporating the erosion process and the internal hardening mechanism is proposed to determine the cavitation erosion rate of alloys. It takes into account both the properties of the material being eroded and the cavitation flow conditions. This calculation approach assumes that during erosion the material is subjected to stress pulse loading conditions. The spatial and the temporal distributions of these pulses are statistical, but the mean level of their amplitude is controlled by the flow conditions. The mechanical properties of the materials (such as the elastic limit and the rupture limit) and the metallurgical parameters (such as the work-hardening coefficient and the stacking fault energy) are introduced into the erosion rate equation. This model can be applied to all types of cavitation in various hydraulic machines. It can also be extended to erosion by liquid drop impacts and to solid particle impact erosion. At this stage of development, only the mechanical aspect of erosion is considered and the effects of coroosion on the erosion rate are not included.