Abrasive Erosion Wear Research Articles

Modelling Wear Phenomena Specific to Mixer Blades in Concrete Production Plants

In the cement concrete manufacturing industry, mixers are critical pieces of equipment that play an essential role. Mixers ensure, by mechanically mixing the materials that make up the concrete, the homogeneity of the mixture. Since the active elements of the mixer in the concrete industry—the mixing blades—come into permanent contact with the mineral aggregates in the mixture formed by water and cement, they are permanently subjected to a strong abrasive–erosive wear process. The authors of this article were concerned with the establishment of tribological models for studying the wear of mixing blades, in order to identify the influence of their constructive parameters on the wear intensity. A complex model (Kraghelsky–Nepomnyashchi model) was adopted for the study. The modeling results revealed that the wear intensity decreases with an increasing blade angle of attack and increases linearly with increasing speed, as well as with an increasing friction coefficient. The modeling results confirm that the wear intensity is lowest when the mixing blade is inclined at a 60° angle, while the highest value is recorded for 30°. By identifying the angle at which the greatest wear of blades occurs, interventions can be made in the design of a more durable mixer (with the optimal installation angle of the mixer blades), thus requiring fewer corrective maintenance interventions. Based on these findings, we conclude that the complex model used in the experiment can provide a convenient and efficient tool for the study of erosive–abrasive phenomena.

Study of the Erosive-abrasive Wear Resistance of Fe-14%Cr-2.8%C High Chromium Cast Iron

Study of the Erosive-abrasive Wear Resistance of Fe-14%Cr-2.8%C High Chromium Cast Iron

A mathematical model for erosive abrasive wear analysis by using abrasive size and material hardness

PurposeErosion and abrasion are the prominent wear mechanisms reducing the lifetime of machine components. Both wear mechanisms are playing a role meanwhile, generating a synergy, leading to a material removal on the target. The purpose of study is to create a mathematical expression for erosive abrasive wear.Design/methodology/approachMany factors such as environmental cases and material character have an influence in erosive abrasive wear. In the work, changes in abrasive size and material hardness have been analyzed. As an abrasive particle, quartz sand has been used. All tests have been done in 20 wt.% slurry. Heat treatment has been applied to different steel specimens (steel grades C15, St 37 and Ck45) to change hardness value, which ranged from 185 to 880 Vickers hardness number.FindingsAfter the four-hour test, it is determined that by an increase in abrasive size and decrease in material hardness, wear rate increases. Worn surfaces of the targets have been examined to figure out the wear mechanisms at different conditions under scanning electron microscopy. The results indicate that by an increase in material hardness, the number and diameter of micro-craters on the worn surfaces decrease. The diameters of micro-craters have been about 3–8 µm in hard materials and about 120–140 µm in soft materials.Research limitations/implicationsIt is determined that by an increase in abrasive size and decrease in material hardness, wear rate increases. The results indicate that by an increase in material hardness, the number and diameter of micro-craters on the worn surfaces decrease.Practical implicationsThe study enables to indicate the dominant factor in worn steel used in mechanical components.Originality/valueAfter analyzing the test results, a novel mathematical expression, considering both abrasive size and material hardness, has been developed.

IMPROVING THE QUALITY OF DIAGNOSTICS OF AN AXIAL COMPRESSOR OF A HELICOPTER GAS TURBINE ENGINE

The aim of the work is to improve the quality with a decrease in the complexity of diagnosing an axial compressor
 of a helicopter gas turbine engine with erosive-abrasive wear of its blades. Regularities of changes in the structural
 and diagnostic parameters of the compressor depending on the operating time and the region of operation of the engine
 are revealed. The values of the main gas-dynamic parameters and the wear of the compressor blades and the links
 between them, which determine the limiting state of the TV3-117 type helicopter gas turbine engine, are substantiated.
 A method for determining the residual life of the compressor is proposed, taking into account the region of operation
 of the helicopter. The quality of compressor diagnostics was assessed using the gas-dynamic parameters of a helicopter
 gas turbine engine in operation.

Anti-erosion effect of an experimental varnish on eroded dentin.

This in vitro study evaluated the effect of an experimental varnish containing 20% nano-hydroxyapatite (nHAP) associated with 5% stannous chloride (SnCl2) against erosive-abrasive wear on bovine dentin. Samples of bovine cervical dentin were pre-eroded (0.3% citric acid, pH 2.6 for 10 minutes) and randomized into 4 groups (n=10): Control group - experimental varnish without active ingredient (CG); experimental varnish containing 20% nHAP (nHG); experimental varnish containing 5% SnCl2 (24.800 ppm Sn2+) (SnG); experimental varnish containing 20% nHAP associated with 5% SnCl2 (18.300 ppm Sn2+) (nHSnG). After applying the materials, the erosive-abrasive challenges were performed for five days. Erosive dentin loss and analysis of the pattern of dentinal obliteration were performed by 3D confocal laser microscopy. A one-way ANOVA/Bonferroni test was performed to analyze the data (α=0.05). The SnG and nHSnG experimental groups presented more effectiveness in preventing erosive wear when compared to the other groups (p<0.05). There was no statistically significant difference between the SnG and nHSnG groups (p = 0.731) in tooth structure dentin loss. Regarding the amount of open dentinal tubules, the highest amount of obstructed dentinal tubules was demonstrated in SnG and nHSnG (p < 0.05) when compared to the others. Between SnG and nHSnG there was no significant difference (p = 0.952) in the amount of closed dentinal tubules in the dentin. Experimental varnishes containing 5% SnCl2 associated or not with 20% nHAP showed to be a promising strategy in preventing erosive-abrasive wear of dentin. In addition, nHSnG was able to obliterate dentinal tubules.

Characteristics of abrasive erosion wear specific for progressive cavity pumps used in petroleum industry

Characteristics of abrasive erosion wear specific for progressive cavity pumps used in petroleum industry

Experimental Study on Deteriorated Performance, Vibration, and Geometry Changes of an Electrical Submersible Pump Under Sand Water Flow Condition

AbstractIn the oil and gas industry, the proppant backflow from fracturing wells severely reduces the lifespan of widely used downhole electrical submersible pumps (ESPs). In field applications, a minimal sand concentration may cause severe damage to ESPs in a short time. In order to resist the three-body abrasive sand wear, flanged tungsten carbide sleeves are used in ESPs. However, the wear-resistant performance of different pump geometry is not well analyzed and understood. Therefore, a 64 h pump erosion and abrasion test was conducted with water at the pump's best efficient flowrate with a sand concentration of 1 wt% to imitate the damage caused by short-term proppant backflow. The test was divided into several periods, after which the pump performance, paint-removal wear pattern, eroded pump geometries, and stage vibration were measured and recorded. The wear-rate on pump stage geometries gradually decreased at the beginning of 8–16 h. Then, the carbide sleeves started to help sustain the pump rotation. As a result, the wear-rate and pump vibration became relatively stable. Therefore, the wear mechanism in the secondary flow region (seal rings and sleeves) is believed to change from abrasive wear to the combined erosive-abrasive wear. The pump overall performance decreased by approximately 10% after the 64 h test. The performance, pump geometry, and vibration data are previous for understanding wear mechanism, predicting failures, improving pump design, and saving the well service cost.

Структурный синтез комплексного многосвязного технологического процесса обработки лопаток компрессора газотурбинных двигателей с функционально-ориентированными покрытиями

It is shown that the compressor of a gas turbine engine consists of a group of blades which experience uneven abrasive-erosion wear characterized with unevenness of three types. To increase compressor blade life it is offered to use function-oriented coatings and to ensure their properties on the basis of the principle of equal resource. In the work there are solved the problems of a structural synthesis of a complex multi-coherent technological process of function-oriented blade group sputtering.

Effect of palm oil alone or associated to stannous solution on enamel erosive-abrasive wear: A randomized in situ/ex vivo study

ObjectivePalm oil has demonstrated preventive potential against initial erosive demineralization in vitro. This in situ study evaluated the effect of palm oil alone or associated with stannous-containing (Sn) solution on preventing enamel loss from an erosive/abrasive challenge. DesignThis single-blind, randomized, crossover in situ/ex vivo study was developed in four phases (one per group of five days) with sixteen volunteers. Enamel blocks (n = 256) were allocated to groups according to the treatment: Palm oil; Palm oil plus Sn solution; Sn solution – positive control; and Deionized water – negative control. Half of the enamel blocks of each group was subjected to erosion and the other half to erosion + abrasion. The daily ex vivo protocol consisted of four citric acid immersions (2 min). Before the first and third acid exposure, the blocks were treated with the test solutions (1 drop/block) for 1 min followed by acid immersion and abrasive challenge (toothpaste was applied on all blocks and half were brushed for 15 s/block). Enamel loss was quantified profilometrically and data were analyzed by two-way ANOVA and Tukey’s test (p < 0.05). ResultsA significant difference was found for type of treatment (p < 0.001); wear condition (p = 0.38) and the treatment x condition interaction (p = 0.33) was non-significant. Palm oil associated or not to Sn solution significantly reduced enamel wear in comparison with the negative control but did not differ from the positive control (p > 0.05). ConclusionsPalm oil was able to prevent enamel loss under erosive and erosive + abrasive challenges in a similar extend to stannous-containing commercial solution.

INFLUENCE OF MATERIAL HARDNESS AND PARTICLE VELOCITY ON EROSIVE WEAR RATE

Many parameters such as medium conditions and material properties are effective on erosiveabrasive wear rate. In this study, effect of particle impact velocity and hardness of material on wear rate and wear mechanism was investigated. All tests were carried out in 20% sand-water mixture. Impact velocities of the particles were ranking between 2.04 m/s and 4.76 m/s. Hardness values of St 37 and Ck 45 steels were changed by applying different heat treatments. After wear tests it was concluded that by an increase of impact velocity and decrease of material hardness, wear rate increased. This increase was by soft materials more dominant than by hard materials. After morphological investigations it is concludedthat by an increase of material hardness, number and size of craters on the surface after erosion tests decreased. By using experimental test results, a new mathematical formulation was developed to emphasize the relation between impact velocity and material hardness on wear rate.

Erosive-abrasive wear behavior of carbide-free bainitic and boron steels compared in simulated field conditions

The wear resistance of carbide-free bainitic microstructures have recently shown to be excellent in sliding, sliding-rolling, and erosive-abrasive wear. Boron steels are often an economically favorable alternative for similar applications. In this study, the erosive-abrasive wear performance of the carbide-free bainitic and boron steels with different heat treatments was studied in mining-related conditions. The aim was to compare these steels and to study the microstructural features affecting wear rates. The mining-related condition was simulated with an application oriented wear test method utilizing dry abrasive bed of 8–10 mm granite particles. Different wear mechanisms were found; in boron steels, micro-cutting and micro-ploughing were dominating mechanisms, while in the carbide-free bainitic steels, also impact craters with thin platelets were observed. Moreover, the carbide-free bainitic steels had better wear performance, which can be explained by the different microstructure. The carbide-free bainitic steels had fine ferritic-austenitic microstructure, whereas in boron steels microstructure was martensitic. The level of retained austenite was quite high in the carbide-free bainitic steels and that was one of the factors improving the wear performance of these steels. The hardness gradients with orientation of the deformation zone on the wear surfaces were one of the main affecting factors as well. Smoother work hardened hardness profiles were considered beneficial in these erosive-abrasive wear conditions.

Abrasive-Erosive Wear of Thermally Sprayed Coatings from Experimental and Commercial Cr3C2-Based Powders

In this paper, high-velocity oxy-fuel sprayed coatings from experimental Cr3C2-Ni powder produced by mechanically activated thermal synthesis and disintegrator milling are compared with coatings from commercial Cr3C2-NiCr powder under room- and elevated-temperature abrasive-erosive wear (AEW) conditions. In a room-temperature AEW test, the coating made from the experimental powder had wear rates that were 1.1-5.3 times higher than the coating from the commercial powder; this difference was the lowest at the highest impact velocity (80 m s−1). Under AEW tests at elevated temperature (300 and 550 °C), the coating made from the experimental powder exhibited wear rates that were 1.2-2.8 times higher in comparison with that made from the commercial powder, but this difference was smaller under an oblique impact angle (30°) and higher temperature conditions. The reasons for the lower resistance against AEW of the coating made from the experimental powder were found to be its lower ability to resist plastic indentation and deformation as well as lower indentation fracture toughness at room temperature, weaker bonding between the matrix and reinforcement and probably lower mechanical properties as well as unfavourable residual stresses at elevated temperatures.

Wear Resistance of Sintered Composite Hardfacings under Different Abrasive Wear Conditions

The article focuses on vacuum liquid phase sintered (PM) composite hardfacings and their behaviour under different abrasive wear conditions. Hardfacings studied contained 30 – 50 vol % fine, coarse or multimodal (fine and coarse) hardmetal reinforcement. For wear resistance studies, we used the Abrasive Rubber Wheel Wear (ARWW) test as a three-body abrasive wear test, the Abrasive Wheel Wear (AWW) test as a two-body abrasive wear test and the Abrasive-Impact Erosion wear (AIEW) test as an abrasive-erosive wear test. Tested materials were compared to Hardox 400 steel and CDP112 wear plate (Castolin Eutectic® Ltd.). It was found that under three-body abrasion conditions (ARWW test) hardfacings with high content of spehrical coarse reinforcement are suitable; their wear resistance is about two times higher than that of unreinforced hardfacings. Under two-body abrasive wear (AWW test), hardfacings with a high content of coarse reinforcement are recommended; their wear resistance is up to eight times higher than that of unreinforced hardfacings from the figures and graphs mentioned in the text. Under abrasive-erosive wear (AIEW test), unreinforced ductile materials are recommended; they have two to three times higher wear resistance than composite hardfacings reinforced with fine or multimodal reinforcement. DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16323

Analysis of progressive cavity pumps specific wear processes using Finnie models

Progressive cavitation pumps are designed to work in aggressive environments thus their wear is inevitable. The specific tribological coupling of these pumps is composed of a helical rotor with a single outward helix and a stator with a double inside helix. These elements are in relative motion and direct contact to each other and also in direct contact with the pumped oil. Therefore the main forms of wear of rotor-stator coupling elements are the abrasive wear and the erosion wear. In this paper is presented the analysis of erosion with Finnie models. The results are useful for estimation of progressive cavity pumps specific abrasive-erosive wear.

Analysis of progressive cavity pumps specific wear processes using Bitter and Hutchings models

Progressive cavitation pumps are designed to work in aggressive environments thus their wear is inevitable. The specific tribological coupling of these pumps is composed of a helical rotor with a single outward helix and a stator with a double inside helix. These elements are in relative motion and direct contact to each other and also in direct contact with the pumped oil. Therefore the main forms of wear of rotor-stator coupling elements are the abrasive wear and the erosion wear. In this paper is presented the analysis of erosion with Bitter and Hutchings models. The results are useful for estimation of progressive cavity pumps specific abrasive-erosive wear.

Effect of bulk heat treatment and plasma surface hardening on the microstructure and erosion wear resistance of complex-alloyed cast irons with spheroidal vanadium carbides

The results of an investigation of the effect of bulk quenching from temperature in the range of 760–1050°C, cryogenic treatment (–196°C) and surface plasma hardening on the abrasive-erosion wear of frugally alloyed V–Cr–Mn–Ni cast irons with spheroidal vanadium carbides have been presented in this article. It has been found that cast irons containing 5.0–7.5% V, 4.5–9.0% Cr, and 5.5–5.7% (total) of Mn and Ni after heat treatment have a 2–3-fold advantage in wear resistance compared to the prototype high-vanadium cast iron (11.9% V, 12.9% Mn). The maximum wear resistance of cast irons studied is achieved by quenching at 760°C followed by plasma surface hardening, as well as quenching at 840°C, followed by cryogenic treatment. These treatments result in the formation of an optimum microstructure that consists of spheroidal vanadium carbides, eutectic carbides M7C3, and a martensite-austenite matrix reinforced by secondary carbides. The increase in quenching temperature leads to an increase in the amount of residual austenite and decrease in the erosive wear resistance of cast irons.

Optimisation of Heat Treatment for Steel Stressed by Abrasive Erosive Degradation

The aim of the present publication is the analysis of refined steels designed for conditions with increased abrasive stress (102Cr6, 54SiCr6, 25CrMo4 and 15230 - does not have DIN equivalent). These include mainly mechanical components used as replaceable parts in machines for tillage, such as plough blades and chisels.The experimental part is focused on the issue of heat treatment of steel materials, which are usually used for the production of machine parts intended for tools designed to withstand abrasive stress. The suitability of individual materials for the production of tools for tillage will be evaluated based on the results of mechanical tests. These include the analysis of the structure of the given material, its hardness (CSN EN ISO 6508-1) and impact toughness (CSN EN 10045-1). Microhardness of individual structural components was also measured. The analysis was processed on a metallographic microscope.The individual tests of abrasive resistance are divided between interaction of two objects and a combination of abrasive erosive wear. Laboratory tests were performed on an abrasive cloth (CSN 01 5084) and in Bond's drum apparatus (this experiment is not standardized).Based on the results of the individual measurements it is possible to make recommendation of a suitable heat treatment of tested materials for environments with considerable abrasive stress.

High-temperature erosion of Fe-based coatings reinforced with cermet particles

High-velocity oxy-fuel sprayed, iron alloy-based powder coatings, reinforced with tungsten carbide–cobalt (WC–Co) and titanium carbide–nickel molybdenum (TiC–NiMo) cermet particles, are compared under high-temperature abrasive–erosive wear conditions. Both WC–Co and TiC–NiMo particles underwent fracture, as well as dissolution, during the spraying process, but in the case of WC–Co particles this process was remarkably less intensive. Under the low impact angle conditions, the WC–Co particle-reinforced coating exhibited 1.1 times lower wear than the TiC–NiMo particle-reinforced coating because of the larger amount of the reinforcement remaining. Under the normal impact angle conditions, the WC–Co particle-reinforced coating showed 1.2 times lower wear than the TiC–NiMo particle-reinforced coating because of the resulting larger size of the WC–Co reinforcement and a more ductile matrix.

Erosive and abrasive wear performance of carbide free bainitic steels – comparison of field and laboratory experiments

Carbide free bainitic (CFB) steels have been tested in two heat treated conditions and compared with currently used quenched and tempered (QT) steel in an industrial mining application subjected to erosive–abrasive wear. A conventional sliding abrasion and a new application oriented high-stress erosion wear tests were performed in laboratory. The results of the erosion and the field tests were compared. The microstructural changes were investigated by optical and scanning electron microscopy. The hardness and hardness profiles of the steels were measured. The results showed that in the laboratory tests, the abrasion and erosion wear rates of the CFB steels were 35% and 45% lower respectively in comparison to the QT steel. In the field test, the mass losses of the CFB steels were about 80% lower in comparison with the QT steel. The improved wear resistance of the CFB steel can be explained by its higher hardness and higher work hardening. The erosion wear test was able to simulate the work hardening effect and the wear mechanisms observed in the field test samples.

Wear resistance of HVOF sprayed coatings from mechanically activated thermally synthesized Cr3C2–Ni spray powder

In the current study a Cr3C2-Ni spray powder was produced by mechanically activated thermal synthesis. The following aspects were studied: (a) production and characteristics of spray powders, (b) spraying and characteristics of coatings by HVOF, and (c) abrasive wear resistance. A HVOF spray system Diamond Jet Hybrid 2700 (propane hybrid gun from Sulzer Metco) was used for deposition. Coating thickness was approximately 350-400 μm. The structure and composition of the coatings were determined by SEM and the phase composition by XRD methods. Coating surface hardness and microhardness in the cross- section were measured. Abrasive rubber-wheel wear (ARWW) and abrasive erosive wear (AEW) were tested. The wear resistance of the coatings produced from an experimental powder was comparable to that of a similar commercial one.