Made available in DSpace on 2016-12-23T14:08:10Z (GMT). No. of bitstreams: 1 Karla Dubberstein Tozetti.pdf: 2038739 bytes, checksum: f6618f8c3d4a6be204f5f15fc187f5a1 (MD5) Previous issue date: 2013-04-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / No trabalho foi investigado o efeito da carga e do tamanho da partícula abrasiva na resistência ao desgaste da liga de ferro fundido branco alto cromo (FFBAC) com composição química de 2,9% de carbono e 19,9% de cromo em massa. A microestrutura da liga é composta por uma matriz de martensita revenida a 200 ºC com carboneto eutético. No ensaio abrasivo pino sobre lixa foram utilizadas lixas de sílica e de granada como abrasivo, com três granulometrias distintas: 63 μm, 149 μm e 177 μm, sob a aplicação de duas cargas: 5 N e 10 N. Em abrasão no roda-deborracha utilizou-se como abrasivo a areia normal brasileira (ANB) com três tamanhos médios: 87 μm, 115 μm e 170 μm e três cargas: 44 N, 80 N e 130 N. As superfícies de desgaste foram analisadas com um analisador tridimensional de superfícies e os micromecanismos de desgaste foram caracterizados usando microscopia eletrônica de varredura. Os resultados obtidos nos ensaios mostraram, de maneira geral, um aumento no volume perdido no desgaste com o aumento da carga e do tamanho da partícula abrasiva e permitiram, para a roda-de-borracha, a observação de um tamanho crítico do abrasivo. No ensaio pino sobre lixa de sílica, para o maior tamanho de abrasivo, o volume perdido no desgaste triplicou com o aumento da carga de 5 N para 10 N / In this research, the effects of different applied load and abrasive size on the martensitic high-chromium write cast iron (with a chemical composition: 2,9% carbon and 19,9% chromium) abrasive wear was investigated. The alloy s microstructure consists of: a matrix martensite tempered at 200 ° C with eutectic carbide. Abrasive wear tests using a pin test on silica and garnet paper were carried out using three different abrasives sizes: 63 μm, 149 μm e 177 μm and two applied load: 5 N e 10 N. And the rubber wheel abrasion test (ASTM standard G-65) was carried out using three abrasives sizes: 87 μm, 115 μm e 170 μm and three distinct applied loads: 44 N, 80 N e 130 N. The specimens wear surface was examined by scanning electron microscopy (SEM) for identifying the wear mechanism. The rubbers wheel abrasion test results show that: the mass loss of the write cast iron alloy increases linearly with the increase of particle size until the critical particle size is reached. In pin test on silica paper, to the largest abrasive size, the lost volume in abrasion tripled with applied load increasing of 5 N to10 N. In general, the mass loss increases with the increase of the load applied and the abrasive size

Made available in DSpace on 2016-12-23T14:08:11Z (GMT). No. of bitstreams: 1 Leandro Rodrigues Pinto da Cunha.pdf: 2983821 bytes, checksum: b06bd053fe594d95a0a35b703e2a664b (MD5) Previous issue date: 2013-03-02 / Neste trabalho foi realizado um estudo comparativo da resistência ao desgaste abrasivo de quatro materiais poliméricos utilizados no setor de transporte de minérios nas plantas de produção, sendo um poliuretano (utilizado como raspador) e três elastômeros (camadas de correias e revestimentos de tambores). Para tal comparação, foram realizados ensaios de desgaste do tipo pino tambor, conforme norma ISO 4649 nos laboratórios TRICORRMAT (Universidade Federal do Espírito Santo) e LFS (Universidade de São Paulo). Um protocolo experimental envolvendo todas as etapas do ensaio, desde a obtenção dos materiais até o armazenamento final, foi elaborado em conjunto pelos dois laboratórios no decorrer desse trabalho. A determinação da repetibilidade e da reprodutibilidade dos resultados de ensaios foi utilizada para a validação do protocolo experimental. A partir da perda de massa de cada material, foram correlacionados alguns parâmetros controláveis de ensaios tais como: lixa, operador e máquina. Foi observado que dentre os parâmetros citados, a máquina foi o parâmetro que exerceu maior influência nos resultados de comparação entre os laboratórios / In this work, we conducted a comparative study of the abrasive wear resistance of four polymeric materials used in ore transport in Vale plants, being a polyurethane (used as a scraper) and three elastomers (belt layers and drums coatings). To make such a comparison, pin-on-drum type wear tests were performed, according to ISO 4649, between TRICORRMAT (Federal University of Espírito Santo) and LFS (University of São Paulo). An experimental procedure involving all stages of the test, from the procurement of materials to final storage, was developed jointly between the labs during this work. The determination of repeatability and reproducibility from the testing results were used to validate the experimental procedure. From the mass loss of each material were correlated controllable test parameters such as the sandpaper, the operator and the machine. It was observed that among the mentioned parameters, the machine was the parameter that exerted greater dispersion in the results between laboratories

This research conducts tribological investigation in three areas. The first area of research is to obtain basic understanding of tribological properties of high performance Inconel alloys. Pin-on-disk testing was conducted through a range of applied normal loads and sliding velocities in an unlubricated condition. Average friction coefficient, friction work, and specific wear rates were calculated from the data and microscopy techniques were used to observe and characterize wear mechanisms. Experimental results show a dependence of average coefficient of friction as a function of frictional work. Also shown is the wear rate dependence on frictional work, predicated by a wear mechanism change. This research gives a tribological baseline for high performance alloys. The second area of research is in the in situ spatial study of friction, complemented by monitoring changes in electrical contact resistance (ECR). Pin-on-disk testing of samples was done under low normal loads and velocities. Friction and electrical contact resistance measurements were taken spatially in the wear track during each friction cycle, giving a spatial evolution of friction and resistance change, in situ. Results show a lowering in the ECR under increased friction cycles, which was closely related to a change in the friction coefficient of the material. Using surface profilometry and X-ray Photoelectron Spectroscopy, we determined that the lowering of resistance is a result of surface modification through wear and development of a friction induced conductive tribo-film. This research provides a simple method for in situ monitoring of friction and solidifies a fundamental relationship between friction and contact resistance. The third area of research is the design of a variable force tribometer, incorporating the fundamental results demonstrated in the first two experiments. The creation of a novel testing apparatus to test materials under dynamic tribological conditions is given in detail. Simple experiments were performed on an Inconel sample and preliminary results show how dynamic normal and tangential forces affect the friction coefficient. These early results utilizing the variable force tribometer will lay the groundwork for more advanced research into the dynamic nature of friction.

Metal matrix composites (MMCs) are emerging as advanced engineering materials for application in aerospace, defence, automotive and consumer industries (sports goods etc.). In MMCs, a metallic base material is reinforced with ceramic fiber, whisker or particulate in order to achieve a combination of properties not attainable by either constituent individually. Aluminium or its alloy is favoured as metallic matrix material because of its low density, easy fabricability and good engineering properties. In general, the benefits of aluminium metal matrix composites (AMCs) over unreinforced aluminium alloy are increased specific stiffness, improved wear resistance and decreased coefficient of thermal expansion. The conventional reinforcement materials for AMCs are SiC and AI2O3. In the present work, boron carbide (B4C) particles of average size 40μm were chosen as reinforcement because of its higher hardness (very close to diamond) than the conventional reinforcement like SiC, AI2O3 etc. and of its density (2.52 g cm"3) very close to Al alloy matrix. In addition, due to high neutron capture cross-section of 10B isotope, composites containing B4C particle reinforcement have the potential for use in nuclear reactors as neutron shielding and control rod material. Al-5%Mg alloy was chosen as matrix alloy to utilize the beneficial role of Mg in improving wettability between B4C particles and the alloy melt. (Al-5%Mg)-B4C composites containing 10 and 20 vol% B4C particles were fabricated. For the purpose of inter-comparison, unreinforced Al-5%Mg alloy was also prepared and characterized. The Stir Cast technique, commonly utilized for preparation of Al-SiC, was adapted in this investigation.The Composites thus prepared was subsequently hot extruded with the objective of homogenization and healing minor casting defects. Finally the unreinforced alloy and its composites were characterized in terms of their microstructure, mechanical and thermo-physical properties, sliding wear behaviour and neutron absorption characteristics. The microstructures of the composites were evaluated by both optical microscope and scanning electron microscope (SEM). The micrographs revealed a relatively uniform distribution of B4C particles and good interfacial integrity between matrix and B4C particles. The hot hardness in the range of 25°C to 500°C and indentation creep data in the range of 300°C to 400°C show that hot hardness and creep resistance of Al-Mg alloy is enhanced by the presence of B4C particles. Measurement of coefficient of thermal expansion (CTE) of composites and unreinforced alloy upto 450°C showed that CTE values decrease with increase in volume fraction of reinforcement. Compression tests at strain rates, 0.1, 10 and 100 s-1 in the temperature range 25 - 450 °C showed that the flow stress values of composites were, in general, greater than those of unreinforced alloy at all strain rates. These tests also depicted that the compressive strength increases with increase in volume fraction of reinforcements. True stress values of composites and unreinforced alloy has been found to be a strong function of temperature and strain rate. The kinetic analysis of elevated temperature plasticity of composites revealed higher stress exponent values compared to unreinforced alloy. Similarly, apparent activation energy values for hot deformation of composites were found to be higher than that of self-diffusion in Al-Mg alloy. Tensile test data revealed that the modulus and 0.2% proof stress of composites increase with increase in volume fraction of the reinforcements. Composites containing 10%BUC showed higher ultimate tensile strength values (UTS) compared to unreinforced alloy. However, composites with 20%B4C showed lower UTS compared to that of the unreinforced alloy. This could be attributed to increased level of stress concentration and high level of plastic constraint imposed by the reinforcing jparticles or due to the presence solidification-induced defects (pores and B4C agglomerates ). Sliding wear characteristics were evaluated at a speed of 1 m/s and at loads ranging from 0.5 to 3.5kg using a pin-on-disc set up. Results show that wear resistance of Al-5%Mg increases with the addition of B4C particles. Significant improvement in wear resistance of Al-5%Mg is achieved with the addition of 20% B4C particles. SEM examination of worn surfaces showed no pull-out of reinforcing particles even at the highest load of 3.5 kg, thus confirming good interfacial bonding between dispersed B4C particles and Al alloy matrix. The neutron radiography data proved that (Al-5%Mg)-B4C composites possess good neutron absorbing characteristics. From the experimental data evaluated in the "study, it may be concluded that (Al-5%Mg)-B4C composites could be a candidate material for neutron shielding and control rod application. The enhanced elevated temperature-strength and favourable neutron absorption characteristics of these composites are strong points in favour of this material.

No description available.

Orientador: Juno Gallego / Resumo: O desgaste abrasivo é uma das causas de falhas em equipamentos e responsável por prejuízos nos processos industriais. Uma técnica capaz de minimizar os efeitos deste fenômeno é a aplicação de revestimentos duros nas superfícies críticas. Recentemente foram desenvolvidos revestimentos contendo carbonetos de titânio formados pela fusão de misturas contendo cavacos das ligas ASTM F67 e ASTM F136 sobre peças de aço-carbono ASTM A-36. Após a aplicação do processo de soldagem GTAW obteve-se significativa fração volumétrica de TiC grosseiro com elevada dureza. No presente trabalho foi investigada a refusão dessas soldas pelo processo de soldagem a Laser Nd:YAG pulsado. A microestrutura das amostras foi analisada por difração de raios-X (DRX), microscopia eletrônica de varredura (MEV) e microdureza Vickers. A caracterização microestrutural mostrou que houve refinamento dos carbonetos de titânio (TiC) na matriz ferrítica refundida com o Laser, cujo principal efeito foi um endurecimento do metal de solda. A caracterização mecânica demonstrou um aumento na microdureza da superfície do material. Este comportamento favorece o uso da refusão a Laser para a melhoria da qualidade das superfícies que demandam maior resistência ao desgaste abrasivo. / Mestre

Made available in DSpace on 2016-12-08T17:19:19Z (GMT). No. of bitstreams: 1 Jeferson Dallmann.pdf: 9554696 bytes, checksum: 3e83174b0575144859c3ad1f9ecb07de (MD5) Previous issue date: 2012-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this paper, the design, construction and validation of a Vertical and Horizontal Rubber Wheel Abrasometer were performed. Based on the equipment proposed by ASTM G-65 and by Hutchings and Stevenson, this paper proposes merging into one abrasive wear testing machine, an equipment capable of operating as a Vertical Rubber Wheel Abrasometer or as Horizontal Rubber Wheel Abrasometer. Contrary to the use of dead weights, the application of force against the wheel in the sample is performed by a pneumatic cylinder, and its intensity is controlled by a load cell. The other dimensional parameters and test conditions follow those proposed by ASTM G- 65. To assess the repeatability of the tests, specimens of SAE 1015 and AISI D2 hardened and tempered were used. The results showed that the equipment operates in satisfactory condition when operated as a Vertical Rubber Wheel Abrasometer, where the samples showed values of volumetric losses of material expected in the literature. Already in operational condition as Horizontal Rubber Wheel Abrasometer, equipment needs a better calibration, because although smaller friction rates being found, the results don t showed good repeatability. / Neste trabalho foram realizados o projeto, construção e validação de um Abrasômetro Roda de Borracha Vertical e Horizontal. Com base nos equipamentos propostos pela norma ASTM G-65 e por Hutchings e Stevenson, este trabalho propõe agregar em uma só máquina de ensaios de desgaste abrasivo, um equipamento capaz de realizar testes operando como um Abrasômetro Roda de Borracha Vertical ou como um Abrasômetro Roda de Borracha Horizontal. Contrário ao uso de pesos mortos, a aplicação da força na amostra contra a roda é realizada por um sistema pneumático, e sua intensidade medida por uma célula de carga. Os demais parâmetros dimensionais e especificações de ensaio seguem os propostos pela norma ASTM G-65. Para avaliar a reprodutibilidade do equipamento, corpos de prova confeccionados em aço SAE 1015 e aço AISI D2 temperado e revenido foram utilizados. Os resultados mostraram que o equipamento opera em condições satisfatórias na configuração de Abrasômetro Roda de Borracha Vertical, onde as amostras apresentaram valores de perdas volumétricas de material esperadas pela literatura. Já na configuração de operação Roda de Borracha Horizontal, o equipamento necessita de uma melhor calibração, pois, apesar de taxas de desgaste menores serem encontradas, os resultados não apresentaram boa repetibilidade.

Submitted by GABRIEL INÁCIO PONTIN null (gabrielguaira@hotmail.com) on 2017-08-15T18:00:10Z No. of bitstreams: 1 Dissertação Final - Gabriel Inacio Pontin.pdf: 2725651 bytes, checksum: f1433687bb33e3c16dd042c87cb686db (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-08-22T17:44:39Z (GMT) No. of bitstreams: 1 pontin_gi_me_ilha.pdf: 2725651 bytes, checksum: f1433687bb33e3c16dd042c87cb686db (MD5) / Made available in DSpace on 2017-08-22T17:44:39Z (GMT). No. of bitstreams: 1 pontin_gi_me_ilha.pdf: 2725651 bytes, checksum: f1433687bb33e3c16dd042c87cb686db (MD5) Previous issue date: 2017-07-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O desgaste abrasivo é uma das causas de falhas em equipamentos e responsável por prejuízos nos processos industriais. Uma técnica capaz de minimizar os efeitos deste fenômeno é a aplicação de revestimentos duros nas superfícies críticas. Recentemente foram desenvolvidos revestimentos contendo carbonetos de titânio formados pela fusão de misturas contendo cavacos das ligas ASTM F67 e ASTM F136 sobre peças de aço-carbono ASTM A-36. Após a aplicação do processo de soldagem GTAW obteve-se significativa fração volumétrica de TiC grosseiro com elevada dureza. No presente trabalho foi investigada a refusão dessas soldas pelo processo de soldagem a Laser Nd:YAG pulsado. A microestrutura das amostras foi analisada por difração de raios-X (DRX), microscopia eletrônica de varredura (MEV) e microdureza Vickers. A caracterização microestrutural mostrou que houve refinamento dos carbonetos de titânio (TiC) na matriz ferrítica refundida com o Laser, cujo principal efeito foi um endurecimento do metal de solda. A caracterização mecânica demonstrou um aumento na microdureza da superfície do material. Este comportamento favorece o uso da refusão a Laser para a melhoria da qualidade das superfícies que demandam maior resistência ao desgaste abrasivo. / The abrasive wear is one of the causes of failures in equipment and responsible for damages in industrial processes. A technique capable of minimizing the effects of this phenomenon is the application of hard coatings on critical surfaces. Recently, coatings containing titanium carbides produced by melting mixtures containing ASTM F67 and ASTM F136 chip blends on ASTM A-36 carbon steel parts have been developed. After an application of the GTAW get process, an important volumetric fraction of coarse TiC with high hardness was obtained. In the present work the remelts is investigated for welds by the pulsed Nd: YAG Laser process. A microstructure of the samples was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Vickers microhardness. The microstructural characterization showed that there was a refinement of the titanium carbides (TiC) in the ferritic matrix remelt with the Laser, whose main effect was a hardening of the weld metal. The mechanical characterization showed an increase in the microhardness of the material surface. This behavior favors the use of laser cladding to improve the quality of surfaces that require high abrasive wear resistance.

Deep water oil production imposes several challenges to the oil companies. One of the greatest difficulties is related to the damages that the flexible riser pipes are subjected. These pipes conduct the produced oil to the platform. They are also used to inject water in the well in order to recover its production capacity. Among the damages mentioned, its worth to mention the abrasive wear that takes place at the touchdown point (TDP). In order to reduce this tribological degradation, PU coats have been used at the TDP region. Considering the diversity of PU that can be used in this application, it is highly desired that the PU plaques quality are controlled before its installation. Based on this demand, a portable apparatus was designed and constructed in the Laboratory for Friction and Wear at the Federal University of Uberlândia to simulate the tribological interactions between the riser pipe and the sea bed. So this work aims to produce WC-Co indenter for this test apparatus. To accomplish that, the following steps were proposed: a) equipment preparation for wear tests; b) determination of test parameters (cycle number and load) through a full factorial design; c) geometric and dimensional control of the indenters before and after machining processes; d) realization of wear tests before and after machining the indenters; e) machining of indenters using honing and lapping and f) analysis of the improvements achieved on the wear results. The results obtained allowed the following conclusions: 1) the proposed machining processes and parameters for are appropriate to manufacture the indenter In accordance with their selected dimensional and geometric tolerances. Roughness values of about 2.0 μm has been reduced by at least 60%, while for values lower than 2.0 μm this reduction was at least 33%, and 2) abrasion tests using the new indenters provide more precise and reliable results. / A extração de petróleo em águas profundas impõe diversos desafios às empresas petrolíferas. Um dos principais são os danos que os dutos flexíveis, as tubulações que levam o petróleo do poço de extração até a plataforma flutuante, sofrem ao serem expostos ao hostil ambiente subaquático. Dentre estes danos, destaca-se o desgaste abrasivo na região onde o duto toca o solo marinho, chamada de touchdown point (TDP). Para prolongar a vida útil do duto e evitar vazamentos de óleo no mar, são empregados revestimentos protetores poliméricos, usualmente chamados de calhas. A partir de uma necessidade da indústria petrolífera de testar e controlar o recebimento destes revestimentos foi projetado e construído um equipamento denominado de Simulador de Interações Marítimo-Mecânicas em Calhas (SIMMC) no Laboratório de Tecnologia em Atrito e Desgaste UFU que visa à realização de testes em campo. Assim sendo, o objetivo deste trabalho foi fabricar, controlar e testar penetradores de metal duro visando à realização de ensaios de desgaste por abrasão que permitam avaliar a resistência ao desgaste abrasivo de materiais poliméricos usados na proteção de risers. Para tanto, foram propostas as seguintes etapas: a) preparação do SIMMC Portátil para realização dos ensaios de desgaste; b) determinação dos parâmetros de teste ideais para o SIMMC Portátil (número de ciclos, carga externa e velocidade de rotação) por meio de um planejamento fatorial completo; c) controle dimensional e geométrico dos penetradores antes e após a usinagem; d) realização de testes de desgaste antes e após a retífica; e) usinagem dos penetradores utilizando afiação e lapidação e f) análise da influência das melhorias trazidas por esses processos para os resultados dos testes de desgaste. Os resultados obtidos permitem concluir que: 1) os processos de usinagem propostos são adequados para fabricação dos penetradores dentro das tolerâncias dimensionais e geométricas definidas no projeto. Valores de rugosidade da ordem de 2,0 μm foram reduzidos em pelo menos 60%, enquanto que para valores menores que 2,0 μm esta redução foi pelo menos de 33% e 2) os ensaios de abrasão utilizando os penetradores fabricados fornecem resultados mais precisos e confiáveis. / Mestre em Engenharia Mecânica

Neste trabalho, foi investigado o efeito do tamanho do abrasivo e do pH do meio na resistência ao desgaste abrasivo do aço H-13 com matriz martensítica e do aço Hadfield com matriz austenítica. Ensaios de abrasão foram realizados utilizando o equipamento roda de borracha a úmido, variando o tamanho do abrasivo entre 0,15 e 2,40 mm e o pH do meio entre 5,5 e 12,8. As microestruturas dos materiais estudados foram analisadas utilizando microscopia óptica, as superfícies de desgaste e as partículas de desgaste foram analisadas em microscópio eletrônico de varredura. A macrodureza e a microdureza, antes e após os ensaios, foram obtidas utilizando durômetro Vickers. A topografia da região central da superfície de desgaste foi obtida utilizando Perfilometria 3D, visando obter valores de profundidade de penetração do abrasivo. Os resultados mostraram que o aço Hadfield é mais resistente do que o aço H-13 em todos os valores de pH e tamanhos de abrasivo utilizados. Para os dois materiais, a perda de massa aumenta linearmente até um tamanho crítico de abrasivo (TCA) e, após este, a mesma continua a aumentar, mas com uma intensidade menor. Para os dois materiais e para todos os tamanhos de abrasivo, o aumento do pH do meio resultou em menores perdas de massa, sendo este efeito maior para os dois menores tamanhos de abrasivo. Para maiores valores de pH, foram observadas menores profundidades de penetração do abrasivo. A microdureza da superfície de desgaste do aço H-13 sofreu um pequeno aumento com o aumento do tamanho do abrasivo enquanto que para o aço Hadfield esse aumento foi mais intenso. A análise das partículas de desgaste mostraram que, para todas as condições ensaiadas, os debris do aço H-13 tinham duas morfologias, contínuas e descontínuas enquanto que os cavacos do aço Hadfield foram sempre descontínuos. Para os dois materiais, foram observados dois micromecanismos de desgaste, sendo eles microcorte e microsulcamento. Por fim, os resultados apresentados neste trabalho sugerem que a análise de desempenho do aço Hadfield em serviço deve considerar o pH do meio bem como a granulometria do abrasivo em contato. / In this work, the effects of abrasive particle size and pH value of the aqueous solution on abrasive wear resistance of the H-13 steel with martensitic matrix and the Hadfield steel with austenitic matrix were investigated. Abrasive wear tests, using a wet rubber wheel abrasion tester, were carried out using abrasive sizes between 0.15 and 2.40 mm and pH values of the aqueous solution between 5.5 and 12.8. The microstructures of the materials studied were analyzed by optical microscopy and the wear surfaces and wear particles were analyzed by scanning electron microscopy. The hardness and microhardness before and after the tests were measured using a Vickers hardness tester. The topography of the middle of wear scars, were obtained by a noncontact 3D profiler in order to measure the depth of abrasive penetrations.The results show that the Hadfield steel is more wear resistant than the H-13 steel at all pH values and abrasive sizes conditions tested. For both materials, mass loss increases linearly up to a critical abrasive size, and after this the mass loss continues to increase, but with a lower intensity. Moreover, for both materials and all the abrasive sizes, increases in the pH values of the aqueous solution resulted in lower mass losses, and this effect is greater for the two smaller grain sizes. For higher pH values, lower depths of penetration of abrasive were observed. The microhardness in the wear scar surface of the H-13 steel presented a slight increase with the abrasive size, while for the Hadfield steel, this microhardness increases in a more intense form with the abrasive size. The analysis of the wear particles showed that, for all test conditions, the chips of H-13 steel has two types of morphologies, continuous or discontinuous, and for Hadfield steel only discontinuous. For both materials, two abrasive wear micromechanisms were observed, microcutting and microploughing. Finally, the results presented in this work suggest that the wear performance analysis of the Hadfield steel, to be used in an abrasive environment, must consider the effects of pH of the aqueous solution and particle size.