Publication: INFLUENCIA DEL APORTE CALÓRICO SOBRE LA MICROESTRUCTURA Y LA RESISTENCIA AL DESGASTE ABRASIVO DE RECUBRIMIENTOS DUROS Ni-WC
Date
2017
Authors
ZAMBRANO MARÍN, SEBASTIÁN ANDRÉS
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Abstract
El desgaste de materiales que deben soportar condiciones particularmente agresivas, como elevadas cargas de interacción, abrasión, corrosión y erosión, no es deseado ya que puede incrementar los costos de mantención de maquinarias, afectar el rendimiento global de operaciones industriales debido a aumentos en la frecuencia de mantenciones, y producir pérdidas prematuras de equipos industriales.En Chile, este efecto a nivel industrial se observa en el rubro minero-metalúrgico, produciéndose como consecuencia de la interacción del material con diferentes especies mineralógicas o metálicas, e intensificándose por la combinación de condiciones agresivas, como la dureza y la abrasividad de los minerales, la acción de cargas de impacto, la presencia de ambientes corrosivos, y las altas temperaturas, entre otras.Actualmente, el uso de recubrimientos duros resistentes al desgaste aplicados sobre la superficie de piezas de acero, mediante procesos de soldadura o de metalizado, ofrece ahorros significativos en términos de costo de material y de mantención, constituyendo una alternativa eficaz para proteger las partes y las zonas específicas de piezas sometidas al desgaste en sus distintas formas y casos. Básicamente, la resistencia al desgaste que poseen los recubrimientos depende de la presencia y la distribución de las fases del material en la superficie expuesta, como también de la composición química del producto depositado y las variables de soldadura y térmicas del proceso.El presente trabajo evalúa experimentalmente el efecto de utilizar diferentes magnitudes de aporte calórico sobre la microestructura de recubrimientos duros base níquel reforzados con carburos de tungsteno, con el fin de identificar los fenómenos de disolución y de decantación que afectan a los carburos de tungsteno en el proceso de depositación, correlacionando esto con la dureza y la resistencia al desgaste abrasivo de los recubrimientos, medido mediante el ensayo normalizado ASTM G65.
The wear of materials that must withstand aggressive wear conditions; such as high interaction loads, abrasion, corrosion and erosion; is undesirable because it can increase maintenance costs of machinery, affect the overall performance of industrial operations due to an increase in the frequency of maintenance, and produce a loss of industrial equipment.In Chile, in particular, the effects of wear can be seen at the industrial level in the mining-metallurgical sector. This wear is produced by the interaction between materials with different mineralogical or metallic species, and it is intensified by the combination of aggressive conditions, such as the hardness and the abrasiveness of minerals, impact loads action, the presence of corrosive environments, and high temperatures, among others.Currently, the use of wear resistant overlays applied to the surface of steel parts, through welding processes or thermal spray, provides significant cost savings in terms of material and maintenance, constituting an effective alternative to protect parts and specific areas of metal parts subjected to wear. The use of wear resistant overlays depends on the presence and the distribution of phases on the exposed surface, as well as the chemical composition of deposited filler metal and the thermal variables of welding processes.The present work evaluates the effect of using different magnitudes of heat input on the microstructure of nickel based hardfacings alloy reinforced with tungsten carbide, to identify the phenomena of dissolution and decantation that affect to tungsten carbides in the deposition process. Additionally, the microstructural variables will be correlated with the hardness and the abrasive wear resistance of hardfacings, measured by the standard test ASTM G65.
The wear of materials that must withstand aggressive wear conditions; such as high interaction loads, abrasion, corrosion and erosion; is undesirable because it can increase maintenance costs of machinery, affect the overall performance of industrial operations due to an increase in the frequency of maintenance, and produce a loss of industrial equipment.In Chile, in particular, the effects of wear can be seen at the industrial level in the mining-metallurgical sector. This wear is produced by the interaction between materials with different mineralogical or metallic species, and it is intensified by the combination of aggressive conditions, such as the hardness and the abrasiveness of minerals, impact loads action, the presence of corrosive environments, and high temperatures, among others.Currently, the use of wear resistant overlays applied to the surface of steel parts, through welding processes or thermal spray, provides significant cost savings in terms of material and maintenance, constituting an effective alternative to protect parts and specific areas of metal parts subjected to wear. The use of wear resistant overlays depends on the presence and the distribution of phases on the exposed surface, as well as the chemical composition of deposited filler metal and the thermal variables of welding processes.The present work evaluates the effect of using different magnitudes of heat input on the microstructure of nickel based hardfacings alloy reinforced with tungsten carbide, to identify the phenomena of dissolution and decantation that affect to tungsten carbides in the deposition process. Additionally, the microstructural variables will be correlated with the hardness and the abrasive wear resistance of hardfacings, measured by the standard test ASTM G65.
Description
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Keywords
ALTAS TEMPERATURAS , AMBIENTES CORROSIVOS , CARBUROS DE TUNGSTENO , MANTENCION DE MAQUINARIAS , MANTENCION DE MAQUINARIAS CHILE , RECUBRIMIENTOS BASE NIQUEL , RECUBRIMIENTOS DUROS , RUBRO MINERO-METALURGICO