The microstructure of a series of experimental high chromium, high carbon cast irons was examined by optical and electron microscopy to determine the mechanisms that impart their resistance to wear by impact of reduced iron pellets at 550°C. The samples were cast following an experimental design in which the amount of different carbide forming elements was varied. The microstructure of these alloys was found to consist of a primary network of M 7 C 3 carbides surrounded by an austenitic matrix and eutectic carbides. It was found that the size distribution of the proeutectic primary carbide exerts an in uence on wear, but no correlation was found between the hardness of the different constituents and wear. The experimental results indicate that the alloys cast with the greatest amounts of molybdenum showed the lowest resistance to wear. Scanning electron microscopy of a low wear resistant sample showed evidence of the localisation of molybdenum in proeutectic carbides.MST/5170
Iron-chromium cast alloys are basically abrasive wear resistant materials particularly employed in mining industry; these alloys are often utilized in the manufacture of milling balls. In particular, high Cr and high C cast alloys have been subjected of significant research; for instance, most reports have been addressed on analyzing the relation between microstructure and the abrasive wear behavior; however, there exist a reduced number of reports on relatively low Cr and low C cast alloys. In this research, five low Cr cast steels containing additions of V and Ti were melted in an open atmosphere induction furnace. Comparisons on the morphology, size, type and distribution of carbides were carried through optical microscopy, SEM and XRD. Hardness testing was employed at room temperature with the purpose of correlate to wear behavior. A laboratory pilotplant ball-mill set with a batch of ore was utilized in order to evaluate the abrasive wear resistance. According to microstructure observations, a martensitic primary matrix was revealed in all specimens. The fraction of M7C3 and M 3 C interdendritic eutectic carbides varied according to alloying level. Further results indicated that variations in the shape and size of M 7 C 3 and M 3 C along with the presence of V and Ti carbides influenced on the abrasive wear behavior of low Cr cast steel mill balls.
Este es un artículo publicado en acceso (Open Access) abierto bajo la licencia Creative Commons Attribution NonCommercial, que permite su uso, distribución y reproducción en cualquier medio, sin restricciones siempre que sin fines comerciales y que el trabajo original sea debidamente citado.Recibido: 12 Jun., 2016 Aprobado: 14 Nov., 2016 E-mails: miguel.f.pamanes@gmail.com (MFDP), smald@uaz.edu.mx (SIMR)Resumen: La soldadura de resistencia por puntos, es el método más importante en la industria ensambladora de carrocería autoportante o monocasco debido a su automatización, su rapidez, flexibilidad de soldar piezas con forma compleja, es económico debido a que no requiere metal de aporte, además de la posibilidad de aplicar pulsos de precalentamiento y de postcalentamiento para mejorar la soldabilidad del punto de soldadura, el cual se define como la capacidad de la estructura de proporcionar protección adecuada a los pasajeros contra lesiones en caso de una colisión, principalmente depende de la integridad y rendimiento mecánico del botón de soldadura. Para extender la vida de los vehículos se producen aceros galvanizados. Sin embargo, los recubrimientos de cinc han incrementado la dificultad de soldabilidad, siendo necesarias corrientes mayores en el proceso, pues se presenta una menor resistencia en la interfase de soldadura debido a una mejor conductividad eléctrica. Este trabajo investiga el efecto del galvanizado en la disminución de la vida de los electrodos, por esta razón, se deduce una pérdida en las propiedades mecánicas en los botones de soldadura conforme se aumenta el número de puntos de soldadura. El objetivo principal del presente estudio es correlacionar el desgaste de los electrodos con las propiedades mecánicas de los botones de soldadura. El procedimiento experimental consiste en hacer 1.000 puntos de soldadura; para cada vigésimo quinto punto de soldadura a partir del primero, los cuales se examinaron por estereoscopia, ensayos de dureza, ensayos de desbotonamiento y ensayos de tensión al corte. En el desgaste del electrodo, se evaluó la cara por impresión en papel carbón, microscopia óptica y espectroscopia de rayos-X (EDX). Palabras-clave:Acero IF; Acero HSLA; Galvanizado; Soldadura de resistencia por puntos; Deterioro de electrodos; Propiedades mecánicas de los puntos de soldadura. Assessment of Impairment of the Electrodes by Increasing the Number of Pulses of the Welding Time on IF and HSLA Steels Galvanized and Involvement of the Mechanical Properties in the Nuggets WeldsAbstract: Resistance welding points, is the most important method in the assembly industry of unibody because of its automation, which is defined as the ability of the structure to provide adequate protection to passengers against injury from a collision, mainly depends on the mechanical performance of the weld nugget. To extend the life of vehicles produced coated steels. However, zinc coatings have increased the difficulty of weldability due to it being higher currents needed in the process because less resistance is ...
A study on the corrosion behavior of a series of experimental high-chromium (18.53–30.48 wt.%), high-carbon (3.82–5.17%) cast irons in NaCl-KCl (1 : 1 M) at 670°C has been evaluated by using weight loss technique and compared with a 304-type stainless steel. It was found that all castings had a higher corrosion rate than conventional 304SS and that the addition of Cr increased the degradation rate of the cast irons. Additionally, corrosion rate increased by increasing the C contents up to 4.29%, but it decreased with a further increase in its contents. Results are discussed in terms of consumption of the Cr2O3layer by the melt.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.