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27 results on '"Alejandro Daniel Basso"'

1. Effect of cast part size on the microstructure and mechanical properties of a bainitic High-Carbon and High-Silicon Cast Steel

Author

Diego Fernandino, Alejandro Daniel Basso, and Nicolás Emanuel Tenaglia

Subjects
cast part size, microsegregation, bainitic transformation, high-carbon high-silicon cast steel, mechanical properties, Mechanical engineering and machinery, TJ1-1570, Structural engineering (General), TA630-695
Abstract

This study aims at assessing the impact of casting size on the bainitic transformation, resulting microstructures, and tensile properties of a high-carbon, high-silicon steel austempered at different temperatures. The casting size was analyzed by using Y blocks of two different thicknesses. The microsegregation, a common occurrence in cast parts, leads to different bainitic transformation rates at the microscopic scale. Specifically, interdendritic areas with higher alloying contents exhibit a slower transformation, resulting in a lower degree of transformation and a higher amount of blocky austenite. Despite differences in solidification structure and distribution of alloying elements, samples obtained from the thinner and thicker Y blocks yield comparable transformation times and mechanical properties, leading to enhanced uniformity in the mechanical behavior of the entire component. However, it is essential to ensure that the bainitic transformation is completed to minimize the detrimental effects of microsegregation in these cast steel components. The presence of very fine microstructures results in ultra-high strength with low ductility cast steel.

Published
2024

2. Effect of Ti addition and cast part size on solidification structure and mechanical properties of medium carbon, low alloy cast steel

Author

Nicolás Emanuel Tenaglia, Diego Fernandino, and Alejandro Daniel Basso

Subjects
Cast steel, Solidification structure, Mechanical properties, Mechanical engineering and machinery, TJ1-1570, Structural engineering (General), TA630-695
Abstract

In this work, the effect of Ti addition and the cast part size on the solidification structure and mechanical properties of a medium carbon, low alloy cast steel was analyzed. The experimental analysis involved the design of the melts by using Thermo-Calc® software, where different amounts of Ti added to a standard chemical composition of an AISI 13XX steel were simulated. Then, the solidification macrostructure (dendritic pattern and grain size) and microstructure were characterized by using conventional and specific metallographic techniques. Finally, the mechanical behavior in terms of hardness and tensile properties were evaluated. The results show that the addition of 0.12% of Ti promotes a fine dispersion of Ti nitrides and carbides, but when the Ti concentration raises to 0.2%, the size of the Ti nitrides and carbides increases while its amount decreases. Ti nitrides and carbides particles act as nucleation sites for the precipitation of ferrite from austenite, and it was found that the addition of Ti in the higher concentrations refines the solidification macrostructure (dendritic pattern) for both cast part sizes evaluated. Regarding mechanical properties, the addition of Ti does not significantly vary the ultimate tensile strength but reduces the total elongation for cast part sizes

Published
2022

3. Effect of the Microsegregation on Martensitic and Bainitic Reactions in a High Carbon-High Silicon Cast Steel

Author

Alejandro Daniel Basso, Isaac Toda-Caraballo, Adriana Eres-Castellanos, David San-Martin, José Antonio Jimenez, and Francisca G. Caballero

Subjects
microsegregation, prior austenite grain size, bainitic transformation, high carbon-high silicon cast steel, Mining engineering. Metallurgy, TN1-997
Abstract

Casting processes show some weaknesses. A particular problem is presented when the workpiece needs to be subjected to heat treatments to achieve a desired microstructure. This problem arises from the microsegregation phenomena typically present in cast parts. The effect of the microsegregation on the martensitic and bainitic transformations has been investigated in a high carbon-high silicon cast steel, with the approximate composition Fe-0.8C-2Si-1Mn-1Cr (in wt. %), which was poured into 25 mm keel block-shaped sand molds. The microsegregation maps of Cr, Si, and Mn characterized by electron probe microanalysis (EPMA) show that interdendritic regions are enriched while dendrites are impoverished in these elements, implying that their partition coefficients are lower that the unity (k < 1). As-quenched martensitic and austempered bainitic microstructures (at 230 °C) were obtained and analyzed after applying an austenitization heat treatment at 920 °C (holding for 60 min). The thermal etching method used to reveal the prior austenite grain size showed a bimodal grain size distribution, with larger grains in the dendritic regions (≈22.4 µm) than in the interdendritic ones (≈6.4 µm). This is likely due to both the microsegregation and the presence of small undissolved cementite precipitates. Electron Backscatter Diffraction (EBSD) analysis carried out on the martensitic microstructure do not unveil any differences in misorientation distribution frequency and block size between the dendritic and interdendritic zones related to the microsegregation and bimodality of the austenite grain size. On the contrary, the bainitic transformation starts earlier (incubation time of 80 min), proceeds faster and bainitic ferrite plates are longer in the dendritic zones, were prior austenite grains are larger and impoverish in solute. The presence of these microsegregation pattern leads to the non-uniform development of the bainitic reaction in cast parts, modifying its kinetics and the resulting microstructures, which would probably have a major impact on the mechanical properties.

Published
2020
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4. Influence of Free Ferrite on the Mechanical Properties of High Strength Intercritical Austempered Ductile Iron

Author

Alejandro Daniel Basso, Martin Caldera, Nicolás Emanuel Tenaglia, Diego Fernandino, and Roberto Enrique Boeri

Subjects
Mechanics of Materials, Mechanical Engineering, heat treatments, Mechanical properties, Mechanical behavior, Ductile Iron, Free ferrite, Civil and Structural Engineering
Abstract

The first stage of this study investigates the precipitation of free ferrite from the austenite on fully austenitized ductile iron. Several sets of samples of low alloy ductile iron are fully austenitized and then cooled down to different temperatures and different times within the intercritical austenite-ferrite-graphite phase field. Based on these results, heat treatment cycles aimed at obtaining microstructures composed of free ferrite and ausferrite are carried out. Tensile, impact and toughness tests are performed to characterize the mechanical properties. The results show that, related to the high strength austempered ductile iron grades, the best combinations of properties were obtained from the mixed structures composed of 5% free ferrite and 95% ausferrite, resulting from the austempering at 280°C. These amounts of free ferrite allow obtaining an increase of the elongation (about 50%) and impact toughness (about 10%) while the tensile strength and fracture toughness decrease by about 1.5 and 15% respectively.

Published
2022

5. The driven flow vacuum infusion process: An overview and analytical design

Author

Juan Ignacio Moran, Alejandro Daniel Basso, Ariel Leonardo Stocchi, Gaston Martin Francucci, and Leandro Nicolás Ludueña

Subjects
Process modeling, Materials science, Polymers and Plastics, Mechanical Engineering, Flow (psychology), technology, industry, and agriculture, Process (computing), Mechanical engineering, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Mechanics of Materials, Materials Chemistry, Ceramics and Composites, Analytical design, Composite material, 0210 nano-technology
Abstract

This article describes a novel variant of the vacuum infusion process based on a multifunctional elastomeric reusable vacuum bag. The main innovation of this process is an elastomeric membrane having resin flow channels that can be controlled during the infusion process: they can be activated for the impregnation stage to enhance resin flow and removed during the curing stage to provide a smooth surface finish to the part. In addition, the size of the resin flow channels can be modified during the infusion providing control on the impregnation rate. This article describes the driven flow vacuum infusion (DFVI) process and presents analytical calculations regarding the effect of the geometrical design of the membrane and the processing variables on the porosity, permeability, and volume of resin transported by the flow medium. Preliminary results of unidirectional resin infusion tests comparing the DFVI process to traditional vacuum infusion and SCRIMP are also presented.

Published
2021

6. Influence of the Austempering Time on the Mechanical Properties of Carbide-Free Bainitic Cast Steels

Author

Roberto Enrique Boeri, Nicolás Emanuel Tenaglia, Juan Miguel Massone, and Alejandro Daniel Basso

Subjects
Austenite, Structural material, Materials science, 020502 materials, Metallurgy, Alloy, Metals and Alloys, 02 engineering and technology, engineering.material, Microstructure, Industrial and Manufacturing Engineering, 020501 mining & metallurgy, Carbide, 0205 materials engineering, Mechanics of Materials, Ultimate tensile strength, Materials Chemistry, engineering, Ductility, Austempering
Abstract

Three medium-carbon, high-silicon cast steels with different alloy contents were austempered at 330 °C for different holding times in order to obtain carbide-free bainitic microstructures. Aiming at evaluating the influence of holding time and microstructural features on strength and ductility, tensile properties were measured for each steel at selected austempering times. The results obtained indicate that it is possible to adjust holding time in order to obtain the best strength/ductility combination at determined austempering temperature. Moreover, it has been shown that the mechanical stability of retained austenite is the key factor in controlling tensile performance. Short austempering times result in low carbon enrichment of the austenite (low stability) and promote higher ultimate tensile strength and lower ductility. For longer austempering times, steels present a slight decrease in ultimate tensile strength but a marked increase in ductility. This work shows that it is possible to obtain cast steels with ultimate tensile strength of 1682 MPa, yield strength of 1493 MPa and total elongation of 12.5% by means of bainitic reaction. This strength/ductility combination and others reported in this study are remarkable for cast steels.

Published
2020

7. Influence of silicon content on mechanical properties of IADI obtained from as cast microstructures

Author

Alejandro Daniel Basso, Roberto Enrique Boeri, Diego Iván Pedro, and Nicolás Emanuel Tenaglia

Subjects
010302 applied physics, Materials science, Silicon, Mechanical Engineering, Metallurgy, 0211 other engineering and technologies, Metals and Alloys, chemistry.chemical_element, 02 engineering and technology, Microstructure, 01 natural sciences, chemistry, Mechanics of Materials, 0103 physical sciences, Austempering, 021102 mining & metallurgy
Abstract

This study investigates the mechanical properties of Intercritically Austempered Ductile Iron (IADI) obtained after the heat treatment of ductile irons having different as-cast microstructures and ...

Published
2020

8. Mechanical properties of a carbide-free bainitic cast steel with dispersed free ferrite

Author

Roberto Enrique Boeri, Alejandro Daniel Basso, and Nicolás Emanuel Tenaglia

Subjects
010302 applied physics, Materials science, Silicon, Bainite, Mechanical Engineering, Metallurgy, chemistry.chemical_element, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, 01 natural sciences, Carbide, chemistry, Mechanics of Materials, Ferrite (iron), 0103 physical sciences, General Materials Science, 0210 nano-technology
Abstract

A high silicon, medium carbon cast steel was designed and heat-treated in order to develop microstructures composed of carbide-free bainite and small amounts of free ferrite, with the aim of obtain...

Published
2019

9. Effect of the Microsegregation on Martensitic and Bainitic Reactions in a High Carbon‐High Silicon Cast Steel

Author

José Antonio Jiménez, David San-Martin, Isaac Toda-Caraballo, Alejandro Daniel Basso, Francisca García Caballero, Adriana Eres-Castellanos, Ministerio de Economía y Competitividad (España), Comunidad de Madrid, and Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina)

Subjects
lcsh:TN1-997, prior austenite grain size, Materials science, Misorientation, microsegregation, High carbon-high silicon cast steel, PRIOR AUSTENITE GRAIN SIZE, 02 engineering and technology, Electron microprobe, 01 natural sciences, BAINITIC TRANSFORMATION, bainitic transformation, chemistry.chemical_compound, Ferrite (iron), 0103 physical sciences, General Materials Science, lcsh:Mining engineering. Metallurgy, MICROSEGREGATION, 010302 applied physics, Austenite, Cementite, high carbon‐high silicon cast steel, Metallurgy, Metals and Alloys, 021001 nanoscience & nanotechnology, Microstructure, purl.org/becyt/ford/2 [https], chemistry, Martensite, HIGH CARBON-HIGH SILICON CAST STEEL, purl.org/becyt/ford/2.5 [https], 0210 nano-technology, Electron backscatter diffraction
Abstract

Casting processes show some weaknesses. A particular problem is presented when the workpiece needs to be subjected to heat treatments to achieve a desired microstructure. This problem arises from the microsegregation phenomena typically present in cast parts. The effect of the microsegregation on the martensitic and bainitic transformations has been investigated in a high carbon-high silicon cast steel, with the approximate composition Fe-0.8C-2Si-1Mn-1Cr (in wt. %), which was poured into 25 mm keel block-shaped sand molds. The microsegregation maps of Cr, Si, and Mn characterized by electron probe microanalysis (EPMA) show that interdendritic regions are enriched while dendrites are impoverished in these elements, implying that their partition coefficients are lower that the unity (k &lt, 1). As-quenched martensitic and austempered bainitic microstructures (at 230 C) were obtained and analyzed after applying an austenitization heat treatment at 920 C (holding for 60 min). The thermal etching method used to reveal the prior austenite grain size showed a bimodal grain size distribution, with larger grains in the dendritic regions (&asymp, 22.4&micro, m) than in the interdendritic ones (&asymp, 6.4 &micro, m). This is likely due to both the microsegregation and the presence of small undissolved cementite precipitates. Electron Backscatter Diffraction (EBSD) analysis carried out on the martensitic microstructure do not unveil any differences in misorientation distribution frequency and block size between the dendritic and interdendritic zones related to the microsegregation and bimodality of the austenite grain size. On the contrary, the bainitic transformation starts earlier (incubation time of 80 min), proceeds faster and bainitic ferrite plates are longer in the dendritic zones, were prior austenite grains are larger and impoverish in solute. The presence of these microsegregation pattern leads to the non-uniform development of the bainitic reaction in cast parts, modifying its kinetics and the resulting microstructures, which would probably have a major impact on the mechanical properties.

Published
2020
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10. Study of dimensional change of high-silicon ductile iron with ADI and Dual-Phase-ADI microstructures starting from different as-cast structures

Author

Amadeo Daniel Sosa, María Dolores Echeverría, Ana Lucía Dai Pra, and Alejandro Daniel Basso

Subjects
Work (thermodynamics), Materials science, Silicon, Ciencias Físicas, chemistry.chemical_element, 02 engineering and technology, DIMENSIONAL CHANGE, engineering.material, Otras Ciencias Físicas, 020501 mining & metallurgy, Phase (matter), Ductile iron, DUAL-PHASE-ADI, HIGH SILICON DUCTILE IRON, Mechanical Engineering, Metallurgy, Metals and Alloys, Microstructure, FUZZY MODELING, 0205 materials engineering, chemistry, Mechanics of Materials, engineering, ADI, Dispersion (chemistry), CIENCIAS NATURALES Y EXACTAS
Abstract

In this work the percent dimensional change (DC%) and its dispersion in high silicon Ductile Iron with ADI and Dual-Phase-ADI structures obtained through heat treatment starting from different as-cast microstructures, was studied. Specimens were obtained from three different melts with Si content ranging from 3.1 to 4.2%. Dual-Phase-ADI structures were obtained using special heat treatment, starting from as-cast structures. Regarding dimensional change, DC% in ADI and Dual-Phase-ADI decrease as Si% and the proportion of ferrite phase in as-cast specimens increased. On the other hand, DC% increased with austenitizing temperature and ausferrite content in the final microstructure. A fuzzy model to predict DC% in ADI parts was adapted to include DC% prediction in Dual-Phase-ADI. The fuzzy model allowed to predict the DC% for ADI and Dual-Phase-ADI parts with an root mean square

Published
2017

11. Study of austempering kinetics of high silicon bainitic cast steels

Author

Roberto Enrique Boeri, Juan Miguel Massone, Alejandro Daniel Basso, A.L. Rivas, and Nicolás Emanuel Tenaglia

Subjects
Materials science, Silicon, Físico-Química, Ciencia de los Polímeros, Electroquímica, Kinetics, 0211 other engineering and technologies, chemistry.chemical_element, 02 engineering and technology, INGENIERÍAS Y TECNOLOGÍAS, 01 natural sciences, Transformation (music), Ingeniería de los Materiales, 0103 physical sciences, Chemical composition, 021102 mining & metallurgy, 010302 applied physics, CARBIDE FREE BAINITE, MICROSEGREGATION, Mechanical Engineering, Metallurgy, CAST STEEL, Metals and Alloys, Ciencias Químicas, chemistry, Mechanics of Materials, Austempering, CIENCIAS NATURALES Y EXACTAS
Abstract

This study investigates the effect of chemical composition and microsegregation on the bainitic transformation of high Si cast steels at two different austempering temperatures. The advance of the bainite precipitation as a function of time and temperature was monitored through measurements of the amount of retained austenite by X-ray diffraction, the evolution of hardness and microstructural characterization. The results showed that the bainitic transformation starts preferentially at zones with lower contents of alloying elements but later covers the entire matrix. The austempering heat treatments resulted in an apparently homogeneous bainitic microstructure throughout the entire matrix after a short period of time. The results encourage the continuation of the development of high Si steels suitable to produce carbide-free austempered cast parts. Fil: Tenaglia, Nicolás Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Rivas, Ana Luisa. Universidad Simon Bolivar; Venezuela Fil: Boeri, Roberto Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Massone, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Basso, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina

Published
2019

12. Rolling contact fatigue behavior of dual-phase austempered ductile iron

Author

Alejandro Daniel Basso, Diego Alejandro Colombo, and Ricardo Dommarco

Subjects
Washer, Materials science, 02 engineering and technology, INGENIERÍAS Y TECNOLOGÍAS, 0203 mechanical engineering, Residual stress, Phase (matter), Ferrite (iron), Ingeniería de los Materiales, Materials Chemistry, DUAL-PHASE AUSTEMPERED DUCTILE IRON, Composite material, ROLLING CONTACT FATIGUE, SURFACE PROPERTIES, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Hardness, Surfaces, Coatings and Films, Grinding, 020303 mechanical engineering & transports, purl.org/becyt/ford/2 [https], Mechanics of Materials, GRINDING, 0210 nano-technology, purl.org/becyt/ford/2.5 [https], Austempering, Surface finishing
Abstract

In this work the rolling contact fatigue (RCF) behavior of dual-phase austempered ductile iron (ADI) was studied and compared to that of conventional ADI. The effect of surface finishing (manual vs. automatic grinding) on the surface properties and RCF endurance was also analyzed. RCF tests were performed in a flat washer type testing rig and using lubricated pure rolling conditions. RCF tests results were analyzed using the two-parameter Weibull distribution and the Weibayes method. The results indicated that the dual-phase ADI metal matrix was composed of 94% ausferrite and 6% free allotriomorphic ferrite, approximately. The hardness of conventional ADI was higher than that of dual-phase ADI. The residual stresses were compressive in all the cases with similar average values for ADI and dual-phase ADI. Relative to manual grinding, the automatic process increased slightly the surface hardness and reduced by around a 50% the residual stresses of both ADI and dual-phase ADI. Regarding RCF, failures were characterized by the typical concentrated damage in the form of spalls. No significant differences in the RCF endurance of ADI and dual-phase ADI were observed. No differences in the RCF endurance attributable to the surface finishing method were identified in the current tests. Fil: Colombo, Diego Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Dommarco, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Basso, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina

Published
2019

13. Assessment of the austemperability of high-silicon cast steels through Jominy hardenability tests

Author

Nicolás Emanuel Tenaglia, Roberto Enrique Boeri, Juan Miguel Massone, and Alejandro Daniel Basso

Subjects
Materials science, Recubrimientos y Películas, Silicon, Alloy, chemistry.chemical_element, 02 engineering and technology, CARBIDE-FREE BAINITE, INGENIERÍAS Y TECNOLOGÍAS, engineering.material, HARDENABILITY, 01 natural sciences, CAST STEELS, Ingeniería de los Materiales, 0103 physical sciences, General Materials Science, Hardenability, 010302 applied physics, Mechanical Engineering, Round bar, Metallurgy, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, Salt bath, HIGH SILICON, chemistry, Mechanics of Materials, engineering, 0210 nano-technology, Austempering, AUSTEMPERABILITY
Abstract

The austemperability of seven high silicon cast steels with different alloy contents was characteri sed. The maximum round bar diameter that can be fully austempered changed from about 10 mm for an unalloyed steel to more than 70 mm for a low-alloy steel. The austemperability was calculated by applying a procedure based on a standard Jominy test and the characterisation of the microstructure along the Jominy sample. The method, which was validated experimentally, creates a relatively simple procedure to measure austemperability. Processing factors such as the ability of the salt bath to extract heat and the austempering temperature are accounted for the method. The metallographic study revealed the influence of microsegregation on hardenability, which is particularly important for cast steels. Fil: Tenaglia, Nicolás Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Boeri, Roberto Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Massone, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Basso, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina

Published
2018

14. Effect of Microsegregation and Bainitic Reaction Temperature on the Microstructure and Mechanical Properties of a High-Carbon and High-Silicon Cast Steel

Author

José Antonio Jiménez, Francisca García Caballero, Nicolás Emanuel Tenaglia, Alejandro Daniel Basso, David San-Martin, Adriana Eres-Castellanos, CSIC - Centro Nacional de Investigaciones Metalúrgicas (CENIM), Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina), Agencia Nacional de Promoción Científica y Tecnológica (Argentina), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), and Comunidad de Madrid

Subjects
lcsh:TN1-997, 010302 applied physics, Austenite, Materials science, Scanning electron microscope, Metallurgy, Metals and Alloys, Mechanical properties, 02 engineering and technology, 021001 nanoscience & nanotechnology, Microstructure, 01 natural sciences, Casting, Bainitic transformation, Martensite, 0103 physical sciences, Ultimate tensile strength, Microsegregation, High-carbon high-silicon cast steel, General Materials Science, 0210 nano-technology, Ductility, lcsh:Mining engineering. Metallurgy, Electron backscatter diffraction
Abstract

Bainitic microstructures obtained in high-carbon (HC) and high-silicon (HSi) steels are currently of great interest. Microstructural evolution and the bainitic transformation kinetics of a high-carbon and high-silicon cast steel held at 280, 330, and 380 &deg, C was analyzed using dilatometry, X-ray diffraction, optical and scanning electron microscopy, and electron backscatter diffraction (EBSD). It is shown that the heterogeneous distribution of silicon (Si), manganese (Mn), and chromium (Cr) associated to microsegregation during casting has a great impact on the final microstructure. The transformation starts in the dendritic zones where there is a lower Mn concentration and then expands to the interdendritic ones. As Mn reduces the carbon activity, the interdendritic areas with a higher Mn concentration are enriched with carbon (C), and thus, these zones contain a greater amount of retained austenite plus martensite, resulting in a heterogeneous microstructure. Higher transformation temperatures promote higher amounts of residual austenite with poor thermal/mechanical stability and the presence of martensite in the final microstructure, which has a detrimental effect on the mechanical properties. Tensile tests revealed that the ultra-fine microstructure developed by the transformation at 280 &deg, C promotes very high values of both tensile and yield stress (&asymp, 1.8 GPa and 1.6 GPa, respectively), but limited ductility (&asymp, 2%).

Published
2021

15. Macro and microstructural characterisation of high Si cast steels–Study of microsegregation patterns

Author

Roberto Enrique Boeri, Juan Miguel Massone, Nicolás Emanuel Tenaglia, and Alejandro Daniel Basso

Subjects
Cast steels, Materials science, Peritectic, Bainite, Otras Ingeniería de los Materiales, 02 engineering and technology, INGENIERÍAS Y TECNOLOGÍAS, 020501 mining & metallurgy, Solidification, Ingeniería de los Materiales, Microsegregation, Macro, Ingeniería Mecánica, Precipitation (chemistry), Mechanical Engineering, Metallurgy, Metals and Alloys, High silicon, 021001 nanoscience & nanotechnology, Microstructure, Partition coefficient, 0205 materials engineering, Mechanics of Materials, Reagent, 0210 nano-technology, Austempering, Otras Ingeniería Mecánica
Abstract

In this study the as-cast macro and microstructures of medium C – high Si cast steels of three different levels of alloying are characterised. The application of a colour-etching reagent sensitive to Si segregation effectively revealed the solidification macrostructure, showing that the patterns of macrostructure and microsegregation are governed by the initial precipitation of δ-ferrite dendrites. A study of microsegregation carried out using advanced EDS techniques showed that, for the studied chemical compositions, Si, Mn, Cr, Ni, Mo and Al tend to concentrate at the last liquid to solidify. Accordingly, effective partition coefficients of values below unity were calculated for all alloying elements tested. It was verified that the minimum local Si contents measured on the steels investigated were greater than 1.7%, value above the minimum value (1.5%) necessary to obtain carbide-free bainite after austempering. Fil: Tenaglia, Nicolás Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Boeri, Roberto Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Basso, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Massone, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina

Published
2016

16. Analysis of mechanical properties and its associated fracture surfaces in dual-phase austempered ductile iron

Author

Alejandro Daniel Basso, R. Martínez, and Jorge Antonio Sikora

Subjects
Matrix microstructure, Materials science, Mechanics of Materials, Mechanical Engineering, Metallurgy, General Materials Science, Humanities
Abstract

Fil: Basso, Alejandro Daniel. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mar del Plata. Instituto de Investigacion en Ciencia y Tecnologia de Materiales (i); Argentina

Published
2013

17. Effect of the ratio Mo/Cr in the precipitation and distribution of carbides in alloyed nodular iron

Author

H.D. Rivero, J. Sicora, E. Cándido Atlatenco, Alejandro Daniel Basso, and José .A. García

Subjects
Materials science, Volume (thermodynamics), Precipitation (chemistry), Metallurgy, Alloy, Volume fraction, engineering, Digital analysis, Fraction (chemistry), engineering.material, Casting, Carbide
Abstract

This investigation deals with the effect of 2/0, 1/1 and 1/0.5 Cr/Mo ratios on the local fraction, distribution and the comparative size of carbides precipitated in cast nodular iron. “Y” block castings with a thickness of 1.5 cm are cast in green sand molds. Two samples are cut from each casting, one located on the center and another on the wall. The carbide volume fraction is evaluated by a digital analysis system. Each sample is analyzed in three zones: bottom, middle and top. Carbide mappings are generated according to the average local carbide fraction in order to get the distribution of carbides on the casting. Results show that higher volume fractions of carbides precipitate for the ratio 2/0 of Cr/Mo with values between 28.5 and 19.5%. The lowest fraction of carbides is presented in nodular iron alloyed with a Cr/Mo ratio of 1/1 between 6.5 and 4.6%. Also a very heterogeneous distribution of the carbides is observed in the three alloys and massive carbides are observed in the last freezing zone of the castings.

Published
2012

18. High Silicon Ductile Iron: Possible Uses in the Production of Parts with ^|^ldquo;Dual Phase ADI^|^rdquo; Microstructure

Author

Alejandro Daniel Basso, M. Caldera, Graciela Leonor Rivera, and Jorge Antonio Sikora

Subjects
Materials science, Silicon, chemistry, Mechanics of Materials, Mechanical Engineering, Ductile iron, Metallurgy, Materials Chemistry, Metals and Alloys, engineering, chemistry.chemical_element, engineering.material, Microstructure
Abstract

Fil: Basso, Alejandro Daniel. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnologia de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingenieria. Instituto de Investigaciones en Ciencia y Tecnologia de Materiales; Argentina

Published
2012

19. Effect of cooling rate on the formation and distribution of carbides in nodular iron alloyed with Cr

Author

Jorge. Sicora, José .A. García, Alejandro Daniel Basso, Ramses Zenil, and Gerardo Ruiz

Subjects
Materials science, Cooling rate, chemistry, Metallurgy, chemistry.chemical_element, Carbon, Casting, Carbide
Abstract

This investigation deals with the effect of cooling rate on the formation of carbide nodular iron alloyed with 2.2 % Cr and equivalent carbon near 4.3%. In the experimental stage three Y-blocks of 1.5, 3 and 5.5 cm in thickness are poured in green sand molds. Castings are sectioned in two positions (wall and center samples) in order to determine the characteristics of the precipitated carbides (fraction, distribution and relative size) from surface to center and from the bottom to the top of the castings applying quantitative analysis of images. The obtained results show the presence of carbides in all of the castings. Finer carbides are obtained in the thinnest casting but with a high variation between the samples located in the wall and center. All castings present massive carbides in the last freezing zone (LFZ). Therefore the cooling rate associated with casting thick has an important effect on the fraction and distribution of carbides.

Published
2012

20. Characteristics of the Transformations Occurring within the Intercritical Interval of Ductile Iron

Author

Jorge Antonio Sikora, R. Martínez, and Alejandro Daniel Basso

Subjects
DUCTILE IRON, Austenite, Materials science, Físico-Química, Ciencia de los Polímeros, Electroquímica, Mechanical Engineering, Metallurgy, Ciencias Químicas, Nucleation, PHASE TRANSFORMATION, CAST IRON, INGENIERÍAS Y TECNOLOGÍAS, engineering.material, Microstructure, Isothermal process, DUAL PHASE ADI, INTERCRITICAL INTERVAL, Mechanics of Materials, Ingeniería de los Materiales, Ferrite (iron), Ductile iron, engineering, General Materials Science, Cast iron, Austempering, CIENCIAS NATURALES Y EXACTAS
Abstract

Austempered Ductile Iron (ADI) and fully ferritic ductile iron are frequently used to produce safety parts. A new kind of ductile iron (DI), usually referred to as “dual phase ADI” is currently under development. The matrix of this new material is composed of ausferrite (regular ADI microstructure) and free (or allotriomorphic) ferrite. This combined microstructure is obtained by subjecting DI to heat treatments comprising incomplete austenitization stages at temperatures within the intercritical interval (three phase α-γ-Gr field of the Fe-C-Si stable diagram) followed by an austempering step in a salt bath in order to transform the austenite into ausferrite. This work describes some alternatives to control morphologies and amounts of phases present in the final microstructure. A revision of the results obtained on this matter by the authors as well as by other researchers is also provided. A ductile iron melt was produced in a metal casting laboratory. Samples were heat treated following different thermal cycles to obtain a wide range of duplex microstructures, containing different amounts and morphologies of microconstituents. The results account for the fact that the transformations occurring within the α-γ-Gr field are strongly affected by the chemical composition, previous matrix, and holding times. The role played by the microsegregation and availability of sites for heterogeneous nucleation is also worth noticing. Starting from ferritic matrices and holding the samples at constant temperature within the intercritical interval, austenite nucleation and growth take place mainly in the last to freeze zones. On the other hand, when starting from fully recrystallised austenitic matrices, allotriomorphic ferrite can precipitate during the isothermal holding within the intercritical interval at the austenite grains boundaries forming a continuous net. The kinetics of the γ α transformation is notoriously slower than the α γ one. The influence that part size exerts on the final microstructure is also analyzed. Fil: Basso, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina Fil: Martinez, Ricardo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina Fil: Sikora, Jorge Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina

Published
2010

21. Experimental and numerical assessment of fracture toughness of dual-phase austempered ductile iron

Author

Alejandro Daniel Basso, Adrián P. Cisilino, Jorge Antonio Sikora, and R. Martínez

Subjects
Materials science, Mechanical Engineering, Metallurgy, Fracture mechanics, engineering.material, Microstructure, Finite element method, Brittleness, Fracture toughness, Mechanics of Materials, Ductile iron, Ferrite (iron), engineering, General Materials Science, Composite material, Austempering
Abstract

The effects of the microstructure topology on the fracture toughness of dual-phase austempered ductile iron are studied in this paper by means of finite element modelling and experimental testing. To this end, specimens with matrix microstructures ranging from fully ferrite to fully ausferrite were studied and the preferential zones and phases for crack propagation were identified in every case. The effectiveness of the ausferrite phase as a reinforcement of the ferritic matrix via the encapsulation of the brittle and weak last-to-freeze (LTF) zones was confirmed. The toughening mechanism is consequence of the increment in the crack path longitude as it avoids the encapsulated LTF zones. Besides, the presence of small pools of allotriomorphic ferrite increase the crack propagation resistance of the ausferrite-ferrite matrices.

Published
2009

22. Influence of austenitising and austempering temperatures on microstructure and properties of dual phase ADI

Author

Jorge Antonio Sikora, Alejandro Daniel Basso, and R. Martínez

Subjects
Toughness, Materials science, Mechanical Engineering, Metallurgy, engineering.material, Condensed Matter Physics, Microstructure, Fracture toughness, Mechanics of Materials, Ferrite (iron), Ductile iron, Crack size, engineering, General Materials Science, Austempering
Abstract

The present work describes studies about the influence of processing variables on the microstructure and properties of dual phase austempered ductile iron (ADI). The upper and lower critical temperatures of conventional ductile iron melt were determined. Heat treatments involving austenitising within the intercritical interval, followed by austempering, allowed microstructures to be obtained composed of different combinations of free ferrite and ausferrite. Mechanical and fracture toughness tests performed on samples with mixed structures showed interesting combinations of strength and toughness, in comparison with fully ferritic and fully ausferritic matrices, particularly when austempering was carried out at 350°C. The results of the critical crack size, expressed by the relationship (K IC/σYS)2, which indicates the relative toughness of the material, showed the best values for ferritic matrices with ∼20% ausferrite. This effect is attributed to the location of the ausferrite in the last to fre...

Published
2007

23. Wear behaviour of carbidic ductile iron with different matrices and carbide distribution

Author

Alejandro Daniel Basso, Ricardo Dommarco, and Sebastian Laino

Subjects
METALLURGICAL ANALYSIS, Materials science, XRD, Mechanical Engineering, Físico-Química, Ciencia de los Polímeros, Electroquímica, Metallurgy, CARBIDES, Ciencias Químicas, Surfaces and Interfaces, INGENIERÍAS Y TECNOLOGÍAS, engineering.material, Surfaces, Coatings and Films, Carbide, Mechanics of Materials, Ductile iron, Ingeniería de los Materiales, engineering, IRONS, CIENCIAS NATURALES Y EXACTAS, ABRASIVE WEAR
Abstract

Just like other properties, wear resistance is entirely dependent on materials microstructure, which, in turn, is related to the chemical composition and solidification rate that controls phases type, size, amount and dispersion. Depending on the tribosystem, the abrasive wear resistance of ductile iron (DI) may be improved by heat treatment as well as by reinforcing the matrix with hard particles like carbides, typically obtained by alloying with elements such as chromium. The solidification rate mainly depends on wall thickness and mould characteristics. In ductile iron, the solidification rate affects microstructural characteristics, such as nodule size, nodule count, carbide size and distribution and matrix refinement, also including the last to freeze (LTF) amount, size and distribution. This study evaluates the influence of the wall thickness (12.5, 25, 50 and 75 mm) on the abrasion resistance and impact toughness of DI with different matrices reinforced with carbides. Carbidic structures were obtained by alloying the melt with Cr; and the different types of matrices such us pearlitic, martensitic and ausferritc (CADI) were obtained under as cast conditions or by heat treatment. The results reflect the influence of cooling rate on the microstructural characteristics and its relationship with the mechanical properties, particularly the abrasive wear resistance. It was demonstrated that, under the present experimental conditions, the highest carbide content and matrix hardness, obtained from the 12.5 mm thick part with a martensitic matrix, resulted in the highest abrasion resistance. Fil: Basso, Alejandro Daniel. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina Fil: Laino, Sebastian. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina Fil: Dommarco, Ricardo. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina

Published
2013

24. Influence of chemical composition and holding time on austenite (γ) → ferrite (α) transformation in ductile iron occurring within the intercritical interval

Author

Alejandro Daniel Basso, R. Martínez, and Jorge Antonio Sikora

Subjects
Austenite, DUCTILE IRON, Materials science, Mechanical Engineering, Ciencias Físicas, Beta ferrite, Metallurgy, Alloy, Metals and Alloys, Nucleation, DUAL-PHASE ADI, engineering.material, MATRIX MICROSTRUCTURE, Mechanics of Materials, Ferrite (iron), Ductile iron, Materials Chemistry, engineering, Grain boundary, ALLOTRIOMORPHIC FERRITE, Cast iron, CIENCIAS NATURALES Y EXACTAS, Física de los Materiales Condensados
Abstract

This work focuses on the influence exerted by the chemical composition on the characteristics of the γ → α reaction occurring within the intercritical interval of the Fe-C-Si diagram, in order to produce a new "dual phase ADI" variant. Three ductile iron melts with different chemical compositions were used and several thermal cycles were performed. The results show a strong dependence between the alloy composition and the characteristics of the γ → α reaction, affecting the amount as well as the morphology of the precipitated allotriomorphic ferrite. Low alloy content promotes ferritic nucleation around graphite nodules and fast growth. Moreover, when the alloy content increases, the ferrite nucleates preferentially at the grain boundaries of the recrystallized austenite, and grows very slowly forming a continuous net. This novel microstructure is expected to enhance the mechanical properties of ductile cast iron. © 2011 Elsevier B.V. Fil: Basso, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Martinez, Ricardo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Sikora, Jorge Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina

Published
2011

25. Development and characterization of a new type of ductile iron with a novel multi-phase microstructure

Author

Mayra Lagarde, Jorge Antonio Sikora, Alejandro Daniel Basso, and Ricardo Dommarco

Subjects
Materials science, Multi phase, Mechanical Engineering, Ausferrite, Metallurgy, Otras Ingeniería de los Materiales, Metals and Alloys, Ferrite, INGENIERÍAS Y TECNOLOGÍAS, Multi-Phase Microstructure, purl.org/becyt/ford/2 [https], Mechanics of Materials, Ingeniería de los Materiales, Materials Chemistry, Adi, Carbides, purl.org/becyt/ford/2.5 [https], Humanities, Ductile Iron
Abstract

Over the last few years two new types of Ductile Iron (DI) have been developed based on Austempered DI (ADI), called Dual Phase ADI and Carbidic ADI (CADI), respectively. In the light of the experience acquired when studying these DI variants, the authors found motivating the possibility of obtaining a new type of multi-phase DI (MPDI), combining their main microstructural characteristics. A DI melt alloyed with 2%Cr, exhibiting free carbides and a pearlitic matrix in its as-cast condition, was used. The upper (UCT) and lower (LCT) critical temperatures of the Fe–C–Si equilibrium diagram region, where ferrite (α), austenite (γ) and graphite (Gr) coexist (called “intercritical interval”), were determined by heat treatment and microstructural analysis on samples previously annealed. Carbides stability was studied, and its dissolution was found to be negligible. It was possible to obtain free or allotriomorphic ferrite and austenite by isothermal austenitizing at temperatures within the intercritical interval, and then transform the remaining austenite into ausferrite after an austempering step. Therefore, multi- phase microstructures composed of graphite nodules, free carbides, free ferrite and ausferrite were obtained. The possibility of obtaining MPDI directly from the as-cast structure was also analyzed, and it was found that very similar microstructures to those previously annealed can be obtained by austenitizing samples at the same temperature range. These results proved that the pearlite → austenite transformation kinetics is rapid, as it took only one hour for the transformation to occur. Fil: Lagarde, Mayra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones En Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones En Ciencia y Tecnología de Materiales; Argentina Fil: Basso, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones En Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones En Ciencia y Tecnología de Materiales; Argentina Fil: Dommarco, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones En Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones En Ciencia y Tecnología de Materiales; Argentina Fil: Sikora, Jorge Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones En Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones En Ciencia y Tecnología de Materiales; Argentina

Published
2010

26. Mechanical characterization of dual phase austempered ductile iron

Author

Jorge Antonio Sikora, Martin Caldera, Mirco Daniel Chapetti, and Alejandro Daniel Basso

Subjects
Materials science, Otras Ingeniería de los Materiales, INGENIERÍAS Y TECNOLOGÍAS, engineering.material, Fracture toughness, Ingeniería de los Materiales, Ductile iron, Ferrite (iron), Ultimate tensile strength, Materials Chemistry, FRACTURE TOUGHNESS, Composite material, DUCTILE IRON, ENDURANCE LIMIT, Mechanical Engineering, Metallurgy, Metals and Alloys, Microstructure, Fatigue limit, DUAL PHASE ADI, purl.org/becyt/ford/2 [https], Mechanics of Materials, engineering, Elongation, MICROSTRUCTURE, purl.org/becyt/ford/2.5 [https], Austempering, MECHANICAL PROPERTIES
Abstract

The fatigue behavior and mechanical properties of Dual Phase Austempered Ductile Iron (Dual Phase ADI) containing 20, 50, and 70% ausferrite were studied and compared to ductile irons with fully ferritic and ADI matrices. The results indicate that as the amount of ausferrite increases, tensile strength, yield stress, fracture toughness and fatigue resistance increase significantly, if compared to fully ferritc ductile irons. The elongation diminishes; nevertheless all Dual Phase ADI matrices have a deformation until failure that satis-fies the minimum value required by ASTM A 536 standard for ferritic ductile iron. All tensile properties of the samples containing 20% ausferrite, located in the last to freeze zones, increased; and so did the endurance limit about 25%. The fact that Dual Phase ADI could offer a wide range of mechanical properties, as a function of the relative percentage of free ferrite and ausferrite, led to the assumption that it could be used in safety parts, thereby replacing ductile irons with other matrices. Fil: Basso, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Caldera, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Chapetti, Mirco Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Sikora, Jorge Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina

Published
2010

27. Influence of section size on dual phase ADI microstructure and properties: Comparison with fully ferritic and fully ausferritic matrices

Author

Jorge Antonio Sikora, R. Martínez, and Alejandro Daniel Basso

Subjects
DUCTILE IRON, Work (thermodynamics), Materials science, Mechanical Engineering, Metallurgy, Otras Ingeniería de los Materiales, SECTION SIZE, INGENIERÍAS Y TECNOLOGÍAS, engineering.material, Condensed Matter Physics, Microstructure, PROPERTIES, Section (fiber bundle), Fracture toughness, Cooling rate, DUAL PHASE ADI, Mechanics of Materials, Ductile iron, Phase (matter), Ingeniería de los Materiales, engineering, General Materials Science, Elongation, MICROSTRUCTURES
Abstract

The present work aims to evaluate and compare the influence that section size has on the microstructure and properties of fully ferritic, fully ausferritic and dual phase ADI matrices. Samples taken from 'Y' blocks of 25, 50 and 75 mm thickness were used to perform metallographic studies and mechanical tests. Cooling rate differences arising from changes in section size promote different microsegregation characteristics affecting solid state transformations and, consequently, the final microstructure and properties. When the section size increases, some properties decrease. The strongest deleterious effect was ascribed to the elongation and impact of ADI samples, where drops of nearly 40% were reached when specimens taken from the thinnest 'Y' blocks were compared to those taken from the thickest ones. Regarding fracture toughness, ferritic matrices exhibited the most noticeable detrimental effect. Dual phase ADI samples, on the other hand, presented the least deleterious section size effect on all the studied properties. © 2009 Institute of Materials, Minerals and Mining. Fil: Basso, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Martinez, Ricardo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Sikora, Jorge Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina

Published
2009

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