Austempering Kinetics in Cu-Mo Alloyed Ductile Iron: A Dilatometric Study

Cisneros-Guerrero, M.M; Campos-Cambranis, R.E.; Castro‐Román, M.; Pérez-López, María Juana

doi:10.4028/www.scientific.net/amr.4-5.415

Cited by 6 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After 60 min a decrease in γ hC is noticed for temperatures of 290 and 320 • C, and for 350 • C this reduction takes place until 120 min, while at 380 • C γ hC content stabilizes. This behavior derives from transformation kinetics, i.e., as the T A diminishes, the ausferritic transformation reaction proceeds faster, consuming γ hC for α ac formation and at possible carbide precipitation [54][55][56]. Figure 7b shows hardness values decreasing as T A increases, consequence of a higher amount of γ hC and the change of ausferritic morphology in the metal matrix.…”

Section: Assumption 1 the Probability Distribution (𝑆𝑡𝑢𝑑𝑒𝑛𝑡'S T) Of A...mentioning

confidence: 99%

Statistical Data-Driven Model for Hardness Prediction in Austempered Ductile Irons

Rodríguez-Rosales

Montes-González

Gómez-Casas

et al. 2022

Metals

View full text Add to dashboard Cite

This research evaluates the effect of temperature and time austempering on microstructural characteristics and hardness of ductile iron, validating the results by means of a statistical method for hardness prediction. Ductile iron was subjected to austenitization at 950 °C for 120 min and then to austempering heat treatment in a salt bath at temperatures of 290, 320, 350 and 380 °C for 30, 60, 90 and 120 min. By increasing austempering temperature, a higher content of carbon-rich austenite was obtained, and the morphology of the thin acicular ferrite needles produced at 290 °C turned completely feathery at 350 and 380 °C. A thickening of acicular ferrite needles was also observed as austempering time increased. An inversely proportional behavior of hardness values was thus obtained, which was validated through data analysis, statistical tools and a regression model taking temperature and time austempering as input variables and hardness as the output variable, which achieved a correlation among variables of about 97%. The proposal of a mathematical model for the prediction of hardness in austempered ductile iron represents a numerical approximation which validates the experimental results at 95.20%.

show abstract

Section: Assumption 1 the Probability Distribution (𝑆𝑡𝑢𝑑𝑒𝑛𝑡'S T) Of A...mentioning

confidence: 99%

Statistical Data-Driven Model for Hardness Prediction in Austempered Ductile Irons

Rodríguez-Rosales

Montes-González

Gómez-Casas

et al. 2022

Metals

View full text Add to dashboard Cite

show abstract

“…Due to its production cost, weight saving, and favorable strength indices related to its density, it can be successfully used for the production of modern and light cast components for operation within a wide temperature range. [1][2][3][4] From the viewpoint of material selection, ADI is, therefore, the most cost-effective solution in many applications, including automotive and light/heavy trucks, construction, railroads, agriculture, and mining equipment. [5][6][7] ADI belongs to the group of high-quality ductile iron that is subjected to heat treatment, i.e., austenitization and austempering.…”

Section: Introductionmentioning

confidence: 99%

Structure Homogeneity and Thermal Stability of Austempered Ductile Iron

Górny

Gondek

Tyrała

et al. 2021

Metall Mater Trans A

View full text Add to dashboard Cite

Solid-state transformation during heat treatment is of great practical importance because it significantly affects the final structure, properties, and thermal stability of cast components. The present study highlights the issue of structure formation and its effect on the thermal stability of high-quality cast iron, namely, austempered ductile iron (ADI). In this study, experiments were carried out for castings with a 25-mm-walled thickness and under variable heat treatment conditions, i.e., austenitization and austempering within ranges of 850 °C to 925 °C and 250 °C to 380 °C, respectively. The X-ray diffraction (XRD) investigations were carried out within a range of − 260 °C to + 450 °C to study the structure parameters related to the XRD tests, which provided information related to the phase participation, lattice parameters, and stresses in the microstructure as well as with an expansion of the crystal lattice. The results also provide insight into the role of the structure and its homogeneity on the thermal stability of ADI cast iron. The present work also aims to develop strategies to suppress the formation of blocky-shaped austenite in the ADI structure to maintain a homogeneous microstructure and high thermal stability.

show abstract

“…Austempered ductile iron (ADI) belongs to the spheroidal graphite cast iron (SGI) family, which is subjected to heat treatment; i.e., austenitization and austempering. As a result of this heat treatment, a rather advantageous combination of strength, ductility, and toughness is obtained [1][2][3][4]. This in turn allows ADI to be an alloy that is competitive with steel and aluminum alloys in terms of its mechanical properties, production cost, and weight saving.…”

Section: Introductionmentioning

confidence: 99%

Role of Austenitization Temperature on Structure Homogeneity and Transformation Kinetics in Austempered Ductile Iron

et al. 2019

View full text Add to dashboard Cite

This paper considers the important factors of the production of high-strength ADI (Austempered Ductile Iron); namely, the austenitization stage during heat treatment. The two series of ADI with different initial microstructures were taken into consideration in this work. Experiments were carried out for castings with a 25-mm-walled thickness. Variable techniques (OM, SEM, dilatometry, DSC, Variable Magnetic Field, hardness, and impact strength measurements) were used for investigations of the influence of austenitization time on austempering transformation kinetics and structure in austempered ductile iron. The outcome of this work indicates that the austenitizing temperature has a very significant impact on structure homogeneity and the resultant mechanical properties. It has been shown that the homogeneity of the metallic matrix of the ADI microstructure strongly depends on the austenitizing temperature and the initial microstructure of the spheroidal cast irons (mainly through the number of graphite nodules). In addition, this work shows the role of the austenitization temperature on the formation of Mg-Cu precipitations in ADI.

show abstract

Austempering Kinetics in Cu-Mo Alloyed Ductile Iron: A Dilatometric Study

Cited by 6 publications

References 0 publications

Statistical Data-Driven Model for Hardness Prediction in Austempered Ductile Irons

Statistical Data-Driven Model for Hardness Prediction in Austempered Ductile Irons

Structure Homogeneity and Thermal Stability of Austempered Ductile Iron

Role of Austenitization Temperature on Structure Homogeneity and Transformation Kinetics in Austempered Ductile Iron

Contact Info

Product

Resources

About