Austempered Ductile Iron (ADI): Influence of Austempering Temperature on Microstructure, Mechanical and Wear Properties and Energy Consumption

Sellamuthu, Prabhukumar; Samuel, D.G. Harris; Dinakaran, D.; Premkumar, V. P.; Li, Zushu; Sridhar, Seetharaman

doi:10.3390/met8010053

Cited by 73 publications

(51 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Figure shows the SEM images of ductile iron after austempering treatment. The matrix of the samples contained retained austenite and acicular ferrite, which are typical microstructural characteristics of ADI . The magnified images of the ductile iron after austempering treatment are shown in Figure d–f.…”

Section: Resultsmentioning

confidence: 93%

See 1 more Smart Citation

Influence of Graphite Nodules on the Microstructure and Mechanical Properties of Hollow Ductile Iron Pipe after Austempering Treatment

Wang

Gao

et al. 2019

steel research int.

View full text Add to dashboard Cite

Herein, the microstructure and mechanical properties of ductile iron with different numbers of graphite nodules before and after austempering treatment are systematically investigated. The results show that the amounts of graphite nodules affect the microstructure and resulting mechanical properties of ductile iron. The ferrite fraction in an as-cast matrix decreases with the increase in graphite nodules; this outcome is mainly attributed to the cooling rate. The matrix of ductile iron after austempering treatment is composed of acicular ferrite and retained austenite. The acicular ferrite is refined with the increase in graphite nodules, because the increase in interface between graphite/austenite provides more nucleation sites during austempering treatment. Meanwhile, the formation of ferrite causes carbon atoms to diffuse into the surrounding matrix, giving rise to the increase in carbon concentration of untransformed austenite and further stabilizing the retained austenite. Hence, the volume fraction of retained austenite and the carbon content in it both increase with the increase in graphite nodules. The amounts in graphite nodules affect the mechanical properties significantly after austempering treatment; this outcome is related to the phase constituents of ductile iron after austempering treatment. Herein, the detailed mechanisms are discussed.

show abstract

Section: Resultsmentioning

confidence: 93%

“…The fracture mode might be related to the retained austenite volume fraction and ausferrite morphology. Generally, the increase in retained austenite would give rise to the ductile fracture . From this viewpoint, the austempered S‐550 sample with more retained austenite should have a high ductility.…”

Section: Discussionmentioning

confidence: 99%

Influence of Graphite Nodules on the Microstructure and Mechanical Properties of Hollow Ductile Iron Pipe after Austempering Treatment

Wang

Gao

et al. 2019

steel research int.

View full text Add to dashboard Cite

show abstract

“…Heat treatment was used to modify resultant structure in order to achieve the highest mechanical strength accompanying by steel-like ductility. Such a treatment requires an interrupted quenching, usually performed into a salt bath, to cool the casting at a defined rate with long enough duration to reach the desired austempering effect [7,8]. The resultant alloy has a combination of exceptional strength and toughness, meeting or even exceeding those of alloyed steels.…”

Section: Methodsmentioning

confidence: 99%

Research on Tensile Behaviour of New Structural Material MoNiCa

Bahdanovich¹,

Bendikienė²,

Česnavičius³

et al. 2019

View full text Add to dashboard Cite

This article presents the results of a set of innovative research to analyse a new structural material – steel like austempered ductile cast iron with mechanical properties similar to heat-treated steel, and with technological and exploitation characteristic close to high-strength cast iron with nodular graphite. Specific examples of its high efficiency for the manufacture of critical, mass and heavy-loaded components of modern machinery and equipment are presented. New structural material MoNiCa was tested on tension and was compared to commercial grades of austempered ductile cast irons and heat treated steels. Unconventional behaviour of examined material was observed: with tensile strength increase to almost 1600 MPa the metal became less brittle. Hardness test revealed another distinctive feature of new material that there is no linear relation between strength and hardness increase, different hardness values ~ 40 HRC or ~ 55 HRC can be achieved with the same tensile strength 1000 – 1200 MPa. Microscopic analysis demonstrated of sophisticated structure formed owing to different regimes of austempering treatment. Specific properties emerged from successful ratio of three elements Mo, Ni, and Cu (carbon equivalent), and properly chosen heat treatment modes. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.23079

show abstract

“…Increasing the fraction of austenite in ADI usually contributes to an increase in impact strength [11,[33][34][35][36]. Such a direction of interaction is related to the increase in austenite fraction due to the higher austempering temperature at a constant austenitizing temperature.…”

Section: Hardness and Charpy Impact Propertiesmentioning

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

Austempered Ductile Iron (ADI): Influence of Austempering Temperature on Microstructure, Mechanical and Wear Properties and Energy Consumption

Cited by 73 publications

References 34 publications

Influence of Graphite Nodules on the Microstructure and Mechanical Properties of Hollow Ductile Iron Pipe after Austempering Treatment

Influence of Graphite Nodules on the Microstructure and Mechanical Properties of Hollow Ductile Iron Pipe after Austempering Treatment

Research on Tensile Behaviour of New Structural Material MoNiCa

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

Contact Info

Product

Resources

About