Effect of Hot Working Parameters on Microstructure Evolution and Mechanical Properties of Ausformed Austempered Ductile Iron

Abstract:

Three ductile irons with different aluminum-and manganese-content were subjected to two thermo-mechanical schedules. In the first schedule, a total deformation of φ_t = 0.3 is applied on the ductile irons in the austenitic region before the austempering process. In the second schedule, the materials are subjected to deformation of 0.2 in the austenitic region and deformation of 0.1 during austempering (ausforming). Mechanical deformation of austenite prior to the transformation “stage I” pronouncedly accelerated the transformation due to increasing the nucleation sites of ausferrite. This increase has its impact on enhancing the microstructural uniformity and refining the ausferrite platelets. On the other hand, the retained austenite content was not significantly affected by the applied ausforming. Remarkable increase in hardness, strength and ductility of the ausformed ductile iron due to the latter effects is observed.

• Periodical: Materials Science Forum (Volume 925)
• Pages: 218-223
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.925.218
• Online since: June 2018
• Authors: Mohamed Soliman*, Adel Nofal, Heinz Palkowski
• Keywords: Ausforming, Austempering, Ductile Iron, Thermo-Mechanical Processing, Transformation Kinetics

References

[1] A. G. F. Alabi, F. I. Aluko, Production and commercialization of austempered ductile iron, International Journal of Innovative Research & Development, 11 (2013) 332-336.

[2] Inc QIT-Fer et Titane, Ductile iron data for design engineers ring-bound, Ductile Iron Group, (1990).

[3] A. Krzyńska , A. Kochański, Austenitization of ferritic ductile iron, Archives of Foundry Engineering 14 (2014) 49-54.

DOI: 10.2478/afe-2014-0085

[4] M. Soliman, H. Palkowski and A. Nofal, Thermo-mechanically processed multi-phase ductile iron: microstructure development, Key Eng. Mat., 457 (2011) 199-204.

DOI: 10.4028/www.scientific.net/kem.457.199

[5] Olson, B.N., Brucke, Ch., Parolini, J., Moore, D.J. & Rundmann, K.B. Ausformed-austempered ductile iron (AADI). International Conference on ADI; DIS and AFS, Louisville, KY, USA, 29-60 (2002) 25-27.

[6] Nasr El-din, H., Nofal, A. & Ibrahim, M., Ausforming of austempered ductile iron alloyed with nickel., Int. J. Cast Metal Res. 19 (2006) 137-150.

DOI: 10.1179/136404606225023381

[7] A. Nofal, Advances in the metallurgy and applications of ADI, J. Metall. Eng. 2 (2013) 1–18.

[8] A. Nofal, The current status of the metallurgy and processing of austempered ductile iron (ADI), 10th International Symposium on the Science and Processing of Cast Iron (SPCI 10), (2014) (Mar del Plata Argentina), INTEMA-Argentina.

[9] M. Soliman, A. Nofal, H. Palkowski, Alloy and process design of thermo-mechanically processed multiphase ductile iron, Materials and Design, 89 (2015) 450-465.

DOI: 10.1016/j.matdes.2015.07.159

[10] Dieter G.E, Kuhn H.A and Semiatin S. L, Handbook of Workability and Process Design, First printing, ASM International, Materials Park, OH, USA,(2003).

[11] D. Myszka, E. Skołek, A. Wieczorek, Manufacture of toothed elements in nanoausferritic ductile iron, Arch. Metall. Mater. 59 (2014) 1217-1221.

DOI: 10.2478/amm-2014-0211