Microstructural characteristics of Al-alloyed austempered ductile irons

Influence of austenitising conditions and aluminium content on microstructure and properties of ductile irons

“…Transmission electron microscopy results have shown that this carbide-free bainite is composed of parallel subunits of ferrite interwoven with interlath films of high-carbon retained austenite [17][18][19]. The effect of Al and Si in ductile cast irons on the bainitic microstructure is discussed in detail [20][21][22][23].…”

The influence of annealing temperature on the graphitisation of CK 45 Steel

“…Also the existence of unknown particles, i.e. initial nucleation centers plays a critical role in the size of these graphite particles [22]. In addition the accumulation of the supersaturated carbon atoms in any region which is preferably in a higher energy level in the system makes the possibility for the nuclei to grow to the critical size and grow in the proper heat treatment conditions.…”

“…In other pictures the shape of the graphite particles and the diffusion region of carbon are well observed by changing colors. The transfer and immigration of carbon from outside regions make these areas poorer in this element compared to the initial substrate and so a halo of low-carbon regions is formed around the graphite particles [22].…”

Microstructural Characteristics, Mechanical and Wear Behaviour of Aluminium-Alloyed Ductile Irons Subjected to Two Austempering Processes

“…Al is a relatively cheap and readily accessible metallic material and its use in the development of Al-alloyed ductile irons have been found applicable in automobile component design. The use of Al as alloying addition in ductile irons has been reported to have the potentials of improving machinability, high strength and good toughness, improved fatigue and wear resistance, as well as enhanced heat and fire resistance [1][2][3][4][5][6]. The improved properties are achieved because Al is a graphitizer and acts by increasing the eutectoid temperature of cast irons, thereby increasing the allowable working temperature [1,5,7,8].…”