Production of spheroidal graphite aluminium cast iron and the factors affecting it

Haque, Md. Mohafizul; Young, J. M.

doi:10.1016/0924-0136(95)01952-9

Cited by 15 publications

(11 citation statements)

References 1 publication

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“…Aluminium is found as a good replacement of silicon in ductile cast irons, with real benefits such as higher strength and hardness, as well as better wear and oxidation resistance [26,27], but its anti-nodularising effect in Mg-treated cast irons must be considered. A high sensitivity must also be expected to cause graphite degeneration in the casting surface layer.…”

Section: Structure Characteristics In the Casting Surface Layermentioning

confidence: 99%

Control of the Mg-Treated Iron Casting Skin Formation by S-Diffusion Blocking at the Metal–Mould Interface

et al. 2020

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Having established that sulphur presence in the mould materials appears to have an important contribution in graphite degeneration at least in the casting surface layer, a research program is undertaken to explore the possible beneficial effect of sulphur diffusion blocking at the metal–mould interface. Test samples, with and without a thin steel sheet (up to 3 mm thickness) application on the inner surface of the mould cavity, before iron melt pouring, are considered for structure analysis. A higher nodulizing potential (0.048% Mgres, 0.015% Ceres, and 0.006% Lares) decreases the occurrence of surface graphite degeneration in castings obtained in rigid chemically bonded resin sand moulds, using P-toluol sulfonic acid (PTSA) hardener (S-including), but it is not enough to avoid this phenomenon (200–400 μm skin in present experimental conditions). The casting skin appears to have different values, depending on the evaluation technique (un- and Nital-etching direct measurement, or graphite parameters variation on the casting section). In the presence of a thin steel sheet at the metal–mould interface, the casting skin thickness decreases or is just excluded. It is supposed that it acts as a barrier, blocking S-diffusion from the mould media into the iron melt. Without this S-diffusion, the graphite degeneration in the casting surface layer could be avoided, or at least diminished. For industrial application, the increasing of residual content of nodulizing elements is a limited solution, and it is recommended to use barriers to block S transfer on the mould/metal surface, such as dense coatings or coatings with desulphurization capacity.

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Section: Structure Characteristics In the Casting Surface Layermentioning

confidence: 99%

Control of the Mg-Treated Iron Casting Skin Formation by S-Diffusion Blocking at the Metal–Mould Interface

et al. 2020

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“…This procedure was followed in order to avoid any turbulence and splashing during pouring of the melt, because high levels of magnesium and silicon in ductile iron increase the possibility of dross formation [13]. However, for better results, in-mould inoculation is also suggested, especially for the production of SG-Al cast iron [11]. The melts were also poured in to the chill moulds for chemical analysis.…”

Section: Melting and Castingmentioning

confidence: 99%

“…They suggested that the solidification of this type of cast iron is much more complex than that of SG-Si cast iron. At the same time, Haque and Young [11] observe that the production of SG-Al is subject to some specific limitations and the inoculation treatment must be performed according to specific criteria in order to be completely effective. However, in this study, an attempt has been made to compare properties and structures of the as-cast SG-Si and SG-Al cast irons produced in 1 m long fluidity moulds.…”

Section: Introductionmentioning

confidence: 99%

Investigation on properties and microstructures of spheroidal graphite Fe–C–2Si and Fe–C–2Al cast irons

Haque

2007

Journal of Materials Processing Technology

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“…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]. It has also been reported that it influences significantly the form, size and distribution of graphite in ductile iron microstructures.…”

Section: Introductionmentioning

confidence: 99%

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

2020

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The effect of aluminium addition and austempering processes on the microstructures, mechanical and wear properties of rotary melting furnace processed ductile irons was investigated. Ductile irons containing 1−4 wt.% Al were produced and subjected to single and two-step austempering processes. Optical microscopy was used to characterize the graphite features and estimate the volume fraction of the matrix phases present, while the x-ray diffractogram was also carried out to analyse the samples. Mechanical and wear properties of the alloys were equally evaluated. From the results, it was observed that both the as-cast and austempered ductile iron microstructures contained nodular graphite, and the matrix structure for the as-cast ductile irons consisted predominantly of pearlite and ferrite, while that of the austempered grades, contained principally, ausferrite. The microstructure and intermetallic compound obtained played dominant role on the properties of the alloys. The aluminium addition and austempering processes had a significant influence on the mechanical properties and wear resistance of the alloys. The austempered ductile irons exhibited superior strength and wear resistance compared to the as-cast samples, albeit ductility values were lower in the composition group. Austempering increased the strength by over 100% while the addition of Al further enhanced the strength. The improved properties were linked to the refined microstructure, increased proportion of ausferrite phase and intermetallic compound formed. For all properties evaluated, the two-step austempering yielded better properties combination than the single step process. The rotary melting furnace processing adopted was found viable for ductile iron production.

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Production of spheroidal graphite aluminium cast iron and the factors affecting it

Cited by 15 publications

References 1 publication

Control of the Mg-Treated Iron Casting Skin Formation by S-Diffusion Blocking at the Metal–Mould Interface

Control of the Mg-Treated Iron Casting Skin Formation by S-Diffusion Blocking at the Metal–Mould Interface

Investigation on properties and microstructures of spheroidal graphite Fe–C–2Si and Fe–C–2Al cast irons

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

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