Effect of Ti, Nb, Cr and B on Structure and Mechanical Properties of High Aluminium Cast Iron

Kopyciński, D.

doi:10.2478/afe-2013-0015

Cited by 3 publications

(3 citation statements)

References 5 publications

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“…2. Both the temperature values and duration of each stage of treatment were selected after careful analysis of some studies on heat treatment of nodular and vermicular graphite cast iron [30][31][32][33][34][35][36][37]. The following variants were finally assumed:…”

Section: The Purpose Of Investigation and The Research Materialsmentioning

confidence: 99%

Archives of Foundry Engineering

Jakubus

2022

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The article presents the results of research on the abrasion resistance of cast iron with vermicular graphite in the as-cast state and after austempering (the latter material is referred to as AVGI -Austempered Vermicular Graphite Iron). Austenitization was carried out at the temperature values of either 900°C or 960°C, and austempering at the temperature values of either 290°C and or 390°C. Both the austenitization and the austempering time was equal to 90 minutes. The change of the pearlitic-ferritic matrix to the ausferritic one resulted in an increase in mechanical properties. Abrasion tests were conducted by means of the T-01M pin-on-disc tribometer. The counter-sample (i.e. the disc) was made of the JT6500 friction material. Each sample was subject to abrasion over a sliding distance of 4000 m. The weight losses of both samples and counter-samples were determined by the gravimetric method. It was found that the vermicular cast iron austenitized at 900°C and austempered at 290°C was characterized by the lowest wear among the evaluated cast iron types. The geometric structure of the surface layer after the dry friction test exhibited irregular noticeable grooves, distinct oriented abrasion traces, plastic flow of the material, microcracks, and pits generated by tearing out the abraded material. The largest surface roughness was found for the AVGI cast iron heat-treated according to the variant 3 (Tγ =900 ºC; Tpi = 390°C), while the smallest one occurred in AVGI cast iron subject to either the variant 2 (Tγ =960 ºC; Tpi = 290°C) or the variant 4 (Tγ =900 ºC; Tpi = 290°C) of heat treatment and was equal to either 2.5 µm or 2.66 µm, respectively. It can be seen that the surface roughness decreases with the decrease in the austempering temperature.

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Section: The Purpose Of Investigation and The Research Materialsmentioning

confidence: 99%

Archives of Foundry Engineering

Jakubus

2022

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“…Evidence from literature shows that the most common melting furnaces used for ductile iron produc-Elements Weight percent(wt.%) tion are induction, gas-fired crucible, and vacuum furnaces [9,10,[12][13][14]. Very little has been reported on the use of rotary melting furnace technology for the production of Al-alloyed ductile irons.…”

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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“…Al equally, increases the eutectoid temperature of cast irons, thereby increasing the allowable working temperatures [10][11][12]. The achievement of these microstructural features in cast irons, which are relevant to the improvement of mechanical properties and oxidation and corrosion resistance [13][14], are reported to be dependent on processing factors, and thus the same outcomes are not guaranteed when process factors are altered.…”

Section: Introductionmentioning

confidence: 99%

Structural characterization and mechanical properties of rotary melting furnace processed aluminium alloyed ductile irons

Adebayo

Alaneme

Oyetunji

2018

Journal of Taibah University for Science

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The microstructural characteristics and mechanical properties of rotary melting furnace processed aluminium alloyed ductile irons were investigated in this study. This was aimed at developing high performance -low material and processing cost ductile irons, suitable for the production of automobile components. Different compositions of the alloys were processed containing 1-4 wt.% aluminium. X-ray diffractometry, optical, scanning electron microscopy and mechanical properties measurements, were used to characterize the alloys. The results show that the ductile irons consists essentially, nodular and vermicular graphite-type distributed in a predominantly pearlite -ferrite matrix structures which attest to the viability of rotary furnace melt processing for ductile iron production. The nodule count were observed to increase with increase in Al wt.% but nodule sizes and degree of sphericity decreased with increase in Al wt.%. The mechanical properties of the ductile irons increased with increase in Al wt.%, except the ductility which decreased slightly with increase in Al wt.%.

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Effect of Ti, Nb, Cr and B on Structure and Mechanical Properties of High Aluminium Cast Iron

Cited by 3 publications

References 5 publications

Archives of Foundry Engineering

Archives of Foundry Engineering

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

Structural characterization and mechanical properties of rotary melting furnace processed aluminium alloyed ductile irons

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