Nodule count effect on microstructure and mechanical properties of hypo-eutectic ADI alloyed with nickel

García, Eduardo Colin; Cruz-Ramírez, Alejandro; Romero-Serrano, J. A.; Sánchez-Alvarado, R.G.; Gutiérrez-Pérez, V.H.; Reyes-Castellanos, G.

doi:10.2298/jmmb200403009c

Cited by 8 publications

(10 citation statements)

References 25 publications

(40 reference statements)

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“…Figure 11 shows the hardness evolution as the austempering time was increased. The hardness behavior is directly related to the microstructural evolution shown in Figures 4 and 5 and also with the %Vγ HC as was previously reported [38,45].…”

Section: Mechanical Propertiessupporting

confidence: 81%

“…The maximum value of %Vγ HC in all cases was obtained for the austempering time of 90 min. The maximum ausferrite amount referred to as a process window (PW) and represented in Equations ( 1)-( 3) occurs as follows: The first stage of the PW is presented to the austempering times of 30 and 60 min where Reaction (1) proceeds; afterwards, the highest amount of ausferrite is obtained at 90 min, reaching the PW (reaction 3), and then, the second stage of the PW window has been reached at the austempering time of 120 min, proceeding Reaction (2) [38]. It is observed from Table 4 that the highest values of %Vγ HC are reached for the highest austempering temperature; this behavior is related to the carbides amount in the ausferritic matrix [39].…”

Section: Volume Fraction Of High-carbon Austenitementioning

confidence: 99%

“…Figure 9 shows the %VγHC behavior as the austempering tim increases first, reaching a maximum value and then decreasing. %VγHC in all cases was obtained for the austempering time of ausferrite amount referred to as a process window (PW) and r (1)-( 3) occurs as follows: The first stage of the PW is presented to of 30 and 60 min where Reaction (1) proceeds; afterwards, the hig is obtained at 90 min, reaching the PW (reaction 3), and then, the window has been reached at the austempering time of 120 min, [38]. It is observed from Table 4 that the highest values of %VγHC est austempering temperature; this behavior is related to the ausferritic matrix [39].…”

Section: Volume Fraction Of High-carbon Austenitementioning

confidence: 99%

“…The effect of the austempering temperature and time on the Rockwell C hardness for ADIs low alloyed with vanadium are shown in Table 6. It is evident that hardness obtained by austempering heat treatment is higher than in the as-cast condition because hardness obtained in as-cast depends directly on phases and microconstituents such as pearlite, ferrite, and carbides formed during the camshaft solidification process; in this case, the camshaft microstructure is constituted mainly of pearlite with lower amounts of ferrite and carbides (Table 2) [38,44]. However, the austempering heat treatment applied to the ductile iron promotes phase transformations forming harder phases as ausferrite and martensite with a low volume fraction of vanadium carbides homogeneously distributed in the camshaft microstructure.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

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Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

García

Ramírez

Castellanos

et al. 2021

Metals

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Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

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Section: Mechanical Propertiessupporting

confidence: 81%

Section: Volume Fraction Of High-carbon Austenitementioning

confidence: 99%

Section: Volume Fraction Of High-carbon Austenitementioning

confidence: 99%

Section: Mechanical Propertiesmentioning

confidence: 99%

See 2 more Smart Citations

Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

García

Ramírez

Castellanos

et al. 2021

Metals

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“…It should be mentioned that austemperability enhancement is resulted from the segregation reduction, which means more uniform distribution of elements concentration. In addition, it was reported that 19,20 increasing the nodule count extremely refines the ausferrite structure in the matrix. Consequently, this leads to improve both strength and ductility of the produced ADI parts.…”

Section: Introductionmentioning

confidence: 99%

Ultrafine Ductile and Austempered Ductile Irons by Solidification in Ultrasonic Field

Ahmed

Riedel

Kovalko³

et al. 2021

Inter Metalcast

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In this research, ultrasonic melt treatment (UST) was used to produce a new ultrafine grade of spheroidal graphite cast iron (SG iron) and austempered ductile iron (ADI) alloys. Ultrasonic treatment was numerically simulated and evaluated based on acoustic wave streaming. The simulation results revealed that the streaming of the acoustic waves propagated as a stream jet in the molten SG iron along the centerline of the ultrasonic source (sonotrode) with a maximum speed of 0.7 m/s and gradually decreased to zero at the bottom of the mold. The metallographic analysis of the newly developed SG iron alloy showed an extremely ultrafine graphite structure. The graphite nodules’ diameter ranging between 6 and 9 µm with total nodule count ranging between 900 to more than 2000 nodules per mm2, this nodule count has never been mentioned in the literature for castings of the same diameter, i.e., 40 mm. In addition, fully ferritic matrix was observed in all UST SG irons. Further austempering heat treatments were performed to produce different austempered ductile iron (ADI) grades with different ausferrite morphologies. The dilatometry studies for the developed ADI alloys showed that the time required for the completion of the ausferrite formation in UST alloys was four times shorter than that required for statically solidified SG irons. SEM micrographs for the ADI alloys showed an extremely fine and short ausferrite structure together with small austenite blocks in the matrix. A dual-phase intercritically austempered ductile iron (IADI) alloy was also produced by applying partial austenitization heat treatment in the intercritical temperature range, where austenite + ferrite + graphite phases coexist. In dual-phase IADI alloy, it was established that introducing free ferrite in the matrix would provide additional refinement for the ausferrite.

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Effect of Austempering Conditions on the Corrosion Behavior of HSADI Alloyed with Niobium

Navarro,

González,

Valdez

et al. 2024

Inter Metalcast

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Nodule count effect on microstructure and mechanical properties of hypo-eutectic ADI alloyed with nickel

Cited by 8 publications

References 25 publications

Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Ultrafine Ductile and Austempered Ductile Irons by Solidification in Ultrasonic Field

Effect of Austempering Conditions on the Corrosion Behavior of HSADI Alloyed with Niobium

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