Abstract
Two gating systems namely stepped and tapered runners were used to cast strip samples with different thicknesses by CO2/silicate process using sand grain sizes of AFS 151 and 171. To assess the effect of mould coating on the properties of thin-wall ductile iron, half of the moulds were coated whilst the rest were not coated. Molten metal with the carbon equivalent of 4. 29% was prepared and poured at 1450 °C. Microstructure of the specimens was analyzed by optical and scanning electron microscopes. Count, area fraction, roundness and diameter of the graphite nodules of the samples were measured by image analyzer. Brinell hardness and tensile tests of all the samples were also conducted. The results show that by using stepped runner gating system with uncoated and coarse sand mould, roundness and count of the graphite nodules decrease whereas diameter and area fraction increase. Although fine sand and coated mould cause longer distance of molten metal travel, hardness and strength of the samples decrease.
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References
Choi J O, Kim J Y, Choi C O, et al. Effect of Rare Earth Element on Microstructure Formation and Mechanical Properties of Thin Wall Ductile Iron Castings [J]. Materials Science and Engineering, 2004, 383A(2): 323.
Sosa A D, Echeverría M D, Moneada O J, et al. Surface Reactivity of Thin Wall Ferritic Ductile Iron. The Effect of Nodule Count and Grinding Variables [J]. Materials Letters, 2008, 62 (1): 100.
Druschitz A P, Fitzgerald D C. Lightweight Iron and Steel Castings for Automotive Applications [C] //Society of Automotive Engineers. SAE 2000 World Congress. Detroit: Society of Automotive Engineers, 2000: 11.
Dommarco R C, Jaureguiberry A J, Sikora J A. Rolling Contact Fatigue Resistance of Ductile Iron With Different Nodule Counts and Matrix Microstructures [J]. Wear, 2006, 261(2): 172.
Bockus S, Venckunas A, Žaldarys G. Relation Between Section Thickness, Mictostructure and Mechanical Properties of Ductile Iron Castings [J]. Materials Science (MEDŽIAGOTYRA), 2008, 14(2): 115.
Katz S, Warren A. Thin Wall Iron Castings: Planning the Future [J]. Foundry Management and Technology, 1997, 125: 34.
Campbell J. Thin Wall Castings [J]. Materials Science and Technology, 1988, 4(3): 194.
Schrems K K, Hawk J A, Dogan Ö N, et al. Statistical Analysis of the Mechanical Properties of Thin-Walled Ductile Iron Castings [J]. SAE Transactions, 2003, 112(5): 420.
Sheikh M A. Production of Carbide-Free Thin Ductile Iron Castings [J]. Journal of University of Science and Technology Beijing, 2008, 15(5): 552.
Horie H, Kowata T, Chida A. Effect of Rare Earth Elements on Chill Formation and Nodule Count in Thin-Section Spheroidal Graphite Cast Iron [J]. Journal of Cast Metals, 1988, 1 (2): 90.
Rundman K B. Metal Casting, Reference Book for MY4130 [M]. Houghton: Michigan Technological University, 2001.
Kippola D E, Goodrich G M. Factors Affecting Ductile Iron’s Impact Tensile Strength [J]. Modern Casting, 2001, 4: 42.
Dommarco R C, Sousa M E, Sikora J A. Abrasion Resistance of High Nodule Count Ductile Rolling Contact Fatigue Resistance of Ductile Iron With Different Matrix Microstructures [J]. Wear, 2004, 257(11): 1185.
Labrecque C, Gagné M, Javaid A. Optimizing the Mechanical Properties of Thin-Wall Ductile Iron Castings [J]. AFS Transactions, 2005, 113(5): 677.
Osafune Y, Yuyama M. Microstructure and Properties of Austempered Ductile Cast Iron With Refined Graphite Nodules [J]. International Journal of Cast Metals Research, 2008, 21(1/2/3/4): 90.
Borrajo J M, Martinez R A, Boeri R E, et al. Shape and Count of Free Graphite Particles in Thin Wall Ductile Iron Castings [J]. ISIJ International, 2002, 42(3): 257.
Costa N, Machado N, Silva F S. Influence of Graphite Nodules Geometrical Features on Fatigue Life of High-Strength Nodular Cast Iron [J]. Journal of Materials Engineering and Performance, 2008, 17(3): 352.
Pedersen K M, Tiedje N S. Graphite Nodule Count and Size Distribution in Thin-Walled Ductile Cast Iron [J]. Materials Characterization, 2008, 59(8): 1111.
Dix L P, Ruxanda R, Torrance J, et al. Static Mechanical Properties of Ferritic and Pearlitic Lightweight Ductile Iron Castings [C] //Frink K. AFS Transactions, Vol. 111 Proceeding of 107th Annual Casting Congress. Milwaukee: American Foundry Society, 2003: 1.
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Jafari, H., Idris, M.H., Ourdjini, A. et al. Influence of gating system, sand grain size, and mould coating on microstructure and mechanical properties of thin-wall ductile iron. J. Iron Steel Res. Int. 17, 38–45 (2010). https://doi.org/10.1016/S1006-706X(10)60195-1
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DOI: https://doi.org/10.1016/S1006-706X(10)60195-1