Effect of Metallic, Nonmetallic, Water Cooled and Cryogenic Chills on Pearlite Content (PC), Eutectic Cell Count (ECC) and Grain Size (GS) of Hypo Eutectic Nickel Alloyed Cast Iron
This paper presents the results obtained, deductions made from solidification behaviour and a series of micro structural studies such as pearlite content, eu-tectic cell count and grain size of hypoeutectic gray cast iron which was sand cast (CO2 moulding) using metallic, nonmetallic, water cooled and subzero (cryogenic) end chills. Hypo-eutectic cast irons containing C 3.42, Si 2.4 and Ni 1.5 with impurity contents (S, P, Mn etc.) were solidified unidirectionally in an American Foundrymen Society (AFS) standard mould, the end of which was provided with different end chills to study the effect of chilling during solidifi-cation. The melts were inoculated with 0.3% Fe-Si to promote graphitization. It was observed that the transition from one structure to another is more gradual than normally obtained in the structure of cast irons solidified mul-ti-directionally in a sand mould at room temperature. Austenite dendrite interactions were shown to be a major factor in determining the microstructure, in which the higher dendrite reaction leads to changes in DAS, ECC and GS. It is observed that, the number of eutectic cells is an index of graphite nucleation and the effect of these on structure, since the eutectic cells are developed on the graphite nuclei during solidification.
References
[1]
Hemanth, J. (2001) Solidification Behavior of Water Cool and Sub Zero Chilled Cast Iron on Mechanical Behaviour. Journal of Materials Engineering and Performance, 10, 28-39. https://doi.org/10.1361/105994901770345231
[2]
Hemanth, J. (2010) Microstructure, Mechanical Properties and Wear Behavior of Metallic, Non Metallic and Deep Cryogenically Chilled ASTM 216 WCB Steel. Journal of Alloys and Compounds, 506, 645-652.
https://doi.org/10.1016/j.jallcom.2010.07.036
[3]
Hemanth, J. (2001) Effect of Sub Zero Chilling (Cryogenic) with Water Cool Chilling on Solidification and Mechanical Behaviour of Cast Iron. Materials Science and Engineering A, 318, 277-286. https://doi.org/10.1016/S0921-5093(01)01327-2
[4]
Hemanth, J. (2010) Effect of Chilling on the Mechanical Properties and Wear Resistance of Cr Added ASTM A216 Grade WCB Steel. International Journal of Materials Science, 5, 131-137.
[5]
Hemanth, J. (1996) Wear Characteristics of Sub Zero Chilled Cast Iron. Wear, 192, 134-140. https://doi.org/10.1016/0043-1648(95)06781-7
[6]
Murthy, K.S.S., Seshadri, M.R. and Ramachandran, A. (1965) Plate-Feeder Design for Al Alloy Castings. Trans AFS, 73, 502-510.
[7]
Murthy, K.S.S., Seshadri, M.R. and Ramachandran, A. (1967) Influence of Chills on Solidification Behavior of Long Freezing Range Alloys. 34th International Foundry Congress, Paris, 56-63.
[8]
Seshan, S., Seshadri, M.R. and Ramachandran, A. (1968) Action of Chills on Soundness of Al-4.5%Cu Alloy Castings. The British Foundryman, 61, 3-12.
[9]
Hemanth, J. (2005) Tribological Behavior of Cryogenically Treated Al-12%Si Alloy/B4C Composites. Wear, 258, 1732-1739.
https://doi.org/10.1016/j.wear.2004.12.009
[10]
Hemanth, J. (2011) Development and Wear Behavior of Al/Al2SiO5/C Chilled Hybrid Metal Matrix Composites by Both Experimental and Finite Element Method. SAE International, PA, USA, Paper No. 2011-01-0223.
[11]
Hemanth, J. (2003) Effect of High Rate Heat Transfer during Casting on Strength, Hardness and Wear Behaviour of Al/Quartz MMCs. Proceedings of the Institution of Mechanical Engineers Part B, 217, 651-659.
https://doi.org/10.1243/095440503322011371
[12]
Dawson, J.V. and Oldfield, W. (1960) Effect of Ferro Silicon Oneutectic Cell Count. BCIRA Journal, 8, 221-234.
[13]
Wallace, J.W. (1975) Effects of Minor Elements in the Structure of Cast Irons. Trans AFS, 88, 363-369
[14]
Church, N. (1966) Control of Cast Grain Size of Steel Castings, Effect of Grain Refinement on Properties. Trans AFS, 74, 113-120.
[15]
Bhur, R.K. (1986) Vermicular Graphite Formation in Heavy Section Nodular Cast Iron. Modern Castings, 54, 497-502.
[16]
Loper, C.R. and Heine, R.W. (1962) Graphite Formation during Solidification of Cast Iron. Trans AFS, 70, 583-589.
[17]
Michael, A.B. and Bever, M.B. (1950) Graphite Morphology in Ductile Irons. Trans AIME, 188, 47-55.
[18]
Tiller, W.A. (1964) Isothermal Solidification of Fe-C and Fe-C-Sialloys. ASM Seminar, Research on Cast Iron, Detroit, No. 12, 34-40.
[19]
Ruff, G.F. and Wallace, J.F. (1976) Control of Graphite Structure and Its Effects Mechanical Properties of Gray Iron. Trans AFS, 84, 705-711.
[20]
Hughes, I.C.H. (1952) Some Effects of Mg on the Formation of Graphite in a Solidifying Cast Iron. Foundry Trade Journal, 92, 417-424.
[21]
Hilbert, H. (1964) Some Theoretical Considerations in Nucleation and Growth during Solidification of Graphite and White Cast Irons. ASM Seminar, Research on Cast Iron, Detroit, No. 23, 56-63.
[22]
Seshan, S. and Ramachandran, A. (1968) Action of Chills on Soundness of Al-4.5%Cu Alloy Castings. The British Foundryman, 61, 339-347.
[23]
Reddy, G.P. and Pal, P.K. (1976) Influence of Chills on Al-4.5%Cu Alloy Casting Soundness. The British Foundryman, 69, 265-272.
[24]
Hemanth, J. and Seah, K.H.W. (1995) Fracture Toughness of Sub Zero Chilled Cast Iron. Journal of Materials Science, 30, 4986-4993.
https://doi.org/10.1007/BF01154513
[25]
Itaka, I. (1951) Theory of Globular Graphite Formation in Cast Iron. Foundry Trade Journal, 91, 498-504.
[26]
Fedriksson, H. and Hillert, M. (1971) Direct and Indirect Formation of Graphite in High Alloyed Cast Iron. The British Foundryman, 43, 54-59.
[27]
Bishop, H.F. (1951) Solidification of Cast Irons. Trans AFS, 59, 435-441.
[28]
Berry, J.T. (1970) Vermicular Graphite Formation in Heavy Section Nodular Cast Iron. Trans AFS, 78, 421-431.
[29]
Ruff, G.F. and Wallace, J.F. (1977) Effect of Solidification Structures on the Tensile Properties of Gray Iron. Trans AFS, 85, 179-184.
[30]
Sun, G.X. and Loper, C.R. (1983) Graphite Flotation in Cast Iron. Trans AFS, 91, 841-848.
[31]
Wallace, J.W. (1975) Effects of Minor Elements in the Structure of Cast Irons. Trans AFS, 88, 363-369.
[32]
Ruddle, R.W. (1950) Solidification of Castings. Institute of Metals, London.
[33]
Igarshi, I., Ohira, G. and Ikawa, G. (1958) Under Cooled Graphite in Cast Irons. Trans AFS, 60, 561-572.
[34]
Alexander, B.H. and Rhines, M.B. (1950) Secondary Dendrite Arm Spacing in Ferrous Alloys. Trans AIME, 188, 1267-1276.
[35]
Glover, D. and Bates, C.E. (1982) The Relationship among Carbon Equivalent, Microstructure and Solidification Characteristics and Their Effect on Strength and Chill in Gray Cast Iron. Trans AFS, 90, 745-755.
[36]
Radzikowska, J.M. (2010) Graphite Flotation in White Cast Iron. Foundry Research Institute, Krakow, 34-45.
[37]
Zeytin, H., Kubiley, K. and Aydin, H. (2009) The Relationship among Carbon Equivalent, Microstructure and Solidification Characteristics and Their Effect on Strength and Chill in Gray Cast Iron. Journal of Iron and Steel Research, International, 6, 32-36. https://doi.org/10.1016/S1006-706X(09)60040-6
[38]
Ruff, G.F. and Wallace, J.F. (1977) Effect of Solidification Structures on the Tensile Properties of Gray Iron. Trans AFS, 85, 167-174.
[39]
Shaha, S. and Dyuti, S. (2010) Effects of Minor Elements in the Structure of Irons. Journal of Applied Sciences, 10, 1196-1199.
[40]
Suzuki, K. and Kayama, N. (1982) Graphite Nucleation out of Residual Graphite Particles in Molten Cast Iron and Its Chill Decreasing Effect. Trans AFS, 90, 423-430.
[41]
Krawczyk, J. and Pacyna, J. (2009) Theory of Globular Graphite Formation in Cast Iron. Metal, 5, 19-21.
[42]
Fedriksson, H. and Hillert, M. (1971) Direct and Indirect Formation of Graphite in High Alloyed Cast Iron. The British Foundryman, 43, 54-61.
