Inoculation Enhancing Effects on Chill Tendency in the Mould Inoculated Grey Cast Iron

Abstract:

Inoculation is a treatment applied to the liquid base iron, to supply one or more elements, such as Al, Ba, Ca, Zr, Sr, Ce, La etc. with active roles in developing graphite nucleation sites. The efficiency of inoculants is directly dependent on the sulphur level: lower sulphur, lower inoculating power or unpredictable results. The objective of this paper is to examine the effects of a S and O containing inoculant enhancer [S,O,Al,Ca-FeSi alloy] to conventional Ca,Ba-FeSi alloy, in the mold treatment of electrically melted grey iron at 0.035%S, 0.002%Al, 0.0005%Zr, (%Mn) x (%S) < 0.02. The wedge test samples [W3 – ASTM A367] were used to evaluate the influence of the cooling rate and inoculation on the carbides formation. It was re-confirmed that for above mentioned critical chemistry conditions, this iron is sensitive to chill formation, despite the carbon equivalent level at 3.8%. Inoculation enhancement increased the effectiveness of the Ca,Ba-FeSi standard inoculant.

• Periodical: Advanced Materials Research (Volume 1128)
• Pages: 98-104
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1128.98
• Online since: October 2015
• Authors: Ion Stefan*, Ciprian Firican
• Keywords: Al, Ba, CA, Carbides, Castings, Chill, Grey Cast Iron, Inoculant Enhancer, Inoculation, O, S

References

[1] I. Riposan, M. Chisamera, S. Stan, C. Hartung, D. White, Three-Stage Model for the Nucleation of Graphite in Grey Cast Iron. Mat. Sci. Techn., 2010, 26 (12) 1439-1447.

DOI: 10.1179/026708309x12495548508626

[2] I. Riposan, M. Chisamera, S. Stan, Enhanced quality in electric melt grey cast irons, ISIJ International, 2013 53, (10) 1683–1695.

DOI: 10.2355/isijinternational.53.1683

[3] T. Skaland, A New Approach to Ductile Iron Inoculation, AFS Transactions, (2001).

[4] J.O. Choi et. al, Effect of rare earth element on microstructure formation and mechanical properties of thin wall ductile iron castings, Journal of Materials Science and Engineering, A 383 (2004) 323–333.

DOI: 10.1016/j.msea.2004.04.060

[5] R.L. Naro, U.S. Patents No. 6, 293, 988 B1 (2001), No. 6, 733, 565 B1, No. 6, 866, 696B1.

[6] R. Gundlach, Observations on Structure Control to Improve the Properties of Cast Irons, The 2008 Honorary Cast Iron Lecture, Div. 5, AFS Metalcasting Congress, Atlanta, Georgia, USA, Paper 08-158 (2008).

[7] S. Stan, M. Chisamera, I. Riposan, E. Stefan, M. Barstow, Solidification Pattern of Un-inoculated and Inoculated Gray Cast Irons in Wedge Test Samples. AFS Transactions, 2010, Vol. 118, 295-309.

DOI: 10.4028/www.scientific.net/amr.23.307

[8] I. Riposan, I.C. Stefan, M.C. Firican, S. Stan, R.L. Naro, D.C. Williams. Increasing the Inoculant Potency of Comm. Inoc. Alloys in Induct. Melted Gray Iron. 119th AFS Congr., April 2015, Columbus, OH, USA, Paper 15-016.

[9] I. Riposan, M. Chisamera, S. Stan, M. Barstow, Improving chill control in iron powder treated slightly hypereutectic grey cast irons. China Foundry, 2011, 8 (2), 228-234.

DOI: 10.1179/1743133611y.0000000010