Skip to main content
SpringerLink
Log in

Integrated System of Thermal/Dimensional Analysis for Quality Control of Gray and Ductile Iron Castings Solidification

  • Published:
International Journal of Metalcasting Aims and scope Submit manuscript

Abstract

The main objective of the present work is to introduce a specific experimental instrument and technique for simultaneously evaluating cooling curves and expansion/contraction of cast metals during solidification, adapted for commercial foundry use. The recorded data are processed using specialized software, which conveniently displays both cooling and contraction/expansion curves and their specific parameter values. Experiments compared hypoeutectic gray (GI) and ductile (DI) irons with white (WI) irons. Three important moments were found on the expansion/contraction-cooling curves: the start of eutectic freezing, the point of maximum expansion and the end of solidification. All of the tested irons have similar values for initial expansion up to the start of eutectic freezing (0.44%) due to the ferrostatic pressure, silica sand mold expansion, mold movement, etc. The maximum expansion, reached between the temperature of eutectic recalescence and the end of solidification, depends on the carbides/graphite ratio and graphite morphology: WI-0.465%, GI-0.552%, DI-1.032%, as averages. Graphitic expansion, absent for WI, increased to 0.109% (GI) and up to 0.596% (DI). For both GI and DI, the expansion at the end of solidification is only 6% lower compared to the maximum level, while for WI it decreased more than 50%. Specifically, the acceleration rate of the graphitic expansion up to the maximum level (Kgr1) is different compared with its deceleration to the end of solidification (Kgr2), and also are different for irons being tested, GI versus DI. Nodular graphite led to the (Kgr1) factor being 2.5 times higher, compared to GI, whereas only a slight difference was observed between GI and DI for the Kgr2 factor. Higher graphitic expansion in DI led to higher shrinkage sensitivity, compared to GI, as measured in furan resin mold test castings.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11

Similar content being viewed by others

References

  1. M. Chisamera, I. Riposan, S. Stan, M. Barstow, Simultaneous cooling and contraction/expansion curve analysis during ductile iron solidification. AFS Trans. 120, 375–388 (2012)

    Google Scholar 

  2. J.F. Wallace, P.K. Samal, J.D. Voss, Factors influencing a shrinkage cavity formation in ductile iron. AFS Trans. 92, 765–784 (1984)

    Google Scholar 

  3. E. Fras, H. Lopez, Eutectic cells and nodule count-an index of molten iron quality. Int. J. Metalcast. 4(3), 35–61 (2010)

    Article  Google Scholar 

  4. T. Skaland, Ductile iron shrinkage control through graphite nucleation and growth. Int. J. Cast Met. Res. 16(1–3), 11–16 (2003)

    Article  Google Scholar 

  5. T. Skaland, A new method for chill and shrinkage control in ladle treated ductile iron, in Proceedings of 2003 Keith Millis symposium on ductile cast iron, 2003, Hilton Head Island, SC, USA, pp. 61–69 and in Proceedings of the 66 th World Foundry Congress, 2004, Istanbul, Turkey, pp. 975–987

  6. D. White, Avoiding shrinkage defects in ductile iron. AFS Trans. 119, Paper 11-141 (2011)

  7. W.Z. Li, B.C. Liu, J.R. Li, Shrinkage behaviour of spheroidal graphite cast iron in green and dry sand molds for the benchmarking of solidification simulation. J. Mater. Sci. Technol. 17(6), 610–614 (2001)

    Google Scholar 

  8. I. Ohnaka, J. Iwane, H. Yasuda, J.D. Zhu, Prediction of porosity defect in spheroidal graphite iron castings. Int. J. Cast Met. Res. 16(1–3), 293–299 (2003)

    Article  Google Scholar 

  9. D.M. Stefanescu, Computer simulation of shrinkage related defects in metal castings—a review. Int. J. Cast Met. Res. 18(3), 129–143 (2005)

    Article  Google Scholar 

  10. B.P. Winter, T.R. Ostrom, D.J. Hartman, P.K. Trojan, R.D. Pehlke, Mold dilatation and volumetric shrinkage of white, gray and ductile cast irons. AFS Trans. 92, 551–560 (1984)

    Google Scholar 

  11. C.E. Bates, G.L. Oliver, R.H. McSwain, Volumetric changes during freezing of ductile cast iron. AFS Trans. 85, 289–298 (1977)

    Google Scholar 

  12. A. Tadesse, H. Fredriksson, Volume change during the solidification of grey cast iron: its relation with the microstructural variation, comparison between experimental and theoretical analysis. Int. J. Cast Met. Res. 30(3), 159–170 (2017)

    Article  Google Scholar 

  13. D.M. Stefanescu, M. Moran, S. Boonmee, W.L. Guesser, The use of combined liquid displacement and cooling curve analysis in understanding the solidification of cast irons. AFS Trans. 120, 365–374 (2012)

    Google Scholar 

  14. G. Alonso, A. Loizaga, G. Zarrabeitia, D.M. Stefanescu, R. Suarez, Kinetics of graphite expansion during solidification of lamellar and spheroidal graphite iron. AFS Trans., 122, Paper 14 – 006 (2014)

  15. A. Regordosa, N. Llorca-Isern, Microscopic characterization of different shrinkage defects in ductile irons and their relation with composition and inoculation process. Int. J. Metalcast. 11(4), 778–789 (2017)

    Article  Google Scholar 

  16. T. Kanno, I. Kang, Y. Fukuda, T. Mizuki, S. Kiguchi, Effect of pouring temperature and composition on shrinkage cavity in spheroidal graphite cast iron. AFS Trans. 114, 525–534 (2006)

    Google Scholar 

  17. R. Hummer, A study of the shrinkage and dilatation during solidification of nodular cast iron-its relationship to the morphology of crystallization, in The Physical Metallurgy of Cast Iron, ed. by H. Fredriksson and M. Hillert eds., MRS Symposia Proceedings, Vanderbilt Avenue (NY), Elsevier, 34, pp. 213–222 (1984)

  18. A. Tadesse, H. Fredriksson, The effects of carbon on the solidification of nodular cast iron—its study with the help of linear variable differential transformer and microstructure analysis. Int. J. Cast Met. Res. 31(2), 108–117 (2018)

    Article  Google Scholar 

  19. D. White, Avoiding shrinkage defects and maximizing yield in ductile iron. AFS Trans. 120, Paper 12-081 (2012)

  20. S. Stan, M. Chisamera, I. Riposan, L. Neacsu, A.M. Cojocaru, I. Stan, Integrated system of thermal/dimensional analysis for quality control of metallic melt and ductile iron casting solidification. J. Mater. Eng. Performances 27(10), 5187–5196 (2018)

    Article  Google Scholar 

  21. T. Thielemann, Zur Wirkung van Spurenelementen in Gusseisen mit Kugelgraphit. Giessereitechnik Issue 1, 16–24 (1970)

    Google Scholar 

  22. M. Chisamera, I. Riposan, S. Stan, P. Toboc, T. Skaland, D. White, Shrinkage evaluation in ductile iron as influenced by mold media and inoculant type. Int. J. Cast Met. Res. 24(1), 28–36 (2011)

    Article  Google Scholar 

  23. P. Svidro, A. Dioszegi, On problems of volume change measurements in lamellar cast iron. Int. J. Cast Met. Res. 27(1), 26–37 (2014)

    Article  Google Scholar 

  24. J. Thiel, M. Ziegler, P. Dziekonski, S. Joyce, Investigation into the technical limitations of silica sand due to thermal expansion. AFS Trans. 115, Paper 07-145 (2007)

Download references

Acknowledgements

This work was partially financed by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS/CCCDI—UEFISCDI, Project Number PN-III-P2-2.1-PED-2016-1793, within PNCDI III. The authors would like to recognize and thank Michael Barstow (Consultant) for reviewing and editing this paper.

Author information

Authors and Affiliations

  1. Politehnica University of Bucharest, Bucharest, Romania

    S. Stan, M. Chisamera, I. Riposan, E. Stefan, L. Neacsu, A. M. Cojocaru & I. Stan

Authors
  1. S. Stan
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. M. Chisamera
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. I. Riposan
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. E. Stefan
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. L. Neacsu
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. A. M. Cojocaru
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. I. Stan
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to I. Riposan.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Stan, S., Chisamera, M., Riposan, I. et al. Integrated System of Thermal/Dimensional Analysis for Quality Control of Gray and Ductile Iron Castings Solidification. Inter Metalcast 13, 653–665 (2019). https://doi.org/10.1007/s40962-018-0285-5

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s40962-018-0285-5

Keywords

Search

Navigation