Journal of Failure Analysis and Prevention

, Volume 13, Issue 4, pp 445–450 | Cite as

Cast Iron Casing Cracking Due to Chunky Graphite Formation

  • Jakub Kaczorowski
  • Karol Jozwiak
  • Marco Innocenti
Technical Article---Peer-Reviewed


Quality inspection of heavy turbomachinery casings made of ductile cast iron has revealed anomalies in the form of characteristic relief pattern on roughly machined surfaces. Detailed microstructural observations determined that this anomaly is related to degeneration of cast iron microstructure where undesired chunky graphite was formed instead of evenly dispersed graphite nodules. Mechanical tests showed that this microstructural alteration led to deterioration of mechanical properties, especially plasticity. Regularity was found as this problem affected mainly thick sections of casts, especially where the cooling rate was limited. This article discusses the consequences of chunky graphite formation, detection methods, acceptance criteria, and preventive actions.


Chunky graphite Degenerated nodular cast iron LCF cracking Preventive actions 


  1. 1.
    Davis, J.: Cast Irons, p. 297. ASM International, Materials Park (1996)Google Scholar
  2. 2.
    Standard Test Method for Evaluating the Microstructure of Graphite in Iron Castings (2010)Google Scholar
  3. 3.
    Microstructure of cast irons. Part 1: Graphite classification by visual analysis, BS (2008)Google Scholar
  4. 4.
    Farrell, T.: The influence of ASTM type V graphite form on ductile iron low cycle fatigue. AFS Trans. 91, 61–64 (1983)Google Scholar
  5. 5.
    Ignaszak, Z.: Study on data base of modelling concerning casting phenomena in cast-iron-mould simulation system. Key Eng. Mater. 457, 305–311 (2011)CrossRefGoogle Scholar
  6. 6.
    Tsumura, O.: Effects of rare earth elements and antimony on morphology of spheroidal graphite in heavy-walled ductile cast iron. Jpn. Cast. 67, 540 (1995)Google Scholar
  7. 7.
    Larranaga, P.: Effect of Sb and Ce on the formation of chunky graphite during solidification of heavy-section castings of near-eutectic spheroidal graphite irons. Metall. Mater. Trans. 3, 654 (2009)CrossRefGoogle Scholar
  8. 8.
    Ignaszak, Z.: Specific structures in heavy ductile iron castings and its identification. Inzynieria Materialowa 140, 716 (2006)Google Scholar
  9. 9.
    Vertesy, G.: Nondestructive characterization of ductile cast iron by magnetic adaptive testing. J. Magn. Magn. Mater. 322, 3117 (2010)CrossRefGoogle Scholar

Copyright information

© ASM International 2013

Authors and Affiliations

  • Jakub Kaczorowski
    • 1
  • Karol Jozwiak
    • 2
  • Marco Innocenti
    • 3
  1. 1.General Electric Company Polska Sp. z o.o.WarsawPoland
  2. 2.Warsaw Institute of AviationWarsawPoland
  3. 3.General Electric Oil & Gas Nuovo Pignone S.r.l.FlorenceItaly

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