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International Journal of Metalcasting

, Volume 9, Issue 4, pp 19–26 | Cite as

Solidification Microstructure of HK Heat Resistant Steel

  • Majid Abbasi
  • Mahdieh Vahdatnia
  • Ali Navaei
Article

Abstract

The as-casr microstructure of HK heat resistant steel produced by the investment casting process has been investigated. The pouring temperature and cooling method effects on the austenite grain size and shape, segregation of alloying elements and formation of eutectic carbides have been evaluated herein. Microscopic studies have shown tliat the microstructure of the steel consists of dendritic austenite with carbides in the grain boundaries and dendritic arm spaces. Decreasing the pouring temperature converts large columnar grains to small equiaxed grains and prevents the large eutectic carbides in the grain and dendritic boundaries. Also, increasing the cooling rate can decrease the formation of grain boundary carbides.

Key wards

HK steel heal resistant steel investment casting solidification microstructure eutectic carbide 

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References

  1. 1.
    ASM Handbook, vol. 15, “Casting,” ASM International (2005).Google Scholar
  2. 2.
    Davis. JR., “Heat Resistant Materials,” ASM Spcciallj Handbook, ASM International (1997).Google Scholar
  3. 3.
    Lampman, S., “Casting Design and Performance,” ASM International (2009).Google Scholar
  4. 4.
    “Steel Casting Handbook, Supplement 9: High Alloy Data Sheets Heat Series,” Steel Founders’ Society of America, SFSA (2004).Google Scholar
  5. 5.
    Kaya, A.A., “Micros true ture of HK40 Alloy after High Temperature Service in Oxidizing/Carburizing Environment 11, Carburization and Carbide Transformations,” Materials Characterization, 49, 23 34 (2002).Google Scholar
  6. 6.
    ASTM Standard A 297, “Standard Specification for Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat Resistant, for General Application,” Approved (2003).Google Scholar
  7. 7.
    ASM Handbook Vol. 1, “Properties and Selection: Irons, Steels and High Performance Alloys,” ASM International (2005).Google Scholar
  8. 8.
    Voicua, R., Lacazca. J., Andricua, E., Poquillona, D., and Furtado, J., “Creep and Tensile Behaviour of Austenitic Fe-Cr-Ni Stainless Steels,” Materials Scieice and Engineering A, 510–511, 185–189 (2009)Google Scholar
  9. 9.
    Zhu, S.O., Zhao, J., and Wang, F.G., “Effects of Groin and Groin Boundary-Strengths on the Creep Crack Growth of HK40 Steel,” Scripta Metallurgica et Materialia, 24, 559–564 (1990).CrossRefGoogle Scholar
  10. 10.
    Zhu, S.J., Li, P.E., and Cao, Z.B., “The Effect of Prior Aging on the Creep Crack Growth Behavior of Austenitic HK40 Steel,” Material Science aid Engineering, 114, 7–12 (1989).CrossRefGoogle Scholar
  11. 11.
    Wi, X.Q., Jing, H.M., Zheng, Y.Z., Yao, Z.M., Ke, W., and Hu, Z.Q., “The Euiceic Carbides and Creep Rupture Strength of 25Cr2ONi Heat-resistant Steel Tubes Ccntrifugally Cast with Different Solidification Conditions,” Materials Science and Engineering A, 293, 252–260 (2000).CrossRefGoogle Scholar
  12. 12.
    Pickarski, B., “Effect of Nb and Ti Additions on Micrestructure and Identification of Precipitates in Stabilized Ni-Cr Cast Austenitic Steels,” Materials Cltaracterizaiion, 47, 181–186 (2001).CrossRefGoogle Scholar
  13. 13.
    Yang, Y., Liu, O., Jioo, Y., Ge, Y., Hu, Z., Ga, Y., Jia, G., and Zhang, J., “Application of Steady Magnetic Field for Refining Solidification Structure and Enhancing Mechanical Properties of 25Cr-20Ni-Fe-C Alloy in Centrifugal Casting,” ISIJ International, 35, 385–392 (1995).Google Scholar
  14. 14.
    Wu, X.Q., Yang, Y.S., Zhang, J.S., Jia, G.L, and Hu, Z.Q., “Structure Characteristics in Industrially Ccntrifugally Cast 25Cr20Ni Stainless Steel Tubes Solidified under Different Electromagnetic Field Intensity,” Materials Engineering and Performance, 5, 525–530 (1999).CrossRefGoogle Scholar
  15. 15.
    Wu, X.Q., Yang, Y.S., Zhang, J.S., and Hu, Z.Q, “Difference in As-cast Structures of Centrifugal Casting Heat-resistant Alloy Caused by Exerted Electromagnetic Field and Cooling Conditions,” Material Sciences, 17, 1403–1405 (1998).Google Scholar
  16. 16.
    ASTM Standard A 781, “Standard Specification for Castings, Steel and Alloy, Common Requirements for General Industrial Use,” (2004).Google Scholar
  17. 17.
    Campbell, J., “Castings,” 4th ed., Butterworth Heinemann Pub., Oxford, p.54 (2000).Google Scholar
  18. 18.
    Peng B., Zhang H., Hong J., Gao J., Wang Q., and Zhang H., “The Effect of Ma23C6 on the High-temperature Tensile Strength of Two Austenitic Heat-resistant Steels, 22Cr-25Ni-Mo-Nb-N and 25Cr-20Ni-Nb-N,” Materials Science and Engineering, 528, 3625–3629 (2011).CrossRefGoogle Scholar
  19. 19.
    Laird, G., Gundlach. R., and Rohring, K., “Abrasion-Resistant Cast Iron Handbook,” AFS (2000).Google Scholar
  20. 20.
    Singh, K.K., Verma, R.S., and Murty, G.M.D., “Optimizing Wear Resistance and Impact Toughness in High Chromium Iron Mo-Ni Alloy,” Journal of Materials Engineering and Performance, 18, 438–440 (2009).CrossRefGoogle Scholar
  21. 21.
    Kurz, W., Fisher, D.J., “Fundamentals of Solidification,” Trans Tech Pub. (1998).Google Scholar
  22. 22.
    Hejazi, J., “Solidification and Metallurgical Fundamentals of Casting,” Iran University of Science and Technology, Tehran, (in Persian) (1998).Google Scholar
  23. 23.
    Bhadeshia, H.K.D.H., and Honeycombe, R., “Steels Micrestructure and Properties,” 3th ed., Elsevier (2006).Google Scholar
  24. 24.
    Kaya, A.A., “Microstructureof HK40 Alloy after High Temperature Service in Oxidizing/Carburizing Environment 1. Oxidation Phenomena and Propagation of a Crock,” Materials Characterization, 49, 11–21 (2002).CrossRefGoogle Scholar

Copyright information

© American Foundry Society 2015

Authors and Affiliations

  • Majid Abbasi
    • 1
  • Mahdieh Vahdatnia
    • 1
  • Ali Navaei
    • 1
  1. 1.Department of Materials EngineeringBabol Noshirvani University of TechnologyBabolIran

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