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Transactions of the Indian Institute of Metals

, Volume 69, Issue 9, pp 1657–1673 | Cite as

Effect of Long-term Ageing on the Microstructure and Mechanical Properties of Creep Strength Enhanced Ferritic P91 Steel

  • C. Pandey
  • M. M. MahapatraEmail author
Technical Paper

Abstract

Present paper describes the microstructural and mechanical properties of creep strength enhanced Cr–Mo P91 steel subjected to a regime of tempering time 720–3000 h. Study on the effect of varying tempering time on microstructure revealed increase in size of precipitates, amount of precipitates and grain size. It was also observed that compared to particle size, effect of tempering time was more pronounced on the grain size. The various phases that formed in the tempered P91 steel were analyzed by X-ray diffraction. Yield strength and tensile strength were observed to be decreasing with increase in tempering time. Increase in duration of tempering time led to decrease in impact toughness of P91 specimens possibly due to cracking of secondary phase particles during straining and decohesion at precipitates and matrix interface. The tempering time also observed to be affecting the hardness of P91 steel but less pronounced compared to the yield strength and tensile strength. Tensile fracture and impact toughness fracture surfaces were studied by using scanning electron microscope. The fracture surface of tempered P91 tensile specimens indicated increased dimples and presence of fewer cleavage facets. The fracture surface of P91impact toughness specimens exhibited both inter lath-decohesion and ductile dimple tearing.

Keywords

CSEF Precipitates Particles Microstructure M23C6 Grain Tempering time 

References

  1. 1.
    Hald J, Int J Press Vessels Pip 85 (2008) 30.CrossRefGoogle Scholar
  2. 2.
    Yoshizawa M, and Igarashi M, Int J Press Vessels Pip 84 (2007) 37.CrossRefGoogle Scholar
  3. 3.
    Scheu C, Kauffmann F, Zies G, Maile K, Straub S, and Mayer K H, Zeitschrift fur Metallkunde 96 (2005) 653.CrossRefGoogle Scholar
  4. 4.
    Norena C H, and Bruzzoni P, Mater Sci Eng A, 527 (2010) 410.CrossRefGoogle Scholar
  5. 5.
    Shibli A, and Starr F, Int J Press Vessels Pip 84 (2007) 114.CrossRefGoogle Scholar
  6. 6.
    Blach J, Falat L, and Sevc P, Eng Fail Anal 16 (2009) 1397.CrossRefGoogle Scholar
  7. 7.
    Zhu L H, Zhao Q X, Gu H C, and Lu Y S, Eng Fract Mech 64 (1999) 327.CrossRefGoogle Scholar
  8. 8.
    Senior B A, Noble F W, and Eyres B L, J Acta Metall 36 (1988) 1855.CrossRefGoogle Scholar
  9. 9.
    Okamura H, Ohtani R, Saito K, Kimura K, Ishii R, Fujiyama K, Hongo S, Iseki T, and Uchida H, Nucl Eng Des 193 (1999) 243.CrossRefGoogle Scholar
  10. 10.
    Maruyama K, Swada K, and Koike J, ISIJ Int 41 (2001) 641.CrossRefGoogle Scholar
  11. 11.
    Sawada K, Taneike M, and Kimura K, ISIJ International 44 (2004) 1243.CrossRefGoogle Scholar
  12. 12.
    Ghassemi-Armaki H, Chen RP, and Maruyama K, Mater Lett 63 (2009) 2423.CrossRefGoogle Scholar
  13. 13.
    Aghajani A, Somsen C, and Eggeler G, Acta Materialia 57 (2009) 5093.CrossRefGoogle Scholar
  14. 14.
    Ghassemi Armaki H, Chen R P, Maruyama K, and Igarashi M. Metall Mater Trans A 42 (2011) 3084.CrossRefGoogle Scholar
  15. 15.
    Kafexhiu F, Vodopivec F, and Vojvodic Tuma J, Mater Tech 46 (2012) 459.Google Scholar
  16. 16.
    Yan W, Wang W, Shan Y, and Yang K, Mater Sci 7 (2013) 1.Google Scholar
  17. 17.
    Dimmer G, Weinert P, Kozeschink E, and Cerjak H, Mater Charact 51 (2003) 341.CrossRefGoogle Scholar
  18. 18.
    Sawada K, Kushima H, Kimura K, and Tabuchi M, ISIJ Int 47 (2007) 733.CrossRefGoogle Scholar
  19. 19.
    Danielsen H K, and Hald J, Mater Sci Eng A 505 (2009) 169.CrossRefGoogle Scholar
  20. 20.
    Golpayegani A, Andren H O, Danielsen H, and Hald J, Mater Sci Eng A 489 (2008) 310.CrossRefGoogle Scholar
  21. 21.
    Pandey C, and Mahapatara MM, in Proc Effect of soaking temperature and time on microstructure and mechanical properties of P91 steel: 23rd Int. Conf: on Processing and Fabrication of Advanced Materials, IIT Roorkee, India (2014).Google Scholar

Copyright information

© The Indian Institute of Metals - IIM 2016

Authors and Affiliations

  1. 1.Department of Mechanical and Industrial EngineeringIndian Institute of TechnologyRoorkeeIndia

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