Journal of Materials Science

, Volume 51, Issue 20, pp 9424–9439 | Cite as

Effect of W on tempering behaviour of a 3 %Co modified P92 steel

  • A. Fedoseeva
  • N. Dudova
  • U. Glatzel
  • R. Kaibyshev
Original Paper


The tempering behaviour of two 9Cr–3Co–0.5Mo–0.2 V–0.05Nb–0.005B steels containing 2 and 3 wt% W was examined. The decomposition of retained austenite induces the formation of semi-continuous films of W-rich M23C6 carbides along boundaries at 525 °C. The increase in W content from 2 to 3 wt% modifies the normal carbide precipitation sequence in the vicinity of these boundaries. The formation of W segregation at prior austenite grain/interlath boundaries leads to formation of the thermodynamically metastable W-rich M6C carbides. Finally, these M6C carbides transform to a stable Laves phase. Two-phase separation of MX carbonitrides into Nb-rich and V-rich dispersoids appears in both steels after tempering at 750 °C. This separation is thermodynamically metastable and attributed to the precipitation of Nb-rich MX carbonitrides with a round shape on dislocations at T ≤ 450 °C and V-rich MX carbonitrides within ferritic matrix at 750 °C. Moreover, in the steel with 2 %W, the additional separation of V-rich MX carbonitrides into W-rich particles located in the vicinity of the prior austenite grain/lath boundaries and W-free ones located within the interiors of laths was observed.


Austenite Cementite Lave Phase Prior Austenite Precipitation Sequence 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors acknowledge with gratitude the financial support received through the Russian Science Foundation, under Grant No. 14-29-00173 (N. D. and R. K., Belgorod State University) and A. F. greatly acknowledges the support by DAAD (Deutscher Akademischer Austausch Dienst) under Project No. A/12/86596 in the part of microstructural investigations by TEM. The authors are grateful to the staff of the Joint Research Center, Belgorod State University, for their assistance with instrumental analysis.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


  1. 1.
    Abe F, Kern TU, Viswanathan R (2008) Creep resistant steels. woodhead publishing in materials, CambridgeCrossRefGoogle Scholar
  2. 2.
    Kern T-U, Staubli M, Scarlin B (2002) The European efforts in material development for 650°C USC power plants-COST522. ISIJ Int 42:1515–1519CrossRefGoogle Scholar
  3. 3.
    Kaybyshev RO, Skorobogatykh VN, Shchenkova IA (2010) New martensitic steels for fossil power plant: creep resistance. Phys Met Metall 109:186–200CrossRefGoogle Scholar
  4. 4.
    Kipelova A, Odnobokova M, Belyakov A, Kaibyshev R (2013) Effect of Co on creep behavior of a P911 steel. Metall Mater Trans A 44A:577–583CrossRefGoogle Scholar
  5. 5.
    Dudova N, Plotnikova A, Molodov D, Belyakov A, Kaibyshev R (2012) Structural changes of tempered martensitic 9%Cr-2%W-3%Co steel during creep at 650°C. Mater Sci Eng A 534:632–639CrossRefGoogle Scholar
  6. 6.
    Abe F (2009) Analysis of creep rates of tempered martensitic 9%Cr steel based on microstructure evolution. Mater Sci Eng A 510–511:64–69CrossRefGoogle Scholar
  7. 7.
    Kostka A, Tak K-G, Hellmig RJ, Estrin Y, Eggeler G (2007) On the contribution of carbides and micrograin boundaries on the creep strength of tempered martensite ferritic steels. Acta Mater 55:539–550CrossRefGoogle Scholar
  8. 8.
    Bhadeshia HKDH, Honeycombe R (2006) Steels: microstructure and properties, 3rd edn. Butterworth-Heinemann, OxfordGoogle Scholar
  9. 9.
    Kipelova AYu, Belyakov AN, Skorobogatykh VN, Shchenkova IA, Kaibyshev RO (2010) Tempering-induced structural changes in steel 10Kh9K3V1M1FBR and their effect on the mechanical properties. Met Sci Heat Treat 52:100–110CrossRefGoogle Scholar
  10. 10.
    Dudova N, Kaibyshev R (2011) On the precipitation sequence in a 10%Cr steel under tempering. ISIJ Int 51:826–831CrossRefGoogle Scholar
  11. 11.
    Dudova N, Mishnev R, Kaibyshev R (2011) Effect of tempering on microstructure and mechanical properties of boron containing 10%Cr steel. ISIJ Int 51:1912–1918CrossRefGoogle Scholar
  12. 12.
    Kitahara H, Ueji R, Tsuji N, Minamino Y (2006) Crystallographic features of lath martensite in low-carbon steel. Acta Mater 54:1279–1288CrossRefGoogle Scholar
  13. 13.
    Wang SS, Peng DL, Chang L, Hui XD (2013) Enhanced mechanical properties induced by refined heat treatment for 9Cr-0.5Mo-1.8 W martensitic heat resistant steel. Mater Des 50:174–180CrossRefGoogle Scholar
  14. 14.
    Yan P, Liu Zh, Bao H, Weng Y, Liu W (2014) Effect of tempering temperature on the toughness of 9Cr–3 W–3Co martensitic heat resistant steel. Mater Des 54:874–879CrossRefGoogle Scholar
  15. 15.
    Xia ZX, Zhang C, Fan NQ, Zhao YF, Xue F, Liu SJ (2012) Improve creep properties of reduced activation steels by controlling precipitation behaviors. Mater Sci Eng A 545:91–96CrossRefGoogle Scholar
  16. 16.
    Abe F (2003) Effect of quenching, tempering, and cold rolling on creep deformation behavior of a tempered martensitic 9Cr-1 W steel. Metall Mater Trans A 34:913–925CrossRefGoogle Scholar
  17. 17.
    Barbadikar D, Deshmukh GS, Maddi L, Laha K et al (2015) Effect of normalizing and tempering temperatures on microstructure and mechanical properties of P92 steel. Int J Press Vess Piping 132–133:97–105CrossRefGoogle Scholar
  18. 18.
    Maddi L, Ballal AR, Peshwe DR, Paretkar RK, Laha K, Mathew MD (2015) Effect of tempering temperature on the stress rupture properties of Grade 92 steel. Mater Sci Eng A 639:431–438CrossRefGoogle Scholar
  19. 19.
    Hong SG, Lee WB, Park CG (2011) The effects of tungsten additions on the microstructural stability of 9Cr-Mo steels. J Nucl Mater 288:202–207CrossRefGoogle Scholar
  20. 20.
    Abe F, Araki H, Noda T (1991) The effect of tungsten on dislocation recovery and precipitation behavior of low-activation martensitic 9Cr steels. Met Trans A 22A:2225–2236CrossRefGoogle Scholar
  21. 21.
    Tsuchida Y, Okamoto K (1995) Improvement of creep rupture strength of high cr ferritic steel by addition of W. ISIJ Int 35(3):317–323CrossRefGoogle Scholar
  22. 22.
    Knezevic V, Balun J, Sauthoff G, Inden G, Schneider A (2008) Design of martensitic/ferritic heat-resistant steels for application at 650 & #xB0;C with supporting thermodynamic modelling. Mater Sci Eng A 477:334–343CrossRefGoogle Scholar
  23. 23.
    Sakasegawa H, Hirose T, Kohyama A, Katoh Y, Harada T, Asakura K, Kimagai T (2002) Effects of precipitation morphology on toughness of reduced activation ferritic/martensitic steels. J Nucl Mater 307–311:490–494CrossRefGoogle Scholar
  24. 24.
    Danielsen HK, Di Nunzio PE, Hald J (2013) Kinetics of Z-phase precipitation in 9–12 pct Cr steels. Metall Mater Trans A 44:2445–2452CrossRefGoogle Scholar
  25. 25.
    Subramanian R, Tripathy H, Rai AK, Hajra RN, Saibaba S, Jayakumar T, Kumar ER (2015) Thermal expansion characteristics of Fe–9Cr–0.12C–0.56Mn–0.24 V–1.38 W–0.06Ta (wt%) reduced activation ferritic–martensitic steel. J Nucl Mater 459:150–158CrossRefGoogle Scholar
  26. 26.
    Pawlowski B, Bala P, Dziurka R (2014) Improper interpretation of dilatometric data for cooling transformation in steels. Arch Metall Mater 59(3):1159–1161Google Scholar
  27. 27.
    Suzuki K, Kumai S, Toda Y, Kushima H, Kimura K (2003) Two-phase separation of primary MX carbonitride during tempering in creep resistant 9Cr1MoVNb steel. ISIJ Int 43:1089–1094CrossRefGoogle Scholar
  28. 28.
    Fedorova I, Kostka A, Tkachev E, Belyakov A, Kaibyshev R (2016) Tempering behavior of a low nitrogen boron-added 9%Cr steel. Mater Sci Eng, A 662:443–455CrossRefGoogle Scholar
  29. 29.
    Zhou DS, Shiflet GJ (1992) Ferrite-cementite crystallography in pearlite. Metall Trans A 23A:1259–1269CrossRefGoogle Scholar
  30. 30.
    Perrard F, Deschamps A, Maugis P (2007) Modelling the precipitation of NbC on dislocations in α-Fe. Acta Mater 55:1255–1266CrossRefGoogle Scholar
  31. 31.
    Hin C, Brechet Y, Maugis P, Soisson F (2008) Kinetics of heterogeneous dislocation precipitation of NbC in alpha-iron. Acta Mater 56:5535–5543CrossRefGoogle Scholar
  32. 32.
    Eysymontt J, Schwedler A (1973) On the dark-field image technique in the identification of very small particles in thin foils. Kristall und Technik 8(11):1281–1286CrossRefGoogle Scholar
  33. 33.
    Pecharsky VK, Zavalij PY (2003) Fundamentals of powder diffraction and structural characterization of materials. Springer, New YorkGoogle Scholar
  34. 34.
    Kipelova A, Belyakov A, Kaibyshev R (2013) The crystallography of M23C6 carbides in a martensitic 9% Cr steel after tempering, aging and creep. Phil Mag 93:2259–2268CrossRefGoogle Scholar
  35. 35.
    Sung HJ, Heo NH, Heo Y-U, Kim S-J (2014) The abnormal segregation behavior of solutes under tensile stress and its effect on carbide reactions in 2.25Cr–1.5 W heat-resistant steels. Mater Sci Eng A 619:146–151CrossRefGoogle Scholar
  36. 36.
    Heo NH, Nam JW, Heo Y-U, Kim S-J (2013) Grain boundary embrittlement by Mn and eutectoid reaction in binary Fe–12Mn steel. Acta Mater 61:4022–4034CrossRefGoogle Scholar
  37. 37.
    Kuzmina M, Ponge D, Raabe D (2015) Grain boundary segregation engineering and austenite reversion turn embrittlement into toughness: example of a 9 wt% medium Mn steel. Acta Mater 86:182–192CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • A. Fedoseeva
    • 1
  • N. Dudova
    • 1
  • U. Glatzel
    • 2
  • R. Kaibyshev
    • 1
  1. 1.Belgorod State UniversityBelgorodRussia
  2. 2.Metals and AlloysUniversity BayreuthBayreuthGermany

Personalised recommendations