Skip to main content
SpringerLink
Log in

Study on the microstructure and toughness of dissimilarly welded joints of advanced 9Cr/CrMoV

  • Article
  • Published:
Journal of Materials Research Aims and scope Submit manuscript

Abstract

Dissimilar joints of advanced 9Cr/CrMoV have been successfully welded by narrow gap submerged arc welding using multi-layer and multi-pass techniques. The objective of our study is to establish the correlation between impact toughness and microstructural characteristics of the welded joints. Impact toughness tests were conducted in a wide range of temperature from −60 °C to 80 °C for different regions in the dissimilar joints. The fracture appearance transition temperature of base metal of 9Cr, CrMoV and weld metal were tested as 23 °C, −9 °C and −2 °C respectively, which all satisfied the service requirement. Optical microscope and scanning electron microscope revealed that weld metal and base metal of CrMoV comprised martensite and bainite while 9Cr was composed of lath martensite. The low toughness in the latter region arose from large grains with excessive carbide precipitates. Nonuniform microstructure in the heat-affected zone of 9Cr side caused different crack propagation paths and subsequently led to large variations of absorbed energy. When crack propagates along carbon-enriched zone in heat affected zone, the absorbed energy was 48 J. With crack deviating far from carbon-enriched zone, the absorbed energy increased to 147 J. Examination on fracture surfaces revealed the typical brittle fracture appearance in 9Cr and inter-granular fracture mode in heat-affected zone of 9Cr side when crack propagated along carbon-enriched zone.

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.

Institutional subscriptions

FIG. 1
FIG. 2
FIG. 3
FIG. 4
FIG. 5
FIG. 6
FIG. 7
FIG. 8
FIG. 9
FIG. 10
FIG. 11

Similar content being viewed by others

References

  1. H. Poules: Advantages of ultra super critical technology in power generation. Presented at the International Conference on Clean Coal Technologies for our Future CCT, 10, 2005.

  2. X.J. Liu, X.B. Kong, G.L. Hou, and J.H. Wang: Modeling of a 1000 MW power plant ultra super-critical boiler system using fuzzy-neural network methods. Energy Convers. Manage. 65, 518 (2013).

    Article  Google Scholar 

  3. W. Kosman: Thermal analysis of cooled supercritical steam turbine components. Energy 35 (2), 1181 (2010).

    Article  Google Scholar 

  4. W. Huo, J. Li, and X. Yan: Effects of coolant flow rates on cooling performance of the intermediate pressure stages for an ultra-supercritical steam turbine. Appl. Therm. Eng. 62 (2), 723 (2014).

    Article  Google Scholar 

  5. W. Kosman, M. Roskosz, and K. Nawrat: Thermal elongations in steam turbines with welded rotors made of advanced materials at supercritical steam parameters. Appl. Therm. Eng. 29 (16), 3386 (2009).

    Article  CAS  Google Scholar 

  6. R. Narula, D. Koza, and H. Wen: Impacts of steam conditions on plant materials and operation in ultra-supercritical coal power plants. In Ultra-Supercritical Coal Power Plants: Materials, Technologies and Optimisation, D. Zhang, ed. (Woodhead Publishing, Cambridge, 2013); p. 23.

    Chapter  Google Scholar 

  7. L. Helis, Y. Toda, T. Hara, H. Miyazaki, and F. Abe: Effect of cobalt on the microstructure of tempered martensitic 9Cr steel for ultra-supercritical power plants. Mater. Sci. Eng., A 510–511, 88–94 (2009).

    Article  CAS  Google Scholar 

  8. P. Verma, G.S. Rao, P. Chellapandi, G. Mahobia, K. Chattopadhyay, N.S. Srinivas, and V. Singh: Dynamic strain ageing, deformation, and fracture behavior of modified 9Cr–1Mo steel. Mater. Sci. Eng., A 621, 39 (2015).

    Article  CAS  Google Scholar 

  9. F. Abe, T. Horiuchi, M. Taneike, and K. Sawada: Stabilization of martensitic microstructure in advanced 9Cr steel during creep at high temperature. Mater. Sci. Eng., A 378 (1–2), 299 (2004).

    Article  CAS  Google Scholar 

  10. C. Gupta, G.K. Dey, J.K. Chakravartty, D. Srivastav, and S. Banerjee: A study of bainite transformation in a new CrMoV steel under continuous cooling conditions. Scr. Mater. 53 (5), 559 (2005).

    Article  CAS  Google Scholar 

  11. E.J. McDonald, K.R. Hallam, W. Bell, and P.E.J. Flewitt: Residual stresses in a multi-pass CrMoV low alloy ferritic steel repair weld. Mater. Sci. Eng., A 325 (1–2), 454 (2002).

    Article  Google Scholar 

  12. D. Meng, F. Lu, H. Cui, Y. Ding, X. Tang, and X. Huo: Investigation on creep behavior of welded joint of advanced 9% Cr steels. J. Mater. Res. 30 (2), 197 (2015).

    Article  CAS  Google Scholar 

  13. F. Lu, X. Liu, P. Wang, Q. Wu, H. Cui, and X. Huo: Microstructural characterization and wide temperature range mechanical properties of NiCrMoV steel welded joint with heavy section. J. Mater. Res. 30 (13), 2108 (2015).

    Article  CAS  Google Scholar 

  14. W. Liu, X. Liu, F. Lu, X. Tang, H. Cui, and Y. Gao: Creep behavior and microstructure evaluation of welded joint in dissimilar modified 9Cr–1Mo steels. Mater. Sci. Eng., A 644, 337 (2015).

    Article  CAS  Google Scholar 

  15. E.M. El-Banna, M.S. Nageda, and M.M. Abo El-Saadat: Study of restoration by welding of pearlitic ductile cast iron. Mater. Lett. 42 (5), 311 (2000).

    Article  CAS  Google Scholar 

  16. H. Furuya, S. Aihara, and K. Morita: A new proposal of HAZ toughness evaluation Method-Part 1: Haz toughness of structural steel in multilayer and single-layer weld joints. Weld. J. 86 (1), 1 (2007).

    Google Scholar 

  17. Q. Wu, F. Lu, H. Cui, X. Liu, P. Wang, and X. Tang: Role of butter layer in low-cycle fatigue behavior of modified 9Cr and CrMoV dissimilar rotor welded joint. Mater. Des. 59, 165 (2014).

    Article  CAS  Google Scholar 

  18. Q. Guo, F. Lu, X. Liu, R. Yang, H. Cui, and Y. Gao: Correlation of microstructure and fracture toughness of advanced 9Cr/CrMoV dissimilarly welded joint. Mater. Sci. Eng., A 638 (0), 240 (2015).

    Article  CAS  Google Scholar 

  19. Q. Guo, F. Lu, H. Cui, R. Yang, X. Liu, and X. Tang: Modelling the crack propagation behavior in 9Cr/CrMoV welds. J. Mater. Process. Technol. 226, 125 (2015).

    Article  CAS  Google Scholar 

  20. M. Taneike, K. Sawada, and F. Abe: Effect of carbon concentration on precipitation behavior of M23C6 carbides and MX carbonitrides in martensitic 9Cr steel during heat treatment. Metall. Mater. Trans. A 35, 1255 (2004).

    Article  Google Scholar 

  21. Q. Wu, F. Lu, H. Cui, X. Liu, P. Wang, and Y. Gao: Soft zone formation by carbon migration and its effect on the high-cycle fatigue in 9% Cr–CrMoV dissimilar welded joint. Mater. Lett. 141, 242 (2015).

    Article  CAS  Google Scholar 

  22. M.L. Zhu and F.Z. Xuan: Effects of temperature on tensile and impact behavior of dissimilar welds of rotor steels. Mater. Des. 31, 3346 (2010).

    Article  CAS  Google Scholar 

  23. A. Shekhter, S. Kim, D.G. Carr, A.B.L. Croker, and S.P. Ringer: Assessment of temper embrittlement in an ex-service 1Cr–1Mo–0.25V power generating rotor by Charpy V-Notch testing, KIc fracture toughness and small punch test. Int. J. Pressure Vessels Piping 79 (8–10), 611 (2002).

    Article  CAS  Google Scholar 

  24. B. Tanguy, J. Besson, R. Piques, and A. Pineau: Ductile to brittle transition of an A508 steel characterized by Charpy impact test: Part I: Experimental results. Eng. Fract. Mech. 72 (1), 49 (2005).

    Article  Google Scholar 

  25. P. Haušild, C. Berdin, and P. Bompard: Prediction of cleavage fracture for a low-alloy steel in the ductile-to-brittle transition temperature range. Mater. Sci. Eng., A 391 (1–2), 188 (2005).

    Article  CAS  Google Scholar 

  26. S.H. Song, H. Zhuang, J. Wu, L.Q. Weng, Z.X. Yuan, and T.H. Xi: Dependence of ductile-to-brittle transition temperature on phosphorus grain boundary segregation for a 2.25Cr1Mo steel. Mater. Sci. Eng., A 486 (1–2), 433 (2008).

    Article  CAS  Google Scholar 

  27. H. Jeong, S-H. Nahm, K-Y. Jhang, and Y-H. Nam: Evaluation of fracture toughness degradation of CrMoV rotor steels based on ultrasonic nonlinearity measurements. KSME Int. J. 16 (2), 147 (2002).

    Article  Google Scholar 

  28. J. Foulds and R. Viswanathan: Determination of the toughness of in-service steam turbine disks using small punch testing. J. Mater. Eng. Perform. 10 (5), 614 (2001).

    Article  CAS  Google Scholar 

  29. Y.J. Chao, J.D. Ward, Jr., and R.G. Sands: Charpy impact energy, fracture toughness and ductile–brittle transition temperature of dual-phase 590 Steel. Mater. Des. 28 (2), 551 (2007).

    Article  CAS  Google Scholar 

  30. J.W. Kim, K. Lee, J.S. Kim, and T.S. Byun: Local mechanical properties of alloy 82/182 dissimilar weld joint between SA508 Gr.1a and F316 SS at RT and 320 °C. J. Nucl. Mater. 384 (3), 212 (2009).

    Article  CAS  Google Scholar 

  31. A. Eghlimi, M. Shamanian, M. Eskandarian, A. Zabolian, and J.A. Szpunar: Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by austenitic filler metal. Mater. Charact. 106, 208 (2015).

    Article  CAS  Google Scholar 

  32. C. Lundin, K. Khan, and D. Yang: Report No. 1: Effect of carbon migration in Cr-Mo weldments on metallurgical structure and mechanical properties (Bulletin-Welding Research Council, 1995).

  33. A. Celik and A. Alsaran: Mechanical and structural properties of similar and dissimilar steel joints. Mater. Charact. 43 (5), 311 (1999).

    Article  CAS  Google Scholar 

  34. A. Salemi and A. Abdollah-Zadeh: The effect of tempering temperature on the mechanical properties and fracture morphology of a NiCrMoV steel. Mater. Charact. 59 (4), 484 (2008).

    Article  CAS  Google Scholar 

  35. M.L. Zhu, D.Q. Wang, and F.Z. Xuan: Effect of long-term aging on microstructure and local behavior in the heat-affected zone of a Ni–Cr–Mo–V steel welded joint. Mater. Charact. 87, 45 (2014).

    Article  CAS  Google Scholar 

  36. A. Eghlimi, M. Shamanian, M. Eskandarian, A. Zabolian, and J.A. Szpunar: Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by super duplex filler metal. Mater. Charact. 106, 207 (2015).

    Google Scholar 

  37. I. Sattari-Far and M.R. Farahani: Effect of the weld groove shape and pass number on residual stresses in butt-welded pipes. Int. J. Pressure Vessels Piping 86, 723 (2009).

    Article  CAS  Google Scholar 

  38. L. Lan, C. Qiu, D. Zhao, X. Gao, and L. Du: Microstructural characteristics and toughness of the simulated coarse grained heat affected zone of high strength low carbon bainitic steel. Mater. Sci. Eng., A 529, 192 (2011).

    Article  CAS  Google Scholar 

  39. T.H. Chen and J.R. Yang: Microstructural characterization of simulated heat affected zone in a nitrogen-containing 2205 duplex stainless steel. Mater. Sci. Eng., A 338, 166 (2002).

    Article  Google Scholar 

  40. A. Lambert-Perlade, A.F. Gourgues, and A. Pineau: Austenite to bainite phase transformation in the heat-affected zone of a high strength low alloy steel. Acta Metall. 52, 2337 (2004).

    CAS  Google Scholar 

  41. J.A. Francis, W. Mazur, and H. Bhadeshia: Review type IV cracking in ferritic power plant steels. Mater. Sci. Technol. 22 (12), 1387 (2006).

    Article  CAS  Google Scholar 

  42. W. Liu, X. Liu, and F. Lu: Creep behavior and microstructure evaluation of welded joint in dissimilar modified 9Cr–1Mo steels. Mater. Sci. Eng., A 644, 337 (2015).

    Article  CAS  Google Scholar 

  43. M. Huang and D.L. Wang: Carbon migration in 5Cr–0.5Mo/21Cr–12Ni dissimilar metal welds. Metall. Mater. Trans. A 29 (12), 3037 (1998).

    Article  Google Scholar 

  44. Y.Y. You, R.K. Shiue, R.H. Shiue, and C. Chen: The study of carbon migration in dissimilar welding of the modified 9Cr–1Mo steel. J. Mater. Sci. Lett. 20 (15), 1429 (2001).

    Article  CAS  Google Scholar 

  45. R. Cao, W. Feng, Y. Peng, W.S. Du, Z.L. Tian, and J.H. Chen: Investigation of abnormal high impact toughness in simulated welding CGHAZ of a 8% Ni 980 MPa high strength steel. Mater. Sci. Eng., A 528 (2), 631 (2010).

    Article  CAS  Google Scholar 

  46. K. Arioka, T. Yamada, T. Terachi, and G. Chiba: Influence of carbide precipitation and rolling direction on intergranular stress corrosion cracking of austenitic stainless steels in hydrogenated high-temperature water. Corrosion 62 (7), 568 (2006).

    Article  CAS  Google Scholar 

  47. N.J. Petch: The influence of grain boundary carbide and grain size on the cleavage strength and impact transition temperature of steel. Acta Metall. 34 (7), 1387 (1986).

    Article  CAS  Google Scholar 

  48. M.A. Islam: Grain boundary segregation behavior in 2.25Cr–1Mo steel during reversible temper embrittlement. J. Mater. Eng. Perform. 16 (1), 73 (2007).

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People’s Republic of China

    Runqi Lin, Haichao Cui, Fenggui Lu, Xin Huo & Peng Wang

  2. Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai, 200240, China

    Runqi Lin, Haichao Cui & Fenggui Lu

  3. Shanghai Turbine Plant of Shanghai Electric Power Generation Equipment, Shanghai, 200240, People’s Republic of China

    Xin Huo & Peng Wang

Authors
  1. Runqi Lin
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Haichao Cui
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Fenggui Lu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Xin Huo
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Peng Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Fenggui Lu.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Lin, R., Cui, H., Lu, F. et al. Study on the microstructure and toughness of dissimilarly welded joints of advanced 9Cr/CrMoV. Journal of Materials Research 31, 3597–3609 (2016). https://doi.org/10.1557/jmr.2016.381

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1557/jmr.2016.381

Search

Navigation