Microstructural Changes in Inconel® 740 After Long-Term Aging in the Presence and Absence of Stress

Unocic, Kinga A.; Shingledecker, John Paul; Tortorelli, Peter F.

doi:10.1007/s11837-014-1208-4

Title: Microstructural Changes in Inconel^® 740 After Long-Term Aging in the Presence and Absence of Stress

Abstract

The Ni-based alloy, Inconel^® 740, is being extensively examined for use in advanced ultrasupercritical steam boilers because its precipitation-strengthened microstructure appears to offer the necessary creep strength under the high temperatures and pressures (up to 760°C and 35 MPa) needed for high efficiency power generation. However, because this application requires extremely long lifetimes under these conditions (up to 30 years), long-term microstructure stability is a major concern. In this study, results from microstructural analyses of Inconel 740 specimens aged at 700 and 750°C in the presence and absence of creep loading for times up to ~31,000 h are presented. The primary focus was on the development of the eta η (Ni₃Ti) phase and coarsening of coherent γ'-Ni₃(Al,Ti) precipitates and its depletion near eta/matrix interfaces. Finally, however, despite these processes, Inconel 740 showed adequate long-term microstructural stability to assure adequate creep strength for the intended application.

Authors:

Unocic, Kinga A. ^[1]; Shingledecker, John Paul ^[2]; Tortorelli, Peter F. ^[1]

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
Electric Power Research Inst. (EPRI), Palo Alto, CA (United States)

Publication Date:: Tue Nov 18 00:00:00 EST 2014

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: USDOE Office of Fossil Energy (FE)

OSTI Identifier:: 1286735

Grant/Contract Number:: AC05-00OR22725

Resource Type:: Accepted Manuscript

Journal Name:: JOM. Journal of the Minerals, Metals & Materials Society

Additional Journal Information:: Journal Volume: 66; Journal Issue: 12; Journal ID: ISSN 1047-4838

Publisher:: Springer

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE

Citation Formats


                    Unocic, Kinga A., Shingledecker, John Paul, and Tortorelli, Peter F. Microstructural Changes in Inconel® 740 After Long-Term Aging in the Presence and Absence of Stress.  United States: N. p., 2014. 
Web.  doi:10.1007/s11837-014-1208-4.

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                    Unocic, Kinga A., Shingledecker, John Paul, & Tortorelli, Peter F. Microstructural Changes in Inconel® 740 After Long-Term Aging in the Presence and Absence of Stress.  United States.  https://doi.org/10.1007/s11837-014-1208-4

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                    Unocic, Kinga A., Shingledecker, John Paul, and Tortorelli, Peter F. Tue .  
"Microstructural Changes in Inconel® 740 After Long-Term Aging in the Presence and Absence of Stress".  United States.  https://doi.org/10.1007/s11837-014-1208-4.  https://www.osti.gov/servlets/purl/1286735.

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@article{osti_1286735,

  title        = {Microstructural Changes in Inconel® 740 After Long-Term Aging in the Presence and Absence of Stress},

  author       = {Unocic, Kinga A. and Shingledecker, John Paul and Tortorelli, Peter F.},

  abstractNote = {The Ni-based alloy, Inconel® 740, is being extensively examined for use in advanced ultrasupercritical steam boilers because its precipitation-strengthened microstructure appears to offer the necessary creep strength under the high temperatures and pressures (up to 760°C and 35 MPa) needed for high efficiency power generation. However, because this application requires extremely long lifetimes under these conditions (up to 30 years), long-term microstructure stability is a major concern. In this study, results from microstructural analyses of Inconel 740 specimens aged at 700 and 750°C in the presence and absence of creep loading for times up to ~31,000 h are presented. The primary focus was on the development of the eta η (Ni3Ti) phase and coarsening of coherent γ'-Ni3(Al,Ti) precipitates and its depletion near eta/matrix interfaces. Finally, however, despite these processes, Inconel 740 showed adequate long-term microstructural stability to assure adequate creep strength for the intended application.},

  doi          = {10.1007/s11837-014-1208-4},

  journal      = {JOM. Journal of the Minerals, Metals & Materials Society},

  number       = 12,

  volume       = 66,

  place        = {United States},

  year         = {Tue Nov 18 00:00:00 EST 2014},

  month        = {Tue Nov 18 00:00:00 EST 2014}

}

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Works referenced in this record:

Grain boundary design and control for high temperature materials
journal, July 1993

Watanabe, Tadao
Materials Science and Engineering: A, Vol. 166, Issue 1-2
DOI: 10.1016/0921-5093(93)90306-Y

Experimental investigation and thermodynamic calculation on phase precipitation of inconel 740
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Zhao, S.; Jiang, Y.; Dong, J.
Acta Metallurgica Sinica (English Letters), Vol. 19, Issue 6
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The Role of Niobium in Wrought Precipitation-Hardened Nickel-Base Alloys
conference, January 2005

Smith, G. D.; Patel, S. J.
Superalloys 718, 625, 706 and Various Derivatives (2005)
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U.S. Program on Materials Technology for Ultra-Supercritical Coal Power Plants
journal, June 2005

Viswanathan, R.; Henry, J. F.; Tanzosh, J.
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Mechanical and microstructural properties of alloy 800
journal, September 1978

Tavassoli, A. A.; Colombe, G.
Metallurgical Transactions A, Vol. 9, Issue 9
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Microtwinning and other shearing mechanisms at intermediate temperatures in Ni-based superalloys
journal, August 2009

Kovarik, L.; Unocic, R. R.; Li, Ju
Progress in Materials Science, Vol. 54, Issue 6
DOI: 10.1016/j.pmatsci.2009.03.010

Microstructure and phase stability in INCONEL alloy 740 during creep
journal, September 2004

Evans, N. D.; Maziasz, P. J.; Swindeman, R. W.
Scripta Materialia, Vol. 51, Issue 6
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Thermal Stability Study on a New Ni-Cr-Co-Mo-Nb-Ti-Al Superalloy
conference, January 2004

Zhao, S.; Dong, J.; Xie, X.
Superalloys 2004 (Tenth International Symposium)
DOI: 10.7449/2004/Superalloys_2004_63_72

Dislocation decorrelation and relationship to deformation microtwins during creep of a γ′ precipitate strengthened Ni-based superalloy
journal, November 2011

Unocic, R. R.; Zhou, N.; Kovarik, L.
Acta Materialia, Vol. 59, Issue 19
DOI: 10.1016/j.actamat.2011.07.069

The Role of Eta Phase Formation on the Creep Strength and Ductility of INCONEL Alloy 740 at 1023 K (750 °C)
journal, January 2012

Shingledecker, J. P.; Pharr, G. M.
Metallurgical and Materials Transactions A, Vol. 43, Issue 6
DOI: 10.1007/s11661-011-1013-4

Nickel Base Superalloys for Next Generation Coal Fired AUSC Power Plants
journal, January 2013

Patel, Shailesh J.; deBarbadillo, John J.; Baker, Brian A.
Procedia Engineering, Vol. 55
DOI: 10.1016/j.proeng.2013.03.250

Works referencing / citing this record:

Electronic structure and mechanical properties of crystalline precipitate phases M ₂₃ C ₆ (M=Cr, W, Mo, Fe) in Ni-based superalloys
journal, September 2019

Adhikari, Puja; San, Saro; Zhou, Caizhi
Materials Research Express, Vol. 6, Issue 11
DOI: 10.1088/2053-1591/ab4fb8

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Title: Microstructural Changes in Inconel® 740 After Long-Term Aging in the Presence and Absence of Stress

Abstract

Citation Formats

Grain boundary design and control for high temperature materials journal, July 1993

Experimental investigation and thermodynamic calculation on phase precipitation of inconel 740 journal, December 2006

The Role of Niobium in Wrought Precipitation-Hardened Nickel-Base Alloys conference, January 2005

U.S. Program on Materials Technology for Ultra-Supercritical Coal Power Plants journal, June 2005

Mechanical and microstructural properties of alloy 800 journal, September 1978

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Microstructure and phase stability in INCONEL alloy 740 during creep journal, September 2004

Thermal Stability Study on a New Ni-Cr-Co-Mo-Nb-Ti-Al Superalloy conference, January 2004

Dislocation decorrelation and relationship to deformation microtwins during creep of a γ′ precipitate strengthened Ni-based superalloy journal, November 2011

The Role of Eta Phase Formation on the Creep Strength and Ductility of INCONEL Alloy 740 at 1023 K (750 °C) journal, January 2012

Nickel Base Superalloys for Next Generation Coal Fired AUSC Power Plants journal, January 2013

Electronic structure and mechanical properties of crystalline precipitate phases M 23 C 6 (M=Cr, W, Mo, Fe) in Ni-based superalloys journal, September 2019

Title: Microstructural Changes in Inconel^® 740 After Long-Term Aging in the Presence and Absence of Stress

Grain boundary design and control for high temperature materials
journal, July 1993

Experimental investigation and thermodynamic calculation on phase precipitation of inconel 740
journal, December 2006

The Role of Niobium in Wrought Precipitation-Hardened Nickel-Base Alloys
conference, January 2005

U.S. Program on Materials Technology for Ultra-Supercritical Coal Power Plants
journal, June 2005

Mechanical and microstructural properties of alloy 800
journal, September 1978

Microtwinning and other shearing mechanisms at intermediate temperatures in Ni-based superalloys
journal, August 2009

Microstructure and phase stability in INCONEL alloy 740 during creep
journal, September 2004

Thermal Stability Study on a New Ni-Cr-Co-Mo-Nb-Ti-Al Superalloy
conference, January 2004

Dislocation decorrelation and relationship to deformation microtwins during creep of a γ′ precipitate strengthened Ni-based superalloy
journal, November 2011

The Role of Eta Phase Formation on the Creep Strength and Ductility of INCONEL Alloy 740 at 1023 K (750 °C)
journal, January 2012

Nickel Base Superalloys for Next Generation Coal Fired AUSC Power Plants
journal, January 2013

Electronic structure and mechanical properties of crystalline precipitate phases M ₂₃ C ₆ (M=Cr, W, Mo, Fe) in Ni-based superalloys
journal, September 2019