skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Toward Improving the Type IV Cracking Resistance in Cr-Mo Steel Weld Through Thermo-Mechanical Processing

Abstract

Detailed microstructure characterization of Grade 91 (Modified 9Cr-1Mo, ASTM A387) steel subjected to a thermo-mechanical treatment (TMT) process was performed to rationalize the cross-weld creep properties. A series of thermo-mechanical processing in the austenite phase region, followed by isothermal aging at temperatures at 973 to 1173 K (700 to 900ºC) was applied to the Grade 91 steel to promote precipitation kinetics of MX (M: Nb and V, X: C and N) in the austenite matrix. Detailed characterization of the base metals after standard tempering confirmed the presence of fine MX dispersion within the tempered martensitic microstructure in steels processed at/and above 1073 K (800 ºC). Relatively low volume fraction of M23C6 precipitates was observed after processing at 1073 K (800 ºC). The cross-weld creep strength after processing was increased with respect to the increase of MX dispersion, indicating that these MX precipitates maintained during weld thermal cycles in the fine grained heat affected zone (FGHAZ) region and thereby contribute to improved creep resistant of welds in comparison to the welds made with the standard “normalization and tempering” processes. Lastly, the steels processed in this specific processing condition showed improved cross-weld creep resistance and sufficient room-temperature toughness. The above data ismore » also analysed based on existing theories of creep deformation based on dislocation climb mechanism.« less

Authors:
 [1];  [2];  [1]
  1. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Mechanical, Aerospace, and Biomedical Engineering
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Fossil Energy (FE)
OSTI Identifier:
1324056
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Accepted Manuscript
Journal Name:
Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science
Additional Journal Information:
Journal Volume: 47; Journal Issue: 5; Journal ID: ISSN 1073-5623
Publisher:
ASM International
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Shassere, Benjamin A., Yamamoto, Yukinori, and Babu, Sudarsanam Suresh. Toward Improving the Type IV Cracking Resistance in Cr-Mo Steel Weld Through Thermo-Mechanical Processing. United States: N. p., 2016. Web. doi:10.1007/s11661-016-3387-9.
Shassere, Benjamin A., Yamamoto, Yukinori, & Babu, Sudarsanam Suresh. Toward Improving the Type IV Cracking Resistance in Cr-Mo Steel Weld Through Thermo-Mechanical Processing. United States. doi:10.1007/s11661-016-3387-9.
Shassere, Benjamin A., Yamamoto, Yukinori, and Babu, Sudarsanam Suresh. Tue . "Toward Improving the Type IV Cracking Resistance in Cr-Mo Steel Weld Through Thermo-Mechanical Processing". United States. doi:10.1007/s11661-016-3387-9. https://www.osti.gov/servlets/purl/1324056.
@article{osti_1324056,
title = {Toward Improving the Type IV Cracking Resistance in Cr-Mo Steel Weld Through Thermo-Mechanical Processing},
author = {Shassere, Benjamin A. and Yamamoto, Yukinori and Babu, Sudarsanam Suresh},
abstractNote = {Detailed microstructure characterization of Grade 91 (Modified 9Cr-1Mo, ASTM A387) steel subjected to a thermo-mechanical treatment (TMT) process was performed to rationalize the cross-weld creep properties. A series of thermo-mechanical processing in the austenite phase region, followed by isothermal aging at temperatures at 973 to 1173 K (700 to 900ºC) was applied to the Grade 91 steel to promote precipitation kinetics of MX (M: Nb and V, X: C and N) in the austenite matrix. Detailed characterization of the base metals after standard tempering confirmed the presence of fine MX dispersion within the tempered martensitic microstructure in steels processed at/and above 1073 K (800 ºC). Relatively low volume fraction of M23C6 precipitates was observed after processing at 1073 K (800 ºC). The cross-weld creep strength after processing was increased with respect to the increase of MX dispersion, indicating that these MX precipitates maintained during weld thermal cycles in the fine grained heat affected zone (FGHAZ) region and thereby contribute to improved creep resistant of welds in comparison to the welds made with the standard “normalization and tempering” processes. Lastly, the steels processed in this specific processing condition showed improved cross-weld creep resistance and sufficient room-temperature toughness. The above data is also analysed based on existing theories of creep deformation based on dislocation climb mechanism.},
doi = {10.1007/s11661-016-3387-9},
journal = {Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science},
number = 5,
volume = 47,
place = {United States},
year = {2016},
month = {2}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 1 work
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Precipitate design for creep strengthening of 9% Cr tempered martensitic steel for ultra-supercritical power plants
journal, January 2008


Advances in Physical Metallurgy and Processing of Steels. Design of Ferritic Creep-resistant Steels.
journal, January 2001


Creep damage and expected creep life for welded 9–11% Cr steels
journal, January 2007

  • Auerkari, P.; Holmström, S.; Veivo, J.
  • International Journal of Pressure Vessels and Piping, Vol. 84, Issue 1-2
  • DOI: 10.1016/j.ijpvp.2006.09.011

Effect of chromium content on loss of creep rupture strength in the heat affected zone of heat-resistant ferritic steel
journal, February 2005


Review Type IV cracking in ferritic power plant steels
journal, December 2006

  • Francis, J. A.; Mazur, W.; Bhadeshia, H. K. D. H.
  • Materials Science and Technology, Vol. 22, Issue 12
  • DOI: 10.1179/174328406X148778

Correlation of precipitate stability to increased creep resistance of Cr–Mo steel welds
journal, April 2013


Development of new nano-particle-strengthened martensitic steels
journal, August 2005


New nano-particle-strengthened ferritic/martensitic steels by conventional thermo-mechanical treatment
journal, August 2007


Influence of Deformation on the Precipitation Behavior of Nb(CN) in Austenite and Ferrite
journal, June 2014

  • Nöhrer, Matthias; Mayer, Walter; Primig, Sophie
  • Metallurgical and Materials Transactions A, Vol. 45, Issue 10
  • DOI: 10.1007/s11661-014-2373-3

Effect of MX type particles on creep strength of ferritic steel
journal, September 2003


Creep behavior and stability of MX precipitates at high temperature in 9Cr–0.5Mo–1.8W–VNb steel
journal, December 2001


Quantification of precipitates in a 10%Cr steel using TEM and EFTEM
journal, October 2000


Effect of carbon concentration on precipitation behavior of M23C6 carbides and MX carbonitrides in martensitic 9Cr steel during heat treatment
journal, April 2004

  • Taneike, Masaki; Sawada, Kota; Abe, Fujio
  • Metallurgical and Materials Transactions A, Vol. 35, Issue 4
  • DOI: 10.1007/s11661-004-0299-x

Advances in Physical Metallurgy and Processing of Steels. Strengthening Mechanisms of Creep Resistant Tempered Martensitic Steel.
journal, January 2001


Crystallography of ausformed upper bainite structure in Fe–9Ni–C alloys
journal, November 2006


The morphology and crystallography of lath martensite in Fe-C alloys
journal, April 2003


Crystallographic features of lath martensite in low-carbon steel
journal, March 2006


Effect of thermo-mechanical treatment on microstructure and mechanical properties of P92 heat resistant steel
journal, January 2013


Stabilization of martensitic microstructure in advanced 9Cr steel during creep at high temperature
journal, July 2004


Phase stability and atom probe field ion microscopy of type 308 cre stainless steel weld metal
journal, March 1996

  • Babu, S. S.; David, S. A.; Vitek, J. M.
  • Metallurgical and Materials Transactions A, Vol. 27, Issue 3
  • DOI: 10.1007/BF02648964

Simulation of role of precipitate in creep void occurrence in heat affected zone of high Cr ferritic heat resistant steels
journal, September 2005

  • Li, Dejun; Shinozaki, K.
  • Science and Technology of Welding and Joining, Vol. 10, Issue 5
  • DOI: 10.1179/174329305X29519

Effect of stress on microstructural change due to aging at 823 K in multi-layer welded joint of 2.25Cr–1Mo steel
journal, March 2004

  • Watanabe, Takashi; Yamazaki, Masayoshi; Hongo, Hiromichi
  • International Journal of Pressure Vessels and Piping, Vol. 81, Issue 3
  • DOI: 10.1016/j.ijpvp.2003.12.017

3D creep cavitation characteristics and residual life assessment in high temperature steels: a critical review
journal, May 2014


Carbide precipitation in 12Cr1MoV power plant steel
journal, April 1992

  • Thomson, R. C.; Bhadeshia, H. K. D. H.
  • Metallurgical Transactions A, Vol. 23, Issue 4
  • DOI: 10.1007/BF02665048

Type IV creep cavity accumulation and failure in steel welds
journal, September 2003

  • Smith, D. J.; Walker, N. S.; Kimmins, S. T.
  • International Journal of Pressure Vessels and Piping, Vol. 80, Issue 9
  • DOI: 10.1016/S0308-0161(03)00134-0

Creep rupture behavior of Grade 91 steel
journal, March 2013

  • Shrestha, Triratna; Basirat, Mehdi; Charit, Indrajit
  • Materials Science and Engineering: A, Vol. 565
  • DOI: 10.1016/j.msea.2012.12.031

Results and consequences of a recalculation of the frank-read and the orowan stress
journal, May 1966


    Works referencing / citing this record:

    Correlation of Microstructure to Creep Response of Hot Isostatically Pressed and Aged Electron Beam Melted Inconel 718
    journal, July 2018

    • Shassere, Benjamin; Greeley, Duncan; Okello, Alfred
    • Metallurgical and Materials Transactions A, Vol. 49, Issue 10
    • DOI: 10.1007/s11661-018-4812-z

    Correlation of Microstructure to Creep Response of Hot Isostatically Pressed and Aged Electron Beam Melted Inconel 718
    journal, July 2018

    • Shassere, Benjamin; Greeley, Duncan; Okello, Alfred
    • Metallurgical and Materials Transactions A, Vol. 49, Issue 10
    • DOI: 10.1007/s11661-018-4812-z