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Effect of inter-critically reheating temperature on microstructure and properties of simulated inter-critically reheated coarse grained heat affected zone in X70 steel

Journal Article


Abstract


  • This study investigated the influence of the inter-critical reheating temperature on the microstructure and mechanical properties of a coarse grained heat affected zone (CGHAZ) in an API 5L grade X70 pipeline steel seam weld. A Gleeble 3500 thermo-mechanical simulator was employed to duplicate particular weld thermal cycles in order to accurately assess specific regions of the weld HAZ. Detailed microstructural analysis, including investigation of the martensite–austenite (M–A) constituent, was performed using optical microscope (OM), scanning electron microscope (SEM) and selective etching techniques. It is shown that the fracture toughness of the CGHAZ is significantly reduced following exposure to a subsequent inter-critical thermal cycle. Fracture toughness gradually improves as the inter-critical temperature is increased, but does not return to the value of the original CGHAZ due to the presence of isolated large M–A particles and coarse microstructure. Significance of M–A particles to the HAZ fracture toughness is first related to the location of particles along prior austenite grain boundaries, followed by the size of individual M–A particles.

UOW Authors


  •   Zhu, Zhixiong (external author)
  •   Kuzmikova, Lenka (external author)
  •   Li, Hui Jun.
  •   Barbaro, Frank (external author)

Publication Date


  • 2014

Citation


  • Zhu, Z., Kuzmikova, L., Li, H. & Barbaro, F. (2014). Effect of inter-critically reheating temperature on microstructure and properties of simulated inter-critically reheated coarse grained heat affected zone in X70 steel. Materials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing, 605 8-13.

Scopus Eid


  • 2-s2.0-84896964328

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/2899

Has Global Citation Frequency


Number Of Pages


  • 5

Start Page


  • 8

End Page


  • 13

Volume


  • 605

Place Of Publication


  • Netherlands

Abstract


  • This study investigated the influence of the inter-critical reheating temperature on the microstructure and mechanical properties of a coarse grained heat affected zone (CGHAZ) in an API 5L grade X70 pipeline steel seam weld. A Gleeble 3500 thermo-mechanical simulator was employed to duplicate particular weld thermal cycles in order to accurately assess specific regions of the weld HAZ. Detailed microstructural analysis, including investigation of the martensite–austenite (M–A) constituent, was performed using optical microscope (OM), scanning electron microscope (SEM) and selective etching techniques. It is shown that the fracture toughness of the CGHAZ is significantly reduced following exposure to a subsequent inter-critical thermal cycle. Fracture toughness gradually improves as the inter-critical temperature is increased, but does not return to the value of the original CGHAZ due to the presence of isolated large M–A particles and coarse microstructure. Significance of M–A particles to the HAZ fracture toughness is first related to the location of particles along prior austenite grain boundaries, followed by the size of individual M–A particles.

UOW Authors


  •   Zhu, Zhixiong (external author)
  •   Kuzmikova, Lenka (external author)
  •   Li, Hui Jun.
  •   Barbaro, Frank (external author)

Publication Date


  • 2014

Citation


  • Zhu, Z., Kuzmikova, L., Li, H. & Barbaro, F. (2014). Effect of inter-critically reheating temperature on microstructure and properties of simulated inter-critically reheated coarse grained heat affected zone in X70 steel. Materials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing, 605 8-13.

Scopus Eid


  • 2-s2.0-84896964328

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/2899

Has Global Citation Frequency


Number Of Pages


  • 5

Start Page


  • 8

End Page


  • 13

Volume


  • 605

Place Of Publication


  • Netherlands