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Influence of heat input on microstructure and toughness properties in simulated CGHAZ of X80 steel manufactured using high-temperature processing

Journal Article


Abstract


  • To determine and demonstrate the weldability of high-Nb high-temperature processed (HTP) steels and provide extremely valuable information for future line pipe steel design and general steel manufacture, in the current study the toughness in simulated coarse-grained heat-affected zone (CGHAZ) of an X80 grade steel manufactured using HTP was evaluated. The simulated CGHAZs subjected to thermal cycles with various heat inputs (HIs) (0.8 to 5.0 kJ/mm) were produced using a Gleeble 3500 simulator. The microstructures and corresponding mechanical properties were investigated by means of optical microscopy, scanning electron microscopy, electron backscatter diffraction, hardness testing, and Charpy V-notch (CVN) testing. The microstructural examination shows that the simulated CGHAZs consisted of a bainite-dominant microstructure and relatively low amount (<2 pct) of martensite–austenite (M–A) constituent. The prior austenite grain size was controlled to be 45 to 55 µm at HIs of 0.8 to 3.5 kJ/mm, and remarkably increased to 85 µm at an HI of 5 kJ/mm. The results of CVN testing suggest that superior toughness can be achieved in the studied range of HIs (0.8 to 5 kJ/mm). This is thought to be associated with the combined effects of bainitic microstructure and low M–A fraction as well as comparatively fine austenite grain size in the studied CGHAZs.

UOW Authors


  •   Zhu, Zhixiong (external author)
  •   Han, Jian (external author)
  •   Li, Hui Jun.

Publication Date


  • 2015

Citation


  • Zhu, Z., Han, J. & Li, H. (2015). Influence of heat input on microstructure and toughness properties in simulated CGHAZ of X80 steel manufactured using high-temperature processing. Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 46 (11), 5467-5475.

Scopus Eid


  • 2-s2.0-84942991290

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/4622

Has Global Citation Frequency


Number Of Pages


  • 8

Start Page


  • 5467

End Page


  • 5475

Volume


  • 46

Issue


  • 11

Place Of Publication


  • United States

Abstract


  • To determine and demonstrate the weldability of high-Nb high-temperature processed (HTP) steels and provide extremely valuable information for future line pipe steel design and general steel manufacture, in the current study the toughness in simulated coarse-grained heat-affected zone (CGHAZ) of an X80 grade steel manufactured using HTP was evaluated. The simulated CGHAZs subjected to thermal cycles with various heat inputs (HIs) (0.8 to 5.0 kJ/mm) were produced using a Gleeble 3500 simulator. The microstructures and corresponding mechanical properties were investigated by means of optical microscopy, scanning electron microscopy, electron backscatter diffraction, hardness testing, and Charpy V-notch (CVN) testing. The microstructural examination shows that the simulated CGHAZs consisted of a bainite-dominant microstructure and relatively low amount (<2 pct) of martensite–austenite (M–A) constituent. The prior austenite grain size was controlled to be 45 to 55 µm at HIs of 0.8 to 3.5 kJ/mm, and remarkably increased to 85 µm at an HI of 5 kJ/mm. The results of CVN testing suggest that superior toughness can be achieved in the studied range of HIs (0.8 to 5 kJ/mm). This is thought to be associated with the combined effects of bainitic microstructure and low M–A fraction as well as comparatively fine austenite grain size in the studied CGHAZs.

UOW Authors


  •   Zhu, Zhixiong (external author)
  •   Han, Jian (external author)
  •   Li, Hui Jun.

Publication Date


  • 2015

Citation


  • Zhu, Z., Han, J. & Li, H. (2015). Influence of heat input on microstructure and toughness properties in simulated CGHAZ of X80 steel manufactured using high-temperature processing. Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 46 (11), 5467-5475.

Scopus Eid


  • 2-s2.0-84942991290

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/4622

Has Global Citation Frequency


Number Of Pages


  • 8

Start Page


  • 5467

End Page


  • 5475

Volume


  • 46

Issue


  • 11

Place Of Publication


  • United States