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The effect of chemical composition on microstructure and properties of intercritically reheated coarse-grained heat-affected zone in X70 steels

Journal Article


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Abstract


  • The current study investigates the effect of different levels of Ti, N, and Ti/N ratios on microstructure and properties in the intercritically reheated coarse-grained heat-affected zone (ICCGHAZ) of two-pass submerged arc welds in API 5L grade X70 pipe. Gleeble simulation was employed to reproduce the ICCGHAZ of actual welds. Hardness and Charpy V-notch (CVN) tests were performed on the simulated samples. The microstructure of simulated ICCGHAZ was characterized by optical microscopy and scanning electron microscopy (SEM). LePera color etching technique was employed to identify and quantify the martensitic–austenitic (M–A) constituent. Results show that the simulated ICCGHAZ exhibited extremely low toughness, but in the studied range of Ti and N, there was no correlation with Ti/N ratio. The beneficial effect of near-stoichiometric Ti/N ratio observed in coarse-grained heat-affected zone (CGHAZ) did not translate to ICCGHAZ. This was because of the negative effect of the blocky M–A constituent formed on prior austenite grain boundaries.

Publication Date


  • 2013

Citation


  • Zhu, Z., Kuzmikova, L., Li, H. & Barbaro, F. J. (2013). The effect of chemical composition on microstructure and properties of intercritically reheated coarse-grained heat-affected zone in X70 steels. Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science, 45 (1), 229-235.

Scopus Eid


  • 2-s2.0-84895063851

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2860&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/1851

Has Global Citation Frequency


Number Of Pages


  • 6

Start Page


  • 229

End Page


  • 235

Volume


  • 45

Issue


  • 1

Place Of Publication


  • United States

Abstract


  • The current study investigates the effect of different levels of Ti, N, and Ti/N ratios on microstructure and properties in the intercritically reheated coarse-grained heat-affected zone (ICCGHAZ) of two-pass submerged arc welds in API 5L grade X70 pipe. Gleeble simulation was employed to reproduce the ICCGHAZ of actual welds. Hardness and Charpy V-notch (CVN) tests were performed on the simulated samples. The microstructure of simulated ICCGHAZ was characterized by optical microscopy and scanning electron microscopy (SEM). LePera color etching technique was employed to identify and quantify the martensitic–austenitic (M–A) constituent. Results show that the simulated ICCGHAZ exhibited extremely low toughness, but in the studied range of Ti and N, there was no correlation with Ti/N ratio. The beneficial effect of near-stoichiometric Ti/N ratio observed in coarse-grained heat-affected zone (CGHAZ) did not translate to ICCGHAZ. This was because of the negative effect of the blocky M–A constituent formed on prior austenite grain boundaries.

Publication Date


  • 2013

Citation


  • Zhu, Z., Kuzmikova, L., Li, H. & Barbaro, F. J. (2013). The effect of chemical composition on microstructure and properties of intercritically reheated coarse-grained heat-affected zone in X70 steels. Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science, 45 (1), 229-235.

Scopus Eid


  • 2-s2.0-84895063851

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2860&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/1851

Has Global Citation Frequency


Number Of Pages


  • 6

Start Page


  • 229

End Page


  • 235

Volume


  • 45

Issue


  • 1

Place Of Publication


  • United States