J. Mater. Sci. Technol. ›› 2015, Vol. 31 ›› Issue (10): 1011-1017.DOI: 10.1016/j.jmst.2015.08.013

• Orginal Article • Previous Articles     Next Articles

Microstructure Characterization of the Fusion Zone of an Alloy 600-82 Weld Joint

Cheng Ma1, Jinna Mei2, Qunjia Peng1, *, Ping Deng1, En-Hou Han1, Wei Ke1   

  1. 1 Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
    2 Suzhou Nuclear Power Research Institute, Suzhou 215004, China
  • Received:2015-04-03 Revised:2015-05-11
  • Contact: * Corresponding author. Ph.D.; Tel.: +86 24 23841676; Fax: +86 24 23894149.E-mail address: qunjiapeng@imr.ac.cn (Q. Peng).
  • Supported by:
    This work was financially supported by the Hundred-Talent Program of Chinese Academy of Sciences. The authors gratefully acknowledge Ms. X.L. Wang and D. Hou for their support to TEM and EBSD analyses.

Abstract: Characterization of the microstructure of the fusion zone of an Alloy 600-82 weld joint was conducted, with focus on the weld residual strain distribution and the comparison of the microstructure of heat affected zone (HAZ) with that of cold worked alloy. Peak of the residual strain was observed to approach to the fusion boundary in HAZ while the strain increased from the top of the weld to the root. Strain distribution in the HAZ was found to be concentrated adjacent to grain boundaries (GBs), with a peak of approximately three times of that in grain. Further, triple junctions of the GB appear to cause a higher strain concentration than single GBs. The microstructure of HAZ consists of partially tangled dislocations, which is different from slip bands of high density dislocations in cold worked alloy. This may cause a relatively higher intergranular cracking resistance of HAZ due to the difficulty in transferring tangled dislocations to GB in HAZ under deformation.

Key words: Microstructure, Fusion zone, Weld joint, Strain concentration, Alloy 600