J. Mater. Sci. Technol. ›› 2018, Vol. 34 ›› Issue (8): 1281-1292.DOI: 10.1016/j.jmst.2017.11.051

Special Issue: Corrosion in 2018

• Orginal Article • Previous Articles     Next Articles

Microstructure and intergranular stress corrosion cracking susceptibility of a SA508-52M-316L dissimilar metal weld joint in primary water

Lijin Dongab, Qunjia Pengb(), En-Hou Hanb, Wei Keb, Lei Wanga   

  1. a Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819, China
    bKey Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2017-08-14 Revised:2017-11-13 Accepted:2017-11-20 Online:2018-08-17 Published:2018-08-22

Abstract:

Correlation of microstructure and intergranular stress corrosion cracking (IGSCC) susceptibility for the SA508-52M-316L dissimilar metal weld joint in primary water was investigated by the interrupted slow strain rate tension test following a microstructure characterization. The susceptibility to IGSCC in various regions of the dissimilar metal weld joint was observed to follow the order of Alloy 52 Mb> the heat affected zone of 316L> the dilution zone of Alloy 52 Mw> Alloy 52 Mw weld metal. The chromium-depletion at the grain boundary is the dominant factor causing the high IGSCC susceptibility of Alloy 52 Mb. However, IGSCC initiation in the heat affected zone of 316L is attributed to the increase of residual strain adjacent to the grain boundary. In addition, the decrease of chromium content and increase of residual strain adjacent to the grain boundary increase the IGSCC susceptibility of the dilution zone of Alloy 52 Mw.

Key words: Dissimilar metal weld joint, Stress corrosion cracking, Microstructure, High temperature water, Slow strain rate tension