J. Mater. Sci. Technol. ›› 2021, Vol. 66: 163-176.DOI: 10.1016/j.jmst.2020.05.074

• Research Article • Previous Articles     Next Articles

Effects of thiosulfate and dissolved oxygen on crevice corrosion of Alloy 690 in high-temperature chloride solution

Fangqiang Ninga,b, Jibo Tana, Ziyu Zhanga, Xinqiang Wua,*(), Xiang Wanga, En-Hou Hana, Wei Kea   

  1. aCAS Key Laboratory of Nuclear Materials and Safety Assessment, Liaoning Key Laboratory for Safety and Assessment Technique of Nuclear Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
    bSchool of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China
  • Received:2020-04-19 Revised:2020-05-27 Accepted:2020-05-28 Published:2021-03-10 Online:2021-04-01
  • Contact: Xinqiang Wu
  • About author:* E-mail address: xqwu@imr.ac.cn (X. Wu).

Abstract:

The crevice corrosion behavior of Alloy 690 was investigated in high-temperature chloride solution containing different concentrations of thiosulfate (S2O32-) and dissolved oxygen (DO). The S2O32- inhibited corrosion of Alloy 690 through consuming oxygen in aerated chloride solution. In deaerated chloride solution, the S2O32- was reduced to S° and S2- and subsequently incorporated into the oxide films, which promoted the pitting corrosion at locations of both TiN inclusions and matrix inside the crevice during the crevice corrosion as well as influenced the composition and thickness of the oxide films. The effect mechanisms of S2O32- and DO on crevice corrosion in high-temperature chloride solution are discussed.

Key words: Alloy, Crevice corrosion, Pitting corrosion, High-temperature corrosion, Thiosulfate, Oxidation