J. Mater. Sci. Technol. ›› 2020, Vol. 47 ›› Issue (0): 76-87.DOI: 10.1016/j.jmst.2020.02.004

• Research Article • Previous Articles     Next Articles

Effects of 405 stainless steel on crevice corrosion behavior of Alloy 690 in high-temperature pure water

Fangqiang Ninga,b, Jibo Tana, Xinqiang Wua,*()   

  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:2019-07-16 Revised:2019-11-19 Accepted:2019-11-25 Online:2020-06-15 Published:2020-06-24
  • Contact: Xinqiang Wu

Abstract:

Effects of 405 stainless steel (405 SS) on crevice corrosion behavior of Alloy 690 in high-temperature pure water were investigated. Results revealed that the corrosion rate of Alloy 690 was low within the crevice. It was likely attributed to the fact that a Cr-rich inner oxide film and a Ni-rich layer beneath this oxide film formed upon Alloy 690, inhibiting the diffusion of oxygen towards the oxide/matrix interface. Moreover, the Fe2+ ions dissolved from 405 SS consumed most of oxygen, leading to less oxygen participating in the oxidation of Alloy 690. In addition, it was found that Fe concentration continuously decreased from the surface of the inner oxide film to the oxide/matrix interface of Alloy 690 within the crevice, which was probably due to the diffusion of Fe2+ ions dissolved from 405 SS into the inner oxide film.

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