Acta Metallurgica Sinica (English Letters) ›› 2022, Vol. 35 ›› Issue (6): 1023-1033.DOI: 10.1007/s40195-021-01329-8

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Effect of Vacuum Pressure on the Initiation and Propagation of Pitting Corrosion of 2205 Duplex Stainless Steel in Concentrated Seawater

Yong Yang, Xue-Ling Hou, Mou-Cheng Li()   

  1. Institute of Materials, School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China
  • Received:2021-05-04 Revised:2021-07-10 Accepted:2021-07-30 Online:2022-06-10 Published:2022-06-15
  • Contact: Mou-Cheng Li
  • About author:Mou-Cheng Li, mouchengli@shu.edu.cn

Abstract:

Pitting initiation and stable propagation behaviors of 2205 duplex stainless steel were investigated in the hot concentrated seawater under vacuum pressures by potentiostatic polarization. Both applied potentials and vacuum pressures greatly influence the pitting corrosion. Higher potentials lead to much faster stable pitting initiation and growth rates in both static (101.3 kPa) and dynamic (28.4 kPa) solutions. The pressure reduction can also accelerate the pitting initiation rate. However, the boiling of solution can influence the pitting propagation mechanism. The dynamic actions of boiling bubbles are unfavorable to the pit propagation and result in the formation of relatively smooth pit bottom without secondary pits.

Key words: Duplex stainless steel, Stable pitting, Vacuum pressure, Hot concentrated seawater, Potentiostatic polarization