Decrease in Pitting Corrosion Resistance of Extra-High-Purity Type 316 Stainless-Steel by Cu2+ in NaCl

Abstract

The effect of Cu2+ in bulk solution on pitting corrosion resistance of extra-high-purity type 316 stainless-steel was investigated. Pitting occurred in 0.1 M NaCl-1 mM CuCl2, whereas pitting was not initiated in 0.1 M NaCl. Although deposition of Cu2+ on the surface occurred regardless of a potential region in 0.1 M NaCl-1 mM CuCl2, Cu2+ in bulk solution had no influence on the passive film formation. The decrease in pitting corrosion resistance in 0.1 M NaCl-1 mM CuCl2 resulted from the deposited Cu or Cu compound and continuous supply of Cu2+ on the surface.

Effect of Cu2+ on Corrosion Behavior of A106B Carbon Steel and 304L Stainless Steels in Seawater

“…Presently, the corrosion of steels in seawater had been widely investigated all over the world [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], and the influence of Cu 2+ on material corrosion is mainly focused on different materials in nonseawater environment, such as steel [21][22][23][24][25][26][27][28][29][30], aluminum alloy [31,32], 690 alloy [33], and copper alloy [34]. However, the works focused on the corrosion behavior of steels in seawater containing Cu 2+ and the influence of the Cu 2+ and copper oxides on the corrosion of the equipment in the secondary circuit system were little reported [35]. Therefore, the corrosion behaviors of steels in seawater containing Cu 2+ were studied by the immersion test, potentiodynamic polarization, and SEM observation, which could provide a certain basis and guidance for the operation of nuclear power stations.…”