Nitrogen significantly enhances corrosion resistance of 316L stainless steel in thiosulfate-chloride solution

• Published in: Corrosion science Vol. 174; p. 108792
• Main Authors: Dai, Jing, Feng, Hao, Li, Hua-Bing, Jiang, Zhou-Hua, Li, Hao, Zhang, Shu-Cai, Zhou, Peng, Zhang, Tao
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.09.2020; Elsevier BV
• Subjects: A: stainless steel; Austenitic stainless steels; B: polarization; B: XPS; C: pitting corrosion; C: repassivation; Corrosion effects; Corrosion resistance; Corrosion resistant alloys; Corrosion resistant steels; Nitrogen; Photoelectrons; Pitting (corrosion); Stainless steel; Thiosulfates; B: polarization; C: pitting corrosion; B: XPS; C: repassivation; A: stainless steel
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2020.108792

[Display omitted] •Effect of N on corrosion of steel in S2O32−-Cl- solution was firstly reported.•N significantly enhanced corrosion resistance of 316 L in S2O32−-Cl- solution.•N restrained reduction of S2O32− by consuming H+ and alleviated its harmful effect.•N reduced defects and raised fraction of Cr2O3 and Fe2O3 in passive film. Thiosulfate is a threat to corrosion resistance of steels in chloride solution. This work revealed the inhibitory effect of nitrogen (N) on thiosulfate-accelerated corrosion of stainless steel by electrochemical measurements, microscopy observation and X-ray photoelectron spectroscopy analyses. Results manifested that N-alloying significantly enhanced pitting corrosion resistance and repassivation ability of 316 L steel in thiosulfate-chloride solution. On the one hand, N consumed H+, then restrained reduction of S2O32− and subsequent formation of S and MS2. On the other hand, N reduced defect density and strengthened passive film by increasing fraction of Cr2O3 and Fe2O3, thus improving protective ability of passive film.