Enhancements of Passive Film and Pitting Resistance in Chloride Solution for 316LX Austenitic Stainless Steel After Sn Alloying

• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2019,（1）
• 页码范围: 98-106
• 页数: 9页
• 语种: 英文

摘要

In the present work,the electrochemical behavior and properties of the passive film of a new Sn-alloyed 316LX austenitic stainless steel were investigated.With the increase in Sn content in 316LX austenitic stainless steel from 0 to 0.21％,the critical pitting temperature value increased from 32.6 to 38.8 ℃,and the pitting potential increased from 0.252 VSCE to 0.317 VSCE.Electrochemical impedance spectroscopy results showed that the corrosion resistance of passive film rose with the increase in Sn content,indicating a more stable passive film.The Mott-Schottky measurement revealed an n-type passive film with a decreased carrier concentration on the 316LX austenitic stainless steel surface.The Cr,Sn2+ and Sn4+ (SnO,SnOHCl or SnO2) enrichments were observed in the passive layer by X-ray photoelectron spectroscopy.The enrichment of Sn and Cr in the passive film can account for the enhanced pitting resistance of 316LX austenitic stainless steel in chloride solution.