Characterization of the Passive Film and Corrosion of Martensitic AM355 Stainless Steel. (3rd May 2017)

• Record Type: Journal Article
• Authors: Man, Cheng; Dong, Chaofang; Liang, Jianxiong; Xiao, Kui; Yu, Qiang; Li, Xiaogang
• Is Part Of: Analytical letters. Volume 50:Number 7(2017)
• Page Start: 1091
• Page End: 1111
• Publication Date: 2017-05-03
• Subjects: Electrochemistry -- inclusion -- passive film -- pitting corrosion -- ultrahigh-strength martensitic stainless steel; Chemistry, Analytic -- Periodicals; Chemistry, Analytic -- Abstracts; 543
• DOI: 10.1080/00032719.2016.1210617
• Languages: English
• ISSNs: 0003-2719

Abstract

ABSTRACT: Electrochemistry methods were used to investigate the influence of pH on the passive film and corrosion behavior of ultrahigh strength AM355 stainless steel in chloride-containing media. Analysis of the Pourbaix diagram indicates that AM355 stainless steel exhibits higher corrosion resistance in natural and near-natural environments than that in acidic and alkaline conditions. Electrochemistry measurements and composition analysis of the passive film show that pitting potential increased due to the enhanced repassivation capacity of AM355 stainless steel with increasing pH. The mixed MnS/oxide inclusions are the main pitting sensitive locations under all conditions. Morphological observations and energy-dispersive spectroscopy showed that the influence of the gap between the martensitic laths is significant with increasing pH. The inclusions, element concentrations, and microstructures weaken the resistance of ultrahigh-strength martensitic AM355 stainless steel against corrosion.