Effect of Nitrogen on the Corrosion Behavior of Austenitic Stainless Steel in Chloride Solutions

Abstract

The effect of partial replacement of nickel with nitrogen on the corrosion resistance of newly designed austenitic stainless steel samples without and with heat treated was investigated in 3.5wt% and 5wt% NaCl solution using open-circuit, potentiodynamic, cyclic anodic polarization and electrochemical impedance spectroscopy techniques. The results showed that, passivation in sample 1 where the highest addition of nickel and low addition of nitrogen is different from that for sample 4 where the nitrogen is greatest and the nickel is reduced almost to the third comparing sample 1. The difference in responses of heat treated samples to localized and general corrosion could be attributed to the difference in their phase compositions. The appearance of ferrite phase for samples (2, 4, 5 and 6) after heat treatment resulted in lowering the general and localized corrosion resistance than as forged samples in contrast with samples 1 and 3, where they still pure austenite. The obtained results are confirmed by surface examination.

Effect of edge print parameters on microstructure and high temperature solution nitriding response of additively manufactured austenitic stainless steel

“…The appropriate HTSN parameters can be obtained from calculated isopleths using CALPHAD databases such as ThermoCalc. Here, the phase stability as a function of temperature and nitrogen content is highly relevant [25][26][27][28]. As an illustration, an isopleth for 316L containing an isobar indicating a nitrogen pressure of 300 mbar is given in Figure 1.…”

Unravelling the Role of Nitrogen in Surface Chemistry and Oxidation Evolution of Deep Cryogenic Treated High-Alloyed Ferrous Alloy

“…Moreover, this incorporation could be the primary mechanism, which is latter accompanied in different environments by the secondary mechanism of formation of NH 4 + ions. This results in electro-potential discharge [37] of the newly formed "ghost layer" (passive layer) and reduced degradation of the material. The next alloying element analyzed was cobalt (ion forms of Co − and CoO − ), Figures 3d, 4d and 5b-g.…”

Effects of Alloying Elements and Microstructure on Stainless Steel Corrosion: A Review

“… may repel the migration of chloride ions toward the metal surface, mitigating the surficial dissolution. [ 69–71 ] Jayaraj et al [ 70 ] suggested that the negatively charged effect of N, like existing in a passive film, decreased the corrosion reaction and corrosion current. Moreover, the anion could repel the negative and ions, increasing the corrosion resistance and decreasing the anodic dissolution.…”