An Electrochemical Study of the Pit Initiation Resistance of Ferritic Stainless Steels

Abstract

A variety of electrochemical techniques has been used to study the resistance of ferritic stainless steels to pit initiation in 1M NaC1 at 80~ Critical pitting potentials have been measured by potentiodynamic anodic polarization and by the "scratch" technique. The effectiveness of passivation potential and alloy content to promote formation of a film that is resistant to breakdown has been studied by pit induction time measurements. The ability of the passive surface to adjust to abrupt changes in passivating conditions has been studied by potential stepping experiments. It has been shown that the effect of Cr on passive film properties is disproportionately great with respect to that of Mo for alloys of comparable pitting resistance. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.192.114.19 Downloaded on 2015-06-05 to IP Vol. 132, No. 3 PIT INITIATION RESISTANCE

Influence of Postbuild Microstructure on the Electrochemical Behavior of Additively Manufactured 17-4 PH Stainless Steel

“…2: a) wrought in the RD plane, b) AM as-built in the XY plane, c) AM as-built in the XZ plane, and d) AM + heat treatment in the XY plane. In the figure, the wrought SS17-4 exhibits significant pitting at what are most likely MnS inclusions as well as some additional pitting at carbide interfaces [24–26]. Both orientations of the AM as-built material exhibit pitting at the carbide interfaces similar to that exhibited in the wrought condition.…”

“…1. Interfaces, such as grain boundaries, lath boundaries, and more importantly, those between second-phase constituents (e.g., carbides), generally produce discontinuities in the local composition and often serve as preferred sites for pit initiation [31] [25–26]. Typically, niobium is added to martensitic stainless steels to minimize the formation of chromium carbides, which would lead to an overall enhancement in the stability of the passive film.…”

The influence of nanocrystalline structure and processing route on corrosion of stainless steel: A review

“…A detailed discussion on the pitting behaviour of SS could be found in [76,112,126,141,147,[177][178][179][180][181][182]. For the purposes of this paper, it is important to understand that Cr content, alloying elements and impurities, chemical homogeneity, morphology and distribution of secondary phases (i.e., MnS, inclusions), and compactness and homogeneity of the passive film are the main parameters influencing the pitting corrosion of SS in given environmental conditions [126,156,157,[183][184][185].…”

Antibacterial drugs as inhibitors for the corrosion of stainless steel type 304 in HCl solution

“…High E HUMO values indicate that the molecule has a tendency to donate electrons to appropriate acceptor molecules with low energy empty molecular orbital. Increasing values of the E HUMO facilitate adsorption (and therefore inhibition) by influencing the transport process through the adsorbed layer [44][45][46]. E LUMO indicates the ability of the molecules to accept electrons.…”

“…E LUMO indicates the ability of the molecules to accept electrons. The lower values of the E LUMO , the more probable it is that the molecule would accept electrons [44][45][46]. Low absolute values of the energy band gap (DE) gives good inhibition efficiencies, because the energy to remove an electron from the last occupied orbital will be low [47].…”