Influence of carbon on the corrosion behaviour of interstitial equiatomic CoCrFeMnNi high-entropy alloys in a chlorinated concrete solution

A photoelectrochemical study of the anodic oxidation of copper in alkaline solution

Corrosion inhibition of carbon-steels by propargyltriphenylphosphonium bromide in H2SO4 solution

The electrochemical and corrosive behaviour of antimony and antimony-tin alloys (Alloy No./Sb(wt. %); I/90, II/80, III/65, IV/50) as anodes in various aqueous concentrations of KOH have been investigated using galvanostatic, potentiodynamic and potentiostatic techniques. Galvanostatic potential–time curves at 4 mA cm−2 revealed that passivation of both antimony and antimony tin alloys is inhibited by an increase in KOH concentration. The opposite effect was observed with an increase in Sn content in the alloy. At high Sn content and low [OH−] a pseudo passivation potential was observed. (Abnormal early passivation occurring in the active anodic region due to the formation of tin oxides, which dissolve in alkali. Then, potential decreases.) The alloy with 50% Sn exhibited immediate passivation. The potentiodynamic curves were swept from Eo.c up to +1000 mV vs SCE. The results showed an increase in the peak current (Ip) for antimony and its alloys with increasing [OH−] on the oxide film. The first three all...

Anodic Behaviour of Antimony and Antimony-Tin Alloys in Alkaline Solutions

Four annealed carbon steels with different carbon contents (0.002, 0.17, 0.43, and 0.7% C), consisting of ferrite, ferrite-pearlite and fully pearlite microstructures, were selected to understand the corrosion behavior of carbon steel as a function of carbon content in freely aerated 3.5% NaCl solution. Dynamic polarization, electrochemical impedance and linear polarization methods were used. The corrosion rate obtained from the different carbon steels was found to increase greatly from ultra-low carbon steel (0.002%) to low carbon steel (0.17%) due to the presence of pearlite in the low carbon steel. However, the increase in corrosion rate was marginal with the increase in carbon content from low carbon (0.17%) to medium (0.43% C) and high carbon steels (0.7% C). The mirostrucural evolution of the steels before and after polarization test without etching as observed by scanning electron microscopy could show that the corrosion behavior of the steels with the presence of pearlite was due to the combined effect from % pearlite, interlamellar spacing and cementite/ferrite area ratio in pearlite. Pearlite morphology also led to the differential corrosion within the pearlite colony in all the steels except the steel with 0.002% C. Catalytic activity of cementite on enhancing oxygen reduction reaction attributes to the higher corrosion rates in case of the steels with the presence of pearlite.

M.M. Anwar

Papers

Anodic passivation of pb in various media

Effect of carbon content on the corrosion and passivity of iron

Potentiokinetic study of the effect of C on corrosion of some steels in alkaline solutions

Corrosion and passivity of some Pb-Sn alloys in various media