TRACK: Safety/Reliability
Corrosion-resistant alloys (like, Iron-alloys, Nickel-alloys, Titanium-alloys etc.) are widely used in highly corrosive process conditions that is strongly correlated to alloys composition and their microstructure. Most of the corrosion study on alloys in industries and academia are focused on aqueous conditions, as, it has been observed that non-aqueous chemistries are not aggressive to corrosion-resistant alloys particularly at not-so-elevated temperatures.
In the present study, it was observed that corrosion-resistant alloys (like, 316L, C-276, Ni-200) experience a very high corrosion rate at temperature as low as ambient in a combination of acidic chloride chemicals (like, thionyl chloride - a commonly used chlorinating agent) and widely used organic solvents (like, acetonitrile, pyridine, tetrahydrofuran etc.) in absence of water. Interestingly, some of the studied alloys (like, C-276) show very low corrosion rate in hydrochloric acid, irrespective of concentrations, at an ambient temperature. Experiments clearly showed a significant impact of water content in the solutions as addition of water resulted in a decrease in the corrosion rate. This is a work-in-progress, but the audience will find the results interesting as it showcases that no material is immune to corrosion attack and equipment's can fail in an unexpected manner. The results were analyzed using analytical techniques, electrochemical technique and traditional corrosion technique.