Inhibition Of Corrosion Process Research Articles

Analytical Solution for the Lifetime of a Spherical Shell of Arbitrary Thickness Under the Pressure of Corrosive Environments: The Effect of Thermal and Elastic Stresses

Abstract This article presents analytical solutions to initial boundary value problems of thermoelasticity with a priori unknown evolving boundaries. To be more precise, we consider a spherical shell of arbitrary thickness subjected to the internal and external pressures of corrosive media at generally different temperatures, with taking into account the mechanochemical effect and inhibition of corrosion process. Conditions under which the circumferential stress can serve as the equivalent stress are determined. It was found that the life of the shell was influenced by the competing effects of the pressures and temperatures on the corrosion rate and stress values, as well as by possible moving the location of the maximal stress. It was also concluded that the elastic stress component played a decisive role in the synergistic growth of the total thermoelastic stress and the corrosion rate.

Investigation of corrosion mechanism in Type 304 stainless steel under different corrosive environments: A SIMS study

Surface imaging, depth distribution and mass spectra analysis features of Secondary Ion Mass Spectrometry has been utilized for investigating the corrosion mechanism in Type 304 austenitic stainless steel under different corrosive environments of H2SO4, HCl and HNO3 solutions of 10M each. Surface distribution analysis revealed non-homogenous distribution of alloying elements S, Cr, Mn, Ni and Fe in case of H2SO4 and HCl treated samples, which was due to the formation of corroded layer and its morphology. Depth distribution and mass spectra analysis revealed that oxides and hydroxides containing species are most abundant in H2SO4 treated sample followed by HCl treated sample. Surface distribution and mass spectra analysis indicated localized attack or pitting corrosion of chloride species in case of HCl treated specimen whereas in case of H2SO4 treated sample, attack of sulfur species was associated with an intensification of oxide and hydroxide species. Depth distribution analysis in case of HNO3 treated specimen concluded the formation of a passive layer enriched with Cr, Ni, Mn and Fe which causes the inhibition of corrosion process under the experimental corrosive parameters. The study also provides a methodology to investigate the type of chemical attack and to find out the root cause of corrosion utilizing various analysis features of SIMS technique.

Whitney Award Lecture—1981: New Data on the Mechanism of Metals Protection with Inhibitors

Understanding of the mechanism of metal passivation with inhibitors requires detailed knowledge of the character of adsorption, the nature of the chemical bonding, the valent state of the adsorbed particles, etc. This study demonstrated that quantum chemistry calculations, x-ray photoelectron spectroscopy methods, radioactive tracers, chemical polarization can provide valuable information. Inhibition of corrosion processes, like same passivity, can be caused by the generation on metal surfaces of both adsorption and phase layers. An example of adsorption inhibition may be found in the pitting corrosion prevention of stainless steels. 16 references.