Abstract
Experimental study of the chromium-nickel steel Cr18Ni10 anodic dissolution in a nitrate solution with electrical conductivity 0.15 S/cm in a pulse – galvanostatic mode at pulse durations 20–100 µs and current densities 0.01–100 A/cm2, with a change in the duty cycle 10–100% (direct current) at various hydrodynamic conditions and control the surface temperature, that the results obtained are consistent with the hypothesis that the process proceeds through the formation of oxide films of a semiconductor nature with a different type of conductivity (a film containing point defects, Point Defect Model, PDM). Under sta-tionary conditions of the existence of PDM-II, the rate of its electrochemical formation is compensates by the rate of its chemical limiting value of the weight loss per unit of a passed charge (0.16–0.18 mg/C) (takes place under pulse conditions), which corresponds to a cur-rent efficiency close to 100% based on the highest degree of oxidation of the steel compo-nents. When transition to direct current takes place, thermokinetic instability of the film is observed (its formation and destruction due to thermal explosion). Under these conditions, the current efficiency can not only reach 100% based on the lowest degree of oxi-dation of the steel components (thermal activation) but also exceed this value due to the chemical interaction of the electrolyte with the film-free surface.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
