It has been considered that the corrosion of passive metals and alloys is not caused by the active metal-dissolution but the dissolution of a nonporous passive oxide film in aqueous solution. The corrosion current density of iron(1)(2), chromium(3) and their alloys(4) is independent of the potential in all the range of passivity, although depending upon the pH of solution. Vetter(1) explained s...

A highly sensitive, passive relative humidity (RH) sensor using polyvinyl-alcohol (PVA) dielectric film is presented. For the first time, PVA is investigated in microwave RF sensing devices for low cost, high resolution and accurate chipless RH sensor realization. Comparative study with traditional humidity sensing Kapton polymer is presented to validate superior performance of PVA film. Result...

We present a simplified point defect model to describe the growth of the primary passive oxide film on the surface of iron. The model postulates a reduced set of elementary interfacial reactions to describe the formation and dissolution of the oxide film. By casting the model in dimensionless form, we obtain a relatively small set of parameters that must be assigned values. Parameter values are...

A nanocrystalline layer was prepared on the surface of 34CrMo4 steel by time controlling shot peening (SP, i.e., 1, 5, 10, and 20 minutes). Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) analysis, and transmission electron microscope (TEM) were applied to analyze the surface, cross-sections, and grain size of the specimens before and after SP. The electrochemical c...

In this study, electrochemical behaviour of passive films formed on AISI 316L stainless steel (AISI 316L) in three acidic solutions concentrations (0.3, 0.6, and 0.9M HNO3) under open circuit potential conditions were evaluated by potentiodynamic polarization, Mott–Schottky analysis and electrochemical impedance spectroscopy (EIS) techniques. The potentiodynamic polarization results showed that...

Successful integration of paraelectric Ba1-xSrxTiO3 (BST) based thin films with affordable Si substrates has a potential significant commercial impact as the demand for high-frequency tunable devices intensifies. Utilizing a coplanar device design we have successfully designed, fabricated, characterized, and optimized a high performance Ta2O5 thin film passive buffer layer on Si substrates, whi...

Four compositions of austenitic Mn-Cr steels have been developed successfully for in-vessel component materials in power plant industry. The phase stability of these Mn-Cr steels was studied by and X-ray diffraction (XRD) patterns. XRD patterns have shown that the matrix of these Mn-Cr steels is a single γ-phase structure. The potentiodynamic polarisation curves suggested that these fabricated ...

The transient response of passivated metallic electrode system under potential step was analyzed based on a linear model, and a technique for calculating the parameters characterizing the growth and dissolution of passive film was proposed. It is believed that the information which is expected to be gained from the impedance measurement can be obtained by this technique and that this technique ...