The corrosion behavior of hard W–C system chemical vapor deposition layers in HCl and H<Subscript>2</Subscript>S aqueous solutions

The results of a study of anticorrosion performance of low carbon containing tungsten-based hard chemical vapor deposition (CVD) coatings with microhardness from 5 to 17 GPa are presented in this work. Their high corrosion resistance in hydrochloric acid and hydrogen sulfide solutions is noted, as their corrosion rate does not exceed 6 μm per year in hydrochloric acid solution and 15 μm per year in hydrochloric acid solution saturated with hydrogen. The open circuit potentials correspond to tungsten (VI) oxide formation so the corrosion process supposedly runs in passive state. Taking into account the low porosity of the CVD layers, which is lower than 0.02%, these coatings are promising for application as anticorrosion wear-resistant coatings for chemical and oil and gas apparatus responsible units.     

Mechanical Properties and Corrosion Resistance of Hard β-W based CVD Coatings in Aqueous NaCl Solution

Protection of Metals and Physical Chemistry of Surfaces - The paper presents the results of studying the mechanical and anticorrosive properties of coatings based on the metastable tungsten phase...     

Chemical and phase composition of nanosize oxide and passive films on Ni-Cr alloys. I. XPS studies of films obtained by alloy oxidation in air

XPS data for thin (less than 100 nm) oxide films obtained by oxidation of Ni-4 Cr and Ni-12.5 Cr alloys at 500°C (0.5 h) are discussed. Thermodynamic analysis of 3 NiO + 2 Cr = Cr₂O₃ + 3 Ni solid-phase reaction is given, in which both the Gibbs energy change in the thermochemical process and the change in the interface energy at the alloy-oxide film boundary are taken into account.     

Corrosion and Electrochemical Behavior of β-W CVD Coatings in NaCl Solution

Protection of Metals and Physical Chemistry of Surfaces - The paper presents the results of a study of the corrosion-electrochemical behavior of coatings based on the metastable phase of tungsten...     

The Corrosion and Electrochemical Behavior of Tungsten-Based CVD Coatings in Alkaline Aqueous Solutions

Protection of Metals and Physical Chemistry of Surfaces - The results of corrosion-resistance analysis for tungsten-based coatings obtained by means of low-temperature chemical-vapor deposition...