Development and optimization of trivalent chromium electrodeposit on 304L stainless steel to improve corrosion resistance in chloride-containing environment

In this study, we developed and optimized a trivalent chromium coating electrodeposited on 304L stainless steel (SS) from a Cr-trivalent bath. The results reveal that the Cr coatings at all bath temperatures except for 80 °C showed clusters of polyhedral grains, however, the grain sizes decreased with an increase in bath temperature. Also,...

Correlating laboratory tests with service life performance of marine coating systems

Accelerated tests have been commonly used by the marine coating industry to evaluate the performance of a coating in a short duration of time. Replicating natural exposure in an artifi- cially simulated manner is a challenging task due to the various factors that induce corrosion in the natural environment. Continuous salt spray testing is a...

Smart protective coatings with self‐sensing and active corrosion protection dual functionality from pH-sensitive calcium carbonate microcontainers

Herein, we report the development of a self-sensing and active corrosion protection coating which incorporates pH-sensitive multilayer chitosan/alginate-covered CaCO₃ microcontainers containing 1,10-phenanthrolin-5-amine (APhen). The microcontainers can respond to pH variation to release APhen which serves not only as a corrosion...

Li leaching from Li carbonate-primer: Transport pathway development from the scribe edge of a primer/topcoat system

Depletion depths of inorganic components from a scribe edge in a polyurethane primer containing Li₂CO₃, MgO, BaSO₄ and TiO₂ beneath a topcoat, were determined using a range of techniques including SEM/EDS and proton induced X-ray and γ-ray emission spectroscopies. SEM of sections cut using an ion...

Formation and stability of lithium protective layer for corrosion protection of AA2024-T3 and AA2198-T8 aluminium alloys

As a possible replacement for chromate-based coatings in the aerospace industry, lithium leaching coatings have been widely studied in recent years. The formation mechanism of protective layer on AA2024-T3 aluminum alloys has been investigated intensively. In order to explore more possibilities for its application in aerospace industry, AA2198...

Li leaching from lithium carbonate-primer: An emerging perspective of transport pathway development

Studies of Li depletion in sections of a Li ₂ CO ₃ -primer comprising a polyurethane binder, MgO, TiO ₂ , BaSO ₄ in addition to Li ₂ CO _3, were performed using a combination of particle induced γ-ray and X-ray emission spectroscopies along with SEM/EDS analysis. A mixture of...

Corrosion monitoring of steel structure coating degradation

An important aspect regarding the sustainability of steel structures is to ensure the structure is protected from corrosion. A number of surface coatings are available that play an important role in protecting these structures. An important part of the management of these structures is reliable and regular inspection along with methods for early...

Compositional study of a corrosion protective layer formed by leachable lithium salts in a coating defect on AA2024-T3 aluminium alloys

Organic primer coatings loaded with environmentally harmful Cr(VI) corrosion inhibitive pigments still play an important role in corrosion protection of aluminium alloys for the aerospace industry. A potential “green” alternative coating system has recently been developed, loaded with lithium salt corrosion inhibitors. Under exposure to...

Particle induced gamma and X-ray emission spectroscopies of lithium based alloy coatings

Lithium based inhibitors in aerospace coatings are seen as excellent replacements for their chromium counterparts which are both carcinogenic and heavier. However, Li is generally difficult to detect and following changes in its distribution due to corrosion is impossible with many standard techniques. Combining MeV Particle Induced Gamma and...