Effect of heating temperature on the behavior of reinforced zinc-rich coating with nanoparticles

Abstract

An experimental study has been conducted to develop unique zinc-rich coatings for the protection of low carbon steel reinforcements. These coatings are applied to low carbon steel substrates and subjected to various temperatures (100 °C, 150 °C, 200 °C, and 250 °C) to assess their mechanical integrity, corrosion resistance, and durability, replicating extreme service environments. The study integrates different nanoparticle concentrations into the zinc matrix (including Zn only, 50% Zn + 50% TiO2, 50% Zn + 30% WC + 20% TiO2, 40% Zn + 40% Ni-Cr Alloy + 20% TiO2, 70% Zn + 30% WC, and 50% Zn + 50% Ni-Cr Alloy) to assess their reinforcement effectiveness and contribution to thermal stability. The performance properties are assessed using adhesion tests, coating ratings, hardness assessments, electrochemical analysis, and field emission scanning electron microscopy (FESEM). The findings reveal that zinc coatings with a composition of 50% Zn, 30% WC, and 20% TiO2 provide excellent adhesion, particularly beneficial for high-temperature applications. Coatings containing Ni-Cr alloy display outstanding thermal stability, a vital characteristic for withstanding high-temperature conditions. At 250 °C, evaluating the compositions for the most favorable potential at the highest current densities is imperative. Microstructural analysis from room temperature to 250 °C shows a significant improvement in the integration and refinement of WC and Ni-Cr within the Zn matrix, resulting in the coatings’ optimal performance.