Comparative study between natural and artificial weathering of acrylic‐coated steel, aluminum, and galvanized steel

Abstract

Since testing organic coatings under natural conditions is a time‐consuming process, accelerated methods are needed to produce results in less time. A simulated environment cannot fully reproduce actual operating conditions, so it is important to investigate the correlation between accelerated and natural aging test results. In this article, the natural aging of painted steel, aluminum, and hot‐dip galvanized steel is studied for 1 year under continental climate conditions. The environmental parameters responsible for the change of the protective system in a continental urban environment were monitored: time of wetness, ultraviolet radiation, and temperature. The extent of deterioration is compared with similar samples weathered by accelerated testing using electrochemical impedance spectroscopy, differential scanning calorimetry, and gloss measurements. Neutral salt spray chamber, prohesion test, immersion in a quiescent salt solution, and ultraviolet B‐rays (UVB) exposure test are considered. The results of the accelerated cabinet tests are discussed, and the effect is evaluated for the various coated metals. This study highlights the major problems encountered in building a model to predict durability in such a critical area as the durability of organic coatings for metal structures.

Artificial Weathering Test Methods of Waterborne Acrylic Coatings for Steel Structure Corrosion Protection

“…The literature presents many results of studies demonstrating a correlation between natural and artificial degradation for specific coating parameters, e.g., electrochemical impedance spectroscopy (EIS) and Fourier-transform infrared spectroscopy (FTIR). Still, some results contradict this thesis [7,17,19,22,25,26].…”

“…of studies demonstrating a correlation between natural and artificial degradation for specific coating parameters, e.g., electrochemical impedance spectroscopy (EIS) and Fouriertransform infrared spectroscopy (FTIR). Still, some results contradict this thesis [7,17,19,22,25,26]. A major problem in obtaining a correlation between natural and artificial weathering is related to limited amounts of data.…”

“…The task poses a challenge due to the diversity and variability in environmental conditions, even in the same country. Further research is indispensable to improve accelerated weathering methods, including but not limited to new groups of corrosion protection coatings and the correlation of accelerated and natural weathering [25]. The literature presents many results of studies demonstrating a correlation between natural and artificial degradation for specific coating parameters, e.g., electrochemical impedance spectroscopy (EIS) and Fourier-transform infrared spectroscopy (FTIR).…”

Exploring the Role of Passivating Conversion Coatings in Enhancing the Durability of Organic-Coated Steel Against Filiform Corrosion Using an Electrochemical Simulated Approach

“…The coating application was conducted using a blade apparatus known as the Elcometer 4340 Automatic Film Applicator. A dry film thickness of 75 μm was obtained by curing at 60 • C in an oven for 1 h, achieving a glass transition temperature of 46 • C [47]. The coated specimens were prepared in accordance with the ASTM 2803 standard [39].…”

Incorporating Physics-Based Models into Equivalent Circuit Analysis of EIS Data from Organic Coatings

“…Environmental exposure of aircraft-grade polymeric coatings to ultraviolet radiation from sunlight and seawater results in coating deterioration, which is observed as a reduction in chemical cross-links and subsequent loss of mechanical properties [2]. This deterioration is characterized by a sequential progression of behaviors, including: diffusion of water and dissolved oxygen; transport of electrolyte ions; development of anodic and cathodic regions at the coating-substrate interface; onset of electrochemical reactions; chemical and hydrolysis reactions; displacement of polymer-surface bonds by water-surface bonds and accumulation of water to form blisters [3] or the formation corrosion products at the coating-oxide interface, both of which result in loss of coating-to-surface adhesion [4,5].…”