Organic coating failure and monitoring in atmospheric corrosion: from mechanisms to applications

Advantage of coalescence-induced droplet jumping behavior of superhydrophobic surfaces as a barrier against marine atmospheric corrosion

Characterization of long-term atmospheric corrosion of iron in indoor and outdoor conditions using Raman spectroscopy coupled to multivariate curve resolution-alternating least squares.

Objective - To numerically evaluate the impact of atmospheric corrosion on the mechanical behavior of steel columns in portal frames, considering different heights and directions of deterioration propagation. The study aims to understand how thickness loss influences the stiffness and stability of the structure, supporting design and preventive maintenance decisions. Methodology - The research was carried out through numerical modeling using the Abaqus® software, based on the theoretical model proposed by Vogel (1985). Simulations were performed with B21 beam elements, using a 200 mm mesh size. Corrosion scenarios with progressive thickness reductions were considered over exposure periods of 7, 15, 25, and 50 years, according to the guidelines of ABNT NBR ISO 9223 (2024). Originality/Relevance - The work proposes an approach that correlates the height and direction of corrosion with the loss of structural performance, highlighting critical regions and typical deterioration patterns in steel columns. Results - The results show that ascending corrosion exhibits gradual effects, becoming significant only when it reaches approximately 1.0 m in height, whereas descending corrosion causes noticeable deterioration with extensions as small as 0.4 m. A reduction in stiffness and an earlier onset of structural instability were observed, even with small displacement variations. Theoretical/Methodological Contributions - The study enhances the understanding of localized corrosion effects in structural steel members, presenting a replicable finite element–based simulation method. Social and Environmental Contributions - The research reinforces the importance of durability and sustainability in steel structures, promoting the rational use of resources through preventive maintenance strategies and extension of service life. The practical application of the results may reduce rehabilitation costs, minimize material waste, and contribute to more resilient and environmentally responsible buildings.

This study investigates droplet-induced corrosion, a localized corrosion phenomenon driven by oxygen depletion within electrolyte droplets, distinct from bulk volume corrosion. To evaluate the performance of corrosion inhibitors under droplet conditions, a rapid screening electrochemical test method was employed, using a two-electrode setup to monitor corrosion currents. The study examined systematically different exposure environments including dissolved oxygen, pH, electrolyte molarity, and droplet geometry as key factors influencing atmospheric corrosion. Results show that dissolved oxygen levels significantly affect corrosion mechanisms, while larger droplets amplify the Evans droplet effect. Importantly, effective corrosion inhibitors mitigate this effect by reducing the cathodic reaction rate in droplet conditions. These findings advance the understanding of droplet corrosion mechanisms and provide insights into designing sustainable protection strategies to improve the longevity of steel structures in aggressive environments.

Coalescence-induced droplet jumping behavior (CIDJB) on superhydrophobic surfaces enables the effective removal of corrosive water films/droplets, thereby showing great potential for marine atmospheric corrosion. However, merely focusing on the superhydrophobic effect is not enough. It is essential to select optimal nanoarchitectures and fine-tune their geometric parameters to achieve a high-efficiency CIDJB and atmospheric corrosion protection. In this study, three kinds of superhydrophobic surfaces with distinct geometrical parameters of microstructures were systematically fabricated. The impact of reaction concentration on the microstructure parameters (diameter, interspace, and height) of superhydrophobic surfaces was investigated, where higher concentrations were found to increase microstructure diameter while reducing height and initially decrease interspace before increasing again. The individual and synergistic mechanisms of how these microstructure parameters affect the droplet self-jumping behavior (droplet surface coverage, droplet average diameter, and anticondensation efficiency) and the corrosion protection performance against marine atmospheric corrosion were analyzed. It was revealed that the spacing of the superhydrophobic surface microstructures is a critical factor influencing both the droplet self-jumping behavior and corrosion protection performance. Smaller spacing can generate larger upward Laplace pressure, thereby accelerating droplet coalescence and jump and facilitating the transition of condensed droplets within the microstructure from partially wetted states to suspended Cassie states. This study enriches the theoretical system of CIDJB and provides design criterion for the development of high-performance anticorrosion superhydrophobic surfaces in marine environments.

Fiber Metal Laminates (FMLs) are composite materials created by layering glass/epoxy between metal sheets. These materials offer both excellent mechanical properties and reduced weight. One specific type, Glass Laminate Aluminum Reinforced Epoxy (GLARE), was examined in this study. The manufacturing materials included the Aluminum alloy (Al3003), which is a medium-strength alloy with good resistance to atmospheric corrosion and good weldability, as well as good cold formability. The reinforced nanofillers consisted of glass fibers/ Nano particles with varying weights. Bending tests were performed on small punch and three-point bending tests. The results show that samples with nanofillers have high mechanical properties compared to samples of glass fibers, with 1 wt.% Al₂O₃ increasing flexural strength by 6.14% and fracture toughness by 96%, whereas glass fiber reinforcement achieved only 2.63% and 80%, respectively.

Abstract Atmospheric exposure of Ag witness coupons yields corrosion products such as AgCl and Ag 2 S that are highly dependent on local atmospheric chemistry. The principal goal of this study was the synthesis of a comprehensive catalog of silver corrosion product standards with characterization using electrochemical and surface analytical methods. Several silver corrosion products were generated using galvanostatic oxidation with good charge efficiency and were analyzed using coulometric reduction, cathodic polarization, and surface techniques. Average reduction potentials estimated by coulometric reduction were –0.22±0.005 V MSE (Ag 2 O), –0.34±0.01 V MSE (AgCl), –0.50±0.001 V MSE (AgBr), –0.74 V MSE (AgI), and –1.25±0.01 V MSE (Ag 2 S). Results from surface analytical techniques confirmed the presence of supporting halides, sulfides, or oxides. Surfaces were also analyzed after the film was reduced, confirming that coulometric reduction consumed the corrosion product. The standards were used to identify Ag 2 O, AgCl, and Ag 2 S on coupons exposed to two outdoor and 1 indoor environment and the reduction potentials from these coupons were within ±0.01 V MSE of the standards.

Strength degradation of steel structures due to corrosion is a significant durability concern globally, particularly in industrial environments where exposure to harsh conditions accelerates material deterioration. This study investigates the impact of long-term atmospheric corrosion on the mechanical properties and load-bearing capacity of circular hollow section (CHS) steel columns. The specimens dismantled from a substation structure exposed to an urban industrial environment for 30 years were subjected to tensile and axial compression experiments to analyze corrosion-induced deterioration. This research explores the correlation between corrosion rate and degradation of mechanical properties, such as yield strength, ultimate strength, and elasticity. A novel Corrosion-Mechanical Interaction Model is proposed to predict the remaining service life of corroded steel structures by integrating the effects of corrosion on these critical properties. Experimental results revealed a significant reduction in yield and ultimate strength due to uniform corrosion, with a direct linear relationship between the bearing capacity degradation and material loss. This study provides a crucial tool for engineers and infrastructure planners in managing the lifecycle of steel structures exposed to harsh environmental conditions.

Atmospheric Corrosion Research of Carbon Steel for Automobile Based on Corrosion Big Data Technology

Weathering steel, particularly Q370qENH, is widely used in bridge construction in China due to its exceptional corrosion resistance and low maintenance costs. However, further study is needed on accelerated corrosion simulation methods and the corrosion mechanisms of weathering steel bridges in medium corrosivity environments (e.g., C3 level). Therefore, this study focuses on the accelerated corrosion methods, corrosion characteristics of Q370qENH and the relationship between accelerated and atmospheric corrosion. Firstly, the wet-dry salt spray corrosion test is employed to accelerate the atmospheric corrosion of Q370qENH, with test parameters defined based on relevant research and standards. Subsequently, scanning electron microscopy, 3D scanning and X-ray diffraction techniques are used to analyse the morphology and composition of Q370qENH at different stages of accelerated corrosion, exploring the rust layer formation mechanism. Additionally, the weight loss method is applied to assess the amount and rate of accelerated corrosion, leading to the establishment of a predictive model for accelerated corrosion over time. Furthermore, an atmospheric exposure test field has been established in Changsha (C3 level), based on which a predictive model for atmospheric corrosion of Q370qENH is developed. The relationship between accelerated and atmospheric corrosion is derived by comparing the two predictive models.

Acoustic emission based corrosion imaging as a possible method for identification of localized atmospheric corrosion of aluminum structures.

Delayed Fracture Mechanism of 1700 MPa-Class Quenched and Tempered Bolt under Atmospheric Corrosion Environment

Preparation of Schiff base derivates from leucine and its inhibition effect on the atmospheric corrosion of mild steel

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This paper is dedicated to long-term atmospheric corrosion behaviour of magnesium alloys. Five different magnesium alloys, namely, AZ31, AM60, AZ61, AZ80, and AZ91, were exposed for 4 years under harsh conditions at the marine corrosion site of Brest (France). From the results, the corrosion performance increased in the following order: AZ31 < AM60 < AZ91 < AZ61 < AZ80. The corrosion was highly localised during the first year of exposure, but more general corrosion prevailed after long-term exposure. All materials followed a power law with rather similar kinetics of corrosion. The observed difference in the corrosion performance of the alloys was explained by the amount of secondary phases as well as that of the Al-content in the α-Mg phase.

Soil corrosion is a critical durability and cost factor for metallic foundations in photovoltaic (PV) power plants, yet it is still addressed with fragmented criteria compared with atmospheric corrosion. This paper reviews the main soil corrosivity drivers relevant to PV installations—moisture and aeration dynamics, electrical resistivity, pH and buffer capacity, dissolved ions (notably chlorides and sulfates), microbiological activity, hydro-climatic variability and geological heterogeneity—highlighting their coupled and non-linear effects, such as differential aeration, macrocell formation and corrosion localization. Building on this mechanistic basis, an engineering-oriented methodological roadmap is proposed to translate soil characterization into durability decisions. The approach combines soil corrosivity classification according to DIN 50929-3 and DVGW GW 9, tiered estimation of hot-dip galvanized coating consumption using AASHTO screening, resistivity–pH correlations and ionic penalty factors, and verification against conservative NBS envelopes. When coating life is insufficient, a traceable steel thickness allowance based on DIN bare-steel corrosion rates is introduced to meet the target service life. The framework provides a practical and auditable basis for durability design and risk control of PV foundations in heterogeneous soils. The proposed framework shows that, for soils exceeding AASHTO mild criteria, zinc corrosion rates may increase by a factor of 1.3–1.7 when chloride and sulfate penalties are considered, potentially reducing coating service life by more than 40%. The methodology proposed enables designers to estimate the penalty factors for sulfates (fpSO42−) and chlorides (fpCl−) in each specific project, calculating the appropriate values of KSO42− and KCl− using electrochemical techniques—ER/LPR and EIS—to estimate the effect of the soluble salts content in the ZnCorr Rate, not properly catch by the proxy indicator VcorrER, pH when sulfate and chloride content are over AAHSTO limits for mildly corrosive soils.

A comprehensive understanding of atmospheric corrosion guides informed design choices and effective anti-corrosion protection strategies. Despite advancements in the understanding of atmospheric corrosion, there exists a knowledge gap in the corrosivity of metals in subarctic regions like Alaska where evaluation is made more difficult. Multi-angle corrosion test racks were deployed at four test sites in Alaska each equipped with weather sensors and chloride candles to evaluate atmospheric and environmental severity. Recorded weather parameters include air temperature, relative humidity, time of wetness, total rainfall, and aerosol chloride and sulfate deposition. 1008 Carbon Steel was chosen for exposure and analysis. Post-exposure coupon mass loss was measured, and corrosion rates were analyzed as a function of exposure angle. Based on experimental results, equations were developed to more accurately model and estimate the corrosive behavior and evaluate the atmospheric corrosivity in Alaska. This model quantifies experimental corrosion rates as a function of air temperature, relative humidity, sulfate deposition, chloride deposition, percent time wet, and exposure duration.

Abstract The atmospheric corrosion behavior of 60Si2MnA spring steel was investigated in environments containing chloride (Cl − ) and sulfate (SO 4 2− ). Bare steel specimens were exposed to controlled laboratory conditions that replicated key parameters of the target atmosphere. The deliquescence and weathering characteristics of the deposited salts were examined using electrochemical impedance spectroscopy, while a custom-built salt deposition system was employed to conduct corrosion tests at constant temperature and humidity (20 °C/75 % RH and 40 °C/75 % RH) with a surface salt load of 10 g/m 2 over varying exposure durations. Pronounced corrosion was observed under both temperature conditions. X-ray diffraction and Raman spectroscopy revealed that the corrosion products were primarily composed of iron oxyhydroxides and iron oxides. Scanning electron microscopy combined with electrochemical analyses showed that, at early exposure stages, the rust layer exhibited abundant cracks and pores, allowing for the ingress of corrosive species. The initial corrosion products acted as strong oxidants, enhancing cathodic reactions and thus accelerating metal degradation. With increasing exposure time, the thickening of the rust layer provided partial protection, slightly improving the corrosion resistance. Elevated temperature was found to significantly accelerate both the corrosion rate and the evolution of corrosion products.

Corrigendum to ''Atmospheric corrosion of Ni-advanced weathering steels in a marine atmosphere of moderate salinity: 10 years of exposure'' [Corros. Sci., 257 (2025) 113322