Spray Test Research Articles

Polymer coating for antiicing and deicing

Ice accretion may cause serious safety risk and huge economic loss for outdoor facilities. Herein, we report a waterborne polymeric coating based on a copolymer network of methacrylic acid (MAA), acrylamide (AM), N-2-hydroxyethyl acrylamide (HEAA), and methoxypolyethylene glycol (MPEG) with free polyethylene glycol (PEG) dispersed in it. Owing to the good compatibility of free PEG chains and the PEG side chains of the copolymer, the hydrogen bonding between acrylic copolymer and PEG, the free PEG chains can well be trapped in the network with some segments out of the mesh as short PEG chains are grafted on the coating surface, so that the surface has liquid-like properties. Water droplets can readily slip off on the coating surface with a small sliding angle (<30°). Particularly, the surface can hold the properties for a long duration upon water flushing, cycle of wetting-drying, and salt spraying tests. The polymer coating can find application in icing prevention and removal.

Self‐healing polyurethane anticorrosive coatings based on alkyd resin microcapsules

AbstractIn this paper, self‐healing microcapsules were prepared by in situ polymerization using poly(vinyl alcohol) as the emulsifier, urea‐formaldehyde resin as the shell material, and alkyd resin as the core material. The average diameter of the obtained microcapsules was about 20 μm and the encapsulation rate of alkyd resin was 50.7 wt.%. The self‐healing coating was prepared by adding 5 wt.% of microcapsules to the pure polyurethane coating and then coated on AA2024‐T3 substrate. The self‐healing effect was evaluated by scanning electron microscopy. Electrochemical impedance spectroscopy tests and neutral salt spray tests confirmed that the self‐healing coating had good anticorrosion properties.

Fatigue Behavior and Fracture Surface Analysis of Corroded High-Strength Bridge Cable Wires.

Bridge cable wires suffer from alternating stress and environmental erosion, leading to premature failure prior to its design life. This paper investigates the fatigue and mechanical behaviors of corroded bridge cable wires with a zinc-aluminum (Zn-Al) alloy coating. Based on the salt spray corrosion test and microstructure analysis, the anti-corrosion resistance and corrosion appearance characteristics of the Zn-Al alloy coating and galvanized coating were investigated. The Zn-Al alloy coating was superior in resistance to corrosion fatigue for the improvement in toughness and the generation of anti-corrosion Zn-Al and Fe-Zn-Al phases. Equations of the accelerated corrosion depth of the steel wires had been regressed to roughly estimate the corrosion life of the Zn-Al alloy coating, which can reach 29.1 years with a thickness of 70 μm. The fatigue and mechanical properties of the bare wires after the salt spray test were further studied based on tensile tests and fatigue tests. The fatigue properties of the bridge cable wire would decrease with the corrosion degree due to the deterioration and embrittlement of materials, where ductility characterized by the elongation rate was the most affected. Fracture surfaces of the wires were captured and analyzed based on a method for recognizing graphical contours. Insufficient fatigue life may occur in the steel wires after corrosion and increase with the degree of corrosion. The pit depth logarithmically weakened the fatigue life of steel wires for the weakening of fatigue toughness and the bearing area. The flat fracture was more common with a single fatigue source, while multiple fatigue sources led to step-like fractures for the generation of multiple dispersed crack propagation regions. Corrosion fatigue was more sensitive to the existence of fatigue sources than the reduction. Multiple initiation sources significantly reduced the fatigue life due to the cracking facilitation of the joint effect of multiple pits. The electrochemical reactions of corrosion can lead to material embrittlement and a reducing effect on the fracture toughness of the steel wires.

Synergistic defense: Compositional regulation and temperature engineering of TMCs for enhanced microwave absorption and corrosion protection

In the context of abundant marine wind energy resources, offshore wind power presents an effective solution to the current energy crisis, however, the challenges of electromagnetic interference and corrosion faced by offshore wind power generation equipment demand urgent resolution. This study addresses these issues by employing a coordination strategy between deprotonated dopamine and transition metal ions, utilizing compositional regulation and temperature engineering to synthesize a series of carbon/transition metal carbides (TMCs) composite materials. Compositional regulation introduces heterojunction interfaces to enhance dielectric loss, while temperature engineering effectively adjusts the material's impedance matching. WM@C, with an extremely thin thickness of 1.66 mm, demonstrates a remarkable effective absorption bandwidth (EAB) reaching 5.52 GHz, accompanied by a maximum reflection loss (RL) of –26.8 dB. Notably, attributed to the outstanding anti-chloride ion pitting ability of TMCs and the stacking effect of dense carbon nanosheets on the surface, the synthesized composite coatings demonstrate excellent corrosion protection capabilities. After 10 consecutive days of salt spray test, the EAB of the WM@C still maintains 5.01 GHz at 1.76 mm, a new idea of dual-function integrated materials for microwave absorption (MA) and corrosion protection has been developed, providing theoretical support for the construction of offshore wind power generation equipment.

High-Loading Smart Carrier Containing 2-Mercaptobenzimidazole-Zn2+-Polydopamine with pH-Responsive Function to Fabricate High-Performance Waterborne Epoxy Anticorrosion Coatings.

Corrosion inhibitor additives are considered to be one of the effective methods to slow down the corrosion of metals, but the corrosion inhibitors will decompose and lose their effect in a long-term corrosive environment. In this work, a smart corrosion inhibitor carrier 2-mercaptobenzimidazole-Zn2+-polydopamine@graphite (MZPG) with excellent pH response was designed and synthesized using a one-pot method. This corrosion inhibitor carrier not only has a very high 2-mercaptobenzimidazole (MBI) loading capacity (38.0%) but also maintains a very low MBI activity to inhibit the decomposition of MZPG in the environment as much as possible. The MZPG/epoxy (MZPG/EP) coatings prepared by the spraying method showed excellent mechanical properties. Electrochemical and salt spray tests showed that the MZPG/EP coatings (1.20 × 1010 Ω·cm2) have excellent corrosion resistance with Rp values up to 3 orders of magnitude higher than that of the EP coating (1.25 × 107 Ω·cm2). Notably, the MZPG/EP coatings maintained good corrosion resistance under acidic conditions due to the pH-responsive release of corrosion inhibitors. This is of great significance for the future development of coatings for highly corrosive environments.

Anti-corrosion behavior of magnesium phosphate (Mg–P) coatings after exposure to elevated temperatures

In this study, Mg–P coatings, prepared on steel alloy substrates, were exposed to temperature from 25 °C to 900 °C. The effects of high temperature exposure and the salt spray test on the anti-corrosion ability of Mg–P coating were investigated in detailed. The results show that the corrosion resistance of coatings decreases continuously from 25 °C to 700 °C, then increases at 900 °C of exposure. However, the corrosion resistance of coatings after 2000h salt spray test was significantly improved. In particular, the corrosion rate of the coating is only one-ninth that of the coating before the salt spray test when the temperature is 900 °C. Furthermore, the microscopic characterization test revealed that a dense oxide layer form between the steel alloy substrate and the coating when temperature exceed 400 °C. Besides the crystal phase transition and oxide layer, the synergistic effect of the secondary reaction of the raw material is the key factor to ensure that the coating still has good corrosion resistance at a high temperature.

STUDYING THE STRENGTH OF DISSIMILAR JOINTS OF AISI 430 AND 301 STAINLESS STEEL WELDED AT DIFFERENT WELDING PARAMETERS

Investigating the best welding parameters for resistance spot welding joints between AISI 430 and AISI 301 stainless steels was the primary focus of this study. This research involved welding samples of these stainless steel types using various welding parameters. Ferritic stainless steel (AISI 430) and austenitic stainless steel (AISI 301) were subjected to resistance spot welding, and different welding conditions were applied to produce a range of samples. The study specifically analyzed the influence of the welding current (2.5, 3.1 and 3.7) kA and welding time (40, 70 and 100) ms on the joining capability of these stainless steels. To determine the best welding parameters, microhardness measurements and tensile-shear tests were performed on the welded materials. The results indicated that increasing the welding current and welding time led to an increase in the tensile load. The maximum tensile-shear load 2036 N was observed at 3.7 kA and 100 ms. However, after a salt spray test (48 and 96) h, a serious decrease in the tensile load from 2036 N to 750 was observed at the high current 3.7 kA and time (70 and 100) ms. At 3.1 kA and 70 ms before and after the salt test, its value remained relatively constant, and the corrosion resistance of the weld joint was at the best level. The microhardness of the heat-affected zone increased, reaching its maximum point (for 3.1 kA and 70 ms: 347.3 HV and for 3.1 kA 100 ms: 369 HV) in the fusion zone. Moreover, the increase in the welding time and current was associated with an increase in the nugget size. The maximum nugget size was 3.61 mm at 3.7 kA and 100 ms.

Double-layer with electroactive and superhydrophobicity based on polymer nanotubes to improve robustness and anti-corrosion performances

The phenomena of corrosion in metals have resulted in significant damage to the day-to-day lives of humans, the routine maintenance of engineering metal materials, and catastrophic corrosion damage has also triggered huge economic losses. Herein, we propose a double-layer PDVB/FSiO2-PDVB@PPy/EP sprayable coating with excellent robust superhydrophobicity and electroactive based on mass-producible polydivinylbenzene nanotubes (PDVB NTs) to apply in anti-corrosion of Q235 steel plate. On one hand, the electroactive base layer of PDVB@PPy/EP can constitute a physical barrier against corrosive media; On the other hand, cross-linked PDVB NTs containing FSiO2 NPs (PDVB/FSiO2 NTs) can form a superhydrophobic surface structure to avoid substrate corrosion from corrosive liquid. The water contact angle (WCA) of the composite coating is 163.9° and the sliding angle (SA) is 3.6°, indicating that the coating possesses excellent superhydrophobic properties. Remarkably, Cross-cut scratch, tape peel, and Taber abrasion tests confirm that the composite coating exhibits excellent robust performance. The pitting pit depth after 30 days of salt spray test is 4 μm, and following 60 days of immersion in a solution containing 3.5 wt% NaCl, the protection efficiency (P.E.%) reaches 94.79 %. These results suggest that the double-layer electroactive superhydrophobic coating exhibits excellent corrosion resistance.

The Effect of Spray Testing Condition on the Corrosion Performance of Hydrothermally Sealed Anodic Oxide on a 5005 Aluminum Alloy: Comparison between Neutral Salt Spray, Acetic Salt Spray and Prohesion Testing Methods

In this work, the output of different accelerated tests on anodic aluminum oxide (AAO) coatings developed on AA5005 aluminum alloy (sulfuric acid bath and hydrothermal sealing) has been investigated. In particular, three corrosion testing methods, namely neutral salt spray test (NSS), acetic acid salt spray (AASS) and prohesion test, have been performed on the sealed AAO-coated panels in order to investigate the reliability of the obtained results to the electrochemical impedance ones. NSS and prohesion testing results are found to align with findings from electrochemical impedance spectroscopy (EIS). The acetic salt spray test appears to be highly corrosive, causing rapid depletion of the oxide layer’s protective capabilities, as indicated the EIS analysis. The findings suggest that the deterioration of the oxide layer’s barrier properties appears to be more pronounced than what optical image analysis suggests.

Study on spray characteristics of a compact pressure swirl nozzle integrating tangential inlet flow channel and swirl chamber

Pressure swirl nozzles are widely applied in various heat and mass transfer applications due to advantages of reliable performance, simple structure, and easy processing. However, the complex design of the nozzle structure makes it difficult to miniaturize the pressure swirl nozzle, which restricts its use in limited spaces. In this study, a compact pressure swirl nozzle is proposed by merging a swirl chamber with the tangential inlet flow channel, addressing the issue of liquid atomization in limited spaces. The key geometric parameters are determined based on the internal flow properties by swirl chamber simulation. A spray test bench utilizing a phase Doppler particle analyzer and a high-speed camera was built to study the effect of pressure drop, geometric size, and nozzle inlet shape on spray characteristics. The simulation results show that the nozzle diameter and inlet shape are the main factors affecting flow in the swirl chamber. The experimental results further demonstrate that increasing nozzle diameter increases flow rate and spray cone angle, causing the droplets to move to the spray edge. The spray characteristics are affected by the inlet shape of the nozzle hole: radial velocity and particle size show a wider range of change with a funnel-shaped inlet. Axial velocity and pressure drop are obviously affected by a cylindrical-shaped inlet. This study provided a new design approach for pressure swirl nozzles and achieved flow rate of 5–35 l/h and Sauter mean diameter below 40 μm with an overall weight of 12 g. This compact nozzle construction is a reference for the design of atomizing nozzles in limited spaces.

Preparation and anticorrosion performance of graphene composited waterborne coatings

Waterborne coatings are safe and environmentally friendly and widely used in automobile, construction and other fields. The low hardness of films formed by water-based anticorrosion coatings and their poor anticorrosion effect can be resulted from the addition of hydrophilic substances, which make it easy for water penetration. In this experiment, glycidyl methacrylate (GMA), butyl acrylate (BA), methyl methacrylate (MMA), and acrylic acid (AA) were used as the polymerization monomers to enhance the hardness, adhesion, and film-forming properties of the coatings by introducing the epoxy bond of GMA in the synthesis. The appropriate formula ratios for the waterborne coatings were determined by conditioning the content of wetting agent, thickener, levelling agent, defoamer, and modified acrylic-based resin. Based on this formula, suitable additive ratios of graphene were determined by condition experiments. When the addition ratio of graphene was 0.6wt% - 0.8wt%, the obtained coatings exhibited satisfactory hardness, film-forming properties, strong adhesion and anticorrosive properties. The results of salt spray tests and potentiodynamic polarization experiments verified that graphene in a certain proportion can effectively block the penetration of water, so that the coating presented excellent properties.

Research on the mechanism and process optimization of pulsed laser descaling of Q235 steel for offshore equipment

Corrosion pervades in every field of the public domain, with a particularly pronounced impact in the marine environment. Laser descaling technology, heralded as an environmentally conscious method, is progressively gaining prominence within the maritime domain. The associated theories and procedures have incrementally assumed a central role in scholarly investigations. This study meticulously delves into the evolution of rust on the surface of the Q235 steel. By employing a salt spray test, we study the growth dynamics of the rust layer on the Q235 steel. The inquiry encompasses an examination of the growth rates in both transverse and longitudinal orientations, coupled with an analysis of the composition of rust layers. Leveraging ANSYS simulation software and thermodynamic analysis, we delve into the parameters governing the descaling process, serving as a crucial reference for subsequent experimental descaling endeavors. The results stand to offer valuable insights into the advancement of descaling technology.

Synergistic enhancement: Ammonium Polyphosphate's impact on hybrid coating performance against corrosion and fire

AbstractThis research demonstrated the impact of ammonium polyphosphate (APP) content on corrosion resistance and flame retardancy properties of hybrid graphene oxide/halloysite/intumescent flame retardant (GO‐HNT‐IFR) coatings. Electrochemical impedance spectroscopy studied indicates that the GO0.6‐H0.3 coating exhibited superior corrosion resistance (Rct = 2.490 × 109 Ω·cm) compared with hybrid GO‐HNT‐IFR coatings. Tafel polarization data revealed a decrease in polarization resistance, Rp simultaneously increases the corrosion rate, Rcorr of the epoxy coatings containing APP compare with GO0.6‐H0.3 coating. Salt spray test result demonstrated that all epoxy coating filled with hybrid nanofillers maintained excellent surface integrity, preventing corrosion for up to 500 h under controlled accelerated corrosive conditions. A reasonable increment of limited oxygen index up to 12.5% was reported by the addition of 1 phr APP, indicating its best flame retardancy and thermal stability properties among coating samples. The appropriate addition of APP (1 phr) enhanced the flame retardancy and thermal stability properties of hybrid GO‐HNT‐IFR coatings to a certain extent but it is impaired by increasing the APP loading. Transmission electron microscopy results validated the formation of aggregation at high APP loading, consequently affecting coating performances as well as its adhesion strength.

Improvement of the anti-corrosion coating properties of waterborne epoxy resin with the incorporation of fluoropolymer-modified silica nanofillers

The objective of this research was to enhance the corrosion resistance and mechanical properties of silica nanoparticles modified by a fluoropolymer (polyhexafluorobutyl acrylate, PHFBA) by incorporating them into a waterborne epoxy resin (WEP) coating system. Initially, polyhexafluorobutyl acrylate (PHFBA)-modified silica nanoparticles were synthesized using a two-step method, involving the grafting of 3-(isobutylloxy) propyl trimethoxysilane (KH570) onto SiO2 to produce SiO2@KH570, followed by a random copolymerization of SiO2@KH570 with hexafluorobutyl acrylate (HFBA) to obtain the fluoropolymer-modified SiO2 (FxSiO2). Subsequently, the chemical structure and elemental composition of SiO2, as well as the prepared SiO2@KH570 and FxSiO2 nanoparticles, were comprehensively investigated. Moreover, FxSiO2/WEP composite coatings with different amounts of fluoropolymer-modified nanofillers and x-F5SiO2/WEP composite coatings with varying amounts of F5SiO2 nanofillers were prepared and characterized. The findings revealed that the functionalized FxSiO2 exhibits superior dispersion, interface, and size effects, significantly enhancing the overall performance of WEP coatings. Notably, when 0.1 wt% F5SiO2 nanofiller was incorporated, the resulting 0.1-F5SiO2/WEP composite coating demonstrated a considerable impedance modulus (1.171 × 108 Ω∙cm2), relatively low water absorption rate (about 11 % after 20 d of immersion in water), and robust mechanical properties: a tensile strength of 6.07 MPa and an elongation at break of 37.36 %. Moreover, the hardness and adhesion of the composite coating remain unaltered. Furthermore, after 20 days of salt spray testing, the electrochemical impedance still reached 8.765 × 106 Ω∙cm2, indicating a favorable long-term anti-corrosion capability. Consequently, the integration of fluoropolymer-modified nanoparticles in water-based epoxy resins holds great potential.

H-BN base triple-functional filler enhances the anti-corrosion performance of epoxy coating

The dispersion of hexagonal boron nitride (h-BN) in resin to prepare anti-corrosion coating has only a single physical shielding function, and does not inhibit the electrochemical reaction process, which significantly reduces the durability of anti-corrosion coating. In this paper, polyaniline with anodic passivating function was synthesized on the surface of h-BN by in-situ polymerization, and Ce3+ cation with corrosion inhibition was loaded into polyaniline/h-BN. Thus, a triple functional anti-corrosion filler Ce3+&PANI/h-BN with physical shielding - anode passivation - cathode corrosion inhibition was prepared. The microstructure, crystal form, element distribution, thermal stability and corrosion inhibition ability of the composite filler were characterized. The anti-corrosion, anti-friction and adhesion properties of EP/Ce3+&PANI/h-BN composite coating was investigated. EIS and Tafel test results show that the corrosion inhibition efficiency of Ce3+&PANI/h-BN is 55.5% and 89.67%, respectively. The low-frequency impedance modulus of the composite coating after 40 days of exposure is 13 times that of the pure EP coating, up to 9.79 × 109 ·cm2. The results of salt spray test also show that the barrier ability and anti-corrosion effect of the composite coating are significantly improved compared with the pure EP coating. The wear mass loss of the composite coating is reduced by 43.69% compared with the pure EP coating. This research provides a way to prepare multi-functional, high shielding, wear resistance anti-corrosion fillers to achieve long-term protection of coatings.

Eco-Friendly Sustainable and Responsive High-Performance Benzotriazole-Metal Organic Frameworks/Silica Composite Coating with Active/Passive Corrosion Protection on Copper.

Coatings with only passive protection cannot offer long-term anticorrosion on metals. Eco-friendly sustainable and responsive coating for active/passive corrosion protection is desirable to extend the service life of metals. Here, benzotriazole (BTA)-metal organic frameworks (Cu-MOFs, UiO-66) were embedded in silica (SiO2) coating by one-step electrodeposition on copper. Combined with passive capability of MOFs and active protection of BTA inhibitor, the composite coating (BTA-MOF/SiO2) exhibited high and stable corrosion resistance, confirmed by microstructure characterizations and electrochemical tests. As a result, the as-prepared composite coating exhibited superhydrophobicity with a water contact angle of 154.2°. With loading of BTA-MOF in SiO2 coating, the impedance modulus at 0.01 Hz increased by ∼10-fold and the corrosion current density decreased to 3.472 × 10-9 A·cm-2. Immersion and salt spray tests confirmed the long-term protection of the composite coating. The responsive release of BTA inhibitor endows the coating with a responsively anticorrosive behavior. The active-passive ability makes the coating a good candidate for protection on metals used in highly salty environments.

Roles of Al and Mg on the Microstructure and Corrosion Resistance of Zn-Al-Mg Hot-Dipped Coated Steel.

In this work, a novel zinc-aluminum-magnesium (Zn-Al-Mg, ZM) coated steel was prepared using the hot-dip method. The microstructure and corrosion resistance of the ZM-coated steel were investigated. Compared to the conventional galvanized steel (GI), the ZM coating demonstrated a distinctive phase structure, consisting of Zn phase, binary eutectic (Zn/MgZn2), and ternary eutectic (Zn/Al/MgZn2). The corrosion resistance of the ZM-coated and GI-coated steels was evaluated by neutral salt spray test (NSST), polarization and electrochemical impedance spectroscopy (EIS). The results indicated that ZM-coated steel provided superior long-term corrosion protection in a NaCl environment compared to GI-coated steel. The scanning vibrating electrode technique (SVET) proved to be an effective method for investigating the evolution of the anodic and cathodic on the local coating surface. GI-coated steel exhibited a potential and current density distribution between the cathodic and anodic sites nearly three orders of magnitude higher than that of ZM-coated steel, suggesting a higher corrosion rate for GI-coated steel.

“Modeling, microstructural characterization, mechanical and corrosion properties of the CrN/CrAlN multilayer coating produced by physical vapor deposition."

In this research, CrN/CrAlN multilayer coating was deposited on X12CrNiMoV12-3 stainless steel samples and compressor blades by the physical vapor deposition (PVD) method. Based on the computational fluid dynamics model, an optimized thickness of less than 10 μm with a roughness of 0.35 μm was deposited. The coating's microstructure and phase composition were characterized by XRD and SEM. Nanoindentation, adhesion, scratch, and roughness tests as well as residual stress were realized in the coated samples. A Salt spray test was also done on the samples and blades to evaluate the corrosion resistance of the coating. The CrN/CrAlN coating's elastic modulus and hardness were 371 GPa and 1745 HV, respectively. The Corrosion resistance of coated samples and compressor blades was 930 and 50 h, respectively. The induced residual tensile stress of 176.23 MPa due to the required machining process of the compressor blade before the coating was the reason for the lower corrosion resistance of coated blades. to eliminate the residual stresses and improve the corrosion performance of the coating, the blades were subjected to the tumbling process before coating. By optimizing the tumbling process for 3 h, the residual tensile stress converted to a compressive stress of −129.11 MPa, and accordingly corrosion resistance of the coated blades increased to 950 h.

Co-deposition of natural particles in the acidic zinc electroplating process

The co-deposition of natural particles was studied in zinc electroplating on mild steel in the acidic sulfate bath aiming a composite coating. Despite most papers reported the effect of natural extracts in such process, the evaluation of natural particles adhered to the coating was not explored yet. The process efficiency, surface morphological changes, and corrosion resistance were evaluated in different concentrations of avocado seed powder (ASP, Persea americana), cocoa bean shell powder (CBSP, Theobroma cacao), and garlic peel powder (GPP, Allium sativum). In general, the current efficiency was not significantly influenced by the presence of any natural particles, reaching values over 90 %. The presence of natural particles impacted the active sites on the substrate surface, modifying the grain growth assessed by scanning electron microscopy (SEM) analysis. The GPP samples showed better visual aspect and higher compactivity. By Fourier transform infrared spectroscopy analysis, such natural particles are constituted by molecules of long carbon chains with chemical groups – amines, carboxylic acids, and phenols. Hence, the presence of natural particles in the coating layer led to different responses in the contact angle test, where GPP samples showed higher wettability (θ < 90°), followed by ASP and CBSP samples (θ > 100°). Such behavior indicates a greater bath penetration during the electroplating process in the presence of more hydrophilic particles, which may have resulted in the refined deposits of the GPP samples. The concentration of 0.330 g/L GPP presented higher impedance modulus (6548.3 Ω.cm2 at 0.03 Hz) in the electrochemical impedance spectroscopy (EIE) and reduced the anodic ionic current density at least four times in the scanning vibrating electrode technique (SVET). The same was observed in the salt spray test (SST) adapting ASTM B117, which revealed to be sensitive enough to indicate that the 0.330 g/L GPP sample showed greater corrosion resistance.

Mechanical performance of Q345 steel after corrosion: Experimental and theoretical investigation

Corrosion significantly influences the mechanical performance of steel, and the accurate prediction of stress-strain curves (S-SC) for steel after corrosion is crucial for the safety evaluation of in-service steel structures in engineering. This study focuses on assessing the degradation performance of Q345 steel following corrosion. Copper accelerated acetic acid salt spray testing (CASS) is employed to corrode Q345 specimens, and a power model is established to relate the mass loss rate to the corrosion time of Q345 steel. Uniaxial tension tests are then conducted to observe the mechanical behavior of corroded Q345 steel. Results indicate that the strength and ductility of Q345 steel decrease with an increase in the mass loss rate, and the yield plateau of the S-SC gradually shortens until it disappears. With the increase of corrosion time, the microstructure of the steel surface is transformed from spherical structure to needle-like structure. Two constitutive models are developed, incorporating the S-SC with and without the yield plateau, based on existing models. These models demonstrate good agreement with various test data, providing valuable insights into the mechanical behavior of corroded Q345 steel.