Q235 Surface Research Articles

Synthesis of Gemini-type imidazoline quaternary ammonium salt using by-product fatty acid as corrosion inhibitor for Q235 steel

Gemini-type imidazoline quaternary ammonium salt is a new type of environmentally friendly corrosion inhibitor has been widely used in engineering materials. However, most of them are hazardous/toxic compounds derived from petroleum-based products, which did harm to environment. In this work, an environmentally friendly Gemini-shaped imidazoline quaternary ammonium salt corrosion inhibitor (G211) was synthesized using cheap fatty acid recycled from dimer acid industry as feedstock. The corrosion inhibition effects of G211 on Q235 steel in 1 M HCl solution were investigated through weight loss experiments, potential polarization curves, and alternating current impedance spectroscopy experiments. The results show that the inhibition rate of G211 as a mixed-type inhibitor is up to 94.4% and the concentration drop as low as 500 ppm at 25 ℃. The adsorption of G211 on Q235 surface follows Langmuir adsorption isothermal curve. The chemical composition of the Q235 steel surface was analyzed through scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Furthermore, the possible corrosion inhibition mechanism of G211 on the surface of Q235 steel is proposed. This article not only presents an outstanding solution for safeguarding Q235 steel against corrosion but also introduces a feasible method for high-value utilization of monomer acid (MA).

Simulation and experimental study on laser cleaning of paint-rust mixed layer on a Q235 surface

In this paper, the theoretical model of laser cleaning of paint-rust mixed layer on the surface of a Q235 steel plate is established from the perspective of the laser ablation effect and the thermal vibration effect. The study simulates the temperature and stress field variations of the mixed layer under different laser power densities. The experiment recorded ablative fumes and vibrational spattering generated during the cleaning process and measured the micro-morphology and surface roughness of the cleaned specimens. The results show that the cleaning mechanism of the paint-rust mixed layer is dominated by the ablation effect at low laser power densities, while the combined effects of ablation and thermal vibration dominate at high laser power densities. However, excessive laser energy can damage the substrate. At a laser power density of 12.37×106W/cm2, the substrate surface is free from contamination residues and exhibits a bright, white, metallic gloss, which can be determined as the cleaning threshold for laser cleaning of paint-rust mixed layers. This study provides a valuable reference for the laser cleaning of mixed pollutants of paint and rust on metal surfaces.

Anticorrosion evaluation of novel Schiff-Imidazole molecules for Q235 steel in 1.0 mol/L HCl by computational and experimental methodologies

This manuscript synthesized successfully two efficient imidazole-Schiff derivatives (FMIX and MIX), and confirmed the structural rationality through infrared spectroscopy (IR), nuclear magnetic resonance(NMR) and elemental analysis, and the corrosion inhibition performance and mechanism in 1.0 mol/L HCl were investigated. The weight loss experiment showed that at 2.0 mmol/L and the corrosion inhibition efficiency of FMIX and MIX were 97.39 % and 98.52 %, respectively, indicating that this corrosion inhibitor has excellent corrosion inhibition performance. The open circuit potential (OCP) and potentiodynamic polarization curve (Tafel) indicated that FMIX and MIX belong to cathodic corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) shown that FMIX and MIX increased the film resistance and charge transfer resistance in the corrosion solution, and adsorbed on the surface of Q235 to form a stable protective film. XPS, EDS, and IR tests have shown that FMIX and MIX could adsorb on the surface of Q235 to form a stable protective film, thereby inhibiting the occurrence of corrosion. Density functional theory (DFT) and molecular dynamics simulation (MD) have also confirmed at the molecular level that FMIX and MIX could spontaneously adsorb on the surface of Q235 and form a stable protective film.

Synergistic effect of new imidazoline derivative and 2‐aminopyridine as corrosion inhibitors for Q235: Experimental and theoretical study

In order to reduce the investment of corrosion inhibitors, based on experimental and theoretical studies, the corrosion inhibition and mechanism of new imidazoline derivatives (SMIS) and 2‐aminopyridine (AMP) were investigated carefully. The best corrosion inhibition effect was at 0.7‐g/L SMIS and 0.3‐g/L AMP, the corrosion inhibition efficiency of weight loss, electrochemical impedance spectroscopy, and potentiodynamic polarization (Tafel) were 90.54%, 98.56% and 97.68%, respectively. Electrochemical research shows that SMIS&AMP belongs to cathodic corrosion inhibition. SMIS&AMP mainly increased the film resistance and charge transfer resistance in 1‐M HCl, thus playing a certain role in corrosion inhibition. X‐ray photoelectron spectroscopy and energy dispersive spectrometer proved that SMIS&AMP can be adsorbed on the surface of Q235, molecular dynamics showed that there was a certain synergy between SMIS and AMP. This study confirmed that SMIS and AMP have a good synergistic effect, improve the corrosion inhibition efficiency, reduce the synthesis cost of SMIS, and have a certain guiding significance for synergistic corrosion inhibition.

Visualization and simulation investigation of Copper-Nickel alloy and carbon steel galvanic corrosion in marine environment

Corrosion of Q235 carbon steel and the BFe30-1–1 copper-nickel alloy was studied in seawater with electrochemical methods and surface characterization. The open circuit potential (OCP) for the copper-nickel alloy and carbon steel were −225 mV and −700 mV, respectively. A Gel visualization test showed that Turnbull's blue was precipitated on the surface of Q235, which indicated accelerated corrosion of the Q235 anode after coupling. The increased Kelvin potential determined for the Q235 surface with a Scanning Kelvin Probe test indicated that the Q235 surface generated electrons and transferred them to the BFe30-1–1 surface, which resulted in the protection of BFe30-1–1. These tests showed that the Q235 anode underwent corrosion, and the BFe30-1–1 cathode was protected after coupling in seawater. Surface analyses showed that Q235 corroded faster over time due to electric coupling, while BFe30-1–1 corrosion was inhibited by a stable passivation film. Analysis of the physical phase showed that the corrosion products of Q235 were β-FeOOH, α-FeOOH and Fe3O4, and the BFe30-1–1 corrosion products were Cu2O and Cu2Cl(OH)3. The electrochemical and numerical results were consistent, indicating an accurate prediction of the galvanic corrosion process.

The inhibition performance of anionic surfactant and zwitterionic surfactant toward the corrosion of carbon steel in NaCl solution

AbstractCarbon steel suffers from serious corrosion in NaCl solution, the development of effective inhibitor has become a hot issue. The corrosion inhibition performance of sodium lauryl ether sulfate (AES) and lauryl betaine (BS‐12) and the mixture of the two inhibitors were studied using electrochemical and weight‐loss methods. Results showed the corrosion inhibition efficiency order is AES + BS‐12 > BS‐12 > AES, the inhibition efficiency of the inhibitor increases with the increasing of concentration and the maximum inhibition efficiency is 95.9% in the solution with 200 mg L−1 AES + BS‐12. Inhibitor can adsorb on Q235 surface through physical and chemical interactions and the adsorption obeys Langmuir isotherm. The migration of the corrosive ions to the metal is hindered and the metal is protected.

Distribution of corrosive microbial communities in rust layers of steel immersed in seawater.

In this paper, high-throughput sequencing technology was adopted to visualize the microbial communities on the surfaces of two types of carbon steel immersed in Sea Area Ⅰ. The results showed that different microbial communities were formed on different carbon steel surfaces, in which the genus with the highest abundance on the surface of Q235 was Escherichia-Shigella, while anaerobic Desulfovibrio on the surface of 921a was the most abundant, and the dominant genus varied with the depth of the rust layer. In addition, the distribution of sulfate-reducing bacteria (SRB) on the surface of Q235 submerged in Sea Area Ⅱ was compared with the sulfate-reducing bacteria's distribution in Sea Area Ⅰ, using the environmental factors correlation analysis. The results showed that the concentrations of Ca2+, Na+, K+, Mg2+, and Al3+ were positively correlated with the distribution of SRB, while the concentrations of Cu2+, Zn2+, SO4 2-, Cl-, NO3 -, and organic carbon were negatively correlated with it. Furthermore, there was a highly significant correlation between each geochemical factor and Desulfotomaculum (p<0.01).

Two metabolic stages of SRB strain Desulfovibrio bizertensis affecting corrosion mechanism of carbon steel Q235

Desulfovibrio bizertensis (D. bizertensis), an SRB isolated and cultured from the rust layer of the South China Sea, is widespread in the corrosive microbial communities on steel surface. Although the corrosion mechanism of SRB was widely studied, the mechanism of different metabolic stages inducing corrosion was still unclear. In this work, D. bizertensis was used to study the corrosion process of carbon steel Q235 at different metabolic stages by surface analysis and electrochemical methods. Combined with the metabolic process of SRB, corrosion pits of carbon steel could be influenced by two stages. In the first stage, the rapid growth of planktonic D. bizertensis cells in culture medium was accompanied by quick consumption of the electron donor (lactate) till complete consumption. D. bizertensis cells began to adhere to Q235 surface and promote anodic dissolution of iron. In the second stage, the growth of planktonic cells was suppressed, thus the colonized D. bizertensis cell in the pitting could obtain energy directly from Fe(0) through DET, which would further aggravate pitting corrosion and the maximum depth of the pits approached 15.7 µm. Sulfides produced by D. bizertensis metabolism would accumulate on steel coupon and form FeS coverage. Thus D. bizertensis could survive for a long time in this conductive FeS particles network. Electrochemical results showed the promotion effect of D. bizertensis on cathodic reaction, and the values of Rct in the SRB medium were much lower than that in the sterile medium.

Biofilm-Induced Corrosion Inhibition of Q235 Carbon Steel by Tenacibaculum mesophilum D-6 and Bacillus sp. Y-6

The corrosion of carbon steel causes dramatic economic losses each year. Since conventional corrosion prevention approaches may cause pollution problems to the environment, ecofriendly and effective corrosion approaches are desired. Microbiologically influenced corrosion inhibition (MICI) has been reported as a sustainable corrosion prevention method. This work aims to evaluate the corrosion inhibition effect of two bacterial strains, Tenacibaculum mesophilum D-6 and Bacillus sp. Y-6 by choosing Q235 carbon steel as a model system. Scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and a series of electrochemical techniques were applied to study the corrosion prevention effect. The electrochemical and pitting results indicated that T. mesophilum D-6 displayed a better corrosion protection effect. T. mesophilum D-6 formed a denser and thicker biofilm on the Q235 surface than Bacillus sp. Y-6. The maximum thickness of the T. mesophilum D-6 biofilms was 11.6 ± 0.7 μm, which is about twice as thick than that of Bacillus sp. Y-6. The corrosion prevention mechanism was ascribed to the formation of biofilms as a barrier to block corrosive agents such as O2. This study provides a theoretical foundation for the application of biofilms as green and effective corrosion inhibitors for carbon steel.

Extraordinary corrosion inhibition efficiency of omeprazole in 1 M HCl solution: Experimental and theoretical investigation

Omeprazole (OL) as a green and efficient drug corrosion inhibitor was first investigated for the corrosion inhibition of Q235 carbon steel at 298, 308, and 318 K. Open circuit potential, Tafel, electrochemical impedance spectroscopy, and weight loss were used to evaluate the inhibition performance toward Q235 carbon steel in HCl medium. The results showed that OL exhibited excellent corrosion protection to carbon steel at different temperatures because of forming the compact and ordered OL adsorption film on Q235 surface. Especially, the inhibition efficiency increased to 96.11%, 95.12%, and 94.04% for 40‐mg/L OL in Tafel at 298, 308, and 318 K. Meanwhile, N–Fe and S–Fe bonds determined from X‐ray photoelectron spectroscopy revealed the multiple anchoring interactions between steel and OL with S and N atoms as the active sites. Density functional theory and molecular dynamics simulations showed the low energy gap and high adsorption energy values, besides the radial distribution function (RDF) indicating the strong chemical sorption of OL on Fe surface, which proved the superior corrosion inhibition efficiency of OL at a molecular or atomic level.

Effect of Q235 Hot-Dip Galvanized and Post-Casting T6 Heat Treatment on Microstructure and Mechanical Properties of Interfacial between AZ63 and Q235 by Solid-Liquid Compound Casting

AZ63 sacrificial anode is widely used to protect buried metal pipelines and reinforced concrete structures and so on. The interfacial metallurgical bonding between AZ63 sacrificial anode and Q235 wiring terminal directly affects its cathodic protection performance. Therefore, microstructure and mechanical properties of interfacial between AZ63 and Q235 by solid–liquid compound casting with hot-dip galvanized and post-casting solution-aging treatment (T6) were investigated. The results indicate that hot-dip galvanizing on the surface of Q235 is beneficial to the formation of intermetallic compounds at the interface. At the same time, it can promote the metallurgical bonding of the interface between AZ63 and Q235. After T6 heat treatment, the intermetallic compound at the interface between AZ63 and galvanized Q235 was refined. The electron-probe microanalyzer (EPMA) revealed that the intermetallic compounds at the interfaces between AZ63 and galvanized Q235 were Fe2Al5 before and after T6 treatment. Push-out testing and microhardness were used to investigate the mechanical properties of interface between AZ63 and Q235. It is shown that the hot-dip galvanization of the Q235 surface and T6 treatment were beneficial to improve the metallurgical bonding shear strength and microhardness of the interface. After T6 heat treatment, the highest shear strength at the interface between AZ63 and galvanized Q235 was up to 31.9 ± 1.9 MPa.

Electrochemical corrosion behavior of Ni-P, AlCrN and Ni-P-AlCrN multilayer composite coatings used on grounding grids

In this work, single NiP alloy, we use cathodic arc ion plating and electroless plating, AlCrN and NiP-AlCrN multilayer composite coatings were sedimented from the teeth outwards Q235 carbon steel. It is surface appearances of the coating that were inspected by using scanning electron microscope method (SEM) and the crystal structure, which was researched by the diffraction of X-ray (XRD). The electrochemical corrosion behaviors were evaluated by electrochemical polarization tests with electrochemical impedance spectrum (EIS). The results of EIS displayed that the impedance increased in the order Q235＜AlCrN coating＜NiP alloy＜NiP-AlCrN composite coating. The corroded surfaces of coated samples were covered by some pitting while the surface of Q235 was totally destroyed.

Inhibition effect of green Betaine type surfactants on Q235 steel in 1 mol·L−1 hydrochloric acid: The experimental and theoretical research

The corrosion inhibition efficiency of Betaine, 3-(N, N-dimethyldodecylammonio) propanesulfonate (SB3–12) and 2-(DodecyldiMethylaMMonio) acetate (BS-12) on Q235 steel in 1 mol⋅L−1 hydrochloric acid (HCl) solution were studied at various inhibitor concentration and temperature by means of the weight loss method (WLM), electrochemical impedance spectroscopy (EIS), potential polarization curve, atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS), Raman spectra, scanning electron microscopy (SEM) and electronic energy spectrum analyzer (EDS). The weight loss results showed that the increase of inhibition efficiency mainly attributed to its high concentration. While Betaine had almost no protective effect for metals, SB3–12 and BS-12 were powerful inhibitors with the inhibition efficiency of 89.06% and 95.98%, respectively at 1 × 10−1 mol⋅L−1 at 30 °C. The blocking effect of BS-12 for metal corrosion that induced by HCl was stronger than SB3–12. The potential polarization curve potential demonstrated that SB3–12 and BS-12 were both mixed type corrosion inhibitors. The surface analysis results revealed that SB3–12 or BS-12 could be well adsorbed on the Q235 surface to form a compact membrane that is responsible for the protection of Q235 steel from corrosion. The theoretical calculations including quantum chemical calculations and molecular dynamics simulations, which based on density functional theory provided strong evidence for the close relationship between the molecular structure of inhibitor and its inhibition efficiency. Our study of corrosion inhibition efficiency of green betaine type surfactants laid a theoretical foundation for the application of betaine derivatives in metal anti-corrosion.

Effect of imidazoline derivatives on the corrosion inhibition of Q235 steel in HCl medium: experimental and theoretical investigation

Abstract In this work, two new imidazoline derivatives (SMF and SMIF) have been synthesized successfully, and their structure have been confirmed by IR, Raman, and NMR techniques. The corrosion inhibition ability and mechanism in HCl solution were proved by experimental and theoretical methods. The inhibition efficiency of SMIF was 94.69% in weight loss experiment, 95.99% (Tafel), and 95.30% (EIS) in electrochemistry. The corrosion inhibition mechanism is that SMF and SMIF form a stable protective film on the surface of Q235 and hinders charge transfer. EDS, FT-IR, and XPS all proved that SMF and SMIF inhibitors could stably adsorb on Q235 surface and form a protective film. The DFT and MD also proved the corrosion inhibiton mechanism. Experiments and theoretical calculations showed that SMF and SMIF exhibited excellent corrosion inhibition performance in 1 M HCl solution.

Experimental and Theoretical Studies on the Inhibition Properties of an Imidazoline Derivative on Q235 Corrosion in a Simulated Concrete Pore Solution

AbstractA novel imidazoline derivative has been synthesized and its molecular structure has been confirmed by IR, Raman, elemental analysis and NMR, the molecular structure of the inhibitor is similar to that of the previous research. In this paper, the inhibition performance and inhibition mechanism of the three inhibitors (SMID, SMIS and SMIF) in concrete simulation solution are analyzed and compared. The corrosion inhibition efficiency of SMIF (96.02 %) &gt; SMIS (93.62 %)&gt;SMID(93.01 %) in weight loss experiment, the SMIS of electrochemistry of Nyquist and potentiodynamic polarization were 89.72 % and 92.03 % respectively, which indicated that SMIS had good corrosion inhibition effect. Electrochemical experiments show that the SMIS belongs to anodic type, and the mechanism of SMIS can form a protective film on the surface Q235 and inhibit the charge transfer. The results of FTIR, EDS and XPS show that SMIS can be adsorbed on the surface of Q235, which is also confirmed by density functional theory (DFT) and molecular dynamics simulation (MD).

Sulphonamide derivatives as the inhibitors for mild steel: The correlation of molecular structure effect and the corrosion efficiency

The corrosion mitigation of different functional groups of the sulphonamide derivatives, sulfadiazine (SD), p-toluenesulfonylhydrazide (p-TSH) and sulfathiazole (STI), were compared in this paper. The strong correlation result between the inhibition efficiency and molecular structure could provide a novel insight in inhibition mechanism. Electrochemical experimental results together with the Langmuir adsorption isotherm observation suggested sulphonamides could spontaneously adsorb on the surface of Q235 to form compact protection films for blocking corrosive media. By density function theory (DFT) calculations for the protonated molecules with the metal (Fe atom), we found that protonated SD molecule had stronger interaction with the metallic surface in comparison with the protonated p-TSH and STI, which fully validated the inhibition efficiency (η) on the mild steel surfaces is in order of SD (η = 92.7%) > p-TSH (η = 79.8%) > STI (η = 66.8%) by using elecetrochemical experiments. Experimental studies together with theoretical calculations have presented a good direction for exploring the mechanism of structural effect of sulphonamides on the corrosion mitigation efficiency, which is beneficial to sheding insight on the design of new organic inhibitors in the future.

Preparation of epoxy/ZrO2 composite coating on the Q235 surface by electrostatic spraying and its corrosion resistance in 3.5% NaCl solution.

The epoxy coating containing ZrO2 nanoparticles modified with 3-aminopropyltriethoxysilane (APTES) was prepared by electrostatic spraying on the surface of Q235 mild steel. The effect of the concentration of APTES-modified ZrO2 nanoparticles on the corrosion resistance of epoxy coating was characterized and tested by FTIR spectroscopy, scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The results show that nano ZrO2 was successfully modified by a silane coupling agent. By adding an appropriate amount of APTES to modify nano ZrO2 in epoxy coating could significantly improve the corrosion resistance of the Q235 surface. When the mass fraction of nano ZrO2 is 2%, the composite coating shows the highest impedance value of about 1.0 × 105 Ω cm2 to achieve the best corrosion resistance.

Facile synthesis of novel hierarchical core@shell structural magnetic nanovehicle Fe3O4@ZnAlCe-MoO4-LDHs for carbon steel protection

A novel dual-stimuli-responsive inhibitor nanovehicle Fe3O4@ZnAlCe-MoO4-LDHs was synthesized via a facile double-drop co-precipitation method. The obtained Fe3O4@ZnAlCe-MoO4-LDHs presents well-defined hierarchical core–shell structure with MoO42− corrosion inhibitor intercalated lamellar ZnAlCe-LDHs nanocrystals of ~30 nm assembling closely to Fe3O4 microspheres surface, possessing moderate inhibitor loading of 9.72% and strong superparamagnetism. The release results reveal that in the same NaCl solution, the releq (equilibrium release amount, 49.1%) and t0.5 (the time for release fraction of 50%, 4.5 h) were delayed much by magnetic field relative to non-magnetic field case (51.6%, 2.5 h). And the releq decreased with magnetic field strength, accompanied by the prolongation of t0.5, up to 6 h under a 1350 Gs magnet. Similarly, with keeping the magnetic field unvaried, the decline of NaCl solution concentration led to lower releq and longer t0.5. The kinetic fittings displayed that for all cases, the release process is inclusive of interlayer diffusion between LDHs layers (path I), interparticle diffusion among stacked LDHs crystals (path II) and diffusion between magnetic nanoparticles (path III). Compared to non-magnetic field, diffusion difficulties of path III was greatly enhanced under magnetic field. While for low-Cl− concentration system, the path I were limited effectively. Thus these two stimulus response factors can be used to regulate release behavior. Meanwhile, the protection efficiency of the nanovehicle for Q235 steel is higher than 88% because of the formation of inhibition film (ferrous or iron molybdate and hydroxide of zinc and cerium) on Q235 surface and the reduction of Cl− concentration in the solution via ion exchange. Moreover, the nanovehicle, presenting outstanding structural and magnetic stabilities, can be regenerated by a series of experiments, owning appreciable recycling performance and good anticorrosion activity in six recycles.

Effect of laser power on cleaning mechanism and surface properties.

In this paper, the mechanism of laser dry cleaning was introduced, and the influence of different power on laser cleaning effect and surface performance after cleaning were investigated. The cleaning effect of 60-120 W cleaning power on the oxidized layer of a Q235 surface was analyzed by experiment and simulation. The results showed that the cleaning power of 70 W makes the surface performance after cleaning of the samples relatively optimized. The best cleaning power is 90 W. The sample surface of 100 W is the smoothest, but it causes slight damage to the matrix. The cleaning power of 120 W has the maximum friction coefficient, but it has the maximum damage to the matrix.

Effect of Heat Treatment on Microstructure and Tribocorrosion Performance of Laser Cladding Ni-65 WC Coating.

The Ni-65wt%WC cladding layers were prepared on the surface of Q235 using laser cladding technology, in which the effect of heat treatment on microstructure and tribocorrosion performance was investigated. The results showed that the coating is mainly consisted of Ni, WC, and W2C, and a significant diffusion phenomenon is formed between the interfaces of WC/Ni matrix, benefited for the improvement of bonding layer between WC/Ni-based matrixes. Meanwhile, the crystallization of WC particles after heat treatment was more obvious than untreatment; the Ni matrix grain size was also grown remarkable, leading to the lower hardness and weaker plastic deformation resistance of Ni-65wt%WC coating. And the erosion results showed that the wear rate of coating gradually decreased with heat treatment temperature increasing, while brittle WC was not suitable for high impact wear conditions. Furthermore, with the increase of heat treatment temperature, the reciprocating wear performance showed that the friction coefficient and wear rate of Ni-65wt%WC coating decreased. And the friction coefficient and wear rate of the coating (700°C) in 3.5% NaCl solution were 0.15 and 4.82 × 10−8 mm3·N−1·m−1, respectively. Therefore, the comprehensive comparison showed that Ni-65WC coating had better performance in low impact reciprocating testing under corrosion environment, and heat treatment was helpful to further improve the tribocorrosion performance of laser cladding Ni-65wt%WC coating.