High-temperature corrosion of phosphate completion fluid and corrosion inhibition method by membrane transformation

By analyzing the corrosion of phosphate completion fluid on the P110 steel at 170 °C, the high-temperature corrosion mechanism of phosphate completion fluid was revealed, and a corrosion inhibition method by membrane transformation was proposed and an efficient membrane-forming agent was selected. Scanning electron microscope (SEM) images, X-ray energy spectrum and X-ray diffraction results were used to characterize the microscopic morphology, elemental composition and phase composition of the precipitation membrane on the surface of the test piece. The effect and mechanism of corrosion inhibition by membrane transformation were clarified. The phosphate completion fluid eroded the test piece by high-temperature water vapor and its hydrolyzed products to form a membrane of iron phosphate corrosion product. By changing the corrosion reaction path, the Zn2+ membrane-forming agent could generate KZnPO4 precipitation membrane with high temperature resistance, uniform thickness and tight crystal packing on the surface of the test piece, which could inhibit the corrosion of the test piece, with efficiency up to 69.63%. The Cu2+ membrane-forming agent electrochemically reacted with Fe to precipitate trace elemental Cu on the surface of the test piece, thus forming a protective membrane, which could inhibit metal corrosion, with efficiency up to 96.64%, but the wear resistance was poor. After combining 0.05% Cu2+ and 0.25% Zn2+, a composite protective membrane of KZnPO4 crystal and elemental Cu was formed on the surface of the test piece. The corrosion inhibition efficiency reached 93.03%, which ensured the high corrosion inhibition efficiency and generated a precipitation membrane resistant to temperature and wear.

Corrosion inhibition of layered double hydroxides for metal-based systems

Layered double hydroxide(LDH),a kind of 2D layered materials,has been recognized as the promising anticorrosion materials for metal and its alloy.The microstructure,physical/chemical properties,usage in corrosion inhibition and inhibition performance of LDH have been studied separately in open literature.However,there is a lack of a complete review to summarize the status of LDH technology and the potential R&D opportunities in the field of corrosion inhibition.In addition,the challenges for LDH in corrosion inhibition of metal-based system have not been summarized systematically.Herein,we review recent advances in the rational design of LDH for corrosion inhibition of metal-based system(i.e.Mg alloy,Al alloy,steel and concrete)and high-throughput anticorrosion materials development.By evaluating the physical/chemical properties,usage in metal-based system and the corrosion inhibition mechanism of LDH,we highlight several important factors of LDH for anticorrosion performance and common features of LDH in applying different metal alloys.Finally,we provide our perspective and recommendation in this field,including high-throughput techiniques for combinatorial compositional design and rapid synthesis of anticorrosion alloys,with the goal of accelerating the development and application of LDH in corrosion inhibition of metal-based system.

Corrosion inhibition of carbon steel in hydrochloric acid by cationic arylthiophenes as new eco-friendly inhibitors: Experimental and quantum chemical study

This study describes the adsorption behavior of three arylthiophene derivatives namely:2-(4-amidino-3-fluorophenyl)-5-[4-methoxy phenyl] thiophene dihydrochloride salt(MA-1217),2-(4-amidinophenyl)-5-[4-chlorophenyll thiophene dihydrochloride salt(MA-1316) and 2-(4-amidino-3-fluorophenyl)-5-[4-ch lorophenyllthiophene dihydrochloride salt(MA-1312) at C-steel in 1.0 mol·L^(-1) HCl interface using experimental and theoretical studies.Electrochemical and mass loss measurements showed that the inhibition efficiency(IE) of the arylthiophene derivatives increases with increasing concentrations and exhibited maximum efficiency 89% at 21×10^(-6) mol·L^(-1)(MA-1217) by mass loss method.The investigated arylthiophene derivatives obey the Langmuir adsorption isotherm.From polarization studies the arylthiophene derivatives act as mixed-type inhibitors.Surface analysis were carried out and discussed.The mode of orientation and adsorption of inhibitor molecules on C-steel surface was studied using molecular dynamics(MD) simulations.Quantum chemical parameters as well as the radial distribution function indices and binding energies confirm the experimental results.

Antibacterial and Corrosion Inhibition Properties of SA-ZnO@ODA-GO@PU Super-Hydrophobic Coating in Circulating Cooling Water System

In order to solve the corrosion problem of circulating cooling water system,SA-ZnO@ODA-GO@PU super-hydrophobic coating was synthesized for pipeline protection.After hydrophobic modification,the contact angle(CA)of the coating was above 150°.The antibacterial ability of coating was essential for corrosion protection.SA-ZnO@ODA-GO can seriously damage the cell structure,make the cell content outflow,increase the leakage rate of protein,and make the bacteria unable to reach logarithmic growth phase within 24 h.The corrosion inhibition mechanism analysis of SA-ZnO@ODA-GO@PU coating indicated that the hydrophobic coating as a physical barrier can prevent the water molecules from entering the carbon steel and prevent the surface charge transfer.

Corrosion Inhibition Studies of Benzoxazole Derivates for N80 Steel in 1 M HCl Solution: Synthesis, Experimental, and DTF Studies

Three benzoxazole corrosion inhibitors, namely 2-(benzo [d]oxazol-2-yl)phenol (BOP), 6-(benzo [d]oxazol-2-yl)pyridin-2-ol (BOPO), and 2-(quinolin-2-yl) benzo [d]oxazole (QBO), were synthesized. Moreover, their corrosion inhibition performance for N80 steel in 1 M HCl solution at 303 K was measured by the electrochemical measurements and surface analysis studies. The results show that the inhibition efficiency of all corrosion inhibitors increases with the increase of concentration. At the same concentration, the order of inhibition efficiency is BOP < BOPO < QBO. Moreover, the studied inhibitors act as mixed-type inhibitors, and the adsorption of all inhibitors on N80 steel followed the Langmuir adsorption isotherm. Further, we have examined the effect of iodide ions on inhibition efficiency. The results show that BOP and KI are synergistic, BOPO and QBO are competitive adsorptions with KI. The quantum chemical parameters such as highest occupied molecular orbital, lowest unoccupied molecular orbital energy levels, and energy gap were calculated by the density functional theory (DTF). The relations between the inhibition efficiency and some quantum parameters have been discussed. The protective effect of the three inhibitors followed the sequence of BOP < BOPO < QBO. The results obtained from quantum chemicals and electrochemical were in reasonable agreement.

Inhibition mechanism of air nanobubbles on brass corrosion in circulating cooling water systems

Air nanobubbles(A-NBs)were used to inhibit the brass corrosion in circulating cooling water for the first time in the study.The results of mass loss method and electrochemical method showed that A-NBs had the obvious corrosion inhibition effect.The inhibition rate reached 52%at 35℃.The impedance and surface characterization results of corrosion samples indicated that the corrosion inhibition mechanisms of A-NBs mainly included adsorption of corrosion ions,promoting the formation of the passivation film on metal surface and the formation of the bubble layer and scale film on metal surface.A-NBs are potential excellent corrosion inhibitors.

Effects of the number of imidazoline ring and the length of alkyl group chain of imidazoline derivatives on corrosion inhibition of carbon steel in HCl solution:Molecular simulation and experimental validation

The effects of the number of imidazoline ring and the length of alkyl group chain of imidazoline derivatives were investigated using quantum chemical calculation,molecular dynamics simulation and experimental techniques.Three corrosion inhibitors including symmetrical lauric acid imidazoline(SAI),tetracyclic lauric acid imidazoline(LAI),and symmetric stearic acid imidazoline(SPI)were synthesized and their inhibition performance was evaluated using weight loss measurement,electrochemical techniques and surface characterization.The results show that SAI and LAI with the same length of alkyl group chain,LAI with more imidazoline rings could supply a better inhibition performance since the increase of active sites.The increase of active sites attached to the metal surface may also change the distribution of corrosion inhibitor,which could limit inhibition performance improvement.While,SAI and SPI with the same number of imidazoline rings,SPI with longer alkyl group chain shows a better inhibition efficiency due to the better hydrophobic performance of alkyl groups.Among the three inhibitors,SPI shows the best inhibition performance,indicating that the alkyl group chain length affects the inhibition performance more obvious than the number of the imidazoline rings.

Bio-inhibitive effect of an algal symbiotic bacterium on corrosion of magnesium in marine environment

It is a longstanding and challenging task to develop sustainable environment-friendly and cost-effective corrosion-protection technologies for Mg alloys, especially under marine conditions in which corrosion can normally be significantly accelerated by bacterial activity. However,this paper reports on the corrosion of highly active Mg interestingly inhibited by an algal-symbiotic bacterium Bacillus altitudinis. The corrosion of Mg in the presence of the bacterium drastically reduced by one order of magnitude after 14 days of immersion. This means that the algal-symbiotic bacterium widely available in natural ocean environments may be employed as a green and sustainable inhibitor in the marine industry. Based on electrochemical measurements, surface analyses and microbe experiments, a combined inhibition mechanism is proposed in the paper to interpret the interesting corrosion behavior of Mg.

A novel green inhibitor for C-steel corrosion in 2.0 mol·L^-1 hydrochloric acid solution

The corrosion inhibition characteristics of aqueous extract of seeds of Melia azedarach L.(MA) have been studied as eco-friendly green inhibitor for corrosion control of C-steel in 2 mol·L^(-1) HCl solution by gravimetric and electrochemical methods. The results depict that, the extract inhibits efficiently the corrosion of carbon steel in hydrochloric acid. The efficiency of extract is increased with increasing the extract concentration but independent on the studied temperature. The adsorption of the extract components onto the steel surface was found to be spontaneous, and follows Langmuir adsorption isotherm. The surface morphology of C-steel, in the absence and presence of MA extract in 2.0 mol·L^(-1) hydrochloric acid solution, was studied using scanning electron microscopy(SEM).

Effects of different simulated fluids on anticorrosion biometallic materials

The corrosion behaviors of SUS316L stainless steel, Co Cr alloy and Ti 6Al 4V alloy in Ringer’s, PBS(-) and Hank’s solutions have been investigated. The results indicate that the corrosion of Ringer’s solution is the strongest, then followed by PBS(-) and Hank’s solution. The presence of HPO 2- 4, H 2PO - 4, SO 2- 4 and glucose in the PBS(-)and Hank’s solution probably reduces the corrosion inhibitor and corrosion current. The decrease of the solution’s pH significantly increases the corrosion rate and susceptibility to localized corrosion of SUS316L SS and Co Cr alloy. However, Ti 6Al 4V alloy exhibits an exceptional stability and has only a slight increase of corrosion rate with decreasing pH.

Effect of corrosion inhibiting compounds on the corrosion behaviour of pure magnesium and the magnesium alloys EV31A, WE43B and ZE41A

This paper studied corrosion of pure Mg and the Mg alloys EV31A,WE43B,ZE41A,coated with commercial corrosion inhibiting compounds(CICs)(LPS 3,LPS2,AMLGuard,Ardrox 3961)immersed in 3.5 wt%(0.6M)Na Cl solution saturated with Mg(OH)_(2).All four CICs reduced corrosion rates.LPS 3 resulted in zero corrosion rates and 100%inhibition in most cases.LPS 2 and AMLGuard had comparable inhibition efficiencies,whilst Ardrox 3961 had the lowest inhibition efficiency.Reduction in corrosion rates was tentatively attributed to barrier films formed by chemical adsorption for LPS 3 and AMLGuard,and by physical adsorption for LPS2 and Ardrox 3961.

Crude Extract of Detergent⁃Like Gleditsia sinensis lam Exhibiting Self⁃Organization for Protection of Mild Steel in Harsh Hydrochloric Acid Solution:How to Seek Crude Natural Plant Extracts as Green Corrosion Inhibitors

This study proposes a thought to employ detergent⁃like renewable low⁃cost crude extract of Gleditsia sinensis lam(GSL)as green corrosion inhibitor for mild steel in HCl solution.Crude Gleditsia sinensis lam extract(GSLE)was gained at mild conditions by simply refluxing in ethanol with a Soxhlet extractor.The target GSLE extract exhibited regular self⁃organization in mixed solvents of organic solvents/H2O such as ethanol/H2 O(v/v,50/50)at room temperature,which was evidenced by different means including scanning electron microscopy,transmission electron microscopy,and dynamic light scattering.The study demonstrates that the yielded assemblies of the crude extract of GSLE displayed chemical adsorption on the studied mild steel sample surfaces.Furthermore,the formed stable crude extract assemblies of GSL presented outstanding anti⁃corrosion capability in 1.0 mol/L HCl aqueous solution based on electrochemical measurements including polarization curves and impedance spectroscopy.It is discovered that the maximal corrosion inhibition efficiency could reach approximate 95%.The molecular modeling was performed to acquire the nature of frontier orbitals of the main representative chemical components of crude GSLE for deep understanding of chemical interactions with iron.The results presented herein would guide us to seek sustainable environmentally friendly low⁃cost detergent⁃like plant crude extracts for corrosion inhibition of various metals in aggressive acid environments.

L-Proline as a Green Corrosion Inhibitor in Aqueous Solutions for Carbon Steel

The chemical technique was used to investigate the inhibition and adsorption properties of L-proline for steel corrosion(weight loss method).As the concentration of L-proline increased,the inhibition efficiency increased,but decreased as the temperature increased,according to the findings.The inhibitor’s adsorption to the steel surface has been shown to be random,involving both electrostatic and chemisorptions.The Temkin adsorption isotherm governs the adsorption of L-proline to the steel surface.Thermodynamic parameters have been determined in some cases.

Corrosion Behavior of API 5L X52 Steel under High Concentrations of H2S/CO2 Gases

In the present work, the susceptibility of API 5L X52 steel to corrosion processes was evaluated in the presence of high contents of hydrogen sulfide and carbon dioxide. Gravimetric tests and surface analyses were carried out to establish both the corrosion rate and damage type exhibited by the metal. The obtained results indicate that the hydrogen sulfide is the most active gas in the corrosion processes that took place, quite above carbon dioxide. The main observed corrosion products were iron sulfides and the typical damage associated with hydrogen sulfide presence was Sulfide Stress Cracking (SSC). The surface damage evidences the presence of cracks with considerable magnitude and metal loss as consequences of the corrosion processes. Likewise, the presence of oxygen in the system modifies the displayed corrosion type, where corrosion products such as iron oxides and reduction in the number and extent of cracks are observed. On the other hand, the addition of a film-forming corrosion inhibitor based on modified imidazolines eliminates completely the development of cracks, although under certain test conditions, it can favor localized pitting corrosion.

Mechanism,quantitative characterization,and inhibition of corrosion in lithium batteries

Rechargeable lithium batteries with long calendar life are pivotal in the pursuit of non-fossil and wireless society as energy storage devices.However,corrosion has severely plagued the calendar life of lithium batteries.The corrosion in batteries mainly occurs between electrode materials and electrolytes,which results in constant consumption of active materials and electrolytes and finally premature failure of batteries.Therefore,understanding the mechanism of corrosion and developing strategies to inhibit corrosion are imperative for lithium batteries with long calendar life.In this review,different types of corrosion in batteries are summarized and the corresponding corrosion mechanisms are firstly clarified.Secondly,quantitative studies of the loss of lithium in corrosion are reviewed for an in-depth understanding of the mechanism.Thirdly,the recent progress in inhibiting corrosion is demonstrated.Finally,perspectives to further investigate corrosion mechanism and inhibit corrosion are put forward to promote the development of stable lithium batteries.

Low-frequency blue energy harvesting for sustainable and active anticorrosion

Engineering materials serving in marine surroundings are inevitably corroded.The corrosive marine conditions can also be utilized to harvest kinetic ocean wave energy to solve this problem.Leveraging water–solid triboelectrification to harvest lowfrequency wave energy for active anticorrosion is promising.Existing techniques are efficient in harnessing environmental energy with frequencies higher than 3 Hz,whereas the dominated ocean waves with optimal wave spectral density fluctuate from 0.45 to 1.5 Hz.Herein,we proposed a highly efficient and sustainable blue energy-powered cathodic protection(BECP)strategy by fusing water–solid triboelectric nanogenerators and cathodic protection technology.Leveraging the highly efficient triboelectrification between the moving water and hydrophobic fluorinated ethylene propylene tube,we developed the built-in power module,enabling the harvest of ocean wave energy lower than 1.5 Hz.The generated volumetric current density is 28.9 mA·m^(-3),5–20 times higher than the values of the reported devices.Moreover,the proposed BECP performs comparably to conventional cathodic protection in corrosion inhibition.Significantly,the proposed approach can be easily applied to ships,buoys,and other offshore platforms to simultaneously realize blue energy harvesting and engineering material protection,providing an alternative to traditional active protection technology.

N,N-Dimethyl fluorosulfonamide for suppressed aluminum corrosion in lithium bis(trifluoromethanesulfonyl)imide-based electrolytes

Effective passivation of aluminum(Al)current collector at high potentials(>4.0 V vs.Li/Li^(+))is of essence for the long-term operation of lithium-based batteries.Unfortunately,the non-aqueous liquid electrolytes comprising lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)and organic carbonates are corrosive toward Al current collector at high potentials(>4.0 V vs.Li/Li^(+)),despite their intriguing features(e.g.,good chemical stability and high ionic conductivity).Herein,we propose the utilization of N,N-dimethyl fluorosulfonamide(DMFSA)as electrolyte solvent for suppressing Al corrosion in the LiTFSI-based electrolytes.It has been demonstrated that the electrolyte of 1.0 M LiTFSI-DMFSA shows decent ionic conductivities(1.76 mS·cm^(−1)at 25℃)with good fluidities(2.44 cP at 25℃).In particular,the replacement of organic carbonates(e.g.,ethylene carbonate and ethyl methyl carbonate)with DMFSA leads to significant suppressed Al corrosion.Morphological and compositional characterizations utilizing scanning electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS)reveal that DMFSA favors the formation of insoluble species(i.e.,aluminum fluoride(AlF_(3)))on the surface of Al electrode,which effectively inhibits continuous exposure of fresh Al surface to electrolyte during cycling.This work provides not only a deeper understanding on the Al corrosion in LiTFSI-based electrolyte but also an elegant path to stabilize the Al current collector at high potentials(>4.0 V vs.Li/Li^(+)),which may give an impetus into the development of lithium-based batteries.

Corrosion Performance of Carbon Steel in CO_(2) Aqueous Environment Containing Silty Sand with Different Sizes

Corrosion performance of carbon steel in CO_2 aqueous environment containing silty sand with different sizes was investigated by immersion tests and electrochemical measurements.Silty sand could form an adsorption layer on steel surface in initial period,and the sand adsorption layer was turned into a mixture film of silty sand with corrosion product in last period.The adsorption layer in 325 mesh condition(large size)had the fewest pores for H_2CO_3 transport,exhibiting the highest cathodic current inhibition.In spite of little corrosion product,the sand adsorption film formed in 325 mesh condition induced the lowest corrosion rate.For 1000 and 5000 mesh silty sand,the sand adsorption layer had some pores for H_2CO_3 transport,leading to low cathodic current inhibition and much matrix dissolution.But the adsorption layer for5000 mesh silty sand(small size)had the largest special surface area to accelerate heterogeneous precipitation of corrosion product FeCO_3.Therefore,the mixture film in 5000 mesh condition was more compact,exhibiting stronger anodic inhibition and lower corrosion rate than those in 1000 mesh condition.

Protective Coatings Containing ZnMOF-BTA Metal–Organic Framework for Active Protection of AA2024-T3

ZnMOF-BTA,a new metal–organic framework with excellent anti-corrosion properties was prepared and characterized.Polarization and immersion tests in 3.5 wt%NaCl were performed on AA2024-T3 alloy to assess the corrosion inhibition ability of ZnMOF-BTA.It showed an inhibition efficiency of more than 90%,indicating excellent corrosion inhibition of ZnMOF-BTA on AA 2024-T3 in NaCl.Moreover,ZnMOF-BTA particles were incorporated into polyurethane coatings to create corrosion-resistant coatings.Electrochemical tests and neutral salt spray analysis were used to assess the corrosion protection ability of ZnMOF-BTA-laden polyurethane coatings.The results of electrochemical impedance spectra clearly showed the outstanding corrosion resistance and durability of ZnMOF-BTA coatings after 1440 h of immersion with a high pore resistance(Rpo)of 1.76×10^(10)Ωcm^(2).In addition,during the cross-cut adhesion test,the coating did not detach from the substrate,and after the impact test,there was scarcely any indication of a fracture,which further supports the notion that the coating has strong adhesion to the substrate.