Q235 Carbon Steel Research Articles

Study on corrosion inhibition performance and mechanism of quinoline quaternary ammonium salt and l-methionine on pre-corrosion Q235 steel

Abstract The corrosion inhibition properties and mechanisms of quinoline quaternary ammonium salt (QA) and L-methionine (LM) on pre-corroded Q235 carbon steel in 1wt% HCl solution were studied using the weight loss method and molecular simulation technology. The degree of pre-corrosion of steel will affect the corrosion inhibition performance of the corrosion inhibitor. QA and LM compete to adsorb to the iron surface to form a film, and the repulsion between the corrosion product and the film reduces the slow-release performance.

Preparation and Corrosion Properties of TiO2-SiO2-Al2O3 Composite Coating on Q235 Carbon Steel

The TiO2-SiO2-Al2O3 composite coatings were fabricated on the surfaces of Q235 carbon steel via the sol-gel method to improve its corrosion resistance. The effects of the sintering temperature and the layer number on the corrosion performances were explored. The coating morphology, microstructure and phase composition were analyzed by scanning electron microscopy (SEM) and X-ray diffractometer (XRD). Friction wear experiment, immersion experiment, and electrochemical impedance spectroscopy techniques were used to investigate the corrosion properties of the coatings as well. The results show that the sample with the TiO2-SiO2-Al2O3 coatings sintered at 850 °C are more uniform and denser and have better corrosion resistance and wear resistance than the other coatings. The Rp value of the 3 L coating sintered at 850 °C was about 114 kΩ·cm2, and the average friction coefficient was about 0.36.

Enhancing the Output Performance of Triboelectric Nanogenerator Based on Soft‐Contact Coaxial Double‐Rotation Structure

AbstractAs a promising energy technology, triboelectric nanogenerator (TENG) has garnered wide attention across various fields. The rotating structure‐based TENG exhibits superior output performance and energy conversion efficiency. However, further improvement is required in terms of output performance, and the issue of serious friction and wear between the materials in the friction layer needs to be addressed. In this work, A coaxial double‐rotation soft‐contact material based TENG (DR‐TENG) with characteristics of low wear and high output is fabricated. The introduction of soft‐contact material reduces frictional resistance and material wear, while the design and optimization of double‐rotation structures further enhance the output performance of TENG. The output current of DR‐TENG using rabbit furs as friction material can reach 144 µA after rectification. Experimental results demonstrate the excellent power supply capability of DR‐TENG. The output of DR‐TENG can be used to power commercial electronic devices after being stored by capacitance. The DR‐TENG is successfully applied for cathodic protection. The outcomes reveal that the open‐circuit potential of Q235 carbon steel can be reduced by 500 mV, which has a remarkable anti‐corrosion effect. These results confirm the broad application prospects of TENG in metal corrosion protection.

Synergistic inhibition of molybdate and phytate on chloride-induced corrosion of carbon steel in simulated concrete pore solutions

Improving the corrosion resistance of reinforcing steel is particularly important to prolong the service life of reinforced concrete (RC) structures. This study proposes a novel mixed corrosion inhibitor of sodium molybdate and sodium phytate to enhance the corrosion resistance of Q235 carbon steel in concrete exposed to aggressive environments. Based on the synergistic inhibition of the mixed corrosion inhibitor with an optimal concentration ratio, the passivation and chloride-induced corrosion of steel in simulated concrete pore solutions were investigated using electrochemical measurements, XPS, AFM, SEM/EDS and ATR-FTIR. The results indicated that the mixed corrosion inhibitor could promote the passivation process of steel by increasing the passive film thickness, despite no significantly improved passivation ability was highlighted for steel. Furthermore, due to the formation of a protective and thick passive film with a specific three-layer structure, the mixed corrosion inhibitor markedly improved the pitting corrosion resistance of steel and exhibited a high inhibition efficiency after 30 days of chloride exposure. Accordingly, the corresponding synergistic inhibition mechanism of the mixed corrosion inhibitor was proposed.

High-Efficiency Corrosion Inhibitor of Biomass-Derived High-Yield Carbon Quantum Dots for Q235 Carbon Steel in 1 M HCl Solution.

Eco-friendly self-doped carbon quantum dots (ZCQDs) with excellent corrosion inhibition ability were prepared via solid-phase pyrolysis only using Zanthoxylum bungeanum leaves as the raw material. Compared with the relevant research, a simpler and higher yield (25%) preparation process for carbon quantum dots was proposed. ZCQDs were characterized by transmission electron microscopy and X-ray photoelectron spectroscopy, and the average size of ZCQDs with multitudes of O- and N-containing functional groups was about 2.53 nm. The prepared ZCQDs were used to inhibit the corrosion of Q235 steel in HCl solution, and the inhibition behavior was investigated through weight loss, electrochemical test, surface analysis, and adsorption thermodynamic analyses. The results showed that the ZCQDs, acted as a mixed corrosion inhibitor, have an effective corrosion inhibition for Q235, the corrosion inhibition efficiency reached 95.98% at 200 mg/L, and at this concentration, effective protection of at least 132h (IE > 90%) is provided. Moreover, the adsorption mechanism of ZCQDs was consistent with that of Redlich-Peterson adsorption, including chemisorption and physisorption. A new corrosion inhibition mechanism of ZCQDs has been thoroughly studied and proposed; ZCQDs have functional groups containing O and N, which can form a protective barrier through physical adsorption and chemisorption, but the coverage of the protective film is low at low concentrations. With the increase of concentration, the protective film formed by ZCQDs on the metal surface will first increase the coverage and then adsorb more ZCQDs on the protective film to form a thicker and denser protective film to protect the metal. The carbon quantum dots prepared in this paper have advantages including a green, renewable precursor, a fast method, high yield, and excellent corrosion inhibition. Therefore, this work can inspire and facilitate, to a certain extent, the future application of doped carbon quantum dots as efficient corrosion inhibitors in HCl solutions.

Corrosion inhibition of extracts from the expired traditional Chinese patent medicines for Q235 carbon steel in hydrochloric acid

During the COVID-19 epidemic, traditional Chinese patent medicine played a significant role in treatment and prevention. However, excessive production of medicines will face serious disposal problems once they are expired, and how to achieve safe and efficient utilization of resources becomes another challenge. In this study, the diverse organic components of traditional Chinese patent medicine-YanReQing Granules (YGE) have been extracted and enriched using a low-temperature extraction method, and the main compositions have been analyzed by liquid chromatography-mass spectrometry (LC-MS). The inhibition performance of YGE for Q235 steel in 0.1 mol L−1 HCl solution was evaluated by various methods. The results indicated that the corrosion rate of metal decreased significantly with the addition of YGE, and the corrosion potential shifted positively as the increase of cathodic and anodic Tafel slopes, indicating that the YGE belongs to a mixed type of corrosion inhibitor with the simultaneously inhibition on cathode and anode. The inhibition efficiency of YGE increased gradually with the more additive amounts, and exceeded 99% calculated by the fitting current density in polarization curves. The active ingredients in YGE are mainly composed of hydroxyl and carbon-based aromatic hydrocarbons, which are easily protonated in hydrochloric acid solution and carry a positive charge, and then adsorb at the metal interface electrostatically to form a shielding layer. Moreover, the theoretical calculations have confirmed that the chemical adsorption can be achieved between the polar atoms and metal to enhance the protective layer ultimately.

CaIn2S4 nanosheets and SnO2 nanoflowers co-sensitized TiO2 nanotubes photoanode for continuous and efficient photocathodic protection of Q235 carbon steel

To solve the problem of poor photocathodic protection (PCP) effect of pure TiO2 nanotubes (NTs) on Q235 carbon steel (CS), CaIn2S4 nanosheets (NSs) and SnO2 nanoflowers (NFs) co-sensitized TiO2 NTs were prepared by anodization, hydrothermal and solvothermal method. Results showed that the absorption edge of CaIn2S4/SnO2/TiO2 NTs extended to 540 nm, indicating the utilization efficiency of visible light was greatly improved. Under light, the CaIn2S4/SnO2/TiO2 NTs exhibited an open circuit potential drop of 530 mV vs. SCE and a photocurrent density of 624 μA cm−2, which was 23 and 48 times that of TiO2 NTs, respectively. The PCP properties of CaIn2S4/SnO2/TiO2 NTs were better than that of TiO2 NTs because the separation and transfer efficiency of electrons and holes were promoted due to the heterojunction structure formed between TiO2, SnO2 and CaIn2S4. Furthermore, the CaIn2S4/SnO2/TiO2 NTs could also provide time-delay protection up to 10 h in the dark state. Obviously, CaIn2S4/SnO2/TiO2 NTs have excellent electron storage capacity and could provide efficient and continuous protection, which may be due to the presence of SnO2 NFs. This work provides an effective strategy of designing more efficient photoanodes for PCP of metals.

Microbiologically influenced corrosion inhibition of two marine structural steels caused by Halomonas titanicae in aerobic environments

Corrosion is a global problem, especially in marine environments. The currently popular corrosion mitigation methods have the drawbacks of being costly, susceptible to environmental limitations, or causing environmental contamination. Microbiologically influenced corrosion inhibition (MICI), as a widespread phenomenon, can provide a new strategy utilizing bacteria to control corrosion. This study investigated the MICI mechanism of Halomonas titanicae on two marine structural steels (EH36-low alloy steel (E-LAS) (with copper) and Q235-carbon steel (Q-CS) (without copper)) in aerobic environments. Results show that the corrosion of E-LAS and Q-CS was both inhibited by H. titanicae in an aerobic enriched seawater. It was found that the aerobic respiration mode of H. titanicae was very different from its anaerobic respiration. The former respiration mode significantly reduced the dissolved oxygen (DO) concentrations in the medium. In addition, the DO levels in the biotic medium immersed with the two steels were similar, but the corrosion inhibition degree of E-LAS (22% drop) caused by H. titanicae was weaker than that of Q-CS (55% drop), indicating that the MICI mechanism of H. titanicae goes beyond simply reducing the DO concentration. The number of sessile cells on E-LAS was only 20% of that on Q-CS due to Cu in E-LAS, which led to a thinner extracellular polymeric substance (EPS) film and a corrosion product film with less Fe(II) content. This reduced the Rf values significantly. Therefore, the EPS and corrosion product films caused by H. titanicae aerobic respiration are also important in the corrosion inhibition process.

Comprehensive analysis of corrosion failure of blast furnace gas pipeline in a steel plant

The corrosion failure of blast furnace gas pipeline made of Q235 carbon steel in a steel plant was investigated. Macroandmicromorphology, thickness loss rate and phase composition of rust layer have been comprehensively studied. The macroandmicromorphology of failed tube in service for 3.5 years were observed by laser scanning confocal microscope (LSCM), scanning electron microscope (SEM) and energy disperse spectroscopy (EDS), and chemical composition of on-site condensed water and materials was examined. Results indicated that Cl is enriched on the surface of loose corrosion products, which is composed of FeOOH and Fe2O3. Large thickness loss rate and corrosion gully or holes suggest that mechanism of pitting corrosion are acid chemical corrosion and electrochemical corrosion.

The divergency of microbiological influenced corrosion for diverse pipe materials in the drinking water distribution system

Microbiological influenced corrosion (MIC) was prevalent in the water supply industry, especially in drinking water distribution systems (DWDS) where ferrous materials are the main component. The MIC behaviors for four popular pipe materials (304 stainless steel, 316 stainless steel, Q235 carbon steel, and nodular cast iron) were studied by the dynamic water supply network simulation in the paper. The biomass densities of surface coupons in the experimental period were ranked as follows: nodular cast iron (20,562 cells/mm2, ICC) > Q235 carbon steel (8697 cells/mm2, ICC) > 316 stainless steel (6350 cells/mm2, ICC) > 304 stainless steel (5520 cells/mm2, ICC). Microbial community structure was mainly influenced by environmental factors, especially in the pipe materials that significantly impacted dominant genera inhabited on experimental materials, among which the 316 stainless steel showed the best biostability. Moreover, the profile of polarization resistance and corrosion current exhibited a similar variation tendency, which increased in the first 30 days and then decreased later. The maximum corrosion current of each material was 2.10 × 10−4 A (304SS), 2.70 × 10−4 A (316SS), 2.58 × 10−4 A (Q235 carbon steel), and 1.30 × 10−4 A (nodular cast iron). SEM and XRD results confirmed that the surficial porous corrosion layer controlled the diffusion process of iron corrosion where β-FeOOH and γ-FeOOH were the main components of the corrosion product. Overall, the results of community diversity, electrochemical parameters, and corrosion layer structure showed that 316 stainless steel possessed the best biological corrosion resistance among the four kinds of pipes.

Development of anti-corrosion and hydrophobicity of a nanostructured Ce-La film via the PDA post-treatment modification

The Ce-La film has been created to improve the adhesion of the organic coatings with the metal surface. However, the development of cracks coincides with the formation of the Ce-La conversion coating. In addition, the high hydrophilicity of the Ce-La conversion coating adversely affects its adherence properties. In this study, poly-dopamine (PDA) in two forms namely PDA-A and PDA-B were employed as post-treatment layers to enhance the adhesion and corrosion resistance of the Ce-La film on Q235 carbon steel. The microstructure, wettability, and corrosion resistance were investigated. The results revealed that the PDA healed the cracks and increased the surface roughness and thickness of the Ce-La conversion coating. Moreover, the Ce-La film becomes more hydrophobic, and the contact angle increased from 6.509° to 61.745° and 85.009° after applying the PDA-A and PDA-B layers, respectively. The application of the PDA-B post-treatment layer significantly improved the overall corrosion resistance (Rt) of Ce-La conversion coating, increasing the Rt from 1180.6 to 1299.6 Ω.cm2 and decreasing the corrosion current density (icorr) from 2.466 to 1.652 µA/cm2. These findings demonstrate that applying PDA can improve both the adhesion and corrosion resistance of the Ce-La conversion coating.

A stable graphene nanofluid for creating slippery, corrosion- and biofouling-resistant surfaces

Marine engineering materials face the challenges of corrosion and biofouling. In this study, a graphene nanofluid has been prepared by dispersing modified graphene in a common lubricant. Porous surfaces on Q235 carbon steel have been generated by applying the highly efficient texturing method—breath figure method and then infused with the graphene nanofluid. The coating thus obtained showed high stability, reduced oil-phase leaching, and a self-healing function. Moreover, the slippery coating exhibited a more than five orders of magnitude superior anti-corrosion performance and improved anti-biofouling properties. The developed graphene nanofluid coating has great potential for applications involving the protection of surfaces exposed to the marine environment.

Ultrafast synthesis of novel coal-based graphene and its anticorrosion properties of epoxy/graphene nanocomposite coatings

Graphene has a wide range of applications in anti-corrosion coatings due to its excellent barrier, shielding, and mechanical properties. However, traditional graphene synthesis methods, including the production of graphene oxide (GO) using Homer's method and then its reduction in the form of reduced graphene oxide (rGO) are time-consuming, energy-consuming, and environmentally polluting, which limits their application in anti-corrosion coatings. This study leveraged the capabilities of flash Joule heating (FJH) to synthesize flash coal-based graphene (FCBG) from Taixi anthracite (TA) within 200 ms without pretreatments or chemical reagents. The FJH had the advantages of low energy consumption and being environmentally friendly. Compared with the rGO, the FCBG prepared by FJH was characterized by fewer defects, larger carbon sheets, and a turbostratic structure. Moreover, carbon steel Q235 was used as the substrate to prepare anti-corrosion coatings by mixing FCBG at different flash voltages with epoxy resin (EP). Based on this, the electrochemical performance of different coatings was compared before and after salt spray corrosion. The results demonstrated that the FCBG composite anti-corrosion coating (EP/FCBG190) prepared using EP and FCBG synthesized at 190 V in the FJH, displayed stronger corrosion resistance than the EP and rGO composite coating (EP/rGO). The FJH synthesis process provides a feasible route for improving the synthesis process of the anti-corrosion coatings and the high value-added utilization of coal.

Patch Loading Design Recommendations for Titanium–Clad Bimetallic Steel Plate Girder

For steel structures service in corrosive environments, corrosion reduces the mechanical properties and effective thickness of the structural steel, which has a significant effect on the durability of steel structures. Titanium–clad bimetallic steel (TCBS), a bimetallic material composed of titanium alloy and carbon steel with excellent corrosion resistance has been suggested to solve the corrosion issue. The TCBS consisting of the TA1 titanium cladding and Q235 carbon steel substrate was introduced in the plate girder as the web to improve durability in this study. The stress–strain properties and failure performance of TCBS and Q235 carbon steel were discussed. Notably, the separation between the cladding and the substrate in the TCBS was observed during the necking stage in the tensile coupon test. Welding method between TCBS web and Q235 carbon steel flange was suggested for processing the plate girder, which was validated to be appropriate according to the experimental results. No crack in welding and TCBS web of plate girder was observed during the patch loading test. A numerical parametric study on the ultimate resistance of TCBS plate girder subjected to patch loading was conducted using the finite element software ABAQUS, in which three different key parameters were included. A comparison between the numerical and predicted results indicated that the design equations suggested in EN 1993–1–5 were too conservative to be directly used for predicting the ultimate resistance of the TCBS plate girder under patch loading, which was caused by the strain–hardening effect and yield plateau of the structural steel. The current design equations were modified to effectively predict the resistance properties of TCBS plate girders.

Intermediate-layer strengthened superhydrophobic coating with stable corrosion resistance, delayed icing and long-term weatherability

Improving the mechanical stability and anti-corrosion durability of superhydrophobic material remains a great challenge that has not been solved. In this paper, we designed and prepared two types of superhydrophobic coatings using PTFE nanoparticles and waterborne epoxy resin, viz. superhydrophobic PTFE@epoxy single layer coating and superhydrophobic Epoxy + PTFE@epoxy double layer coating. It was found that the mechanical stability and interfacial bonding of the superhydrophobic composite coatings were further improved by introducing an epoxy resin intermediate layer. The superhydrophobic Epoxy + PTFE@epoxy double layer coating maintained excellent non-wetting superhydrophobicity even after 150 sandpaper abrasion and 160 tape-peeling cycles. The electrochemical testing results showed that the Rct and low-frequency modulus values of the superhydrophobic double layer coating improved by 7–8 orders of magnitude compared with the bare Q235 carbon steel substrate, demonstrating excellent corrosion resistance. In addition, the coating maintains good corrosion protection after 60 days of outdoor atmospheric exposure and 30 days of neutral salt spray acceleration tests, indicating superior weathering resistance and long-term anti-corrosion properties. The coating also features delayed icing, self-cleaning, anti-fouling, chemical stability, and high substrate applicability, which provides long-lasting multifunctional superhydrophobic materials with comprehensive functions.

Study on the influence law and mechanism of industrial atmospheric environment on the corrosion behavior of Q235 carbon steel

This paper combines the traditional hanging test and corrosion sensor technology to study and explore the corrosion law and its mechanism of Q235 carbon steel in industrial atmospheric environment. The results show that Hangzhou’s industrial atmospheric corrosion is a constantly changing and highly variable corrosion intensity process with the corrosive strength shows a seasonal trend. Through the analysis of weight loss, macroscopic corrosion morphology, microscopic corrosion morphology and elemental distribution, it showed that the traditional hanging test results and sensor test results had a good correspondence, indicating that the sensor values can be used to study the corrosion of the outdoor samples.

Reliance of Corrosion Characteristics for Two Iron-Based Alloys on the Water Content in 1-Butyl-3-Methylimidazolium Tetrafluoroborate

Although the corrosion of iron-based alloys by ionic liquids (ILs) has been reported, the influence of trace water in ILs on its corrosion mechanism is often ignored. In this work, we investigated the corrosion behavior of Q235 carbon steel (Q235 CS) and 304 stainless steel (304 SS) exposed to 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) with trace water (0.5 wt% to 4.0 wt%) at 323 K. Electrochemical tests and surface analysis manifested that the increasing water content accelerated corrosion of the two iron-based alloys in [BMIM]BF4. A nontypical passivation zone was observed for Q235 CS, while 304 SS exhibited completely active dissolution and its corrosion situation was not as serious as Q235 CS. The occurrence of pitting corrosion is responsible for 304 SS behaviors in [BMIM]BF4. Some corrosion products accumulated on the surface of both iron-based alloys were similar, including FeF2, FeF3, FeO, Fe2O3, and/or FeOOH. Gas products during corrosion were also monitored to avoid the complicated cathodic depolarization process, and it was found to be composed of BF3, HF, and H2. Finally, the corrosion mechanism of iron-based alloys in ILs with trace water was proposed. The illustrated mechanism would be meaningful for understanding the similar corrosiveness to iron-based alloys.

Core-Shell Spheroid Structure TiO2/CdS Composites with Enhanced Photocathodic Protection Performance.

In order to improve the conversion and transmission efficiency of the photoelectron, core-shell spheroid structure titanium dioxide/cadmium sulfide (TiO2/CdS) composites were synthesized as epoxy-based coating fillers using a simple hydrothermal method. The electrochemical performance of photocathodic protection for the epoxy-based composite coating was analyzed by coating it on the Q235 carbon steel surface. The results show that the epoxy-based composite coating possesses a significant photoelectrochemical property with a photocurrent density of 0.0421 A/cm2 and corrosion potential of -0.724 V. Importantly, the modified composite coating can extend absorption in the visible region and effectively separate photoelectron hole pairs to improve the photoelectrochemical performance synergistically, because CdS can be regarded as a sensitizer to be introduced into TiO2 to form a heterojunction system. The mechanism of photocathodic protection is attributed to the potential energy difference between Fermi energy and excitation level, which leads to the system obtaining higher electric field strength at the heterostructure interface, thus driving electrons directly into the surface of Q235 carbon steel (Q235 CS). Moreover, the photocathodic protection mechanism of the epoxy-based composite coating for Q235 CS is investigated in this paper.

A New Imidazole Derivative for Corrosion Inhibition of Q235 Carbon Steel in an Acid Environment.

Q235 carbon steel is a commonly used engineering material, but its application in marine environments is limited by its susceptibility to corrosion, especially localized corrosion that can lead to material perforation. Effective inhibitors are crucial to addressing this issue, particularly in acidic environments where localized areas become increasingly acidic. This study reports the synthesis of a new imidazole derivative corrosion inhibitor and evaluates its effectiveness in corrosion inhibition performance using potentiodynamic polarization curve and electrochemical impedance spectroscopy techniques. High-resolution optical microscopy and scanning electron microscopy were employed for surface morphology analysis. Fourier-transform infrared spectroscopy was used to explore the protection mechanisms. The results demonstrate that the self-synthesized imidazole derivative corrosion inhibitor offers an excellent corrosion protection performance for Q235 carbon steel in a 3.5 wt. % NaCl acidic solution. This inhibitor can provide a new strategy for carbon steel corrosion protection.

Synergistic inhibition effect of imidazoline and thiourea on pitting corrosion of Q235 carbon steel

Pitting corrosion is a significant issue which significantly shorten the service life of carbon steel. In this study, imidazoline and thiourea are combined to assess the synergistic in the localized corrosion of Q235 carbon steel by a combined system. In detail, five different proportions of corrosion inhibitors are used in the simulated corrosion solution (5 wt. % NaCl + 0.5 wt. % CH3COOH + 1.0 wt. % Na2S) in the closed area to investigate the corrosion inhibition performance of Q235 steel at 80 °C. The corrosion behavior of the steel in the simulated solution was investigated using potentiodynamic polarization test and electrochemical impedance spectroscopy test. Due to the combination of imidazoline (IM) and thiourea (TU) corrosion inhibitors, the corrosion inhibitors in the simulated solution of the occlusion zone reduce the migration of corrosive anions to the occlusion zone and slowed the acidification of the solution resulting in lower concentrations of Cl- and S2- to varying degrees and reaching a higher pH of the solution. As a result, the compounded corrosion inhibitors exhibit improved corrosion inhibition rate (80 mg/L IM+20 mg/L TU (86.91 %), 50 mg/L IM+ 50 mg/L TU (95.67 %), 20 mg/L IM+ 80 mg/L TU (86.16 %)) to Q235 steel, which is superior to that using imidazoline (63.42 %) or thiourea (92.77 %) alone. This enhanced performances fully prove the synergistic effect of imidazoline with thiourea.