Carbon Steel Substrate Research Articles

Corrosion-sensing and self-healing dual-function coating based on 1,10-phenanthroline loaded urea formaldehyde microcapsules for carbon steel protection

In this work, a smart coating with corrosion-sensing and self-healing dual functions was developed on carbon steel by incorporating the urea formaldehyde (UF) microcapsules loaded with 1,10-phenanthroline (Phen) molecules. Phen as both the corrosion-sensing indicator and corrosion inhibitor was encapsulated into the UF microcapsules via the oil-water (O/W) emulsion in-situ polymerization method. When the coating was damaged, the Phen molecules released from UF/Phen microcapsules would react with the Fe2+ ions generated from the active anodic corrosion site of the carbon steel substrate, and displayed a prominent red color chelate compound for corrosion-sensing application. During the neutral salt spray test, the corrosion evolution underneath the damaged coating can be rapidly detected within 15 min. Besides, the corrosion activity near the coating scratch can be effectively inhibited due to the adsorption of released Phen on the exposed substrate surface. After 72 h of immersion in 3.5 wt% NaCl solution, the low frequency impedance modulus of the scratched coating containing 10 wt% UF/Phen microcapsules was almost 7 times that of the scratched blank coating. The smart coating can not only achieve timely corrosion sensing, but also suppress the corrosion activity, which is of great importance for practical corrosion protection applications.

Corrosion resistance and antibacterial activity of a surface coating created by super-spread wetting of liquid copper on laser-ablated carbon steel

In this work, a Cu coating on carbon steel with a fine crevice structure created by laser modification was produced without the use of contaminants by exploiting the super-spread wetting properties of liquid metal. The chemical composition, microstructure, bonding properties, corrosion resistance, and antibacterial activity of the Cu coating were investigated. The coating consisted of metallic Cu containing a minor fraction of Cu2O, with surface flakes and a dense inner layer with 0.1 % porosity and thickness of 337 ± 10 μm. Three-point bending tests showed the Cu coating had good adhesion with the carbon steel substrate. Corrosion tests demonstrated that the dense structure of the Cu coating blocked electrolyte contact with the carbon steel substrate for at least 336 h, indicating that the coating provides a barrier against galvanic corrosion. Assays of antibacterial activity and biofilm inhibition suggested that growth of Escherichia coli and Staphylococcus epidermidis on the Cu coating was 99.9 % lower than that on the substrate after 2 h surface contact, and biofilm formation on the coating was >90 % lower than that on the substrate. The combined anti-corrosive properties and antibacterial activity demonstrate the potential for the Cu coating to prevent transmission of bacterial infections in hospitals and public environments.

Friction Properties of the Heat-Treated Electroless Ni Coatings Embedded with c-BN Nanoparticles

The nickel (Ni) coatings without and with embedded (5–7 vol. %) cubic boron nitride (c-BN) nanoparticles (10 nm in diameter) were deposited on carbon steel substrate by an electroless plating process. Coatings were tested in as-deposited and heat-treated (heating at 300 °C for 6 h) conditions. Coating structure characterisation was performed, as well as hardness and roughness measurements. Friction properties were tested in dry and in water (seawater) lubricated contact conditions, with bronze as a counter-body material. Both static and kinetic coefficients of friction were measured for two different surface texture preparations (initial and working). The first surface texture simulated the running-in condition, and the second surface texture represented the steady-state conditions. The enhancement of the abrasive and erosive wear resistance of heat-treated electroless Ni coatings with embedded c-BN nanoparticles was already proved in our previous studies. This study aims to investigate those influences on friction properties of electroless Ni coatings in different sliding conditions. The results show that the coefficients of friction did not differ too much between the coatings and that the surface roughness and presence of seawater had a much stronger influence.

Corrosion and conductivity properties of Ni–P/Ti4O7 coating on carbon steel as bipolar plates for proton exchange membrane fuel cells

PurposeThe purpose of this paper is to investigate the interfacial conductivity and corrosion resistance of the Ni–P/Ti4O7 composite coating that is deposited on a carbon steel substrate as bipolar plates for proton exchange membrane fuel cells.Design/methodology/approachThe Ni–P/Ti4O7 coating was prepared by electroless plating. Scanning electron microscopy, white light interference, energy dispersive spectrometry and X-ray diffraction were used, respectively, to study the surface morphology, chemical composition and phase composition of coated samples. Electrochemical impedance spectroscopy, potentiodynamic and potentiostatic polarization were used to test the electrochemical performance and corrosion behavior. The interfacial contact resistance (ICR) was measured via the standard method.FindingsThe surface of the Ni–P/Ti4O7 coating is complete and dense and without obvious defects. The electrochemical test results show that the Ni–P/Ti4O7 coating provides better corrosion resistance than the Ni–P coating and substrate. Compared with the Ni–P coating, the ICR of the Ni–P/Ti4O7 coating is lower by about 82.7%. This is because the coating has more conductive contact points. The more exciting thing is that the ICR of the Ni–P/Ti4O7 coating only increases to 12.38 mΩ·cm2 after 5 h of polarization.Originality/valueThis paper provides a method for achieving surface modification of metal bipolar plates. Introducing Ti4O7 particles in the Ni–P layer reduces the contact resistance before and after polarization while ensuring good corrosion resistance.

Efficient Synthesis of 6,7-Dihydro-5H-cyclopenta[b]pyridine-3-carbonitrile Compounds and Their Applicability As Inhibitor Films for Steel Alloy Corrosion: Collective Computational and Practical Approaches.

An effective method for designing new heterocyclic compounds of 6,7-dihydro-5H-cyclopenta[b]pyridine-3-carbonitrile derivatives (CAPDs) was presented through cyclocondensation reaction between 2,5-diarylidenecyclopentanone derivatives and propanedinitrile, and the cyclocondensation reaction succeeded using a sodium alkoxide solution (sodium ethoxide or sodium methoxide) as the reagent and the catalyst. The synthesized CAPD derivatives were employed as novel inhibitors for carbon steel (CS) corrosion in a molar H2SO4 medium. The corrosion protection proficiency was investigated by electrochemical measurements (open circuit potential vs time (EOCP vs t), potentiodynamic polarization plots (PDP), and electrochemical impedance spectroscopy (EIS)) and surface morphology (scanning electron microscopy (SEM)) examinations. The results show that the CAPD derivatives exhibit mixed type inhibitors and a superior inhibition efficiency of 97.7% in the presence of 1.0 mM CAPD-1. The adsorption of CAPD derivatives on the CS interface follows the Langmuir isotherm model, including physisorption and chemisorption. Scanning electron microscopy (SEM) exploration confirmed the adsorption of the CAPD derivatives on the CS substrate. Monte Carlo (MC) simulations and DFT calculations revealed that the efficacy of the CAPD molecules correlates well with their structures, and this protection was attributed to their adsorption on the CS surface.

Effects of processing conditions on the solidification and heat-affected zone of 309L stainless steel claddings on carbon steel using wire-directed energy deposition

Directed energy deposition and laser cladding technologies are suitable advanced manufacturing techniques for applying corrosion-resistant claddings to large carbon steel components. In this work, we clad 309L stainless steel wire onto carbon steel substrates and examine the effects of processing parameters (laser power and travel speed) on metallurgical bonding and microstructures. Wire dripping defects correlate to excessive heat input, while cracking, stubbing and delamination defects are linked with insufficient heat input. Spectroscopic scans of the weld microstructure show the amount of base metal mixing in the weld is a function of processing parameters and the number of cladding layers. In the first cladding layer, the weld metal is diluted with base metal ranging from 1.7 to 45.6 %; this amount dramatically decreases in the second layer (0–8.6 %), promoting primary ferrite solidification, which decreases solidification cracking susceptibility. Martensite forms in the heat-affected zone from the high cooling rates associated with laser processing. Subsequent laser passes temper the martensite and carbon diffuses from the substrate into the first cladding layer. Cladding two or more layers is beneficial for mitigating defects, lowering dilution, and producing a highly alloyed surface suitable for corrosion protection.

Corrosion inhibition performance of silver nanoparticles embedded-gloss paint on carbon steel and aluminium substrates in 2.0 M H2SO4 solution

Corrosion control of metals in aggressive environments has attracted a lot of attention due to its associated economic losses. However, most corrosion control techniques have not satisfactorily minimized these losses. This study examined the inhibition effects of silver nanoparticles (AgNPs) incorporated in gloss paint on corrosion of carbon steel and aluminium in 2.0 M H2SO4 solution. The AgNPs were biosynthesized via green chemistry and characterized using Fourier Transform Infrared, UV-Vis spectrometer, and Transmission Electron Microscope. Samples of carbon steel and aluminium were uniformly coated with a thin layer of gloss paint mixed with AgNPs solution at five different concentrations of 0, 5, 10, 15, and 20 µg/ml. The inhibition efficiency of the AgNPs modified paint was conducted via gravimetric, gasometric, and potentiodynamic polarization analyses. Results of the gravimetric analysis revealed an increased weight loss with an increased period of exposure and decreased concentration of AgNPs in the paint. The corrosion rates for the mild steel and aluminium samples were 0.051 and 0.005 mmpy with inhibition efficiencies of 42% and 69%, respectively, when immersed in 20 µg/ml AgNPs-incorporated coating and exposed for 120 hours. Potentiodynamic polarization analysis revealed that the presence of AgNPs in the paint (as inhibitor) retarded the anodic dissolution by the formation of protective films on the mild steel and aluminium sample surfaces. The evolution of hydrogen gas from 20 µg/ml AgNPs-incorporated coating was significantly reduced by 81% and 14% for mild steel and aluminium, respectively when compared with the control samples at 200 minutes of exposure. These results revealed that the incorporation of AgNPs into the gloss paint matrix minimizes the degradation due to corrosion of the mild steel and aluminium samples.

Green synthesis of zinc sulfide nanoparticles-organic heterocyclic polyol system as eco-friendly anti corrosion and anti-bacterial corrosion inhibitor for steel in acidic environment

ABSTRACT Green synthesis, characterization and evaluation of nanoscale zinc sulfide (ZnS) by precipitation chemical method. The zinc sulfide nanoparticles were prepared by chemical precipitation method using heterocyclic polyvinyl alcohol, PVA as a sensitizer. The prepared heterocyclic compounds system ZnS nanoparticles, PVA, EG were used as anti-bacterial corrosion towards sulfate-reducing bacteria (SRB) and anti-corrosion for carbon steel substrate in sulfuric acid and hydrogen sulfide bacterial corrosive environment using chemical, analytical, and electrochemical techniques. Effect of adding PVA, and ethylene glycol, EG to ZnS nanoparticles were studied. Effect of ZnS nanoparticles concentrations and the reaction temperature on the corrosion inhibition efficiency were studied. The inhibition due to adsorption of nanoparticles on steel surface, the adsorption agree well with Langmuir isotherm with suggested chemical adsorption mechanism. Potentiodynamic polarization (PD) and Electrochemical impedance spectroscopy (EIS) data explain that the used inhibitor is mixed-type and improves polarization resistance and inhibition performance by adhering to metal/electrolyte interface. The cathodic and anodic reactions are delayed when inhibitor molecules are added to an aggressive medium, which results in a negative shift in the open circuit potential. Addition of both PVA, and EG as organic polyol materials enhance the adsorption and inhibition properties of zinc sulfide nanoparticles on steel surface.

Wavy microstructure for improvement of bonding strength in titanium to carbon steel brazed joints

Multi-interlayer composed of Ni and microcracked Cr (MC-Cr), formed by electrochemical deposition, was applied to induce the formation of wavy microstructure enhancing bonding strength of titanium to carbon steel brazed joints with BAg45CuZn filler. Effect of microcrack density in Cr layer on microstructure evolution and mechanical properties of joints has been studied. Phase identification and formation mechanism of joints were analyzed systematically. Introducing multilayer with microcracks avoided the formation of brittle Ti-C and Fe-Ti phases near carbon steel substrate. During bonding, the diffusion of Ti atoms was hindered by compact Cr while promoted by Ni at microcracks. The inhomogeneous diffusion of Ti atoms led to the generation of a wavy microstructure unit that is crater-shaped structure, accompanied by the enrichment of β-CuZn, Fe0.2Ni4.8Ti5 and Cu2TiZn phases. The fracture results showed that these structures improved the shear strength of joints up to 242 MPa by altering the direction of crack propagation.

Anticorrosive behavior assessment of electrodeposited zinc salicylate coating on carbon steel

The study focuses on the evaluation of a novel composite coating obtained from zinc salicylate (ZnSal). Ion distributions of salicylic acid and zinc(II) were surveyed at various acidities, and pH 9.5 was selected for the direct current electrodeposition of ZnSal/K2SO4 on carbon steel substrate. The surface morpholgy of the ZnSal-steel coating was revealed by scanning electron microscopy, and compact deposited films with dendrite structures (specific surface area 247 m2 g−1, type-H3 BET hysteresis loop at relative pressures from 0.4 to 1.0) could be formed within 25-min plating time. NSST was conducted, and the test duration was 120 h. Preliminary assays were employed to assess its anticorrosive performance in salt spray, and the corrosion rate of the steel plates exhibited a nonlinear relationship with the exposure time. The results showed that the ZnSal-steel had a low corrosion rate <0.11 μm h−1, thereby increasing the potential of ZnSal composites on actual carbon steel for anticorrosive coatings.

Fabrication of macrocrack-free thick chromium duplex plating for remanufacturing applications

The remanufacturing process of a hydraulic cylinder rod becomes a challenging prospect in the industrial sector producing heavy equipment. That is because remanufactured components can have the same product quality as new components with a more economical price. Hard chromium electrodeposition is a well-known technique to provide a protective coating for the cylinder rod so that it has favorable wear and corrosion resistance properties. Associated with remanufacturing applications, the used chromium plating covering the cylinder rod should be removed first before applying the new chromium one. Whereas the removal process often slightly consumes the base metal and fresh thicker chromium should be deposited in order to preserve its original diameter. The main problem is that the thick chromium may experience macrocrack after the baking process at 200 °C. Hence, the observation of as-plated and as-baked thick and hard chromium deposit properties is the novelty of this research. In this work, the thick and hard chromium plating over a flat carbon steel substrate was produced by the electrodeposition method. A conventional single-layer chromium deposit with a plating current density greater than 40 A/dm2 shows macrocracks after the baking process at 200 °C for an hour. For the chromium duplex plating composed of two Cr layers, the maximum thickness of the deposit was 261.0±8.5 microns, and the macrocrack was observed. Meanwhile, the as-baked duplex chromium plating composed of a polished Cr-C layer and a Cr layer has a microcrack density of 337±8 cracks/cm and hardness of 924.8±22.2 HV0.3 without macrocracks. EPMA characterization confirmed the presence of a carbon element in the Cr-C layer, and it is presumed due to carbon co-deposition from formic acid additives.

Dynamic recrystallization in severely plastically deformed iron aluminide coatings obtained by friction surfacing

In the present work, the friction surfacing process was applied to produce iron aluminide (Fe-24.5Al-0.31C) coatings on a low carbon steel substrate under different deposition conditions and the influence of process parameters on coating geometry, microstructure and hardness was analysed. Thermographic data obtained during the tests indicated average deposition temperatures in the range of 862–951 °C, according to consumable rod rotation speed. By the proposed method, it was possible to obtain homogenous coatings with up to 0.75 mm thickness. Additionally, with increasing tool rotation a considerable reduction of grain size relative to the initial as-cast structure was observed. Keywords: Friction Surfacing, Intermetallics, Dynamic Recrystallization, Severe Plastic Deformation.

Corrosion Behavior of Epoxy/Polysulfide Coatings Incorporated with Nano-CeO2 Particles on Low Carbon Steel Substrate

The corrosion resistance properties of epoxy coatings applied to St37 carbon steel were modified with polysulfide and nano cerium oxide (CeO2). The surface chemistry of the epoxy/polysulfide coating was studied by Fourier transform infrared spectroscopy, which confirmed the presence of the thiol group. The toughness and corrosion properties of epoxy/polysulfide composites were investigated by cupping and electrochemical impedance spectroscopy (EIS) tests, respectively. Results showed that the addition of 10 wt% of polysulfide to epoxy, led to a notable increase in toughness and corrosion resistance. Epoxy/polysulfide/CeO2 nanocomposites were prepared by incorporating 0.5 wt%, 1 wt%, 2 wt%, 4 wt%, and 6 wt% of CeO2 nanoparticles into the epoxy coating with 10 wt% of polysulfide. Field emission scanning electron microscopy observations indicated the uniform dispersion of 1 wt% nano CeO2 and agglomeration of higher concentrations of particles in the composite. The effect of nano CeO2 on the corrosion behavior of the coatings was investigated in a 3.5% NaCl solution using EIS and salt spray tests. The adhesion strength of the nanocomposites was measured by a pull-off adhesion tester. Results revealed that the incorporation of 1 wt% CeO2 nanoparticles significantly increased the corrosion resistance and adhesion strength of the epoxy/polysulfide coatings.

Influence of soil chemical characteristics on corrosion behaviour of galvanized steel

Hot-dip galvanized steel is widely used for the construction of underground structures, thanks to the presence of a zinc coating that is able to protect the carbon steel substrate through the formation of a corrosion products layer. Soil corrosion is a very complex process and hence it is difficult to predict the corrosion resistance of a specific component because many factors can directly influence the behavior of material immerged in soil. This work focused on the effect of chlorides and sulphates concentrations on the corrosion of hot-dip galvanized steel wires buried in soil. In particular, the wires were monitored by means of electrochemical techniques, as open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization. Moreover, at the end of the exposure, the samples were extracted and observed by optical and electron microscopy, to examine the corroded surface and the corrosion morphology. The analysis evidenced that the effect of chlorides and sulphates is very severe, producing a great degradation of the zinc coating. In particular, the synergistic effect performed by the combined action of these elements caused, in the most critical situation, the protection loss of the external layer, putting steel substrate in direct contact with soil, and therefore obtaining a substantial reduction in material corrosion resistance.

Anti-corrosive Polystyrene Coatings Modified with Tannic Acid on Zinc and Steel Substrates

Polystyrene (PS) polymer layers were prepared and studied as anti-corrosive barrier layers on both carbon steel and zinc substrates. To increase the corrosion resistance of the coatings, two different approaches were considered: (i) the use of mesoporous silica-nanocontainers impregnated with a corrosion inhibitor (tannic acid) introduced into the polystyrene matrix and (ii) direct impregnation of polystyrene coatings with the same corrosion inhibitor. The impregnated nanocontainers were characterized by Transmission Electron Microscopy. The thickness and the adhesion of the coatings were measured, and their corrosion behavior was investigated by Electrochemical Impedance Spectroscopy. Results showed that the used inhibitor slightly decreased adhesion, but significantly increased the corrosion resistance of the coatings. The direct introduction of tannic acid into the polymer matrix offers higher corrosion resistance than in the case of polystyrene coatings doped with impregnated silica nanocontainers.

Fluidization‐based chemical vapour deposition for alumina coating on tubular carbon steel substrates—Modelling and validation

AbstractThe degradation of carbon steels due to corrosion and gaseous permeation phenomena can be significantly reduced by a thin alumina coating. Tubular carbon steel structures, commonly employed in nuclear establishments are particularly vulnerable to chemical degradation on the inner surface due to the flow of corrosive fluids. In the present work, a fluidization‐based chemical vapour deposition process is applied as a one‐step solution for simultaneous chemical passivation of both inner and outer substrate surfaces meanwhile optimizing precursor inventory by utilizing fluidized bed sublimation and induction heating techniques. The process is studied by using a 2D‐1D mathematical model, which has been validated with experimental results for different carbon steel grades. It was observed that there exists an optimum fluidization velocity for a specified initial mass fraction of precursor powder at which mass of alumina deposited per unit mass of precursor sublimated is maximized.

Fatigue Bending of V-Notched Cold-Sprayed FeCoCrNiMn Coatings

Cold-spray coatings were produced by FeCoCrNiMn high-entropy alloy powders deposited on carbon steel substrate. The coatings were realized at intermediate temperature and high pressure (at 1100 °C and 7 MPa). The coating microstructure was characterized by scanning electron microscopy and X-ray diffraction, revealing a very dense deposition and high flattening ratio of the splatted particles. This had a large influence on the strong adhesion of the coating to the substrate. The hardness and residual stress profiles were measured through nanoindentation and X-ray diffraction from the peak broadening measured layer by layer. The cyclic behavior of the coatings was evaluated through three-point bending tests performed on V-notched samples coated via cold spray. Cyclic tests were performed at different maximum strokes from 0.3 to 3.6 mm in order to monitor the crack initiation and propagation during bending tests. The fracture surface aspect was analyzed by scanning electron microscopy in order to reveal the fracture mechanisms in different deformation conditions.

Study on fatigue properties of post-fire bimetallic steel bar with different cooling methods

Bimetallic steel bars (BSBs) composed of cladding (stainless steel) and substrate (carbon steel, also called black steel) are produced to improve the durability of reinforced concrete (RC) structures. Fire has a lasting effect on reinforcing steel. To assess the service ability of RC structures experiencing fire incidents, fatigue performances of BSB subjected to different exposure temperatures and cooling methods were investigated experimentally. After the heating test, the stainless steel cladding was tightly connected to the carbon steel substrate. When subjected to cooling in air (CIA), the metallographic structures of the substrate in the test specimens after 800 and 900 °C consisted of ferrite and lamellar and granular pearlite. Additionally, martensite was formed because of the quenching process caused by cooling in water (CIW). For BSB specimens subjected to CIA, the effect of temperature on the hysteresis curve is relatively small. When temperature exceeds 700 °C, the cyclic curve of test specimens subjected to CIW becomes slender. Failure performances of BSB specimens with different cooling methods were discussed. A predictive model was suggested to quantify the low-cycle fatigue properties of BSB specimens. Variation trends of stress and strain coefficients were discussed to reveal low-cycle fatigue performances comprehensively.

Studying the effect ZnONP Deposited on ST37-2 by Pulse Laser Depositions Technique for Corrosion Protection Using in Oil Storage Applications.

In the study, zinc oxide nanoparticles (ZnONP) were coated on carbon steel substrates via pulse laser deposition (PLD) process, in order to achieve passive layers of nanocoating. ST37-2 a type of steel is used in the manufacture of tanks that are used in oil applications, which suffers from corrosion, this will lead a large losses. Electrochemical technique (Tafel polarization completion) has been carried out for study the corrosion behavior of this steel coating type. The specimens of steel were examined in aqueous solution containing about 3.5 wt. % NaCl using polarization method, with power of hydrogen (pH) held to value 4.0, in order to evaluated the corrosion rate. ZnONP. Characteristics and topographic nanocoating by PLD technique were evaluated by Field Emission Scanning Electron Microscope (FESEM) and X-ray Diffraction (XRD) tests. Where semi uniform nanoparticles of ZnONP were achieved with a nanoscale approximately ranging from 33-56 nm, While XRD pattern indicated the presence of ZnONP with different crystal structures. In other side the input parameters of (PLD) technique were substrate temperature, number of pulse and fluencies energy have been examined, in order to study their influence on the rate of corrosion reduction. The results indicate that number of shoots pulse has a significant effect the corrosion rate in operation of PLD technique, which is highest among the contributions of the other parameters. Enhancement about 56% is achieved of ST37-2 coated with (ZnONP) deposition, as compared with uncoated steel.

Newly synthesized quaternary ammonium bis-cationic surfactant utilized for mitigation of carbon steel acidic corrosion; theoretical and experimental investigations

New quaternary ammonium bis-cationic surfactant namly; 4,4′-(((1Z,5Z)-pentane-1,5-diylidene)bis(azaneylylidene))bis(1-dodecyl-1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-1-ium bromide (QABCS) was synthesized and characterized via various spectral techniques. Surface tension measurements were performed for the investigation of surface-active parameters. QABCS's effectiveness as a corrosion inhibitor for carbon steel (CS) in 1.0 M HCl was evaluated using a variety of techniques. Inhibition potency progresses via rising QABCS dose while decreases with the temperature increasing. QABCS boosts the impedance of CS corrosion via 94.67% at 1 × 10−3 M. In addition, QABCS adsorption is consistent with Langmuir dsorption isotherm model. QABCS regards a mixed-type inhibitor. The explanation of density-functional theory (DFT) and Monte Carlo (MC) findings shows that the QABCS compound has a high adsorption potential on CS surface due to active centers in the QABCS' molecular structure. According to the scanning electron microscope (SEM) and atomic force microscope (AFM) findings, QABCS creates a shielding layer over carbon steel substrate. Theoretical discussions, as well as SEM and AFM findings, are compatible with laboratory corrosion assessment studies.