Steel Substrate Research Articles

Prediction of HVAF thermal spraying parameters and coating properties based on improved WOA-ANN method

In this study, high-velocity air fuel (HVAF) thermal spray technology was utilized to deposit Hastelloy C276 powder onto 316L stainless steel substrates. The effects of various spray process parameters such as propane pressure, air pressure, spray distance, and powder feeding rate on the microstructure, microhardness, and corrosion resistance of the coatings were investigated. In addition, the coupling effects among multiple spray parameters were considered by employing a combined approach with the Improved Whale Optimization Algorithm (IWOA) and Artificial Neural Network (ANN) model, and the mapping relationships between the spray process parameters and coating porosity, microhardness, and corrosion current density was established. The results revealed that the prepared C276 coating exhibits lower porosity, higher microhardness, and exceptional corrosion resistance. And the IWOA-ANN model outperforms the ANN model and WOA-ANN model in the prediction accuracy and stability for all three performance measures, particularly for porosity and microhardness. Furthermore, the comparison between experimental results and predicted results validates the reliability and accuracy of the trained IWOA-ANN model, demonstrating its efficacy in predicting HVAF spray parameters and coating properties.

Corrosion behavior and mechanism of FeCoNi high-entropy alloy compared with X100 pipeline steel in a simulated alkaline soil environment

In this work, the corrosion behavior of FeCoNi HEA and X100 pipeline steel in a simulated Golmud soil environment was systematically studied utilizing electrochemical tests, surface analysis techniques and immersion measurement. The results indicate that FeCoNi HEA possesses superior anti-corrosion property than X100 steel by comparing the charge transfer resistance (Rct), passive current density (ip) and corrosion morphology. The microstructure and surface film are the principal factors causing the difference in corrosion resistance of the two alloys. More intact, uniform and dense passive film enhances the anti-corrosion performance of the HEA, while the nonprotective, loose and defective corrosion product film covering the surface of X100 steel is not conducive to inhibiting the corrosion of the steel substrate. The appearance of inclusions within the HEA can generate the micro-galvanic corrosion effect with the matrix, which promotes the substrate as an anode to induce pitting. Furthermore, multiple phases of X100 steel exhibits higher electrochemical activity compared to the HEA with a single Face Center Cubic (FCC) phase, which accelerates the corrosion of the steel. Moreover, the matrix of the HEA primarily experiences selected dissolution of Ni element.

Investigating the Electrocatalytic Oxygen Evolution Reaction of Hydrothermally Synthesized NiFe2O4 Nanoparticles

In this study, nickel ferrite (NiFe2O4) nanoparticles were synthesized using the hydrothermal method at various pH values. The objective was to investigate the influence of pH variation on particle size and electrocatalytic activity. The formation of cubic phase nanoparticles was confirmed through X-ray diffraction (XRD) analysis. To characterize the electrochemical properties, the nickel ferrite nanoparticles were coated onto a stainless steel substrate using the doctor blade technique. The microstructural analysis was conducted using scanning electron microscopy (SEM). The samples were further analyzed using linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). The average crystallite size, determined from the XRD pattern, was approximately 40 nm. SEM images revealed a conversion from nanoplates to a granular morphology. The synthesized electrode exhibited an overpotential of 392 mV at 10 mA/cm2 and demonstrated good stability for 5 hours. These findings highlight the excellent electrocatalytic activity of nickel ferrite nanoparticles for the oxygen evolution reaction (OER).

Effect of atmosphere on the high-temperature interaction of molten Mg-10Ca alloy with steel substrates

Effect of atmosphere on the high-temperature interaction of molten Mg-10Ca alloy with steel substrates

Assessment of HVAF thermally sprayed coatings: Unraveling microstructural, electrochemical, and tribological performance using glass former Fe-Cr-Mo-Nb-B feedstock powder

In this paper the microstructural features of the glass former Fe68Cr8Mo4Nb4B16 coatings are unveiled and related to their electrochemical and tribological responses. The coating was mostly glassy with some embedded borides (M3B2, M2B-tetragonal; M being the metallic elements of the alloy) and ferrite. The tribological behavior of the HVAF coated sample, characterized by a thickness of about 200 µm, ∼6% porosity and a Vickers hardness of 357 HV0.5, was assessed in a sphere-on-plate configuration, revealing a specific wear rate of approximately 5 ×10−4 mm3∙N−1m−1. The wear mechanism was dominated by delamination caused by fragile intersplats. The corrosion resistance of HVAF coatings was evaluated in 0.6 M NaCl solution and compared with the results obtained for the crystalline Fe68Cr8Mo4Nb4B16 ingot, produced by melting in an induction furnace, and for the AISI 1020 steel substrate. The HVAF coating showed satisfactory corrosion resistance compared to the carbon steel substrate and the crystalline ingot, with the highest corrosion potential, Ecorr, values (−533 mVSCE) and the lowest corrosion current density, icorr, (10−6 A∙cm−2) followed by a clear passivation window upon anodic polarization in 0.6 M NaCl solution. Evaluations of HVAF coating showed a higher glassy content compared to the gas-atomized feedstock powders. This suggests that during spraying, certain particles were molten and experienced cooling rates adequate to inhibit crystallization, resulting in the freezing of the supercooled liquid. This phenomenon contributes to the good corrosion resistance observed in the present work and offers an opportunity to enhance the electrochemical behavior of HVAF coatings.

Erosion behaviour of low-pressure cold-sprayed Ni coatings for concentrating solar power receivers

Nickel-based coatings provide outstanding wear and erosion resistance making them particularly suitable for several applications, from aerospace and naval to automotive, energy, and electrical. Cold spray (CS) is encountering a growing interest as a promising technology to deposit thick and dense coatings for components used in energy power generation systems, such as the concentrating solar power (CSP) plants. In this article, nickel coating was deposited onto steel substrates by using a low-pressure CS. The erosion behaviour of the coating was evaluated by a solid particle impact test at two different impact angles. The coating erosion rate was 10 × 10−4 at a 60° impact angle, showing a combination of ploughing and cutting mechanisms.

Wear Resistance Behavior of Low-, Mid-, and High-Phosphorus Electroless Ni-P Coatings Heat-Treated in the Air Environment

The high-temperature heat treatment of electroless nickel–phosphorus (Ni-P) coatings in an air environment, and its consequences have scarcely been investigated. This work investigated tribological characteristics of the high-temperature, heat-treated, electroless Ni-P coatings on steel substrates with low-, mid-, and high-phosphorus content for which the average phosphorus content was 2.4 wt.%, 7.1 wt.%, and 10.3 wt.%, respectively. X-ray fluorescence and energy dispersive spectroscopy were implemented to determine the phosphorus content of the coatings. The oxidation of Ni and the formation of the NiO layer on the coating surface was confirmed by the X-ray diffraction technique. A reciprocating sliding method on a ball-on-flat system was utilized to evaluate the coating’s friction and wear behavior. Among the coatings with varying phosphorus content, a high hardness of 1086 HV was found for high-phosphorus coating when heat-treated at 400 °C in an air environment, and that was decreased to 691 HV when heat-treated at 650 °C. The oxidation of nickel in the electroless Ni-P coating occurred when heat-treated at 400 °C in an air environment, and this phenomenon was increased more when the temperature was increased to 650 °C. The characteristics of the NiO layer that formed on the surface of the heat-treated electroless Ni-P coating were influenced by the concentration of phosphorus, which caused different colors of NiO to be seen on the Ni-P coating surface. A greenish black NiO layer on the low-phosphorus and black NiO layer on the mid- and high-phosphorus Ni-P coating was developed during heat treatment at 650 °C in an air atmosphere. The adhesion and tribological characteristics of the Ni-P coatings were affected by the NiO layer developed on the heat-treated Ni-P coating surfaces. The Ni-P coatings with mid- and high-phosphorus content showed enhanced wear-resistance characteristics when they underwent heat treatment in an air atmosphere at the high temperature of 650 °C. The wear volume obtained for as-plated mid-phosphorus and high-phosphorus Ni-P coatings was 0.111 mm3 and 0.128 mm3, respectively, and that was reduced to 0.031 mm3 and 0.051 mm3, respectively, after the high-temperature heat treatment.

Investigation of the Compound Strength of Hybrid Casting Components with Different Variations of Coated and Undercut Sheet Metal

AbstractLightweight design can reduce CO2 emissions and improve energy efficiency, especially in the fuel-intensive transportation sector. Multi-material design approaches can combine specific properties of materials for effective lightweight design. A multi-material component made from two metals used widely in industry could combine the exceptionally lightweight properties of aluminum with the strength and structural integrity of steel. However, joining aluminum and steel is a challenge due to their different thermo-physical properties and the possible formation of brittle intermetallic phases. In hybrid casting, aluminum is cast around a steel sheet insert in a high-pressure die casting process to produce complex parts. In a first approach, a cold gas sprayed aluminum coating on the insert was tested as a bonding agent between the steel substrate and the molten aluminum. The joint was achieved by a combination of metallurgical bonding and micro-clamping. As a second option, surface structures with undercuts were applied to the steel sheet by modified cold rolling, which allowed the molten aluminum to flow into the channels and interlock with the solid steel. Different orientations of the structure on the insert were tested. In addition, the combination of both approaches was used to potentially enhance the positive effect of the pretreatment techniques. Given the critical importance of joint strength, the quality of these approaches was tested by static tensile tests and dynamic fatigue tests. The results show that the joint by coatings is strongly influenced by the process temperature. The improvement of the joint by the surface structure depends on its orientation to the melt flow.

Mechanical and Tribological Behavior of Nitrided AISI/SAE 4340 Steel Coated with NiP and AlCrN

In this study, novel surface engineering strategies to improve the wear performance of AISI 4340 were investigated. The strategies were as follows: (i) NiP deposition on a previously nitrided steel substrate, followed by NiP interdiffusion heat treatment at either 400 °C or 610 °C (referred to as duplex treatment); (ii) the deposition of AlCrN PVD coating on NiP layers on a previously nitrided steel substrate (referred to as triplex treatment). Prior to the deposition of AlCrN, the NiP was subjected to the interdiffusion heat treatment at either 400 °C or 610 °C. These strategies were compared with the performance of the AlCrN coating directly applied on nitrided steel. To characterize the microstructural features of each layer, X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) analysis were conducted. We also carried out mechanical and tribological behavior assessments. The tribological tests were carried out using a ball-on-disc tribometer under a constant load of 20 N and a tangential speed of 25 cm/s; cemented carbide spheres with a diameter of 6 mm were the counterpart body. The friction coefficient was continuously monitored throughout the tests. The results reveal that the wear mechanism for the AlCrN coating is predominantly oxidative. The most wear-resistant surface architecture was the one comprising AlCrN over the NiP layer subjected to interdiffusion heat treatment at either 400 °C or 610 °C.

Catalysis effect of rare earth element Ce on paste boriding treatment of AISI 410 steel

Abstract Surface hardening techniques of steel are of great practical interest for applications in various industrial sectors. Boriding is one of the most economical choices. However, the chief deterrent to the widespread application of the technique is the difficulty in attaining a thick, dense boride layer. To solve this problem, a paste boriding process was performed on the surface of AISI 410 steel by introducing 6 wt.% CeO2 addition into the boriding agent. The microstructure of the boride layer is comprised of (Fe, Cr)B and (Fe, Cr)2B, which lie in the external and internal layers of the boride layer, respectively. CeO2 addition makes it possible to prepare a thick, dense boride layer on the surface of the steel substrate, thereby improving both wear and corrosion resistance of the steel. The catalysis mechanism of the rare earth element Ce can be ascribed to three aspects. First, CeO2 addition can take part in the chemical reactions involved in the boriding process to produce more active boron atoms. Second, Ce can facilitate the adsorption of active boron atoms onto the surface of the steel through preventing the formation of iron oxides on the steel’s surface. Third, Ce can diffuse into the surface of the steel and generate severe lattice distortion due to large atomic size, thereby promoting the boron diffusion. These results provide a high-quality, low-cost pathway for the surface hardening of steel in practical industrial applications.

Investigating replacement core-shell strategies for optimizing photocatalytic chromium reduction with MOF-on-MOF heterostructure on steel mesh

While cerium-based metal-organic frameworks (Ce-MOFs) exhibit inherent limitations in standalone photocatalytic efficacy, their potential amplifies when integrated into heterostructures with other semiconductors, leveraging the advantageous heterojunction effects. This study systematically explores the establishment of heterojunctions between Ce-MOFs and zirconium-based frameworks, delineating the performance variance based on the positioning of Ce-MOFs within the MOF-on-MOF architecture. When situated as the outer shell in these configurations, Ce-MOFs significantly enhance the photocatalytic capabilities compared to their placement in the core. Further, immobilizing these composite structures onto steel substrates demonstrates remarkable efficiency in the purification of hexavalent chromium from water under visible light exposure. Initially, Ce-MOF-801-on-Zr-MOF-801 and Zr-MOF-801-on-Ce-MOF-801 heterojunctions were synthesized to explore their combined and MOF-on-MOF effects. Subsequently, Ce-MOF-801-on-Zr-MOF-801 was applied onto a steel mesh substrate using the spraying method. The results demonstrated exceptional efficiency in Cr(VI) extraction and remarkable durability. Crucially, leaching tests and ICP-OES analysis confirmed the material's strong adhesion to the substrate, enabling repeated use. Impressively, even after multiple cycles, the material efficiently purified Cr(VI) from water within 120 min under visible light. With all these merits, the Cr(VI) removal efficiency of Ce-MOF-801-on-Zr-MOF-801/mesh with an initial Cr(VI) concentration of 5 ppm is near 100% for 2 h. This work presents a feasible and promising route to filter suitable photocatalyst materials by using mesh substrates for fixing environmental issues.

On the Possibility of Improving the Oxidation Resistance of High-Chromium Ferritic Stainless Steel Using Reactive Element Oxide Nanoparticles

AbstractHigh-chromium ferritic steels are current the only viable candidates for cheap interconnect materials for application in high-temperature solid oxide fuel and electrolyzer cells (HT-SOFCs/SOECs). The durability and operating characteristics of interconnects manufactured using these materials may be improved significantly by applying a protective-conducting MoCo2O4 coating and depositing an intermediate layer consisting of nanoparticles of Gd2O3—a reactive element oxide—on the surface of the steel substrate. The study demonstrated that the conditions of the thermal treatment of this layered system determine the efficacy of the applied modification with the reactive element. The persistence of this effect was tested over 7000 hours of quasi-isothermal oxidation in air at 800 °C.

Micro-structures and dry sliding wear properties of novel AlCrFeNiMo0.5-x(WC) high entropy alloy-ceramic composite coatings

Based on the problems of micro defects (cracks, pores, etc.), uneven distribution of strengthening particles, and poor bonding between strengthening particles and metal matrix in practical engineering applications, the new AlCrFeNiMo0.5-x(WC) (x = 0, 5, 15, 30 wt%) composite coatings have been designed, and further prepared using laser cladding. Their micro-structures, micro-hardness and dry sliding wear properties were deeply explored. They exhibited the dendritic morphologies and consisted of BCC1, BCC2, and carbide phases. The AlCrFeNiMo0.5-30 wt%(WC) coating had the highest hardness (772 HV), which was approximately 5 times that of Q235 steel substrate. With the increase of WC content, dry sliding wear properties showed an increasing trend, that is, AlCrFeNiMo0.5-30 wt%(WC) coating had the lowest friction coefficient (0.50) and wear rate (9.23 × 10−6 mm3/(N · m)), exhibiting excellent tribological properties, which was attributed to the coupling effect of hard carbide and ductile BCC phases. It would be a promising wear-resistant coating material under dry sliding environment. This study not only has significant theoretical significance for understanding the failure patterns and performance evolution of new high entropy alloy/WC composite coating materials in dry sliding environments, but also demonstrates important value for expanding the application of new high entropy alloy/WC composite coating materials in practical engineering.

Electrodeposited ZIF-67 reinforced polypyrrole coating on ferritic stainless steel substrate with durable anticorrosion performance

The harsh acidic environment containing chloride ions has created serious corrosion hazards for ferritic stainless steels. Zeolitic imidazole frameworks (ZIFs) are a promising material for corrosion protection due to their microstructural and physicochemical properties. In this study, we proposed the electrodeposited ZIF-67 reinforced polypyrrole (PPY) coating (PPY/ZIF-67) for corrosion protection of 430 ferritic stainless steel (430SS). The morphology, microstructure, and anticorrosion behavior of the pristine PPY and hybrid PPY/ZIF-67 coating systems were characterized. The successful electrodeposition of ZIF-67 nanoparticles on the surface of the PPY layer resulted in a uniform distribution and a compact coating structure, which contributed to the overall uniformity of the coating and enhanced both the barrier and activity inhibition functions of the coating. The protective performance of PPY/ZIF-67 coatings was evaluated through electrochemical tests, the results indicated that the anticorrosion efficiency of PPY/ZIF-67 coating (with 0.4 mol/L pyrrole monomer content) reached to 99 %, and the coating demonstrated a durable corrosion protection ability (744 h) in 0.1 mol/L HCl solution. Such performance of can be attributed to the combined effect of the anodic protection provided by the inner PPY film, the active corrosion inhibiting properties of the ZIF-67 nanoparticle layer, and the hindrance of aggressive species by the compact coating structure over the prolonged service time.

Multi-Pass Laser Polishing of As-Built Directed Energy Deposition Surfaces

Abstract Laser polishing (LP) provides a fast and efficient way of remelting part surfaces manufactured by additive manufacturing to alter both their geometric as well as physical properties. Depending on the laser parameters, remelted surfaces with different properties are achieved, with a majority exhibiting lower surface roughness compared to the original surface. In this study, a high-power continuous fiber laser is used to polish Inconel 718 (IN718) surfaces produced by depositing a single layer of clads on a steel substrate by the powder-blown directed energy deposition (DED) process. Polishing was performed under different sets of parameters, namely, laser power, beam diameter, feed rate or feed, hatch spacing, and the number of polishing passes. Their effects on the surface roughness profiles and the microstructural properties of the sample cross section were analyzed after one and two polishing passes. Optical microscopic images of the sample's cross sections show the presence of supersaturated γ phase particles, γ′+γ″ precipitates, Laves phases, and δ phase needles. The combined effect of high-temperature gradients and lower solidification rates in certain regions within the cross section results in undercooled regions and pseudo-heat treatment of unmelted regions close to the undercooled regions. These results are corroborated by indenting the various regions of the IN718 sample cross section with a pyramidal diamond indenter in the form of a grid, resulting in different micro-hardness values due to different densities of precipitate and phase transformed δ particles.

Dual-Function Hybrid Coatings Based on Polytetrafluoroethylene and Cu2O for Anti-Biocorrosion and Anti-Wear Applications

Corrosion and wear issues of motion components exposed to water-based corrosion mediums, e.g., naval vessels and oil extraction equipment, pose challenges for the lifespan and reliability of the motion systems. In this work, epoxy-based coatings modified with polytetrafluoroethylene (PTFE) and cuprous oxide (Cu2O) nanoparticles were prepared. The anti-corrosion performance of the coatings was comparatively investigated by electrical impedance spectroscopy and Tafel tests in sterile and sulphate-reducing bacteria (SRB) mediums. Moreover, the tribological behaviors of the coatings were examined under water lubrication conditions. Our results demonstrate that the epoxy coatings lower significantly the corrosion current density icorr and the charge transfer resistance of the electrical double layer Rct of the carbon steel substrate. Interestingly, the hybrid coatings filled with both PTFE and Cu2O exhibit excellent anti-corrosion and anti-wear performance. After being immersed in the SRB medium for 18 days, the icorr of the pure EP coating and hybrid coatings are 1.10 × 10−7 Amp/cm2 and 0.3 × 10−7 Amp/cm2, and the Rct values are 1.04 × 103 Ω·cm2 and 3.87 × 103 Ω·cm2, respectively. A solid tribofilm forms on the stainless steel counterface sliding against the hybrid coating, which is surmised to be essential for the low friction coefficients and wear. The present work paves a route for formulating the dual-function coatings of anti-biocorrosion and anti-wear.

Enhanced Supercapacitive Performance in Catalyst‐Free Binary Composite SnO2–RuO2 Nanostructured Thin Films for Symmetric Supercapacitor Device

In the present work, thin film electrodes of ruthenium oxide (RuO2), tin oxide (SnO2), and their composite SnO2–RuO2 are deposited on 304 stainless steel substrates using pulsed laser deposition (PLD). These nanostructured electrodes are then evaluated for their suitability in electrochemical energy storage applications. A symmetric supercapacitor device (SSD) is constructed using the SnO2–RuO2 composite electrodes. Compared to individual SnO2 and RuO2 electrodes, the composite electrodes exhibit enhanced specific capacitance and cycle life. This improvement is attributed to modifications in surface morphology and electronic properties. This modified surface morphology of the composite electrode, creates favourable conditions for electrolyte interaction and ion transport, ultimately contributing to the observed increase in specific capacitance. Specifically, the composite electrode demonstrates a specific capacitance of 170.2 Fg−1 at a current density of 0.1 mA cm−2, outperforming SnO2 (37.4 Fg−1). The SnO2–RuO2//SnO2–RuO2 SSD exhibites a specific capacitance of 70.0 Fg−1 at a current density of 0.1 mA cm−2, coupled with energy density and power density values of 19.05 Wh kg−1 and 645 W kg−1, respectively, within a voltage window of 1.4 V. The SSD displays an impressive capacitive retention of 81.27% over 10 000 cycles, indicating its potential for practical energy storage applications.

Three-dimensional ordered FeTe-SmCoO3 nanocomposite: As efficient electrocatalyst for water oxidation

In this work, FeTe-SmCoO3 is fabricated through a hydrothermal method and then coated on a stainless steel (SS) substrate to enhance the electrocatalytic performance. The crystal structure, surface chemical state, and morphological features of pure (FeTe and SmCoO3) and heterogeneous catalysts (FeTe-SmCoO3) are determined via XRD, XPS, and TEM/EDX techniques. The fabricated FeTe-SmCoO3 electrocatalyst is attributed to the particular morphological design resulting from the synergistic effect of FeTe and SmCoO3 phases. The as-developed high exposure level of active sites with structural transformation greatly promoted the oxidation property with an overpotential only of 199 mV to derive a current density of 10 mA/cm2, also observed a small Tafel slope of 72 mVdec−1 with extraordinary stability of 90 h. The modified heterogeneous catalyst provides outstanding catalytic behavior toward OER in the alkaline solution, due to flexibility and multiple accessible oxidation states of samarium, cobalt, and iron ions. The catalyst not only acquires additional reaction sites and opens up new channels through the dispersion of the metal centers, but also achieves quick electron transfer in FeTe-SmCoO3 nanocomposite through the interconnection between two phases.

Study of Ultrasound Effect on Macrophyte Fouling of Artificial Substrates as a Way to Control Bio-Damage in NPP Water Supply Systems

The results of the study of ultrasound influence on the formation of macrophytoperiphyton on steel and concrete substrates in field conditions (sea water area) are presented. On the example of macroalgae in the conditions of full-scale experiment the ability of ultrasound to complicate, but not completely inhibit the development of plant colonizers is shown. The greatest sensitivity to the impact of ultrasound is shown by red algae. It is recommended to expand the experiments with the use of ultrasound installation of higher power in order to assess the effect of ultrasound on different groups of algae during the operation of NPP.

Effect of alloy 625 buffer layer on corrosion resistance of nickel base hardfacing

Nickel base hardfacing alloys serve to mitigate corrosion losses at elevated temperatures. Efficacy of Nickel base hardfacing alloys can be compromised when applied onto Fe base substrates due to iron dilution in hardfacing. The degree of Fe dilution can be reduced by using advanced deposition methods and optimized deposition parameters. Gas Tungsten Arc Welding (GTAW) method is commonly employed for its cost-effectiveness and versatility, but it tends to induce higher Fe dilution due to increased heat input. This study aims to reduce the degree of Fe dilution and enhance corrosion resistance by introducing a nickel base buffer layer (alloy 625) between the nickel base hardfacing alloy and AISI 316L stainless steel substrate. For comparative purposes, Ni base hardfacing alloy was deposited on the substrate without any buffer layer. Hardfacing depositions were prepared using manual GTAW process. Process parameters namely, deposition current, voltage, travelling speed, pre-heating temperature, and cooling method were kept constant. Samples underwent aging at 1123 K for 4 h, followed by microstructural examination via optical and scanning electron microscopes. Iron (Fe) dilution quantification was performed using energy dispersive spectroscopy (EDS). The EDS analysis showed that the use of buffer layer between the hardfaced deposit and the substrate decreased the degree of Fe dilution in the hardfaced deposit. X-Ray diffraction (XRD) analysis was performed to identify various phases formed in the hardfaced deposit. Potentiodynamic polarization test was performed to assess the corrosion resistance of hardfaced deposit in 3.5 wt% NaCl solution. Results show significant improvement in corrosion resistance of hardfacings deposited sample with buffer layer as compared to those without buffer layer. Aging treatment further enhanced corrosion resistance. The corrosion resistance data is correlated with the microstructure and phases formed in various samples.