Stability Of Passive Film Research Articles

Effect of overlap rate on the microstructure and properties of Cr-rich stainless steel coatings prepared by extreme high-speed laser cladding

In this work, Cr-rich stainless steel coatings at different overlap rates were prepared by extreme high-speed laser cladding (EHLA) technology, and microstructures, elemental distributions, phase compositions, electrochemical corrosion behaviors, and frictional wear properties were analyzed. The results indicated that increasing the overlap rate enhanced the coating's surface quality and microstructural density. The grain sizes of the coatings at overlap rates of 60 %, 70 %, and 80 % were 2.63 μm, 2.08 μm, and 1.14 μm, respectively. The coatings were predominantly composed of martensite and residual austenite, and residual austenite was extensively distributed within the coatings with a high overlap rate. Electrochemical corrosion results revealed that the coating with an 80 % overlap rate exhibited the best corrosion resistance, with a transfer resistance (Rt) of 981.05 kΩ·cm2 and a passive film resistance (Rc) of 227.31 kΩ·cm2, surpassing other coatings. Under the load of 5 N, the coating's wear rate at 80 % overlap rate was 3.91 × 10−6 mm3/N·m, demonstrating excellent wear resistance. The dense microstructure and refined grain structure assisted the coating in forming a stable passive film during the corrosion stage. The enhancement in coating hardness promoted the rapid development of the oxide film, thereby strengthening the coating's wear resistance properties.

Corrosion behavior of SiC/Ti6Al4V titanium matrix composites fabricated by SLM

In this paper, Ti6Al4V alloy and Ti6Al4V-SiCw composites were formed by selective laser melting (SLM) and electrochemical corrosion experiments were carried out. The effects of different SiCw contents and solid solution aging heat treatment on the corrosion properties of the composites were systematically studied, and the corrosion mechanism of Ti6Al4V-SiCw composites was revealed. The results show that Ti6Al4V-1SiCw composites have better corrosion resistance than Ti6Al4V alloy. After solution and aging heat treatment at 1050 °C, Ti6Al4V-1SiCw composites have better corrosion resistance. The main reasons for the improvement of the corrosion performance of the composites are as follows: (i) The high-density grain boundaries formed by grain refinement of the composites have higher energy and are more likely to react to form a stable passivation film. (ii) The microstructure of Ti6Al4V-SiCw composites is equiaxed α phase, which is easier to form stable passivation film than metastable α′-Ti phase. (iii) The presence of ceramic particles makes more microcells formed in the titanium matrix, which promotes the formation of soluble [TiCl6]2- complexes. The formation of passivation film on the surface of Ti6Al4V-SiCw composites was accelerated.

Corrosion mechanisms of Zr-based bulk metallic glasses in NaBr solution

In this paper, the corrosion mechanisms of Zr55Cu35Al10 and Zr56Co28Al16 bulk metallic glasses (BMGs) in 3.5 wt.% NaBr solution was systematically investigated by the kinetic potential polarization and electrochemical impedance spectroscopy. Both Zr55Cu35Al10 and Zr56Co28Al16 BMGs were subjected to pitting damage during the polarization process in NaBr solution due to the presence of Br− ions. However, Zr56Co28Al16 BMG exhibits better corrosion resistance compared to Zr55Cu35Al10 BMG. Zr55Cu35Al10 BMG experiences selective dissolution of alloying elements under the attack of Br−, and Cu element was enriched in the corrosion pit. The surface of Zr56Co28Al16 BMG shows a more uniform distribution of elements after corrosion. Simultaneously, the substitution of Cu by Co changes the composition of the passive films and increases the relative content of ZrO2, which is a principal factor contributing to the enhanced stability of Zr56Co28Al16 BMG's passive film.

Anodic Electrochemical Behaviors of 2219 Aluminum Alloy in NaNO3 and NaCl Electrolytes

Because to its exceptional performance, 2219 aluminum alloy is extensively employed in the aerospace sector for large thin-wall structures. However, the machining of such structures commonly results in issues like chatter and deformation, making electrochemical machining (ECM) the preferred method. The primary focus of ECM for anode materials involves understanding their behavior during the electrochemical dissolution process. The anode electrochemical behavior of 2219 aluminum alloy in 10 wt% NaNO3 electrolyte and 10 wt% NaCl electrolyte is reported for the first time. Passivation-related characteristics and interface structures were assessed through linear sweep voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy curves. The growth and composition of passivated films were determined through open-cricuit potential and X-ray photoelectron spectroscopy analyses. Results indicate that in NaNO3 electrolyte, a thicker and more stable passivation film forms, enhancing corrosion resistance and inhibiting material dissolution. ECM tests reveal pitting in 2219 aluminum alloy under low current density, with the oxide layer breaking at higher densities. Notably, ECM of 2219 aluminum alloy with NaNO3 electrolyte yields superior surface morphology, evident in both microstructure and macro-morphology.

Corrosion Behavior of Nacre-Inspired (TiBw-TiB2)/Al Composites Fabricated by Freeze Casting.

Nacre-inspired metal matrix composites have received much attention due to their excellent deformation coordination ability, which can achieve the synergy of strength and ductility. The preparation of nacre-like Al matrix composites by freeze casting has been a promising application, but the continuous ceramic-rich layer affects the corrosion resistance of the composites, facing complex corrosion problems during service. In this work, the microstructure and corrosion behavior of the nacre-inspired (TiBw-TiB2)/Al composites fabricated by freeze casting and squeeze casting were systematically studied. The results indicated that the Al layers and ceramic-rich layers had little change, about 35 μm and 31 μm, respectively, with an increasing ratio of the Ti/TiB2. Meanwhile, a high Ti/TiB2 ratio resulted in an increase in the Fe-Ti intermetallic phases, which was detrimental to the corrosion performance of the composites and was prone to pitting. The electrochemical test results showed that the 3Ti7TiB2 composite had the lowest corrosion current density (15.9 μA) and intergranular corrosion depth (231 μm), indicating that it had the best corrosion resistance, which can be attributable to its stable and dense passivation film. Two different corrosion phenomena during the intergranular corrosion test existed in the present nacre-inspired (TiBw-TiB2)/Al composites: intergranular corrosion in the Al matrix layer and pitting corrosion in the ceramic-rich layer. Among all the composites, the corrosion depth of the 3Ti7TiB2 composite was the smallest and significantly less than that of the 2024Al alloy. In addition, the continuous ceramic-rich layer acted as a corrosion channel during corrosion, significantly degrading the corrosion resistance of the nacre-like Al composites.

Enhanced pitting resistance for high-entropy alloys by precipitating nano-sized L12-strengthened phase

Precipitation-strengthened HEAs exhibit outstanding integration of strength and toughness at ambient temperature. Nevertheless, precipitates generally reduce the localized corrosion resistance in aggressive solution environments. To solve this problem, a strategy of introducing nano-sized L12 precipitates in CoCrFeNiAlTi HEAs has been proposed in this work. Results demonstrate the pitting corrosion potential can be elevated from 258 mVSCE to 603 mVSCE by increasing the precipitate content to 38 wt.%. Such an improvement in localized corrosion resistance can be attributed to two aspects. Firstly, L12 precipitates tend to be dissolved during the corrosion process, which promotes the heterogeneous nucleation of protective Cr2O3 due to the rapid deposition of oxides/hydroxides of Al/Ti, and improves the passive film stability due to the Cr-rich FCC matrix. Secondly, the dissolution kinetic inside the pits can be suppressed on account of the enrichment of Cr element in the FCC matrix, thus inhibiting the pitting growth. In summary, the current work not only reveals the mechanisms of the nano-sized L12 precipitates upon the corrosion behavior, but also provides a strategy for designing corrosion-resistant HEA.

First principles calculation and corrosion resistance study of Fe60CrxNi40-x medium entropy alloy

In this paper, Fe60CrxNi40-x medium entropy alloys (MEAs) were synthesized through vacuum arc melting. Based on the plane wave pseudo-potential and density functional theory, the solid solution structure is modeled by virtual crystal approximation (VCA). The first principle method was employed to examine how Cr content affects the phase structure, elastic constant, and elastic properties of the Fe60CrxNi40-x. Physical phase analysis of the MEAs by X-ray diffraction reveals that the Fe60CrxNi40-x maintain a single FCC solid solution structure. Meanwhile, the impact of Cr content on MEAs' resistance to corrosion in a Cl- setting was examined and contrasted with 316 L stainless steel. The result indicated that as the Cr content rises, the MEAs exhibit an extended passivation period, a reduced dimensional passivation current, and a more compact and stable passivation film. When considering the aggregate outcomes of pitting potential (Epit), self-corrosion potential (Ecorr), and corrosion current density (icorr) for 316LSS and MEAs, it's evident that Fe60CrxNi40-x in 3.5 wt% NaCl solution exhibits superior corrosion resistance compared to 316 L stainless steel, with Fe3 alloy leading in corrosion resistance among medium entropy alloys.

Laser remelting of high-velocity arc-sprayed Fe-based amorphous coating for improving corrosion resistance in 3.5 % NaCl solution with varying Na2S concentrations

In this study, high-velocity arc-spraying (HVAS) was employed to produce Fe-based amorphous coatings, and subsequent to that, laser remelting (LR) technology was applied on the as-sprayed coatings (ASC) to prepare laser remelted coatings (LRC). The corrosion resistance of both coatings was tested in 3.5 wt% NaCl solutions containing varying Na2S concentrations (0, 20, 50, 100, and 200 ppm) to accurately simulate the corrosion environment of offshore components. The corrosion behavior was investigated using electrochemical workstation, scanning electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The experimental results revealed that LR resulted in the elimination of defects in Fe-based amorphous coatings, a substantial reduction in porosity, the disappearance of the laminar structure, and the achievement of a homogeneous composition. The corrosion tendency of ASC and LRC both exhibited a pattern of initially decreasing, then increasing and finally decreasing with increasing sulfide concentration. This was attributed to the deposition of corrosion products on the surface and the dissolution of the corrosion products. When the sulfide concentration exceeded 50 ppm, the corrosion current density of both coatings slowly and was lower than that at 20 ppm, indicating that both coatings possessed strong corrosion resistance at higher sulfide concentrations. Highly polarized anions in solution (e.g. HS−, S2−) occupied vacancies in the passivation film, destabilizing the coating's passivation film and consequently diminishing its corrosion resistance. From the electrochemical analysis, it was evident that LRC exhibited greater corrosion resistance than ASC at all sulfide-containing solution concentrations, which was attributed to its smoother surface, denser structure and more stable passivation film.

Effect of early CO2 curing on the chloride induced steel bars corrosion in cement mortars

Early CO2 curing acting as a new curing technique is an effective way to cut down on carbon footprint in cement industry. It also improves the strength development and long-term durability of concrete without reinforcement. Given the fact that reinforcement concrete is most widely used in construction and building fields, the carbon sequestration potential will be enhanced remarkably if this curing technology can be used in reinforced concrete. However, the impacts of early CO2 curing on the corrosion behavior of steels, which is the major concern for reinforced concrete exposure to chloride, is unclear yet. In this work, the permeability of chloride, threshold chloride value and corrosion behaviors of steels in cement mortar were determined to comprehensively study the effect of early CO2 curing on the chloride induced corrosion of steels. Early CO2 curing lowers the chloride ions permeability of mortars, in particular for the mortars with 28 day curing ages. Steels take longer time to form stable passive films in early CO2-cured mortar than in conventional moist-cured ones. Early CO2 curing reduces the chloride threshold concentration of mortar, in particular for the mortars that the whole cross section is carbonated, the reduction reaches ∼50%. However, it exerts few effects on corrosion induction phase of steel rebar. Moreover, early CO2 curing decreases the corrosion rate of steel bars in corrosion propagation phase and thus the overall corrosion rate of steels during the whole testing process due to slower chloride ingress rate. Thus, early CO2 curing can act as an alternative curing technique in the production of pre-cast reinforced concrete exposed to chloride.

Exceptional combination of mechanical properties and cavitation erosion-corrosion resistance in a Fe23.7Co23.8Ni23.8Cr23.7Mo5 multi-principal element alloy

This study analyzed cavitation erosion (CE) and cavitation erosion-corrosion (CE-C) of single-phase face-centered cubic structured Fe23.7Co23.8Ni23.8Cr23.7Mo5 multi-principal element alloy (MPEA) with varying grain sizes obtained through post-deformation annealing (PDA). The average grain sizes of the samples after annealing at 1100 °C for 60 s, 1150 °C for 60 s, and 1100 °C for 200 s are 4.1 µm, 10.3 µm, and 15.2 µm, respectively. Among them, the 4.1 µm sample exhibits the best combination of high ultimate tensile strength (889 MPa) and large elongation (40.3%), as well as good electrochemical corrosion resistance in NaCl solution. Under the conditions of CE and CE-C for a duration of 10 h, the 4.1 µm specimen exhibits cumulative mass losses of approximately 1.4 mg and 2.6 mg, respectively. In contrast, under identical conditions, the 316 L SS registers cumulative mass losses of approximately 16.7 mg and 24.8 mg, respectively. Due to the excellent mechanical properties and work hardening ability of the 4.1 µm sample, it can effectively resist the plastic deformation caused by cavitation erosion, reducing mass loss. In addition, the stable passivation film enhances its resistance to Cl- destruction, thus demonstrating notable corrosion resistance. Ultimately, under conditions where cavitation erosion and corrosion coexist, these combined properties enable the 4.1 µm sample to exhibit the least mass loss and damage.

Effect of Cu addition on the mechanical properties and corrosion behaviours of Al–9.2Mg–0.8Mn alloy

Microalloying is an effective method to improve the properties of Al–Mg alloys. The microstructure, mechanical properties and corrosion behaviours of Al–9.2Mg–0.8Mn– xCu ( x = 0–1.2 wt-%) alloys are studied to promote the application of Al–Mg alloys. The addition of Cu increases the strength of the alloy, where the ultimate tensile strength of 0.6 wt-% Cu alloy is improved by 43 MPa. Moreover, the addition of Cu significantly affects the corrosion behaviours of alloys. For as-sensitised alloys, compared to the matrix, the 0.1 wt-% Cu alloy shows a 28.3% reduction in pitting corrosion mass loss, which is attributed to the Cu element can form a stable passivation film, and the 0.3 wt-% Cu alloy shows a 15% reduction in intergranular corrosion mass loss, which is attributed to the addition of Cu can restrict the β phase precipitation at grain boundaries. The study shows that Cu-alloying can improve the comprehensive properties of Al–9.2Mg–0.8Mn alloys.

Structural and property regulation of double ceramic phase–reinforced AlCoCrFeNiTiZr–based high entropy alloy coatings by pulsed–wave lasers

In-situ synthesis ZrC and TiC reinforced AlCoCrFeNiTiZr–based high entropy alloy (HEA) coatings were successfully synthesized on R60702 using pulsed–laser cladding. The effects of pulse frequency (5, 50, 500, and 5000 Hz) on microstructure evolution, microhardness, wear resistance, and corrosion resistance were investigated. The results demonstrate that the HEA coatings consists of phases including BCC, HCP, and metal carbides (MC). The phase composition and proportion are influenced by changes in pulse frequency. At pulse frequencies of 5 and 50 Hz, the predominant MC phase is ZrC. As the pulse frequency increases, it transitions to a coexistence of ZrC + TiC before ultimately becoming predominantly TiC. Concurrently, the size of the ceramic phase and the proportion of the HCP phase initially decrease, then increase. A pulse frequency of 500 Hz yields optimizations in microhardness, wear resistance, and corrosion resistance. The favorable mechanical properties are attributed to the synergistic effect of solid solution strengthening, fine crystal strengthening, and ceramic phase strengthening. The optimal corrosion resistance is due to the formation of a stable passivation film while local corrosion and galvanic corrosion are weakened.

Effect of microstructure on the corrosion-friction behavior of low-carbon martensitic stainless steel

The effect of microstructure on the corrosion-friction behavior of 11Cr4NiMo steel was investigated for three different microstructure states. Quenched martensite and low-temperature tempered martensite with high density dislocations exhibit severe wear under the dual effects of corrosion and abrasion, and their wear mechanism include three-body wear, adhesive wear, and fatigue wear. While high-temperature tempered microstructure mixed structure of tempered martensite, reversed austenite, and M23C6 carbides exhibits weakened wear. Reversed austenite greatly promotes the generation of a dense and stable passivation film with corrosion product of α-FeOOH, and plays a lubricating role and attenuates three-body wear. Utilizing the passivation film induced by corrosion to improve the wear resistance of materials is of great significance in engineering applications.

Enhancing corrosion resistance of Al50Ni50 alloy by increasing cooling rate plus annealing

Monophasic Al50Ni50 ribbons were fabricated by melt spinning at circumferential speeds (Sc) of 21 and 42 m/s, and subsequently annealed at various temperatures. The microstructure and corrosion behavior of ribbons were studied through various experimental methods. With increasing Sc, the as-spun and annealed ribbons at 42 m/s show a higher (100) crystal orientation factor F(100), a lower barrier to recrystallization and a higher total film resistance than the counterparts with 21 m/s. The as-spun ribbon at 42 m/s demonstrated a denser and more stable Al2O3 passive film compared to the as-spun and annealed ribbons at 21 m/s. This improvement in passive film can be further enhanced by 700 °C annealing. Therefore, the corrosion resistance of AlNi ribbons can be improved by increasing Sc and additional annealing at an appropriate temperature.

One-step in situ preparation of Zr(Ti)-MOFs on titanium alloys at a low temperature of 80 °C and atmospheric pressure

Preparing metal-organic frameworks (MOFs) film in situ on the surface of the Ti-6Al-4V (TC4) titanium alloy is challenging owing to the dense and stable surface TiO2 passive film. In this study, titanium-doped zirconium-based MOFs (Zr(Ti)-MOFs) film was constructed in situ on the TC4 alloy in one step at a low temperature and atmospheric pressure, with ZrCl4 as the source of Zr metal ions. ZrCl4 attacked and dissolved the TiO2 film to form Zr-O-Ti bonds on the surface of TC4 to provide nucleation sites for further reactions. At the same time, Zr4+ and dissolved Ti4+ combined in solution to form Ti containing Zr-O cluster nodes, which aggregated and grafted to the Zr-O-Ti bonds on the substrate surface, and reacted with organic ligands (terephthalic acid) to form Zr(Ti)-MOFs film. The Ti4+ dissolved from the TC4 participate in the Zr-MOFs formation, thereby changing the high temperature and high-pressure conditions required for the traditional preparation of Zr-MOFs (UiO-66). The in situ preparation of Zr(Ti)-MOFs on TC4 was achieved at 80 °C under atmospheric pressure conditions. This study elucidated the growth mechanism of Zr(Ti)-MOFs on the TC4 surface, providing a reference for the design and In-situ preparation of multifunctional MOFs on the TC4 titanium alloy.

Microstructural evaluation and corrosion behaviour of Inconel 82 and Inconel 625 overlays on 304L stainless steel weld used in nuclear fuel reprocessing plant

Weld overlays are considered the most cost-effective surface modification technique to mitigate corrosion in the nuclear industry. Considering this, an attempt to overlay the 304L weld metal at some critical weld locations of the nuclear fuel reprocessing plant with Inconel alloy was initiated. The work focuses on the microstructural evaluation and corrosion behaviour of Inconel 82 and Inconel 625 weld overlays on 304L stainless steel (SS) weld metal in a nitric acid and chloride medium. Scanning electron micrographs of the 304L SS weld metal revealed a duplex microstructure containing δ-ferrite as a minor phase in the austenite matrix. The microstructure of the Inconel 82 and Inconel 625 weld overlays was found to be fully austenitic, with Nb-rich laves phases at the inter-dendritic region. The hardness of the Inconel weld overlays was found to be higher than that of the 304L SS weld metal. X-ray diffraction measurements showed austenite and δ-ferrite in the 304L SS weld metal and a single austenite phase in the Inconel weld overlays. Potentiodynamic anodic polarization experiments carried out in 4M and 8M nitric acid indicated superior passive film stability in the Inconel weld overlays when compared to the 304L SS weld metal. Comparatively, Inconel 625 weld overlay was found to be much superior to Inconel 82 weld overlay in nitric acid medium. The 304L SS weld metal exhibited inferior pitting resistance in chloride medium by virtue of the high δ-ferrite present in the weld fusion zone. The pitting resistance of the Inconel 82 weld overlay marginally improved, while a substantial enhancement occurred in the Inconel 625 weld overlay.

Bimetallic lattice doped fillers with durable oxygen vacancies for corrosion resistance of coated steel in hostile environments

A series of Ca-doped Co3O4 nano-sheets (Ca-Co3O4) rich in oxygen vacancies were prepared using the alkali precipitation method at different pH values and added to the coating. Scanning electron microscopy and X-ray diffraction were performed to confirm the successful synthesis of the nano-fillers. The electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) spectroscopy determined that the nano-filler has abundant oxygen vacancies. The corrosion resistance test results showed that the epoxy coating containing the Ca-Co3O4 (pH = 12.5) filler exhibited the best corrosion resistance. After 48 h of corrosion in a high-temperature and high-pressure oxygen-rich (HTHP-O2) environment, the |Z|0.01 Hz is 5 orders of magnitude higher than that of the pure Co3O4 coating. Furthermore, the scanning vibrating electrode technique and O2-adsorption-desorption test indicated that Ca-Co3O4 with durable and stable oxygen vacancies could provide a complete, stable and dense passive film for the substrate (Q235B steel). Because oxygen vacancies can selectively transport O2 to the coating-substrate interface ahead of other corrosive media.

Molybdenum effects on the stability of passive films unraveled at the nanometer and atomic scales

Data recently obtained on model FeCrNi(Mo), 316 L stainless steel, and FeCrNiCo(Mo) passivated surfaces by advanced surface analysis and density functional theory modeling are comprehensively discussed to unravel the multiple effects that molybdenum might have at the nanometer and atomic scales to enhance the stability of passive films. The key role played on corrosion protection by the compositional and structural nanoscale defects of the passive film that originate from the pre-passivation mechanisms of the surface is considered. It is shown how Mo, enriched together with Cr in the nanometer-thick passive film, can combine several effects to enhance the resistance to Cl--induced passivity breakdown. Enriched as Mo(VI) species in the outer exchange layer of the passive film, Mo impedes the deep penetration of Cl- ions and limits their access to the inner barrier layer. Dispersed as Mo(IV) at the interface with the inner layer, Mo protects against the entry of Cl- ions into the defect sites of the Cr(III) oxide barrier. Present as Mo(IV + δ) in the Fe-rich compositional nanoscale defects self-generated by the local failure of Cr supply upon initial formation of the barrier layer, Mo enhances the selective dissolution of iron and its replacement by chromium and molybdenum. By impeding the formation of O vacancies, Mo also increases the resistance against chloride entry in the oxide matrix, thereby curing these the Fe-rich weak sites against Cl--induced passivity breakdown.

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

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

Development of Novel Coating on Metallic Bipolar Plates for Proton Exchange Membrane Water Electrolyzer Application

Considering the demand for a more environmentally friendly system, renewable and sustainable energy sources, such as wind and solar power are regarded as a promising substitute for fossil fuels in the generation of electricity. Since these energy sources exhibit intermittency and unpredictability, there is a need to develop a highly efficient and rapidly responsive energy conversion system for the purpose of storing this energy as a chemical fuel. Due to their ability to manage the variability of intermittent energy sources, proton exchange membrane electrolyzer cells (PEMECs) are garnering considerable interest. However, their broad commercial adoption is hindered by their relatively modest performance and elevated costs. PEM electrolysis is a promising technology for generating substantial quantities of hydrogen from surplus electricity generated by renewable sources. Nonetheless, the expense of the electrolyzer stack arises primarily from the metallic bipolar plates, because it possesses heavy weight and expensive precious metal coatings. Significant efforts have been performed on the development of titanium-based bipolar plates, but it has high base material and fabrication cost. In recent years, there has been a substantial focus on stainless steel bipolar plates for PEM electrolyzer application. Stainless steel can serve as an alternative, but it requires a coating to enhance its anti-corrosion properties. Electroplated chromium coatings exhibit favorable mechanical characteristics and find extensive application in precision mechanical components such as molds and surgical instruments. Their outstanding wear resistance, high hardness, impressive corrosion resistance, and glossy finish make them appropriate for many other applications, including both decorative and functional coatings. As a result, chromium electroplating has emerged as one of the most extensively employed techniques within the electroplating sector. The dense pack chromium layer is prepared on a 316L stainless steel substrate to enhance the anti-corrosion property and electronic conductivity.Herein, the role of gold striking underlayer, and thick chromium coating is studied for preparing the anti-corrosive stainless steel bipolar plates. First, a gold striking film as an underlayer on the stainless-steel substrate is electroplated to passivate the chromium-based oxides. Further, a thick and dense chromium layer is deposited on the gold underlayer by electroplating. The electroplating bath is operated using platinized titanium felt as an anode and 316L stainless steel as a working electrode without the separation of anodic and cathodic compartments. The electroplating solution is consisting of Cr (VI) oxide and H2SO4 (pH = 2). The nanocrystalline chromium coating with a thickness of approximately 2 µm is bright and uniform. Furthermore, gold as a protective layer of thickness approximately 1 µm is coated by electroplating on the chromium surface. The Cr and Au/Cr coatings are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron microscopy (XPS) analysis. Subsequently, the protective layer-coated substrates were analyzed in a simulated PEM electrolyzer environment, and these coatings facilitated promising protective properties on the stainless-steel substrate. The corrosion testing was carried out in 0.5 M H2SO4 + 2 ppm HF solution at 70 0C purged with oxygen. The stable passive film and high corrosion resistance were obtained by gold striking underlayer and chromizing the 316L stainless steel substrate. As a result, the potentiodynamic polarization analysis showed the corrosion current density of 0.84 µA/cm2 for the Au/Cr-Au underlayer sample in a simulated operating environment. In contrast, the absence of the gold striking underlayer between Cr and stainless steel causes the pitting corrosion. The Au/Cr coating is tested in an acidic corrosion media for a long duration of 24 hours and it showed lower degradation as compared to without gold striking underlayer and without Cr film. The findings presented in this study illustrate the feasibility of employing stainless steel as the foundational material for the bipolar plate of a PEM electrolyzer.