Corrosion Resistance Of Stainless Steel Research Articles

Enhancing corrosion resistance of carbon steel and stainless steel through pothocathodic protection using TiO2-polyvinyl butyral electrophoretic deposition coating

Photocathodic protection (PCP) is a promising eco-friend method to reduce the corrosion of metals. Considering industrial applicability, it is imperative to adopt cost-effective materials for implementing PCP on corrosion-vulnerable carbon steel (CS). This study examined the potential of photocatalytic TiO2-polyvinyl butyral (PVB) materials for PCP of CS and stainless steel (STS) using commercially available P-25 photocatalyst particles. The TiO2-PVB-electrophoretic deposition (EPD) film exhibited the improved cathodic protection time of STS owing to PVB addition. When the film was applied to various substrates, it achieved a PCP of −0.6 to −0.7 VSCE due to the photogenerated electrons under UV irradiation. For the CS, the PCP potential was maintained for more than 1.5 hours, even after light irradiation. We have found that PCP was achieved by Ecorr > EPCP of CS in an acidic environment, while in a neutral and basic environment, the corrosion of CS and photocathodic electronation contributed simultaneously to Ecorr ≈ EPCP. One findings is that the application of PCP effectively reduces the corrosion rate of CS in a 3.5% NaCl solution, regardless of the pH of the corrosive environment. This highlights the capability of PCP as a viable method for mitigating corrosion on CS.

Research on the Effect of Load and Rotation Speed on Resistance to Combined Wear of Stainless Steels Using ANOVA Analysis.

This research was carried out with the aim of obtaining appropriate principles for describing the influence of working parameters and the aggressive action of an acidic medium on the wear and corrosion resistance of martensitic stainless steels. Tribological tests were performed on induction-hardened surfaces of stainless steels X20Cr13 and X17CrNi16-2 under combined wear conditions at a load of 100 to 300 N and a rotation speed of 382 to 754 min-1. The wear test was carried out on a tribometer with the use of an aggressive medium in the chamber. After each wear cycle on the tribometer, the samples were exposed to corrosion action in a corrosion test bath. Analysis of variance revealed a significant influence of rotation speed and load due to wear on the tribometer. Testing the difference in the mass loss values of the samples due to corrosion using the Mann-Whitney U test did not show a significant effect of corrosion. Steel X20Cr13 showed greater resistance to combined wear, which had a 27% lower wear intensity compared to steel X17CrNi16-2. The increase in wear resistance of X20Cr13 steel can be attributed to the higher surface hardness achieved and the effective depth of hardening. The mentioned resistance is the result of the creation of a martensitic surface layer with dispersed carbides, which increases the resistance to abrasion, dynamic durability, and fatigue of the surface of the protective layer.

Investigation of coated 316L steel surface: Surface morphology, composition, corrosion, and biocompatibility using hydroxyapatite mixed-EDM process

316L stainless steel belongs to insufficient biological responses and corrosion resistance. Although hydroxyapatite powder (HAp)-based coating improves biological responses and corrosion resistance of the 316L stainless steel, these coatings have resulted in inferior adhesion strength and cracked surface. This study aims to synthesize a highly biocompatible and corrosion resistant coating on the 316L stainless steel with a high adhesion strength and surface integrity using the electro discharge machining (EDM) method. The study also aims to explore the impacts of process parameters on the surface features. To reach the set objectives, several characterisation methods including atomic force microscopy (AFM), scanning electronic microscopy (SEM), X-ray powder diffraction (XRD), Potentiostat (electrochemical cell), MTT assay and X-ray photoelectron spectroscopy (XPS) were adopted. The HAp-mixed EDM method synthesized a biocompatible and corrosion resistant coating with an average thickness of 14.6 μm and 20.8 MPa adhesion strength comprising of Ca-P based oxides and carbides. The modified surface showed nano surface roughness of 18.5 nm. The oxides and carbides formed in the coating improved the cell viability of 316L stainless steel surface to 87 % and corrosion resistance to 0.00123 mm per year. This study is trying to gain the attention of 316L stainless steel-based bioimplant manufacturers to launch the hydroxyapatite mixed-EDM method for concurrent machining and coating.

Effect of heat input on microstructure and corrosion resistance of high-nitrogen austenitic stainless steel welded joints

In this study, the microstructure and corrosion resistance of high-nitrogen austenitic stainless steel welded joints with different heat inputs were investigated. A high heat input leads to a large width and depth of the fusion pool and a low fraction of δ-ferrite in the weld sea. However, a high fraction of Cr-rich precipitates is formed under a high heat input and low heat promotes the formation of δ-ferrite. Therefore, following corrosion tests, the weld seam suffers severe intergranular corrosion under high heat input and low heat input, and the corrosion resistance of the weld is the highest at a heat input of 6.8 kJ/cm. A high heat input results in a high fraction of Cr-rich precipitates and a random boundary in the heat affected zone (HAZ), which decreases corrosion resistance. Furthermore, corrosion test results indicate that the Cr-depleted area and random boundary are initially corroded, and high heat input decreases corrosion resistance of the HAZ.

An efficient strategy for enhancing the corrosion resistance of S31254 super austenitic stainless steel through slight Mo segregation

Super austenitic stainless steel (SASS) is one kind of high Mo-alloy steel with excellent corrosion resistance when applied in an extremely corrosive environment. However, high contents of Cr and Mo tend to form precipitates along the grain boundary at high temperatures, leading to a great deterioration of corrosion resistance. Herein, a method of short-time aging treatment at 500 °C and 550 °C was explored, which was intended to regulate the distribution of elements at grain boundaries to improve corrosion resistance. The results indicate that before the precipitates nucleation, as the temperature rises from 500 °C to 550 °C, the Mo element has obvious diffusion behavior towards the grain boundary. Also, the uniform distribution of a small amount of Mo at the grain boundary can be conducive to improving the corrosion resistance. In addition, B inhibits the separation of Mo to grain boundary and delays the formation of the precipitated phase. The addition of B improves the intergranular corrosion resistance of SASS, especially after aging at 500 °C, which is attributed to the passivated film's Cr2O3 and Mo(VI) content. However, when the aging temperature reaches 550 °C, more Mo segregates to the grain boundaries, resulting in Mo-depleted zones, which decreases corrosion resistance.

Investigation of austenitic stainless steel corrosion resistance against ash deposits from co-combustion coal and biomass waste

A high chromium concentration in the boiler material is believed to increase corrosion resistance, especially at high temperatures. It is related to the formation of a protective layer on the surface of the metal, called a chromium oxide (Cr2O3) layer. However, the impact of alkali and chlorine from co-combustion coal with biomass in power plants can harm this protective layer, reducing its effectiveness and potentially leading to increased corrosion. Therefore, it is important to evaluate the impact of these factors on the corrosion resistance of high-chromium materials. This research investigates coal co-combustion with empty fruit bunch (EFB) and plastic waste on the corrosion resistance of austenitic stainless-steel material on a laboratory scale using drop tube furnaces. The investigation steps included probe observation, SEM-EDS on ash and probe material, and XRD. The analysis indicates that the ash from the coal sample did not affect the probe, unlike the coal with EFB or EPL (mixture of EFB and plastic crackles), which caused up to 14% oxide layer degradation. The existence of alkali chloride, sulfate, and silicate in the ash that is still adhered to the surface of the probe can reduce the corrosion resistance of the metal.

Mechanical and electrochemical properties of NbMoSiC gradient films deposited by adjusting sputtering power of carbon target

NbMoSiC gradient films were successfully deposited on 316L stainless steel by adjusting sputtering power of carbon target, and their microstructure, mechanical and electrochemical properties were comprehensively investigated through SEM, XRD, XPS, Raman, nanoindenter and electrochemical workstation. The results show that the NbMoSiC gradient films exhibit a carbon composition gradient across the thickness direction, which impedes the continuous columnar growth and results in a compact and flawless microstructure. The films also possess multiphase structures of Nb2C, MoSi2, silicon and amorphous carbon, leading to a significant improvement in hardness value and elastoplasticity. Furthermore, the electrochemical experiments demonstrated a substantial reduction in the corrosion current density for the NbMoSiC gradient films (3.008 × 10−8 A/cm2) compared to bare 316L substrate (3.687 × 10−7 A/cm2) in artificial seawater medium. The charge transfer resistance of the gradient films (3.482 × 106 Ω cm2) has increased by an order of magnitude, indicating an enhanced inhibition effect on the ion transport during the corrosion reaction. The improved corrosion resistance of 316L stainless steel is mainly attributed to strong passivation ability and the dense microstructure formed by the carbon composition gradient structure.

Effect of the culture medium on the behavior of the austenitic stainless steel with the specific 316L grade

The use of 316L stainless steel as an orthopedic bone plate material or as a substrate for coating implies the need to study its properties in a biological medium simulating human body environment. Therefore, the aim of this work is to investigate the microstructural characteristics, corrosion resistance, and mechanical properties of 316L stainless steel in the culture medium and then to check the cytotoxicity of the stainless steel in the presence of human mesenchymal stem cells. The characteristics of the stainless steel were evaluated by studying the microstructure of the samples in untreated state and after soaking in minimum essential medium‐alpha (α‐MEM) for 7 days. The results indicated the formation on the surface of the 316L stainless steel of goethite and deposits composed of Ca and P with porous and amorphous structures, which led to the decrease in the elastic modulus and the hardness of the soaked stainless steel as shown by nanoindentation test. Nevertheless, the hardness and the elastic modulus of the steel after soaking were influenced only for a surface depth of approximately 0.1% of the thickness of the sample. The potentiodynamic polarization curves exhibited that the corrosion resistance of the soaked stainless steel was reduced because of the higher passive current density. However, it should be noticed that the breakdown potential of the steel after soaking was slightly higher, leading to a wider range of passivation. In addition, microscopy examination showed the mesenchymal stem cell adhesion on the materials after 9 days of culture.

Effect of aging on the microstructure and properties of ASTM A890 3A duplex stainless steel

Exposure of duplex stainless steels to high temperatures could result in microstructure changes generating precipitated phases and significantly affecting material properties. In this paper, the effects of aging at 450–850 °C on the microstructure and properties of ASTM A890 3A duplex stainless steel were studied. The microstructures were different after aging at different temperatures: only γ2 was precipitated after aging at 450 and 550 °C, γ2, M23C6, and σ phases were observed at 650 °C, and an additional phase of χ was found at 750 °C. Aging at 450 °C increased the strength of duplex stainless steel while aging at other temperatures negligibly affected strength. Aging at 450 °C and 650–850 °C significantly decreased the impact toughness. Correspondingly, the fracture was partially or completely transformed from a ductile fracture mode before aging to a brittle fracture mode after aging. Aging deteriorated the corrosion resistance of duplex stainless steel. Aging at 750 °C had the most significant effect: the breakdown potential decreased by 28%, and the membrane resistance decreased by 81.9% relative to those without aging. The above changes in properties were closely related to the embrittlement of duplex stainless steel at 475 °C and the precipitation of the σ-phase and χ-phase.

Corrosion performance of NV E690 steel and 316L stainless steel coating fabricated by underwater direct metal deposition

The corrosion resistance of NV E690 steel and 316L stainless steel (SS316L) coatings fabricated by underwater laser direct metal deposition (UDMD) was investigated. The corrosion resistance of the as-deposited NV E690 was improved by coating SS316L layers. The dilution effect coupling with macro-segregations (peninsula, island, and banded zone) deteriorated the corrosion resistance by forming preferential dissolution and crevice-shaped corrosion when depositing monolayer SS316L coating. While the above-mentioned drawbacks were alleviated when depositing bilayer SS316L coatings, thereby leading to higher corrosion resistance by forming a compact passive film.

Compressive performance of SWSSC-filled CFRP-stainless steel composite tube columns

The structure of concrete confined by carbon fiber-reinforced polymer (CFRP) and stainless steel tubes was investigated. The columns, which take advantage of the ductility and corrosion resistance of stainless steel, are composed of stainless steel tube, core seawater and sea sand concrete (SWSSC) and outer FRP. Forty circular SWSSC-filled FRP-stainless steel composite tube columns (SCFSSCTs) were manufactured and subjected to axial compression tests. After fracturing of the FRP, the failure modes of the specimens mainly showed extrusion expansion, with a small amount of shear failure. The increase in the thickness of the stainless steel and the number of FRP layers resulted in a significant improvement in the load capacity and deformation capacity of the structure, which was more evident in the specimens with higher steel contents. With the increase in the number of FRP layers, the increases in ultimate stress and ultimate strain were 40.4% − 130.0% and 118.6% − 282.4%, respectively, compared with the column with single stainless steel confinement. The stress–strain curves for the SCFSSCTs were similar to those of structures reinforced by FRP and carbon steel and were divided into four stages. Models were proposed to predict the full axial stress–strain curves of SCFSSCTs, including the ultimate point and the peak point.

Passivation Effect of the Chlorinated Paraffin Added in the Cutting Fluid on the Surface Corrosion Resistance of the Stainless Steel.

Cutting fluids are the most effective method to lower the cutting temperature and decrease the cutting tool wear. At the same time, the cutting fluids influence the corrosion resistance property of the machined surface. In this study, chlorinated paraffin (CP), which is a common additive in the cutting fluid, was selected as the research objective to study its corrosion resistance property. The passivation effect of CP with different concentrations on the machined surface of stainless steel was studied. Electrochemical measurements and surface morphology investigation were used to characterize the passivation effect of CP with different concentrations. The test results showed that the corrosion resistance of stainless steel in the cutting fluid was enhanced with the increase in CP additive. This reason is that the charge transfer resistance increases and the corrosion current density decreases with the increase in CP additive. The X-ray photoelectron spectroscopy (XPS) results show that the proportion of metal oxides on the processed surface of the stainless steel sample was increased from 20.4% to 22.0%, 32.9%, 26.6%, and 31.1% after adding 1 mL, 2 mL, 4 mL and 6 mL CP in the cutting fluid with a total volume of 500 mL, respectively. The oxidation reaction between CP and the stainless steel sample resulted in an increase in metal oxides proportion, which prevented the stainless steel sample from corrosion in cutting fluid.

Corrosion resistance of austenitic stainless steel using cathodic plasma electrolytic oxidation

Substantial improvement of corrosion resistance of austenitic stainless steel (SS) has been demonstrated with a protective oxide layer formed by the cathodic plasma electrolytic oxidation (CPEO) process. Two distinct layers, a porous-structured outer layer comprising Fe oxides and a compact inner layer comprising Cr oxides, were created on the SS surface after the CPEO process. The thicknesses of the outer and inner layers were approximately 7 μm and 12 μm, respectively, and the oxide layers were fabricated in an exceptionally short time of <30 s. A potentiodynamic polarization analysis exhibited a 65 % decrease in the corrosion current after the formation of the protective oxide layer, verifying the effectiveness of the CPEO treatment on the corrosion resistance of SS. An electrochemical impedance spectroscopy study revealed that the outer layer captured corrosive species due to its porous structure, while the inner layer had high resistance to reactions with corrosive species due to the compact structure of Cr oxides. Additionally, a Rockwell C indentation test demonstrated the robust mechanical property of the protective oxide layer with a strong bonding strength to the substrate.

Effect of heat treatment atmospheres on microstructure evolution and corrosion resistance of 2205 duplex stainless steel weldments

The effects of post heat treatment atmosphere on microstructure and corrosion resistance of duplex stainless steel welded joints were investigated. Post weld heat treatment (PWHT) was carried out with and without protective atmospheres. Nitrogen and argon are used as protective gases individually. Detailed microstructure examination (optical and SEM) demonstrates that nitrides precipitates are highly observed in the welded zones for nitrogen protected samples. An observed drop of ferrite volume fraction in post weld heat treated samples compared with welded samples without heat treatment leading to corrosion resistance enhancement of heat treated welded joints. An exception for using nitrogen as heat treatment atmosphere a decreased corrosion resistance of weldments is investigated due to nitride precipitates. An increase in the weld zone hardness for post weld heat treated samples compared with base alloy. The initial hardness of duplex stainless steel was 286 Hv while average hardness of weld zone was 340, 411, 343, and 391 Hv for as welded, PWHT using air, argon, and nitrogen atmospheres, respectively. Weld zone hardness increased to 33, 44, 20, and 37%. A significant decrease in the ultimate tensile strength and elongation after PWHT. The initial Ultimate tensile strength duplex stainless steel base material was 734.9 MPa while Ultimate tensile strength of the welded joints was 769.3, 628.4, 737.8, and 681.4 MPa for the following conditions: as welded, PWHT using air, argon, and nitrogen atmospheres, respectively.

Improvement in Corrosion Resistance and Interfacial Contact Resistance Properties of 316L Stainless Steel by Coating with Cr, Ti Co-Doped Amorphous Carbon Films in the Environment of the PEMFCs.

In order to obtain films with high corrosion resistance and excellent interfacial contact resistance (ICR) on 316L stainless steel used for bipolar plates in proton-exchange membrane fuel cells (PEMFCs), Cr, Ti co-doped amorphous carbon films were prepared on 316L stainless steel. The preparation method for the coating was magnetron sputtering. The doping amount of the Ti element was controlled by a Cr target and a Ti target current. The change in the structure and properties of the coating after the change from Cr single-element doping to Cr and Ti co-doping was studied. The change rule of the structure and properties of the coating from Cr single-element doping to Cr and Ti co-doping was studied. An increase in the Ti content led to a decreased grain boundary, a flatter surface, and a higher sp2-hybridized carbon content. TiC and CrC nanocrystals were formed in the amorphous carbon structure together. The amorphous carbon films doped with Cr and Ti simultaneously achieved a low ICR and high corrosion resistance compared with single-Cr-doped amorphous carbon. The enhanced corrosion resistance was attributed to the decreasing grain boundary, the formation of the TiC crystal structure, and the smaller grain size. The best performance was obtained at a Ti target current of 2A. Compared with bare 316L stainless steel, the corrosion resistance of Cr, Ti co-doped amorphous carbon (Icorr = 5.7 × 10-8 A/cm2, Ti-2 sample) was greatly improved. Because Ti doping increased the content of sp2-hybridized carbon in the coating, the contact resistance of the coating decreased. Moreover, the interfacial contact resistance was 3.1 mΩ·cm2 in the Ti-2 sample, much lower than that of bare 316L stainless steel. After the potentiostatic polarization test, the coating still had excellent conductivity.

Corrosion caused by fertigation with urea and potassium chloride solutions resembles that generated by irrigation

AbstractCorrosion is a common problem in irrigation systems consisting of metal parts. Fertigation can aggravate this phenomenon because fertilizers, once dissolved in water, usually tend to be corrosive. In this study, the effects of corrosion resulting from fertigation with solutions of white potassium chloride (10 g L−1) and urea (10 g L−1) on galvanized steel and AISI 304 stainless steel specimens, materials similar to the centre pivots and injection pumps, were evaluated by simulation tests. During the experiment, the mass loss, corrosion penetration rate, thickness loss and estimated useful life of the specimens were calculated. The results showed that the variation in the fertilizer source as well as the type of metal influenced the corrosion effects. Furthermore, the useful life expectancy of steels intended for irrigation in systems that practice fertigation practically does not differ from the systems where only irrigation is practiced. The corrosion resistance of stainless steel is significantly higher than that of galvanized steel, so its use should be considered in irrigation systems. In addition, it is interesting that the Zn coating on the galvanized steel pipes used for irrigation presents at least twice the thickness to ensure greater protection of the steel substrate.

Enhancement of microbiologically influenced corrosion resistance of copper-containing nickel-free high nitrogen stainless steel against marine corrosive Pseudomonas aeruginosa

The antibacterial performance and marine microbiologically influenced corrosion (MIC) resistance of a novel copper-containing nickel-free high‑nitrogen stainless steel (HNS) against marine Pseudomonas aeruginosa were studied. The electrochemical tests indicated that the copper content (0, 2 and 4 wt%) would hardly affect the corrosion resistance of HNS in abiotic simulated seawater. In the presence of bacteria, HNS-4Cu showed the best MIC resistance, while MIC rates of HNS-0Cu and HNS-2Cu were comparatively faster. Addition of 4 wt% copper significantly improved the antibacterial effect and the quality of the passive film of HNS, achieving a better MIC resistance.

Effects of Ar-N2-He shielding gas on microstructure, mechanical properties and corrosion resistance of the Laser-MIG additive manufacturing 316L stainless steel

Effects of Ar-N2-He shielding gas on microstructure, mechanical properties and corrosion resistance of the Laser-MIG additive manufacturing 316L stainless steel

Corrosion Resistance of AISI 310s Stainless Steel in Lead Melt at a Temperature of 450°C

Corrosion Resistance of AISI 310s Stainless Steel in Lead Melt at a Temperature of 450°C

Effect of Mn on Microstructure and Corrosion Resistance of Duplex Stainless Steel Surfacing Layer

Effect of Mn on Microstructure and Corrosion Resistance of Duplex Stainless Steel Surfacing Layer