Corrosion Resistance Of Steel Research Articles

Corrosion resistance enhancement for 6Mo austenitic stainless steel through B alloying coupled with a simple pre-aging method

The effect of boron (B) addition coupled with 500 ℃ pre-aging on the corrosion resistance of S31254 was systematically investigated. The results suggested that the diffusion of Mo to grain boundaries (GBs) played a crucial role in enhancing intergranular corrosion resistance. Additionally, the addition of B further promoted the uniform distribution of Mo during the pre-aging process by suppressing Mo segregation at GB. Ultimate, the B microalloying coupled with the pre-aging strategy optimized the composition of passive film through promoting the formation of Mo-rich passivation film, which significantly enhanced the corrosion resistance of Mo-containing stainless steel.

Optimizing Surface Hardness and Corrosion Resistance in 316L Stainless Steel via SMRT and Plasma Nitriding.

Increasing the mechanical strength of stainless steel is fundamental to expanding its applications and extending its useful life, especially due to its impressive corrosion resistance. However, many processes that make possible increasing the hardness and wear resistance of these steels also compromise their performance when they are subjected to corrosive environments. Because of the need to increase surface hardness without jeopardizing corrosion resistance, this study explores the impact of a surface mechanical rolling treatment (SMRT) with volumetric reductions of 50% and 70%, together with high-temperature plasma nitriding (PN) (450, 500, and 550 °C), on 316L steel. X-ray diffraction analysis analyzed the composition and structure of the resulting coatings. Mechanical strength was assessed using Vickers microhardness, while corrosion resistance was tested in a 3.5%-by-weight NaCl solution. The results indicate a substantial increase in surface hardness in all of the nitrided samples. Notably, the samples were subjected to rolling with 50% and 70% volumetric reduction, and subsequent nitriding at 550 °C showed a reduced impairment of corrosion resistance. This shows that the methodology adopted in this study, consisting of SMRT and PN, can increase the useful life and expand the applicability of stainless steels commonly used in various industry sectors.

Evaluation of Corrosion Performance of LDX 2101 and UNS S32205 in Flexible Pipeline Applications: A Comparative Study

Lean duplex stainless steel (LDSS) has been used in various applications, including flexible pipelines in offshore and other industrial settings. In recent years, LDSS has become the preferred choice over standard duplex stainless steel (DSS) for flexible pipeline applications due to its lower costs, achieved by reducing nickel and molybdenum content, while still providing comparable corrosion resistance and mechanical strength properties to DSS. However, there is still limited reporting on the corrosion effects of reducing these alloys on the behaviour of lean duplex stainless steel in flexible pipelines. This comparative study investigates the corrosion resistance of lean duplex stainless steel, LDX 2101 and duplex stainless steel, UNS S32205 in flexible pipeline applications using linear polarization resistance (LPR). The research focuses on assessing material performance in environments containing CO2 and H2S, commonly found in oil and gas production, by conducting short-term and long-term tests to evaluate pitting and selective corrosion. The samples, LDX 2101 and UNS S32205 were immersed in a 3.5M NaCl solution, and corrosion measurements were performed using the Metrohm Autolab potentiostat. The results indicate that both materials exhibit good corrosion resistance, but there are differences in their performance under specific conditions. While lean duplex stainless steel, LDX 2101, can be used as a substitute for duplex stainless steel UNS S32205, its corrosion resistance and mechanical properties gradually decrease over time due to the reduced nickel and molybdenum content. As a result, it would not be as effective as duplex stainless steel UNS S32205 in withstanding corrosion in aggressive conditions over a prolonged period.

Preparation of Stainless Steel Superhydrophobic Surface and Analysis of Hydrophobic Mechanism.

By analyzing the application conditions of hydrothermal oxidation equipment, we found that the corrosion resistance of stainless steel is crucial. It is necessary to prepare superhydrophobic surface to improve the corrosion resistance and find a cost-effective and environmentally friendly preparation method. Therefore, this paper proposes a method combining nanosecond laser and post-treatment, which uses nanosecond laser to etch microstructure and reduces the surface energy through diverse post-treatment methods to achieve hydrophobicity. The surface morphology characteristics were studied, the wettability of various post-treatment methods was compared, and the hydrophobic mechanism was analyzed. The results show that the groove width has a significant impact on the surface morphology. Superhydrophobic surface can be obtained immediately after heat treatment and fluorosilane modification, while natural storage requires more than one month. All of the post-treatment can obtain hydrophobicity by reducing the surface energy, but the chemical composition is distinct. The cost-effective composite process of laser and heat treatment plays a guiding role in future research on the preparation of stainless steel superhydrophobic surface and has broad prospects in the future in large-scale production and application.

Improving corrosion resistance of super-13Cr martensitic stainless steel by a homogenized amorphous film

Super 13Cr martensitic stainless steel (UNS S41426, S13Cr MSS in the case) developed for gas fields is being applied more broadly. However, the stress corrosion cracking induced by pitting limits its application range. To enhance the corrosion resistance, a new amorphous film was pre-formed on its surface by a modified alkaline solution. The nanoscale amorphous film contained FeO, Fe2O3, Cr2O3 and Cr(OH)3, growing logarithmically after a short dissolution duration. The general corrosion resistance of S13Cr MSS improved significantly, as evidenced by a decrease in corrosion current density by an order of magnitude. Additionally, the pitting potential of S13Cr MSS increased by nearly 100 %. This work provides a strategy for addressing surface defects in S13Cr MSS.

Effect of different heat-treatment processes on corrosion resistance of 17-4PH steel

Effect of different heat-treatment processes on corrosion resistance of 17-4PH steel

Trifolium repens extracts as a green corrosion inhibitor for carbon steel in a 3.5% NaCl solution

BackgroundMaterial degradation is a major issue that has been the subject of intense research and investigation by the scientific community. It has harmful consequences that require serious and careful intervention. However, restrictions on the use of inhibitors containing toxic compounds pose a significant challenge to the implementation of effective corrosion treatments. This has necessitated a continuous search for new and innovative ways to protect against material damage. Plant-derived natural inhibitors offer several advantages, including potent inhibitory effects, lack of toxicity, biodegradability, and environmentally sustainable origins. The purpose of this research was to evaluate the corrosion resistance of API5LX60 carbon steel in a 3.5 % NaCl environment using Trifolium repens as an environmentally friendly inhibitor. MethodsThe inhibitor extract was analysed using Fourier Transform Infrared (FTIR) spectroscopy. However, gravimetry and electrochemical methods (potentiodynamic polarization and electrochemical impedance spectroscopy (EIS)) were used to investigate the corrosion behaviour. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to examine the surface morphology. Significant findingsAfter testing a range of concentrations in a 3.5 % NaCl medium, the highest level of inhibition (98 %) was obtained at 20 ppm, confirming the mixed action of the inhibitor with predominantly cathodic action. The inhibition mechanism involved physical adsorption on metal surfaces according to the Langmuir model, which enhances the corrosion-inhibiting ability; the extract forms a protective layer that successfully inhibits corrosion, as confirmed through electrochemical and surface analysis. These results demonstrate that the extract acts as a potent anticorrosive agent.

Effects of dual-phase deformation behaviors on simultaneously enhanced tensile properties and stress corrosion resistance of 2Cr13 martensitic stainless steel treated by laser shock peening

Effects of changes in martensite and carbide induced by laser shock peening (LSP) on tensile properties and stress corrosion behaviors of 2Cr13 martensitic stainless steel (MSS) were investigated. Results indicated that LSP not only caused plastic deformation of the martensite and carbide but also brittle deformation of carbide. Based on fine/coarse grain heterostructure, carbide plastic and brittle deformation, carbide local decomposition, compressive residual stress and grain coarsening caused by tensile stress, 14.7 % and 44.5 % increase in the strength and ductility in NaCl solution are respectively achieved for MSS with a surface where the formation of corrosion pits is significantly suppressed.

Mechanistic role of vanadium microalloying in improving corrosion resistance of low carbon bainitic steel

We here investigated the effect of vanadium microalloying on the microstructure, mechanical properties, especially corrosion performances of low carbon bainitic steels. The corrosion behaviors of the steels with different vanadium contents in 3.5 wt% NaCl solution were evaluated by electrochemical tests (including polarization curves and electrochemical impedance spectroscopic measurements) and alternating immersion test (including weight loss and rust layer observation). Results show that the mechanical properties and corrosion resistance of low carbon bainitic steels can be synergistically improved with vanadium microalloying. With help of the electron backscatter diffraction characterization and scanning Kelvin probe force microscopy, we first discovered that although the number of micro-galvanic couples increases because of grain refinement, the Volta potential gradient between the matrix and grain boundaries are decreased with vanadium microalloying, which can promote the formation of compact protective rust layers and improve the corrosion resistance of vanadium micro-alloyed low carbon bainitic steels.

Detecting the Sigma Phase in Duplex Stainless Steel by Magnetic Noise and First Harmonic Analysis.

Non-destructive electromagnetic tests based on magnetic noise analysis have been developed to study, among others, residual stress, heat treatment outcomes, and harmful microstructures in terms of toughness. When subjected to thermal cycles above 550 °C, duplex stainless steels form an extremely hard and chromium-rich constituent that, if it is superior to 5%, compromises the steel's corrosion resistance and toughness. In the present work, a study was carried out concerning the interaction of excitation waves with duplex stainless steel. Hence, by analyzing the magnetic noise and variations in the amplitude of the first harmonic of the excitation waves, the detection of the deleterious sigma phase in SAF 2205 steel is studied. To simplify the test, a Hall effect sensor replaced the pick-up coil placed on the opposite surface of the excitation coil. Sinusoidal excitation waves of 5 Hz and 25 Hz with amplitudes ranging from 0.25 V to 9 V were applied to samples with different amounts of the sigma phase, and the microstructures were characterized by scanning electron microscopy. The results show that the best testing condition consists of applying waves with amplitudes from 1 V to 2 V and using the first harmonic amplitude. Thus, the test proved effective for detecting the formation of the deleterious sigma phase and can follow the ability to absorb energy by impact and, thus, the material embrittlement.

Improvement of Tribological Properties and Corrosion Resistance of AISI 4340M Steel by Shot Peening and Plating Technologies

Improvement of Tribological Properties and Corrosion Resistance of AISI 4340M Steel by Shot Peening and Plating Technologies

Effect of Solution Treatment Temperature on Microstructure, Mechanical Properties and Corrosion Resistance of Ultra-High Nitrogen Stainless Steel

Effect of Solution Treatment Temperature on Microstructure, Mechanical Properties and Corrosion Resistance of Ultra-High Nitrogen Stainless Steel

Corrosion behaviour of 110SS steel in hydrochloric acid and blended acid system at 200°C

The influence of organic acids (formic acid, acetic acid) on the corrosion behaviour of 110SS steel, a hydrogen sulphide corrosion resistant alloy steel, in hydrochloric (HCl) acid environments was studied. The corrosion rates of 110SS steels in HCl acid and blended acid were measured using the high-temperature and high-pressure corrosion tester. Scanning electron microscopy was utilised to observe the morphology of corrosion products on steel samples corroded by different acid systems, and the energy dispersive X-ray spectrometer was used to analyse the elemental composition of the corrosion products. The corrosion morphology was observed using a 3D laser scanner. The results indicated that the corrosion rate of 110SS steel in HCl acid at 200 °C was an exponential function of HCl concentration. Reducing the HCl concentration significantly decreased the corrosion rate of 110SS steel. Organic acids and corrosion inhibitors synergistically reduced the corrosion of 110SS steel in HCl acid. Adding 3 wt.% organic acid to the 15 wt.% HCl acid system further reduced the corrosion rate, with a more pronounced effect observed in the HCl–formic acid system compared to the HCl–acetic acid system. Organic acids chemically adsorbed onto the steel surface and decomposed to produce CO, which hindered the attack of hydrogen ions on the metal. The added corrosion inhibitor and intensifier Sb2O3 resulted in the formation of a compact adsorption film on the steel surface, further inhibiting corrosion. The optimal mass ratio of HCl acid to organic acid was found to be 15% to 3%.

Effect of Mo and Sn co-regulation on low alloy steel corrosion in tropical marine atmosphere

The influence of co-regulating Mo and Sn on the corrosion resistance of low alloy steel in tropical marine atmospheric was investigated. The combined addition of Mo and Sn has been found to significantly improve the corrosion resistance of low alloy steel, augmenting the protective capabilities of the rust layer. This combined addition promotes the formation of protective compounds like α-FeOOH and FeCr2O4 within the alloy rust layer. Furthermore, it facilitates the conversion of Cr, Ni and Cu into corrosion-resistant oxides such as Cr2O3, NiFe2O4 and CuO, thereby enhancing the density of the rust layer. Additionally, as corrosion progresses over time, higher levels of Sn addition lead to increased Sn content within the inner rust layer, consequently bolstering the protective qualities of the rust layer. This comprehensive understanding sheds light on the synergistic effects of Mo and Sn in fortifying the corrosion resistance of low alloy steel, offering insights for the development of advanced corrosion-resistant materials in marine environments.

Enhanced electrochemical corrosion resistance of 316L stainless steel manufactured by ultrasonic rolling assisted laser directed energy deposition

Enhanced electrochemical corrosion resistance of 316L stainless steel manufactured by ultrasonic rolling assisted laser directed energy deposition

Study on the influence mechanism of austenitizing temperature on the surface of corrosion-resistant mold steel

Abstract The microstructure of 4Cr13 corrosion-resistant plastic mold steel was studied. The martensitic experimental steel obtained by different heat treatment processes was used as the object. The effect of austenitizing temperature on its corrosion behavior was studied by microstructure characterization and electrochemical test. The results show that the microstructure of the test steel is mainly composed of martensite laths. Under the same experimental conditions, the corrosion resistance of the test steel decreases with the increase of austenitizing temperature, and the corrosion products are mainly composed of iron-containing oxides. The austenitizing temperature of 1000°C improves the corrosion resistance of the material, because the precipitation of a large number of small-sized Cr-containing carbides hinders the further erosion of the material and improves the surface quality.

Зависимость предельной осевой нагрузки на сферические подшипники скольжения от состава и структуры спеченных коррозионностойких сталей

Зависимость предельной осевой нагрузки на сферические подшипники скольжения от состава и структуры спеченных коррозионностойких сталей

Microstructural evolution and mechanical properties of maraging steel by additive manufacturing

Laser powder bed fusion (LPBF) is a revolutionary and innovative technology that provides advanced technical support for the forming of parts with high precision and complex structures. In this work, a new type of Fe-Ni-Mo-Ti-Al-Y cobalt-free maraging steel was successfully fabricated by LPBF. The additive manufacturing parameters and the microstructural evolution of cobalt-free maraging steel under different heat treatment parameters were systematically studied. The results show that the parts without cracks and close to complete density can be fabricated under a wide LPBF process window. The dislocation cell with 500 nm in the printing state makes the material have good plasticity. After post-heat treatment, the preferred orientation of LPBF maraging steel is reduced, but the typical characteristics of molten pool and cellular structure in maraging steel disappeared, which is the result of local composition and microstructure homogenization. The elongation of LPBF maraging steel in solution annealed state is higher than that in as-printed state, which is due to the reduction of dislocation density and grain coarsening. However, after direct aging, due to the formation of nano-sized Ni3(Ti, Mo) precipitates in the matrix, the mechanical properties of the material were effectively enhanced, and the tensile strength increases from ∼1.1 GPa in as-printed state to ∼1.6 GPa in aging state. In contrast, the corrosion resistance of as-printed maraging steel is higher and comparable to that of traditional cobalt-containing maraging steel. However, the corrosion resistance of LPBF maraging steel after being aged is reduced, which is due to the existence of precipitates and dislocations. This study provides a theoretical reference for the composition design and strengthening mechanism of LPBF cobalt-free maraging steel.

Effect of heat treatment on the corrosion resistance of 316L stainless steel manufactured by laser powder bed fusion

Understanding the influence mechanism of microstructures and inclusions during heat treatment on the corrosion resistance of L-PBF 316L stainless steel (SS) is crucial for steel quality control and subsequent industrial application. In this study, the evolution of microstructure, inclusions and passive film in the L-PBF 316L SS during heat treatment at the temperature of 1000 °C and 1200 °C for 2 h, including crystal characteristics, dislocation density, passivation film composition and so on, were characterized by electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of L-PBF 316L SS samples was evaluated by Tafel test and electrochemical impedance spectroscopy test. The corrosion mechanisms of L-PBF 316L SS before and after heat treatment were clarified to elucidate the intrinsic effect of microstructure and inclusions on the corrosion resistance of the steel. Results showed that the heat treatment conducted at 1200 °C effectively reduced the number of grain boundaries and induced a substantial number of Σ3 twin grain boundaries in the L-PBF 316L SS, thereby efficiently impeding the precipitation of detrimental phases and reducing corrosion susceptibility at the grain boundaries. Meanwhile, the recrystallization-induced rearrangement of dislocations and the homogenization of grains effectively facilitated the growth of passivation film, thereby increasing the corrosion resistance of HT1200 sample. Additionally, the increase of MoO3 content compensated for the detrimental impact on the stability of the passivation film resulting from the reduction in chromium oxide content. Transformation from the MnO–SiO2–Cr2O3 inclusions in the as-built sample to the SiO2 inclusions in the HT1200 sample would also retard the penetration of corrosive ions into the steel matrix.

Insight into the corrosion resistance of mild steel in an acidic environment in the presence of an organic extract: Experimental and computational approach

Green corrosion inhibitors are crucial in lowering the rate at which metals corrode as well as the negative environmental effects of hazardous substances. Considering this, Curcuma longa (CL) root extract was used as an effective and safe corrosion inhibitor in this study. The inhibitory efficacy was thoroughly investigated using the weight loss (WL), open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) techniques, respectively. The inhibitor was found to be effective at impeding the rate of deterioration of mild steel in 1 M HCl and 0.5 M H2SO4 environments. In a mixed-type mode, the CL reduced the anodic and cathodic reactions. However, in a 0.5 M H2SO4 environment, CL proved to be slightly more effective compared to a 1 M HCl environment. Inhibition efficiency values of 91.8 % (0.5 M H2SO4) and 89.6 % (1 M HCl) were obtained. The Langmuir adsorption isotherm (LAI) was used to validate the results. Some surface probe analysis such as scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FR-IR), and X-ray photoelectron spectroscopy (XPS), were used to complement the electrochemical results. Quantum chemical computations confirmed some active sites on the molecular structures of a few selected active constituents of the CL extract.