Corrosion Resistance Of Stainless Steel Research Articles

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

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

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.

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.

A Study of the Corrosion Resistance of 316L Stainless Steel Manufactured by Powder Bed Laser Additive Manufacturing

Commercially available 316L (1.4404) stainless steel is commonly used for industrial filtration due to its combination of good material properties, particularly its corrosion resistance, which is a critical factor for filters in corrosive (e.g., saltwater) environments. Recently, laser powder bed fusion (LPBF) has enabled new more complex and efficient filtration pieces to be manufactured from this material. However, it is critical to know how the corrosion resistance is affected by this manufacturing strategy. Here, the corrosion resistance of LPBF manufactured 316L stainless steel is compared with wrought 316L sheet. The corrosion of the samples in saltwater was assessed with asymmetric electrochemical noise, potentiodynamic polarisation curve, and electrochemical impedance spectroscopy. The samples before and after corrosion were examined with scanning electron microscopy and energy-dispersive spectroscopy. The LPBF samples had higher corrosion resistance than the sheet samples and were more noble. The corrosion resistance of the LPBF sample increased with time, while the wrought sample corrosion resistance reduced over time. The corrosion mechanism of both samples was stable with time, formed of a passive film process and a bared material process. This paper presents the first study about the temporal evolution of the LPBF 316L stainless steel corrosion mechanism.

Study of Effects of Post-Weld Heat Treatment Time on Corrosion Behavior and Manufacturing Processes of Super Duplex Stainless SAF 2507 for Advanced Li-Ion Battery Cases.

Lithium-ion batteries are superior energy storage devices that are widely utilized in various fields, from electric cars to small portable electric devices. However, their susceptibility to thermal runaway necessitates improvements in battery case materials to improve their safety. This study used electrochemical analyses, including open-circuit potential (OCP), potentiodynamic polarization, and critical pitting temperature (CPT) analyses, to investigate the corrosion resistance of super duplex stainless steel (SAF 2507) applied to battery cases in relation to post-weld heat treatment (PWHT) time. The microstructure during the manufacture, laser welding, and PWHT was analyzed using field-emission scanning electron microscopy, X-ray diffraction, and electron backscatter diffraction, and the chemical composition was analyzed using dispersive X-ray spectroscopy and electron probe micro-analysis. The PWHT increased the volume fraction of austenite from 5% to 50% over 3 min at 1200 °C; this increased the OCP from -0.21 V to +0.03 V, and increased the CPT from 56 °C to 73 °C. The PWHT effectively improved the corrosion resistance, laying the groundwork for utilizing SAF 2507 in battery case materials. But the alloy segregation and heterogeneous grain morphology after PWHT needs improvement.

Corrosion Resistance of FeCrMnSiB Austenitic Stainless Steels Processed by Plasma Transferred Arc

Corrosion Resistance of FeCrMnSiB Austenitic Stainless Steels Processed by Plasma Transferred Arc

The effect of tempering temperature on microstructure and corrosion resistance of M390 powder metallurgical martensitic stainless steel

The corrosion resistance of M390 powder metallurgical martensitic stainless steel with different tempering temperatures was investigated by potentiodynamic polarization measurements, salt spray tests, and microstructural analyses utilizing scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The tempering temperature had no significant effect on the size and volume fraction of carbides. The corrosion resistance of M390 steel gradually deteriorated with increasing tempering temperature, and a loss passivation (LOP) effect was observed when tempered at 450 °C, 500 °C, and 550 °C. Transmission electron microscopy (TEM) analysis showed that the width of the Cr-depleted zones around the undissolved M7C3 carbides increased with increasing tempering temperature, while the Cr content in these zones decreased, which was the main reason for the deterioration of corrosion resistance. This study offers valuable insights into optimizing the tempering process to improve the corrosion resistance of M390 steel for practical applications.

Effect of nitrogen pressure on the microstructure, conductivity, and corrosion resistance of ZrN-coated stainless steel as bipolar plate for proton exchange membrane fuel cell

Effect of nitrogen pressure on the microstructure, conductivity, and corrosion resistance of ZrN-coated stainless steel as bipolar plate for proton exchange membrane fuel cell

Al2O3-MnS Inclusions and Pitting Corrosion in the Weld Heat-Affected Zone

Manganese sulfide inclusions have been identified as a key factor contributing to the degradation of pitting corrosion resistance in both carbon and stainless steels. However, the precise reasons behind the differential reactivity of various sulfides, with some serving as active sites for pitting while others remain inactive, are not yet fully understood. The effect of debonding occurring at the interface between these inclusions and the steel matrix in relation to pitting corrosion has not been extensively investigated. In this study, an examination of a service-exposed pipeline girth weld was conducted. Immersion testing in blowdown water and multiscale characterization techniques investigated the inclusion-matrix interface debonding within the heat-affected zone. Our findings suggest that interfacial debonding is more likely at the Al2O3- MnS cluster interface. This observation offers a rationale for the selective reactivity of sulfides that form clusters with oxides, highlighting the likelihood that only sulfides clustering with oxides act as active pitting initiation sites.

The corrosion properties of ferritic stainless steel with varying Cr and Mo contents in the early stages of a simulated proton exchange membrane fuel cell environment investigated using experimental and joint calculation method HKD

The initial corrosion resistance of ferritic stainless steels with various Cr and Mo levels in simulated fuel cell environments is evaluated using the HKD calculation method and electrochemical tests. HKD utilizes high-throughput DFT, KMC, and AIMD statistical coverage calculations to study passivation film development and ion/molecule adsorption behaviors, like O2-, F-, H2O, and OH-. Super-high Cr-containing Mo steel shows reliable corrosion resistance due to their stable structure and effective passivation film integrity at various F- concentrations and pH values. Furthermore, the impact of F- competes with O2-, influencing film formation as pH lowers and concentration rises.

Enhancing corrosion resistance of 316L stainless steel through electrochemical deposition of polyaniline coatings in acidic environments

Stainless steel is widely used because of its excellent corrosion resistance in typical environments. However, it is susceptible to corrosion in acidic media, therefore, to address this issue, the electrochemical deposition of polyaniline coatings on 316L stainless steel was investigated using cyclic voltammetry at different potential windows and scan rates. The successful polymerization and surface morphology were analyzed using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Moreover, thermal stability of the PANI coating was assessed through thermo gravimetric analysis while the corrosion behavior of bare and coated steels immersed in 1M H2SO4 was studied using electrochemical impedance spectroscopy (EIS). Based on the Nyquist plots obtained from the EIS revealed that the corrosion resistance of the PANI coating improved significantly with a decrease in scan rate and by limiting the upper potential, especially during longer exposure times up to 72 h. Results suggest that controlling the deposition parameters and optimizing the electrochemical conditions can lead to even greater improvements in the corrosion resistance of the stainless steel. These findings offer valuable insights for researchers and engineers in the field of materials science and corrosion protection, enabling them to develop more precise and efficient strategies for enhancing the durability and performance of stainless steel in acidic environments.

Thin Layers of Cerium Oxynitride Deposited via RF Sputtering.

Thin films of transition metal oxides and oxynitrides have proven highly effective in protecting stainless steels against corrosion in both chemically aggressive environments and biological fluids. In the present work, cerium zirconium oxynitride thin films were deposited to enhance the corrosion resistance of surgical-grade stainless steel to be used in osteosynthesis processes. Two techniques were employed: co-sputtering and radiofrequency (RF) sputtering, and the morphology and corrosion efficiency of the coatings deposited by each technique were evaluated. X-ray diffraction, X-ray photoelectron spectroscopy and field emission transmission electron microscopy were used to characterize the morphological and chemical structure, respectively. Additionally, the corrosion resistance of the oxynitride-coated surgical grade stainless steel system (ZrCeOxNy-AISI 316L) was assessed using Hank's solution as the corrosive electrolyte, to determine its resistance to corrosion in biological media. The results show that ZrCeOxNy coatings increase the corrosion resistance of surgical grade stainless steel by two orders of magnitude and that the Ce(III)/Ce(IV) equilibrium decreases the corrosion rate, thereby increasing the durability of the steel in a biological environment. The results show that Ce coatings increase the corrosion resistance of surgical grade stainless steel by two orders of magnitude and that the Ce(III)/Ce(IV) equilibrium decreases the corrosion rate, thereby increasing the durability of the steel in a biological environment.

Unsupervised learning-enabled pulsed infrared thermographic microscopy of subsurface defects in stainless steel

Metallic structures produced with laser powder bed fusion (LPBF) additive manufacturing method (AM) frequently contain microscopic porosity defects, with typical approximate size distribution from one to 100 microns. Presence of such defects could lead to premature failure of the structure. In principle, structural integrity assessment of LPBF metals can be accomplished with nondestructive evaluation (NDE). Pulsed infrared thermography (PIT) is a non-contact, one-sided NDE method that allows for imaging of internal defects in arbitrary size and shape metallic structures using heat transfer. PIT imaging is performed using compact instrumentation consisting of a flash lamp for deposition of a heat pulse, and a fast frame infrared (IR) camera for measuring surface temperature transients. However, limitations of imaging resolution with PIT include blurring due to heat diffusion, sensitivity limit of the IR camera. We demonstrate enhancement of PIT imaging capability with unsupervised learning (UL), which enables PIT microscopy of subsurface defects in high strength corrosion resistant stainless steel 316 alloy. PIT images were processed with UL spatial–temporal separation-based clustering segmentation (STSCS) algorithm, refined by morphology image processing methods to enhance visibility of defects. The STSCS algorithm starts with wavelet decomposition to spatially de-noise thermograms, followed by UL principal component analysis (PCA), fine-tuning optimization, and neural learning-based independent component analysis (ICA) algorithms to temporally compress de-noised thermograms. The compressed thermograms were further processed with UL-based graph thresholding K-means clustering algorithm for defects segmentation. The STSCS algorithm also includes online learning feature for efficient re-training of the model with new data. For this study, metallic specimens with calibrated microscopic flat bottom hole defects, with diameters in the range from 203 to 76 µm, were produced using electro discharge machining (EDM) drilling. While the raw thermograms do not show any material defects, using STSCS algorithm to process PIT images reveals defects as small as 101 µm in diameter. To the best of our knowledge, this is the smallest reported size of a sub-surface defect in a metal imaged with PIT, which demonstrates the PIT capability of detecting defects in the size range relevant to quality control requirements of LPBF-printed high-strength metals.

Investigating microstructure, mechanical properties, and pitting corrosion resistance of UNS S32760 super duplex stainless steel after linear friction welding

High-performance alloys such as super duplex stainless steels (SDSS) are of interest to the oil and gas industry, especially in deep and ultra-deep reservoirs where high pressures and highly corrosive environments are prevalent. SDSS have high nitrogen contents and pitting resistant equivalent number (PREN) values greater than 40, however, fusion welds of these alloys can exhibit unsuitable microstructures and defects that may result in failure during usage. Solid-state linear friction welding (LFW) offers an alternative for the effective joining of SDSS with a less detrimental effect on microstructure and properties. In this work, four LFW joints in UNS S32760 SDSS were produced and investigated by evaluating the process parameters required to achieve a high-quality joint with the desirable metallurgical, mechanical, and localized corrosion properties. These properties were assessed through metallography (optical microscopy and scanning electron microscopy), tensile and microhardness tests, and corrosion analysis according to the ASTM G48A standard. Results indicated that one specific combination of LFW parameters led to a defect-free joint, and that the mechanical properties of the weld in this case were comparable to those of the base material. Additionally, an adequate balance between ferrite and austenite phases was achieved throughout the microstructural gradients seen in the weld region. Microhardness values were below 350 HV, thus complying with the DNV–OS–F101 standard. Furthermore, no pitting corrosion was observed in this joint under the testing conditions suggested by ASTM G48A.

Effect of N and Nb Microalloying on Corrosion Resistance of 309S Stainless Steel for Canister-Stored Nuclear Waste

Effect of N and Nb Microalloying on Corrosion Resistance of 309S Stainless Steel for Canister-Stored Nuclear Waste

Microstructure, Mechanical Properties, and Corrosion Resistance of ER2209 Duplex Stainless Steel Manufactured by Plasma Arc Welding

Microstructure, Mechanical Properties, and Corrosion Resistance of ER2209 Duplex Stainless Steel Manufactured by Plasma Arc Welding

In-situ fabrication of martensitic stainless steel via heterogeneous double-wire arc-directed energy deposition

ABSTRACT In recent years, there has been a growing focus on additive manufacturing of martensitic stainless steel with exceptional performance. This study introduces a new pathway to fabricate martensitic stainless steel through heterogeneous double-wire arc-directed energy deposition (DED). ER316L and ER70-G are used as raw materials, melting together and forming a common molten pool. A steel block with a chemical composition of Fe-11.38Cr-7.52Ni-1.44Mo-1.54Mn-0.497Si (wt.%) is successfully manufactured. The microstructure, mechanical properties and corrosion resistance of the martensitic stainless steel are investigated. The results indicate that the microstructure of the steel consists of martensite and austenite, achieving satisfactory microhardness (381.38 ± 11.94 HV), tensile strength (1172.1 ± 25.7 MPa), ductility (11.3 ± 1.3%), toughness (146.3 ± 8.0 J) and corrosion resistance (0.865 μA/cm2). This work demonstrates great potential of fabricating martensitic stainless steel using heterogeneous double-wire arc DED, providing a new choice to manufacture martensitic stainless steel and potentially other alloys.

Post-Processing Effect on the Corrosion Resistance of Super Duplex Stainless Steel Produced by Laser Powder Bed Fusion.

This study examines the microstructural characteristics and corrosion resistance of super duplex stainless steel (SDSS) produced through laser powder bed fusion (LPBF). The analysis shows that the as-printed samples mainly exhibit a ferritic microstructure, which is due to the fast-cooling rates of the LPBF technique. X-ray and microstructure analyses reveal the presence of minor austenite phases in the ferritic matrix. The process of solution annealing led to a more balanced microstructure. Analyses of corrosion resistance, such as potentiodynamic polarization tests and EIS, indicate that heat treatment has a significant impact on the corrosion behavior of SDSS. Solution annealing and stress relieving at 400 °C for 1 h can improve corrosion resistance by increasing polarization resistance and favorable EIS parameters. However, stress relieving at 550 °C for 5 h may reduce the material's corrosion resistance due to the formation of chromium nitride. Therefore, stress relieving at 400 °C for 1 h is a practical method to significantly enhance the corrosion resistance of LPBF-printed SDSS. This method offers a balance between microstructural integrity and material performance.

Corrosion studies of duplex surface-treated M420 stainless steel by plasma nitrocarburizing and WCrAlTiSiN multilayer coating

M420 stainless steel has good mechanical properties, but its corrosion resistance is poor, which limits its application in marine conditions. Single-technology processing has been unable to meet the development needs of modern industry. In this work, plasma nitrocarburizing (PNC) and CrN/CrTiAlSiN/WCrTiAlN multi-layer coating were carried out on M420 martensitic stainless steel by hollow cathode-assisted plasma treatment and multi-arc ion plating, respectively. The modified layers were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The results show that the nitrocarburized layer effectively improves the hardness gradient between the coating and the substrate. The presence of the composite strengthening layer enables the sample to obtain a thick and dense corrosion-resistant surface, effectively blocking the invasion of the corrosive medium. The corrosion rate of the PNC + C sample decreased by an order of magnitude. Combining hollow cathode-assisted rapid nitrocarburizing technology and multi-arc ion plating technology can significantly improve the mechanical properties and corrosion resistance of M420 stainless steel in a shorter time. The duplex surface-treated M420 stainless steel by plasma nitrocarburizing and WCrAlTiSiN multilayer coating exhibited excellent corrosion resistance compared to the nitrided and coated M420 stainless steel.