Pulsed Treatment Research Articles

Synchronous improvement in strength and ductility of Cu-bearing stainless steels through formation of bimodal grain structure induced by short-time electric pulses

Excellent strength and favorable formability are two important mechanical properties of stainless steel, but there is usually a trade-off between both properties. However, it has been suggested in recent studies that preparing microstructures with a non-homogeneous structure can effectively achieve strength-ductility synergy. Given these facts, a microstructure with bimodal grain structures was prepared in this study by short-time electric pulse treatment (EPT). Besides, the evolution of microstructures and mechanical properties of Cu-bearing stainless steel during EPT was analyzed. The results demonstrated that the non-uniform heating in the EPT process can rapidly promote localized grain growth, thus forming a bimodal grain structure compared with conventional heat treatment. The microstructure of the fine grains formed random textures, while the coarsened grains showed stronger textures. After EPT, the amount of S {123} < 634 < 634 >-type textures increased significantly, with the proportion reaching up to 30.1 %. There was also a certain amount of brass {110} < 112 >- and copper {112} < 111 >-type textures. Compared with the solution-treated samples, the best overall mechanical properties were detected under the optimal electric pulse parameters, which ultimately realized a synergistic increase of 11.8 % and 10.2 % in the ultimate tensile strength and ductility. The excellent strength-ductility synergy was closely related to heterogeneous deformation-induced (HDI) strengthening and textures induced by the bimodal grain structure. This finding may provide novel insights for enhancing the formability of biomedical metallic materials.

Inactivation of murine norovirus and hepatitis A virus on various frozen fruits using pulsed light

The frozen fruit sector has experienced significant growth due to improved product quality as well as the advantage of long-term preservation. However, freezing alone does not eliminate foodborne viruses, a major public health concern and considerable economic burden. One promising disinfecting treatment is pulsed light, shown previously to inactivate hepatitis A virus (HAV) and murine norovirus-1 (MNV-1) on the surface of fresh berries. Viral loads were reduced by 1–2 log, with minor visual quality deterioration observed. In this study, an FDA-compliant pulsed light treatment (11.52 J/cm2) was applied to frozen fruits and berries. Infectious MNV-1 and HAV titers were reduced by 1–2 log on most frozen fruits. A noteworthy finding was that reductions of both viruses on cranberries exceeded 3.5 log cycles. Although pulsed light caused a measurable rise in temperature on the product surface, no visible physical changes (e.g., color) were observed, and the fruit pieces were still frozen after treatment. Although the reduction of infectious titer by pulsed light alone was not large (1–2 log), considering the low amount of virus typically found on fruit, it may be beneficial in the frozen fruit sector. It would be easy to combine with other treatments, and synergic interactions might increase virus inactivation.

Different duration of exposure to a pulsed magnetic field can cause changes in mRNA expression of apoptotic genes in oleic acid-treated neuroblastoma cells

Purpose Neuroblastoma, a prevalent childhood tumor, poses significant challenges in therapeutic interventions, especially for high-risk cases. This study aims to fill a crucial gap in our understanding of neuroblastoma treatment by investigating the potential molecular impacts of short- and long-term pulsed magnetic field exposure on the neuronal apoptosis mechanism in an in vitro model of neuroblastoma treated with oleic acid (OA). Materials and methods Cells were cultured and divided into six following experimental groups: (I) Nontreated group (NT); (II) OA-treated group (OA); (III) Group treated with OA after being exposed to the pulsed magnetic field for 15-min (15 min PEMF + OA); (IV) Group treated with OA after being exposed to the pulsed magnetic field for 12 h (12 h PEMF + OA); (V) Group exposed to the pulsed magnetic field for 15 min (15 min PEMF); and (VI) Group exposed to the pulsed magnetic field for 12 h (12 h PEMF). Cell viability, rates of apoptosis, and mRNA levels of key apoptotic genes (TP53, Bcl2, Bax, and Caspase-3) were assessed. Results Significant reductions in cell viability were observed, particularly in the group treated with OA following long-term pulsed magnetic field exposure. Flow cytometry revealed elevated apoptosis rates, notably in the early stages of apoptosis. qRT-PCR analysis demonstrated increased expression of cleaved Caspase-3, Bax/Bcl2 ratio, and TP53 in cells treated with OA following long-term pulsed magnetic field exposure, signifying enhanced apoptotic pathways. Conclusions The findings indicate that long-term pulsed magnetic field exposure and OA treatment exhibit potential synergistic effects leading to the induction of apoptosis in SH-SY5Y cells. We have concluded that stimulations of pulsed magnetic field have the potential to serve as an adjuvant therapy for oleic acid-based treatment of neuroblastoma.

Pulsed electric field treatment applied to barley before malting reduces Fusarium pathogens without compromising the quality of the final malt

The growth of micromycetes and the associated production of mycotoxins during malting represents a potential safety issue and an economic challenge regarding the quality of beer as a product manufactured from malt. The treatment of malted cereals with a pulsed electric field (PEF) may be one method to overcome this issue. In this work were tested PEF conditions that would lead to a reduction in fungal growth without suppressing germination and thus causing deterioration in the technological parameters of the malt. Pre-soaking the grain for more than 3.5 h prior to PEF treatment was found to significantly reduce the germination energy and, compared to the untreated sample, enzymatic activity of the resulting malt. Therefore, a modification consisting of a short pre-soaking (10 min) and PEF treatment (field intensity 3.8 kV/cm, 100 pulses with peak width 20 μs) in a high conductivity environment (0.05 mol/L phosphate buffer) was implemented. This treatment led to a reduction (up to 80%) in growth of some Fusarium species (F. sporotrichoides and F. poae) and the production of corresponding mycotoxins, mainly trichothecenes A and ennianthins. Moreover, the treated malt did not differ significantly from the control malt in terms of enzymatic activity.

A prospective, randomised, controlled, double blinded, cross-over study on the effect of a single session of pulsed electromagnetic field therapy on signs of hip osteoarthritis in dogs

BackgroundCanine coxofemoral joint osteoarthritis is a common, painful and debilitating condition. The objective of this study was to evaluate if any measurable changes in pain or lameness occurred in this patient group immediately after a single treatment with pulsed electromagnetic field therapy. Eight dogs with coxofemoral joint osteoarthritis presenting with signs of pain and lameness were prospectively recruited to this randomised, controlled, double blinded, cross-over study. Subjects attended the research facility on two occasions for one active and one placebo treatment with pulsed electromagnetic field therapy. The immediate effect of one pulsed electromagnetic field therapy treatment on pain and lameness was measured subjectively with the Helsinki Chronic Pain Index and Visual Analogue Scale and objectively using a pressure sensitive walkway.ResultsA statistically significant difference (P = 0.03) for change in stride length in the affected limb was recorded for subjects between the active and placebo treatments with pulsed electromagnetic field therapy. Within the active treatment results, there was a statistically significant change in the measurement for reach (P = 0.04) and stride length (P = 0.047) which got shorter in the affected limb post treatment. For the subjective outcome measures, there was no statistically significant difference between the active and placebo treatments for the evening of the treatment day or the next morning from pre-treatment values. Within the placebo treatment results a statistically significant change (improvement) was detected in Visual Analogue Score (P = 0.03) between pre-treatment and the next morning values.ConclusionsThe findings of this study do not show demonstrable improvement in owner assessed pain levels or temporospatial performance in dogs with coxofemoral joint osteoarthritis immediately after a single application of pulsed electromagnetic field therapy.

Achieving Stress Relief in Martensitic Stainless Steel Via High-Density Pulsed Electric Current Treatment

Achieving Stress Relief in Martensitic Stainless Steel Via High-Density Pulsed Electric Current Treatment

Pulsing Addition to Modulated Electro-Hyperthermia.

Numerous preclinical results have been verified, and clinical results have validated the advantages of modulated electro-hyperthermia (mEHT). This method uses the nonthermal effects of the electric field in addition to thermal energy absorption. Modulation helps with precisely targeting and immunogenically destroying malignant cells, which could have a vaccination-like abscopal effect. A new additional modulation (high-power pulsing) further develops the abilities of the mEHT. My objective is to present the advantages of pulsed treatment and how it fits into the mEHT therapy. Pulsed treatment increases the efficacy of destroying the selected tumor cells; it is active deeper in the body, at least tripling the penetration of the energy delivery. Due to the constant pulse amplitude, the dosing of the absorbed energy is more controllable. The induced blood flow for reoxygenation and drug delivery is high enough but not as high as increasing the risk of the dissemination of malignant cells. The short pulses have reduced surface absorption, making the treatment safer, and the increased power in the pulses allows the reduction of the treatment time needed to provide the necessary dose.

The effect of pre- and post-harvest sodium nitroprusside treatments on the physiological changes of cut Alstroemeria aurea ‘Orange Queen’ during vase life

Cut flowers deteriorate rapidly after harvest, lasting mere days. To extend their vase life, various postharvest techniques are employed. Due to limited knowledge about the postharvest physiology of Alstroemeria cut flowers and the specific role of secondary compounds and antioxidant systems in their protection, this study investigated the optimal dosage of sodium nitroprusside (SNP) as a nitric oxide (NO) donor to enhance quality and antioxidant defenses. Preharvest foliar application of SNP at 0, 50, 100, and 200 µM followed by short-term pulsing treatments upon harvest at the same concentrations were applied in a factorial design. Results revealed that a preharvest 100 µM SNP treatment combined with a 50 µM postharvest pulse significantly increased the total amount of phenols (over 20%), antioxidant capacity (more than doubled), and the activity of two antioxidant enzymes (ascorbate peroxidase by over 35% and guaiacol peroxidase by about 20%). Notably, this combination also diminished ion leakage (by about 20%), ultimately extending the vase life by more than 40% compared to untreated plants. Therefore, SNP application at these specific dosages proves effective in bolstering Alstroemeria cut flower quality and vase life through enhanced total phenols and a strengthened antioxidant system.

Tackling Challenges of Long-Term Electrode Stability in Electrochemical Treatment of 1,4-Dioxane in Groundwater.

Electrochemical advanced oxidation is an appealing point-of-use groundwater treatment option for removing pollutants such as 1,4-dioxane, which is difficult to remove by using conventional separation-based techniques. This study addresses a critical challenge in employing electrochemical cells in practical groundwater treatment─electrode stability over long-term operation. This study aims to simulate realistic environmental scenarios by significantly extending the experimental time scale, testing a flow-through cell in addition to a batch reactor, and employing an electrolyte with a conductivity equivalent to that of groundwater. We first constructed a robust titanium suboxide nanotube mesh electrode that is utilized as both anode and cathode. We then implemented a pulsed electrolysis strategy in which reactive oxygen species are generated during the anodic cycle, and the electrode is regenerated during the cathodic cycle. Under optimized conditions, single-pass treatment through the cell (effective area: 2 cm2) achieved a remarkable 65-70% removal efficiency for 1,4-dioxane in the synthetic groundwater for over 100 h continuous operation at a low current density of 5 mA cm-2 and a water flux of 6 L m-2 h-1. The electrochemical cell and pulse treatment scheme developed in this study presents a critical advancement toward practical groundwater treatment technology.

Epidemic dynamics of complex networks under pulse treatment and vaccination

The dynamics of a new Susceptible-Vaccinated-Infected-Recovered (SVIR) epidemic model in complex networks under constant and pulse control are investigated. Firstly, the epidemic model in complex networks under constant control is proposed. Utilizing the basic reproduction number, the sufficient conditions for stabilizing the epidemic under constant control are established. Since constant control is not conducive to resource conservation, it has been replaced by pulse control in epidemic model. The paper demonstrates the global attractiveness of the disease-free periodic solution of the model under pulse treatment and pulse vaccination. In addition, a sufficient condition is put forward to make sure that the system persists under pulse control, indicating periodic outbreaks of the epidemic. Furthermore, the epidemic is uniformly persistent when the pulse period is greater than the pulse period threshold or the vaccination rate is less than the vaccination threshold. Finally, several numerical simulations prove the feasibility of the theoretical results. By comparing the pulse period with a critical value, the strategy that most contributes to controlling the epidemic propagation is chosen from constant control and pulse control to achieve maximum utilization of resources. Moreover, it shows that decreasing the fraction of pulse treatment and pulse vaccination or prolonging the pulse period is beneficial to epidemic propagation. The topology of complex networks has a non-negligible influence on the epidemic propagation under pulse control, which is demonstrated both theoretically and numerically.

Effects of atmospheric pressure plasma treatment on the quality and cellulose modification of brown rice

This study investigates the effect of atmospheric pressure dielectric barrier pulsed discharge plasma treatment on cooking quality and cellulose modification of brown rice. The results showed that 15 min of plasma treatment reduced the cooking time, hardness, and chewiness of brown rice by 27.40%, 30.68%, and 40.23%, respectively, compared to the control. The etching of the brown rice skin and the formation of water channels lead to increased water absorption. This led to a significant increase in palatability of the treated brown rice. In addition, the crystallinity and average particle size (Dhkl) of the treated brown rice were reduced to 10.93% and 42.85% of the initial level, respectively, and the cellulose solubility increased from 8.20% to 55.20%. The surface microstructure was also found to fracture and destroy of the cellulose structure. These findings suggest that plasma made the originally dense fiber structure of brown rice epidermis loose through the etching effect, thus improving the cooking quality of brown rice. The present conclusions offer fundamental insights into the interaction between plasma treatment and brown rice, which should be beneficial for applying plasma in whole-grain processing.

Structural features of steel pulsed laser treatment within a permanent magnetic field

Structural features of steel pulsed laser treatment within a permanent magnetic field

Can pulsed laser treatment reduce microbial adhesion on the surface of resin denture base materials?

Objectives. The present work investigates the influence of pulsed nanosecond laser patterning of two commercial heat cure poly (methyl methacrylate) denture base materials, Trevalon and DPI heat cure, on their surface characteristics such as roughness, hydrophobicity, and microbial adhesion. Methods. A Q-switched Nd:YAG solid state nanosecond pulsed laser at a wavelength of 532 nm with a fluence of 2.55 × 1010 W cm−2 having a pulse frequency of 10 Hz was used at varying translation stage speed and vertical spacing for the surface patterning of denture base materials. The surface properties of control and patterned materials were characterized by measuring the compositional changes, wettability, and roughness. Microbial adhesion was assessed by incubating the specimens in Candida albicans suspension at 37 °C for 2 h followed by estimating the number of adherent Candida cells. Results. The micro-Raman spectroscopic studies indicated no chemical changes in the materials due to laser patterning. However, laser patterning increased the average surface roughness from 0.02 ± 0.005 and 0.04 ± 0.003 μm to 3.85 ± 0.20 μm and 3.70 ± 0.12 μm respectively for Trevalon and DPI heat cure materials. In addition, a reduction in the surface wettability was evident as manifested by an increase in water contact angle from 76 ± 2° to 105 ± 1° for Trevalon and from 72 ± 1° to 97 ± 1° for DPI heat cure. Finally, the microbial adhesion studies clearly indicated that the surfaces with higher hydrophobicity and roughness following laser patterning exhibited reduced microbial adhesion. Significance. Laser patterning can be utilized to tune the surface features of denture base materials and thus offer a promising method to create microbial adhesion resistant surfaces. Clinically, such surfaces help in reducing the incidence of denture stomatitis, especially in immunocompromised patients, without altering the composition and bulk properties of denture base materials.

Treatment of telangiectasias with a 595-nm pulsed dye laser following hemangioma involution: a retrospective analysis.

Telangiectasias are the most frequent type of sequelae of infantile hemangiomas after involution. Few studies have reported the treatment of telangiectasias with 595-nm pulsed dye lasers. Therefore, the objective of this study was to assess the efficacy and safety of a 595-nm pulsed dye laser for treating residual telangiectasias following hemangioma involution. This is a retrospective case series that analyzes the medical records and reviews the charts of 22 patients who had undergone 595-nm pulsed dye laser treatment for residual telangiectasias. Pre- and post-treatment digital images were independently assessed, and the changes were scored to ascertain the efficacy of the treatment (0 = no change, 4 = complete improvement). Of the 22 patients, 59.1% experienced complete resolution of telangiectasias following treatment. No serious complications or side effects were reported. The observations indicate that the 595-nm pulsed dye laser is effective and safe for treating residual telangiectasias following hemangioma involution.

Direct shoot regeneration from cotyledonary node of Uraria picta (Jacq.) Desv. ex DC., an important plant of dashmula drugs, and assessment of genetic fidelity, metabolic profiling, and anti-diabetic activity

Uraria picta root is used in the polyherbal product ‘Dashmula’. Its exploitation for formulation preparation has depleted its availability, leading to medicine adulteration. Direct shoot regeneration from the cotyledonary node holds promise as a source of raw material. This study aimed to develop a regeneration protocol for U. picta and validate its genetic and metabolic fidelity. The seeds of U. picta showed low germination rates, prolonged dormancy, and poor viability. Root exploitation in the wild poses a threat to its availability in nature. Seedling’s derived cotyledonary nodes cultured on B5 medium supplemented with BAP (0.5–3 mg L−1), Kinetin (0.5–3 mg L−1), Thidiazuron (0.01–1 mg L−1), and meta-Topolin (0.1–4 mg L1). To address hyperhydricity in regenerated shoots, cotyledonary nodes were cultured on high-agar concentration media. Microshoots were exposed to IBA solution (50–800 mg L−1) pulse treatment for rooting. Tissue-cultured plants genetic fidelity was assessed using ISSR and SCoT markers, while metabolic fidelity was studied with HRMS. The chlorophyll content, antioxidant, and antidiabetic activity of micropropagated plants were evaluated. The highest shoot regeneration frequency, with a maximum of 6.57±0.278 shoots per explant, was achieved using 2 mg L−1meta-Topolin. The shoots were elongated, had expanded leaves, and were hyperhydrated. BAP (2 mg L−1) induced a maximum of 9.83±0.333 shoot buds per explant. BAP caused explant browning, profuse callus formation, dwarfing, and hyperhydric shoots. Hyperhydricity was alleviated with a higher agar concentration (1 %). IBA (400 mg L−1) induced a maximum of 2.18±0.090 roots per shoot and a root length of 9.23±0.033 cm. Tissue-cultured and mother plants exhibited clonal fidelity, similar metabolite and chlorophyll content, strong antioxidant activity, and equal efficacy for inhibiting α-amylase and α-glucosidase. This method can propagate elite clones of U. picta and offer its improvement via genetic transformation.

Mechanical behavior and underlying mechanism of nickel-based superalloy during coupling electrical pulse and ultrasonic treatment

Coupling electric pulse and ultrasonic treatment (CEPUT) is a multi-energy field-assisted forming technology that can improve the forming efficiency of materials. The current research focused on the surface modification of materials by CEPUT, lacking the explanation of its coupling mechanism. In this study, Inconel 718 was adopted as the research object to observe the mechanical behavior and microstructure after CEPUT uniaxial tension experiment. The deformation tendency of grain under coupling multi-energy field was described by analyzing the texture evolution and dislocation morphology. The coupling mechanism of ultrasonic vibration and pulsed current was revealed in CEPUT. The experimental results revealed that there was a nonlinear relationship between the increase of flow stress softening efficiency and the increase of ultrasonic energy density and current density. This phenomenon was the macroscopic manifestation of interference between initial ultrasonic vibration and vibration after energy attenuation, which was related to dislocation slip and recrystallization under coupled multi-field. In addition, more efficient path of dislocation slip was demonstrated through the CEPUT. Among them, ultrasonic vibration caused local resistance to rise at the dislocation source and dislocation pile-up, which strengthened the local Joule heating effect; while the pulsed current reduced the activation energy required for dislocation slip near the waning points. This effectively reduced the resistance of dislocation motion near the pinning point, promoting the chance of dislocation crossing and annihilation. Meanwhile, the high temperature caused by pulsed current and local high strain caused by ultrasonic vibration were more favorable to dynamic recrystallization, and the change of grain orientation was more active. The texture strength and grain orientation of the matrix can be effectively controlled by adjusting the input power of ultrasonic vibration and pulsed current.

Effect of Electric Pulse Treatment on Microstructure and Mechanical Property of Laser Powder Bed Fused IN718

This study investigated the impact of electric pulse treatment (EPT) on the microstructure and mechanical properties of laser powder bed fused Inconel 718 (IN718). Through a comprehensive experimental characterization, we found that EPT induced significant improvements in the microstructure of IN718. In the YOZ plane of EPT-700, the molten pool diminished and replaced by a grain boundary with granular Ni3Nb precipitates, and the dislocations increased while the irregular porosity decreased. Concurrently, enhanced mechanical properties of EPT-700 were obtained, including a hardness of 354.7 HV, an ultimate tensile strength of 930.21 MPa, and an elongation of 34.35%. Fractographic analysis revealed a transition in fracture mechanisms, highlighting the intricate relationship between microstructural modifications induced by EPT and mechanical response under load. These findings underscore the potential of EPT as a promising post-processing technique for optimizing the microstructure and mechanical properties of IN718 components fabricated via laser powder bed fusion additive manufacturing. This study contributes to the advancement of knowledge in the field of additive manufacturing and provides valuable insights for the development of high-performance metallic components.

Coupling pulsed magnetic treatment coated WC-12Co cemented carbide and magnetofluid to enhance milling performance of TC4 alloy

To explore an eco-friendly approach to improve the milling performance of TC4 (Ti-6Al-4 V) alloy, pulsed magnetic field treatment and magnetofluid are simultaneously applied to the NbN-coated cemented carbide (WC–12Co) milling tools. To evaluate the coupling effect of pulsed magnetic field treatment with magnetofluid, milling experiments of TC4 were conducted under cutting fluid and magnetofluid lubrication, respectively. The milling force, tool wear, and workpiece surface quality of magnetic field treated tools were compared with those of untreated tools. When the cutting fluid was lubricated, the magnetic field treatment reduced the feed force by 8.8 %. In contrast, the magnetic field treatment reduced the feed force by 20.7 % when the magnetofluid was lubricated, which reduced tool wear and also weakened coating flaking. The coupling of the magnetic field treatment and the magnetofluid significantly improved the milling performance of the tool, reducing surface roughness by 40.9 % compared to the untreated tool with cutting fluid lubrication. The enhanced milling performance mainly results from the coupling effect of magnetic field treatment and magnetofluid, which has a strong magnetic response to the treated tool and the magnetofluid was attracted to the magnetized tool, enhancing the lubrication of the contact area. In addition, the enhanced mechanical properties (8.2 % increase in hardness, 13.1 % decrease in elastic modulus, and 4.5 % increase in thermal conductivity) resulting from the pulsed magnetic field treatment reduces the milling temperature (11.7 °C) also contribute to the enhanced milling performance.

Mechanisms underlying the changes in the structural, physicochemical, and emulsification properties of porcine myofibrillar proteins induced by prolonged pulsed electric field treatment

This study aimed to explore how pulsed electric field (PEF) treatment affects the structural, physicochemical, and emulsification properties of porcine-derived myofibrillar proteins (MPs). Increasing PEF treatment induced partial polarization and protein unfolding, resulting in notable denaturation that affected both the secondary and tertiary structures. PEF treatment also improved the solubility and emulsification ability of MPs by reducing their pH and surface hydrophobicity. Confocal laser scanning microscopy confirmed the effective adsorption of MPs and PEF-treated MPs at the oil/water interface, resulting in well-fabricated Pickering emulsions. A weak particle network increased the apparent viscosity in short-term PEF-treated Pickering emulsions. Conversely, in emulsions with long-term PEF-treated MP, rheological variables decreased, and dispersion stability increased. These results endorse the potential application of PEF-treated porcine-derived MPs as efficient Pickering stabilizers, offering valuable insights into the creative use of PEF for enhancing high-quality meat products, meeting the increasing demand for clean-label choices.

In Situ Electronic Structure Analysis of Water-Corroded UNx in High Vacuum

Nitriding technologies are promising surface modification techniques of uranium based on pulsed laser irradiating and glow plasma treatment. Nitrided layers with different nitrogen contents (UN0.35, UN0.75, UN1.08 and UN1.5) were prepared on the surface of uranium. The present study aims to investigate the microstructure and corrosion properties of the reaction of the UNx layers with ultra-low water vapor at room temperature. The electronic structures were analyzed in situ by X-ray photoelectron spectroscopy in high vacuum. The results showed that the UN0.35, UN0.75, and UN1.08 samples were mainly composed of uranium nitride (UN) and metallic uranium, while the surface microstructure of the UN1.5 sample was U2N3. The dense and uniform nitride layer with a grain size of 20 to 50 nm was obtained on the uranium surface, which acted as a barrier and prevented the further diffusion of anions into the matrix. The corrosion products of the UN0.35, UN0.75, and UN1.08 samples were mainly UO2-xNy and UO2 after reaction with the water vapor. The contents of UO2-xNy increased with increasing nitrogen contents, and the corrosion rate decreased significantly. The intermediate compounds UO2-xNy reacted slowly with the water vapor, and eventually converted to UO2. Meanwhile, the corrosion products of the UN1.5 sample were mainly U2N3+xOy and UO2-xNy after reaction with the water vapor. The percentage of U2N3+xOy and UO2-xNy remained almost stable over a long period of time, which indicated that the high contents of U2N3+xOy and UO2-xNy prolonged the time for complete conversion to UO2. It can be concluded that the U-N-O ternary compounds retarded the corrosion process and the UNx layers with high nitrogen contents showed excellent corrosion resistance.