Microstructural Evolution Characteristics Research Articles

Low-cycle fatigue property of Inconel 617 alloy at 700 °C: Mechanisms of cyclic deformation, precipitation and cracking behavior

Effects of strain amplitude ranging from 0.2 % to 1.0 % on the low-cycle fatigue properties of Inconel 617 alloy at 700 °C were studied. Much attention was paid to reveal the physical mechanisms of the cyclic deformation, γ′ phase precipitate and cracking behaviors based on the methods of flow stress partitioning and microstructure evolution characterization. Results showed that the material demonstrated a two-slope cyclic hardening behavior with different hardening rates. The strain amplitude of 0.4 % was found to be the threshold value in terms of both the precipitation behavior and dynamic strain aging (DSA). The diameter of γ′ phase precipitate was decreased from 28 nm to 12 nm when the strain amplitude increased from 0.2 % to 0.4 % and became disappeared at the larger strain amplitudes. The DSA activity characterized by the DSA strain range and maximum stress drop got significantly intensified with the increasing strain amplitude, about five times larger at 1.0 % than that at 0.4 %. Further, the mutual interaction between precipitation behavior and DSA was thoroughly analyzed. The number of crack initiation sites was increased with the increasing strain amplitude, and the dominant damage mechanism responsible for the crack propagation behavior was elucidated.

Intercritically Annealed Medium-Manganese Steel: Insights into Microstructural and Microtextural Evolution, Strain Distribution, and Grain Boundary Characteristics.

Aluminum-incorporated medium-manganese steel (MMnS) has potential for lightweight transport applications owing to its impressive mechanical properties. Increasing the austenite volume fraction and making microstructural changes are key to manufacturing MMnS. However, the grain boundary character and strain distribution of intercritically annealed low-density MMnS have not been extensively scrutinized, and the effects of crystallographic texture orientation on tensile properties remain ambiguous. Therefore, in this study, the microstructure, microtexture, strain distribution, and grain boundary characteristics of a hot-rolled medium-Mn steel (Fe-0.2 C-4.3 Al-9.4 Mn (wt%)) were investigated after intercritical annealing (IA) at 750, 800, or 850 °C for 1 h. The results show that the 800 °C annealed sample exhibited the highest austenite volume fraction among the specimens (60%). The duplex microstructure comprised lath-type γ-austenite, fine α-ferrite, and coarse δ-ferrite. As the IA temperature increased, the body-centered cubic phase orientation shifted from <001> to <111>. At higher temperatures, the face-centered cubic phase was oriented in directions ranging from <101> to <111>, and the sums of the fractions of high-angle grain boundaries and coincidence-site-lattice special boundaries were significantly increased. The 800 °C annealed sample with a high austenite content and strong γ-fiber {111}//RD orientation demonstrated a noteworthy tensile strength (1095 MPa) and tensile elongation (30%).

Deterioration micro-mechanism of graded aggregates with different gradations under vibratory compaction using X-CT testing

This study aims to explore the compaction deterioration micro-mechanism of high-speed railway graded aggregate (HRGA) fillers and further improve the compaction quality of HRGA fillers, contributing to improving subgrade service performance. Firstly, based on the vibratory compaction experiments, the compaction deterioration macro-characteristics of HRGA fillers with different gradations were revealed from the mechanical properties (i.e., dynamic stiffness Kd and subgrade reaction modulus K20). Secondly, X-ray Computed Tomography (X-CT) testing was conducted based on the multiple typical compaction stages selected from the Kd curve. The internal microstructure (i.e., particles and voids) characteristics within HRGA fillers with different gradations were measured by high-precision image processing approaches. Finally, the evolution characteristics of Kd, K20, and microstructure were used to reveal the compaction deterioration micro-mechanism of HRGA fillers with different gradations, and further explore the relationship between filler gradation and compaction deterioration. The results indicated that compaction deterioration characteristics of HRGA fillers with different gradations could be characterized by the inflection points of Kd and K20 curves. Besides, during compaction deterioration, particle abrasion crushing and the increase in surface edges and corners of the void reduced the stability of the skeleton structure within HRGA fillers with different gradations, resulting in a gradual decrease of Kd and K20. Furthermore, the relationship between Kd, K20, and microstructure with gradation could be quantitatively characterized by quadratic functions. Hence, based on X-CT measurement, it was feasible to reveal the compaction deterioration mechanism of HRGA fillers from macro- and micro-perspectives. This study contributes to establishing a theoretical framework for revealing the compaction deterioration of high-speed railway subgrade fillers and improving the quality of vibratory compaction for on-site subgrade construction.

Observation and Analysis of Micro- and Meso-structure of Soil in the Shear Zone of Guoyemoli Landslide in Zhouqu County

An X-ray diffraction mineral composition test was conducted on the shear zone soil of the Guoyemoli landslide in Zhouqu County to analyze the deformation and strength characteristics of the shear zone soil under different stress states. A scanning electron microscope and a stereo microscope were used to observe the microstructure of the shear surface of the shear zone soil, revealing the microstructure evolution characteristics of the shear zone soil sample. The findings of this study provide a data basis for slope stability and risk assessment from a micro perspective.

An in-situ investigation on the microstructure and viscosity characteristic of mold flux during slag-metal reaction process

The slag-metal reaction during the continuous casting of high Al steel changes the molten slag structure from silicon-oxygen to silicon-oxygen-aluminum network structure, greatly affecting the viscosity properties of mold flux. In order to reveal the internal mechanism of the viscosity change during slag-metal reaction, the molecular dynamics simulation was employed to monitor the microstructure evolution characteristics of molten slag under different Al2O3/SiO2. The results showed that Q3Al decrease from 25.48% to 22.26%, Q4Al and Q5Al increase from 68.82% and 1.70% to 71.26% and 2.88%, respectively with an increase of Al2O3/SiO2 from 0.1 to 1.2. The [AlO4]5- tetrahedral structure changed from low coordination to high coordination structure, the degree of polymerization increased, and the viscosity increased. The viscosity calculated by molecular dynamics is in good agreement with the experimental measurement. Finally, A dynamic link model between structural transformation and viscosity was innovatively established.

Hot deformation behavior and process optimization of TC4-DT alloy fabricated by wire and arc additive manufacturing with in-situ forging

The near net shape forging of a preform fabricated using additive manufacturing (AM) technique has attracted significant attention due to its exceptional material utilization rate. However, the complexity of the parts hinders its further development. This study investigated the hot deformation behavior of TC4-DT titanium alloy fabricated by wire and arc additive manufacturing (WAAM) with in-situ forging. The isothermal compression samples underwent homogenizing treatment to eliminate layer bright lines before being subjected to deformation at temperatures ranging from 800 to 950 °C and strain rates ranging from 0.01 to 1 s−1 with the height reduction of 60%. Subsequently, the hot deformation constitutive equations and hot processing map were established to analyze the characteristics of hot deformation and microstructure evolution. The results demonstrate that the hyperbolic sine constitutive equation considering strain can accurately predict flow stress under arbitrary deformation conditions, with an average relative error of 7.23%. Furthermore, microstructure analysis under different deformation conditions validated the applicability of the hot processing map, which identified preferable and easily achievable in-situ hot forging regions at temperatures between 900 and 950 °C and strain rates between 0.05 and 1 s−1 with the strain exceeded 0.4. Finally, WAAM combined with optimized in-situ hot deformation processing enables the production of macrostructures consisting of fully equiaxed prior-β grains while maintaining isotropy in mechanical properties, thereby providing a solid foundation for direct additive manufactured complex forgings featuring uniformly fine equiaxed grains and highly comprehensive properties.

Microstructure and microtexture evolution characteristics of a powder metallurgy Ni-based superalloy during static recrystallization

Microstructure and microtexture evolution characteristics of a powder metallurgy Ni-based superalloy during static recrystallization

Effect of caliber rolling temperature on the deformation behavior and mechanical properties of dual-phase medium Mn steel

Dual-phase medium manganese steel (MMS) was caliber rolled at 800, 900 and 1000 °C, respectively, in order to clarify the deformation behavior and mechanical properties of warm deformed MMS. Herein, the microstructure evolution, tensile behavior and fracture characteristics exhibit obvious dependence on the caliber rolling temperature. The warm rolled steel contains martensite and austenite phases with heterogeneous grains including coarse fiber grains (CFG) and ultrafine equiaxed grains (UFG), which shows different microstructural stability. With the increase of rolling temperature, dynamic recrystallization (DRX) is more obvious, corresponding with the increasing percent of UFG, as well as the decreasing percent of CFG and martensite volume fraction. Meanwhile, high deformation temperature also leads to high austenite stability and the decreasing Transformation Induced Plasticity (TRIP) effect. The strength, strain hardening behavior and total elongation are gradually increased with the decrease of rolling temperature, which is attributed to severe strain partitioning and unique laminated structure in the caliber rolled MMS with low rolling temperature. Moreover, the warm rolled MMS reveals obvious ductile-ductile transition behavior in the temperature range from 25 °C to −60 °C. In addition, the low caliber rolling temperature also results into high impact energy, which is attributed to the high volume fraction of CFG.

Spatiotemporal prediction and characterization of microstructure evolution during in-situ heat treatment using a deep learning algorithm

The austenite grain growth plays a significant role in improving the structures and properties of carbon steels. Modeling, characterizing, and predicting the temporal evolution of microstructures is crucial for understanding the relationship of processing-structure-property. Therefore, in this study, we designed a customized in-situ heating device that could be installed in the scanning electron microscope chamber to observe the temporal evolution process of the microstructures of 45# steel. We collected the in-situ experimental images during heating for downstream deep learning-based grain boundary extraction, spatiotemporal sequence characterization, and prediction. The proposed pipeline was fully verified in three experimental datasets under two distinct heating schemes in terms of (1) short-term and long-term prediction, (2) feeding different lengths of input sequence, and (3) transferring to other datasets. The proposed pipeline presented a high performance in quantitative evaluation metrics and qualitative comparisons between the predicted results and the ground truths in all three verification scenarios. These results are inspiring for researchers as they can preview the evolutional state in advance, thereby saving money, labor, and time with the assistance of deep learning-based predictive models. We believe that this pipeline opens opportunities for modeling, characterizing, and predicting evolutional state, which will aid in the analysis of processing-structure-property relationship, tailoring heat treatment, and improving material properties.

Modeling coupled growth and motion of solid-air dendrite induced by convection in liquid hydrogen using phase-field lattice Boltzmann method

The safety hazard arising from the growth, condensation and accumulation of trace air in liquid hydrogen deserves attention. In order to predict the microstructural growth evolution and oxygen solute segregation distribution characteristics during solid-air dendrite motion induced by solution convection, a partially saturated bounce-back lattice Boltzmann coupled non-isothermal phase field method (PSLBM-PF) is proposed in this study. The partially saturated bounce-back lattice Boltzmann method (PSLBM) is employed to calculate the flow field and the forces and moments between the fluid and solid phases, and the phase field method (PF) is utilized for the computation of the growth of solid-air dendrites and the distribution of solute segregation. The motion of solid-air dendrites is determined by the momentum equation. The accuracy of the calculated interaction forces between fluid and solid phases was validated through the sedimentation process of circular particles in the liquid, and the capability of the present model to preserve the shape during solid-air dendrite motion (translational and rotational) was confirmed. Subsequently, this model was employed to investigate the growth and sedimentation motion of solid-air dendrites with different growth orientations in the solution. During dendrite settlement, the growth of the lower dendrite arms is promoted, while the settlement velocity and the solid phase fraction are almost unaffected by the growth orientation. Then, the differences in morphology evolution and solute distribution under conditions of forced convection for both stationary and motion are comparatively investigated, utilizing the free growth of solid-air dendrites under convection-free conditions as a reference. Finally, the model was utilized to study the growth of individual solid-air dendrites as well as translational and rotational motion under the action of shear flow. The presence of convection significantly alters the solute and temperature distributions at the solid-liquid interface, thereby influencing the dendrite growth process. The simulation results indicate that this model can predict the solid-air dendrites microstructural growth evolution and oxygen solute segregation distribution accompanying the convection and motion.

Hypergravity-exacerbated cracking in high-speed rotating 7075 aluminum blades

On Earth, high-speed rotating blades and rotors experience hypergravity, which is mainly derived from centrifugal force. Aluminum alloys are widely used in high-speed rotating machines. In particular, 7075 aluminum has excellent properties, providing it with great potential for application in high-temperature rotating parts. In this work, the cracking behavior and microstructural evolution characteristics of high-speed rotating blades under different stresses were studied. A specifically designed instrument and blades with multiple necks were assembled, and the stress was tuned by adding weight to the blade tip. Each rotating blade cracked on its root neck, indicating that the gradient hypergravitational force decreased from the root to the tip. The degree of high-temperature cracking obviously increased with a sawtooth-like tip, but the degree of low-temperature cracking did not obviously increase with a smooth tip. A comparison under a constant uniaxial force required a greatly increased ultimate cracking strength that was approximately 10–18 times greater than that under hypergravitational force at the same temperature. Force analysis indicated that the coupling of hypergravitational forces in the normal direction and torsional forces in the tangential direction accelerated cracking. A uniaxial force caused grains to extend along the blade direction. However, a tangential force cut these extended grains to accelerate cracking and grain refining. In this study, real-world simulated service conditions for commercial alloys rotating at high speeds and a new understanding of the mechanical properties of alloys under various severe conditions were provided.

Microstructure evolution characteristics of a powder metallurgy Ni-based superalloy during hot deformation

Microstructure evolution characteristics of a powder metallurgy (PM) Ni-based superalloy during hot deformation were investigated by isothermal compression tests at 1050 ˚C–1200 ˚C for strain rates of 0.001 s−1–1 s−1 in this work. And the relationships between the dynamic recrystallization (DRX) behavior, DRX mechanisms, twins, and γ´ were discussed. The results showed that discontinuous dynamic recrystallization (DDRX) which was nucleated by grain boundary bulging, occurred in all deformation parameters in this superalloy. For γ/γ´ poly-phase region deformation (1050 ˚C-1140 ˚C), the volume fraction of dynamically recrystallized (DRXed) grains increased with the increase in strain rates. The finding suggested that γ´ particles promoted the nucleation of subgrains in deformed grains, causing the continuous dynamic recrystallization (CDRX) mechanism, characterized by subgrain continuous rotation, to be another dominant DRX mechanism except for DDRX. Moreover, the formation of twin boundaries occurred under the comprehensive control of DRX and grain boundary migration. DRX promoted the formation of twin boundaries, but at high temperatures, the reduction of the free energy from grain growth was higher than twin formation, causing the possibility of twin formation to be reduced. For γ/γ´ poly-phase deformation, the area fraction and size of γ´ increased with decreasing compression temperatures and increasing strain rates, and high compression temperatures and low strain rates promoted the further dissolution of γ´. The optimum hot deformation processing conditions for PM Ni-based superalloy is 1110–1140 ˚C/0.01–0.1 s−1.

In-situ synthesis of high-performance TiN/TC4 sandwich structures via nitrogen-controlled laser directed energy deposition

Laser Directed Energy Deposition (LDED) additive manufacturing offers a versatile approach for fabricating composite materials, encompassing a wide range of heterogeneous and transition materials, known for their exceptional mechanical properties. In this study, we focus on the synthesis of TiN/TC4 sandwich structural materials in atmospheres characterized by varying nitrogen-to-argon ratios. This study includes the in-situ synthesis, microstructural evolution, and mechanical characteristics of these TiN/TC4 sandwich structures during the LDED process. Through this process, TiN was formed in-situ by the interaction of Ti and N atoms, exhibiting in robust metallurgical bonding with the TC4 matrix. Notably, the microhardness of the TiN/TC4 sandwich structures exhibits periodic variations along the deposition direction, ranging between 314.4 HV0.2 and 661.5 HV0.2. The tensile strength of the TiN/TC4 sandwich structures experiences significant enhancement, while maintaining toughness due to the laminate structure and reinforced with ceramic particles inside. The resulting sandwich composites demonstrate outstanding ultimate tensile strength, which can achieve 1123.3 ± 29.7 MPa. This represents a notable improvement of 20.3% over the TC4 deposited in a pure Ar environment, with a corresponding plastic strain of 2.5 ± 1.7%. This study demonstrates that layered heterogeneous materials with superior mechanical strength can be synthesized in-situ through flexible integration of LDED process and reaction atmospheres.

Investigation on the damage mechanism of micro-cutting surface layer of aluminum alloy 7075 with different heat treatment processes

This paper investigates the machinability and microscopic surface damage mechanisms of aluminum alloy 7075 subjected to different heat treatment processes during micro-cutting. Focusing on T6 and T73 heat-treated aluminum alloy 7075, the study employs a combination of experiments and simulations to analyze micro-cutting surface morphology, cutting forces, microstructure evolution, residual stress, and damage characteristics. The findings reveal that micro-cutting of aluminum alloy 7075 after T6 heat treatment exhibits no apparent speed sensitivity in the primary cutting force, while T73 heat treatment demonstrates noticeable speed sensitivity. The surface microscopic damage during micro-cutting is influenced by both cutting speed and depth, resulting in distinct forms and degrees of damage under varying conditions. An analysis of the residual compressive stress field indicates that the magnitude of residual compressive stress on the micro-cutting surface determines crack initiation, and the maximum depth of residual compressive stress dictates crack propagation. Microscopic damage in T6 heat-treated aluminum alloy 7075 predominantly occurs in the second and third deformation zones, while T73 heat treatment leads to most damage in the third deformation zone. Notably, crack propagation is evident in T6 heat treatment at any cutting speed with a cutting depth of 150 μm, whereas it is inconspicuous in T73 heat treatment at cutting speeds below 540 m/min. Furthermore, at cutting speeds below 540 m/min and a cutting depth of 150 μm, T6 heat-treated micro-cutting is prone to oxidative wear. In contrast, at a cutting speed of 72 m/min and a cutting depth of 150 μm, the predominant wear form in T73 heat-treated micro-cutting is oxidation wear. This study underscores the intricate interplay between heat treatment processes, cutting conditions, and microscopic damage in aluminum alloy 7075 micro-cutting. The nuanced insights provided contribute to a deeper understanding of the machining characteristics of this alloy, paving the way for improved processing methodologies.

Exploring the Influence of SiC Particles on Temperature Variations, Microstructural Evolution, and Mechanical Characteristics in the Friction Stir Processing of AA6061-T6 Plates

Exploring the Influence of SiC Particles on Temperature Variations, Microstructural Evolution, and Mechanical Characteristics in the Friction Stir Processing of AA6061-T6 Plates

Synthesis of cemented paste backfill by reutilizing multiple industrial waste residues and ultrafine tailings: Strength, microstructure, and GA-GPR prediction modeling

Industrial waste residues are increasingly reutilized in the preparation of cemented paste backfill for reducing the cost of mine filling. Therefore, to promote the utilization of the bulk industrial waste residues (IWRs), mechanical and microstructure properties of cemented ultrafine tailings backfill (CUFTB) manufactured by reutilizing 5–10 wt% steel slag (SS), 5–10 wt% fly ash (FA), 16–22 wt% carbide slag (CS), 0–3 wt% desulfuration gypsum (DG), and 40–74 wt% blast furnace slag (BFS) and ultrafine tailing (d50 = 10.84 μm) were investigated after curing of 1-, 3-, 7-, 14-, 28-, 56- days. Unconfined compressive strength (UCS) test was adopted to determine strength and the regression analysis was applied to establish UCS prediction model. XRD, SEM, and MIP were used to evaluate the evolution characteristics of CUFTB microstructure. The obtained results indicate that the cementitious material synthetized by IWRs can completely substitute Portland Cement (PC) for CUFTB. After curing of 28 days, CUFTB exhibit UCS values with increasing of 10.80% ∼ 44.89% than those made of PC. Logarithmic function UCS=α⋅lnt+β is constructed to characterize UCS development with curing time. By optimizing the hyperparameters of Gaussian process regression (GPR) using Genetic algorithm (GA), GA-GPR model is established with high accuracy for predicting UCS. Microscopic analysis reveals that under the alkaline environment, the hydration reaction of SS, FA, BFS occurred to generate calcite (CaCO3), ettringite (AFt) and hydrate calcium silicate gel with a low Ca/Si ratio. Microtopography formed with more refined pore distribution of 0.003- and 1- μm inside CUFTB. To substitute PC using the cementitious material synthesized by IWRs can reduce the mining cost and CO2 emission. The findings provide the guidance for the synthesis of sustainable filling material by reutilizing IWRs.

Comprehensive investigation of the impact of milling time on microstructural evolution and tribological properties in Mg-Ti-SiC hybrid composites

This research delves into the effects of milling time on the properties of Mg-Ti dual matrix composites reinforced with nano SiC powders, processed via spark plasma sintering. The study, driven by the need for advanced materials with enhanced wear resistance for the aerospace and automotive sectors, focuses on microstructural evolution and wear characteristics. It aims to understand how varying milling durations influence particle morphology, crystallite structure, and consequently, tribological behavior. Initial observations indicate a decrease in average particle size to 5.72 µm, followed by an increase to 14.83 µm due to cold welding and particle trapping, demonstrating the dynamic nature of particle morphology under different milling conditions. X-ray diffraction analysis reveals a notable reduction in magnesium's crystallite size with increased milling, suggesting plastic deformation. This study underscores that smaller crystallite sizes do not always correlate with strain, especially in smaller dimensions. Additionally, the research records variations in density and hardness, influenced by milling time and particle dispersion, with hardness showing a complex variation, peaking at 108 HV. Overall, the findings highlight the critical role of milling duration in shaping the microstructure and determining the mechanical and wear properties of Mg-Ti-SiC composites. This investigation contributes to the optimization of wear resistance in these composites, enhancing their applicability in high-performance industrial applications.

Nanotwining induced by tensile fatigue and dynamic impact of laser powder bed fusion additively manufactured CoCrFeNi high-entropy alloy

The laser powder bed fusion (L-PBF) additively manufactured CoCrFeNi high-entropy alloy (HEA), with face-centered cubic (FCC) crystal structure, demonstrates better comprehensive mechanical properties in the building direction (BD). Loading quasi-static, dynamic fatigue, and dynamic separated Hopkinson press bar (SHPB) impact stress conditions along the BD of the L-PBF processed HEA exhibit intriguing microstructural evolution characteristics. The L-PBF generates hierarchical dislocation grids containing numerous cell substructures within the HEA FCC grains, impeding dislocation motion during deformation and improving the strength. When subjected to dynamic fatigue loading, the dislocation grids restrict the mean free path of dislocations and thus trigger the activation of abundant stacking faults. Hence, numerous nanotwins form near the end of the fatigue life. Multiple twinning systems can also be activated under dynamic high-speed impact loading. Especially at a low temperature of 77 K, the stacking fault energy of the CoCrFeNi HEA decreases, resulting in increased activation of nanotwins, exhibiting exceptional toughness and resistance to dynamic loads. Additional twin boundaries also impede dislocation movement for the strain hardening. These findings hold valuable implications for the study of additively manufactured HEA parts working in extreme environments.

Study on Hot Deformation Behavior and Dynamic Recrystallization Mechanism of Cu‐Ti‐Fe Alloy

Hot compression experiments with the deformation temperatures of 750–950 °C and the strain rates of 0.01–10 s−1 are carried out on a Gleeble‐3500 thermal‐mechanical simulator. The flow behavior and dynamic recrystallization (DRX) mechanism of the Cu‐Ti‐Fe alloy are systematically studied under different hot deformation conditions. According to the curves of flow stress and work hardening rate, the DRX critical condition of the alloy is obtained, and the critical stress value of DRX is small under high‐temperature and low‐strain rate. After fitting, the logarithmic values of the critical stress and critical strain have a linear relationship with lnZ, which indicates that the alloy is more prone to DRX at high temperatures and low‐strain rates. The Arrhenius constitutive model of the alloy is established, the linear correlation coefficient (R2) is 0.984. Combined with the microstructure of Cu‐Ti‐Fe alloy, the microstructure evolution characteristics and DRX mechanism are elucidated. The dominant mechanism of the alloy under the deformation temperature of 750–950 °C is the DRX mechanism. The low‐angle grain boundaries (LAGBs) transform into high‐angle grain boundaries (HAGBs) and continuous dynamic recrystallization (CDRX) grains form. Abundant dislocations gather near the HAGBs, causing grain boundaries to protrude. High‐temperature conditions make the dislocations disappear, forming discontinuous dynamic recrystallization (DDRX) grains.

MICROSTRUCTURAL EVOLUTION AND ANTI-CORROSION CHARACTERISTICS OF AS-CAST AND LPBF PRINTED INCONEL PLATES IN SEAWATER ENVIRONMENT

Inconel 718 (IN 718) belongs to the category of nickel-based superalloys with outstanding mechanical characteristics such as high strength, better corrosion resistance, greater hardness, fatigue and wear resistance. This alloy is mostly implemented in manufacturing the components of aeroengines, nuclear reactors, space shuttles, pressurized boilers and so on. In most cases, the parts made from this alloy work in severe aggressive environments. A prolonged exposure of this alloy in such environments will pave the way for corrosion phenomenon which will minimize the service life of the components. It is reported that the parts made via additive manufacturing will exhibit better mechanical characteristics than the casted and forged parts. This work is aimed to investigate the anti-corrosion characteristics of both as-cast and LPBF printed IN 718 samples at various time intervals in the seawater environment. By means of FESEM micrographs, the microstructural evolution in both as-cast and LPBF printed IN 718 samples was analyzed. The anti-corrosion characteristics of both samples were investigated in the environment containing 3.5 wt.% NaCl (seawater) in terms of EIS and potentiodynamic polarization curves along with the corroded morphology. The results showed that the LPBF printed IN 718 samples exhibit fine cellular and columnar grains decorated with the NbC precipitates along their boundaries, whereas the casted samples have larger and coarser grains with uneven segregation of NbC precipitates. From the Tafel and EIS (Nyquist and Bode) plots, the LPBF IN 718 sample showed greater corrosion resistance in terms of current density and polarization resistance values. In particular, the 15 h LPBF sample has a strong, compact passive film formed on it. This compact passive film paved the way for this sample to exhibit lower current density (3.03 × 10[Formula: see text] A/cm2) and higher polarization resistance (3678 Ω · cm2) when compared with the LPBF and cast samples at other intervals.