Degree Of Deformation Research Articles

Thixoforming of the Hot Extruded Aluminum AlSi9Cu3(Fe) Machining Chips

The main aim of this research was to investigate the aluminum AlSi9Cu3(Fe) machining chips recycling possibility utilizing a direct hot extrusion process and thixoforming. The thixo feedstock was prepared directly from the aluminum alloy AlSi9Cu3(Fe) machining chips waste without any remelting step. The machining chips were compacted, and direct hot extruded to create the solid samples and thixo feedstock. The aluminum alloy AlSi9Cu3(Fe) machining chips had a high degree of plastic deformation and after extrusion and heating in the semisolid temperature range, the suitable globular microstructure was achieved, which is a precondition for a successful thixoforming process. This approach can be characterized as a semisolid recycling process with a lower energy consumption, a higher material yield, and reduced greenhouse gas emissions into the atmosphere compared with conventional casting and recycling. Optical metallography, scanning electron microscopy accompanied with energy dispersive spectroscopy, electrical conductivity, and mechanical properties investigation were performed on the reference casted sample with a dendritic microstructure, the extruded sample with a severely deformed microstructure, and finally the thixoformed samples with a globular microstructure produced with different parameters, according to the Taguchi L4 (23) experimental plan.

Radon and carbon dioxide emissions from the surface rupture zone produced by the 1920 Haiyuan M8.5 earthquake in Northwest China

A M8.5 earthquake struck the Haiyuan area in 1920 and resulted in a 240-km long surface rupture zone along the Haiyuan fault (HYF). In this study, to determine the spatial relationship between soil gases and fault activity on a regional scale, radon (Rn) and carbon dioxide (CO2) concentrations in soil gas were measured in situ with a grid spacing of 5 ∼ 10 km along the Haiyuan surface rupture zone (HYSRZ). Ordinary Kriging (OK) and Inverse Distance Weight (IDW) interpolation were used to investigate spatial variations in Rn and CO2 concentrations. Synchronous soil gas anomalies were identified in southern Haiyuan County and at the southern end of the HYSRZ, and were correlated with higher slip rate, larger deformation, and larger degree rupture size than other segments. Moreover, soil gas anomalies were spatially highly coupled with seismically active zones and low b value areas, suggesting that the permeability and porosity of gas emissions are enhanced by higher stress. Two seismic velocity profiles across the gas anomaly area confirmed that low-velocity bodies exist at 0 ∼ 10 km below the surface, as revealed by magnetotelluric (MT) sounding results, indicating that gas emissions are associated with the migration of deep fluids. Our results provide new insight into the source of fluids in the HYSRZ and offer support for the design of a continuous geochemical measurement network in this area.

Stress-induced martensitic transformation during cold rolling of metastable β Ti–5Al–5V–5Mo–3Cr alloy

The present study focuses on modifying the microstructures and mechanical properties of a recently developed metastable β Ti–5Al–5V–5Mo–3Cr (Ti-5553) alloy through cold rolling technique. Three different degrees of deformations (5 %, 10 %, and 20 % thickness reductions) are employed on the as-cast Ti-5553 alloy. Microstructural analysis reveals presence of single β-phase in the as-cast alloy, which is further confirmed through X-ray diffraction technique. Cold rolling however activates different deformation mechanisms with increasing degree of rolling and hence evolve the microstructure as well. While the alloy subjected to the lowest extent of thickness reduction, deforms mainly via slip, that with the highest degree of rolling deforms through formation of slip lines, zigzag slip lines, and deformation bands. Overall, activation of specific twins such as {332} <113>β along the closed packed direction of the β matrix is noted for the optimally cold rolled specimen. Most interestingly, occurrence of stress-induced martensitic phase is also confirmed for all the cold rolled specimens with its volume percentage being directly proportional to the degree of deformation. This cold rolling imparted microstructural modifications also influence the local and global mechanical performance of Ti-5553 alloy. Highest values of hardness and compressive yield strength are noted for the Ti-5553 alloy cold rolled up to the highest extent. This systematic study is the first of its kind to report the influence of cold rolling on the stress induced martensite formation and hence establishes the processing-structure-property correlation for Ti-5553 alloy.

Evolution of copper ions in nanostructured Cu[formula omitted]O according to X-ray absorption spectroscopy data

Soft X-ray absorption spectroscopy (Cu L and O K spectra ) was applied to identify changes in the charge states of copper ions in quasi-statically loaded (torsion under pressure) Cu2O. As was found from our X-ray diffraction and X-ray absorption experiments, an increase in the degree of deformation lead to a decrease in the areas of coherent scattering (sizes of nanograins), to partial amorphization of oxides, and to a slight increase in the concentration of Cu2+ ions on the surface of the Cu2O samples. No new phases were detected using X-ray diffraction measurements. The repeated measurements of the Cu L and O K spectra of the nanostructured Cu2O samples after two years showed significantly more intense signals at high photon energies, indicating the appearance of Cu2+ ions on the surface of nanostructured Cu2O, corresponding to the CuO phase. It was shown that two types of Cu2+ ions on the surface of Cu2O samples with different binding energies of Cu 2p electrons could be formed.

Effect of different freezing conditions on ice crystal formation behavior and ice-growth inhibition by cryoprotectants.

The formation of ice crystals will have adverse effects on aquatic products, and the key to ensure the long-term preservation and better quality preservations of the product is to evaluate the intercellular ice crystal formation to find suitable refrigeration conditions and cryoprotectants. The ice crystal formation was successfully captured by using an inverted microscope cryomicroscopic system equipped with a low-temperature stage, the ice crystals formed under different freezing methods between tuna muscle cells were observed directly, the deformation degree of muscle tissue pores during crystallization was evaluated, and the effect of freeze-thaw times on tuna samples was analyzed. The effects of the use of cryoprotectant such as cellobiose and carboxylated cellulose nanofibers on ice-growth inhibition were investigated, and the reliability of the ice crystal observation results was further verified by the determination of physical properties. The results showed that carboxylated cellulose nanofibers had the best ice-growth inhibition effect, they prevented about 50% cell deformation compared with the control group, and also reduced the minimum size of ice crystal formation. In addition, the addition of cellobiose and sodium tripolyphosphate gave the ice crystals a more uniform size and roundness. The experiment proposed a stable and clear observation method for the process of intercellular ice crystal formation, and the accuracy of the observation method was further verified by some physical indicators. This may help in the selection of suitable measurement methods to directly observe ice crystal formation behavior and screen cryoprotectants. © 2024 Society of Chemical Industry.

Research on the Analysis of Residual Stress in Heat Treatment of Bellows Using ABAQUS.

Taking austenitic stainless-steel bellows as the research object, a finite element model for the heat treatment of austenitic stainless-steel bellows was constructed based on ABAQUS CAE 2022. The physical properties of the bellows after the heat treatment were analyzed using experimental and simulated curve processing analysis methods. The changes in residual stress and deformation in relation to the bellows under different cooling times were explored, as well as the distribution of residual stress and deformation at a certain cooling time. The results show that as the cooling time of the heat treatment increases, the residual stress of the bellow decreases significantly, the reduction rate accelerates, and the degree of deformation gradually decreases. When the cooling time of the heat treatment is 900 s, the residual stress of the wave peak in the middle position of the bellow is relatively small, and the residual stress value of the wave valley along the axis direction does not change significantly. The deformation degree of the wave peak and valley axis direction is relatively uniform.

Damage behavior of cold-rolled sintered fiber felts

Porous Materials, such as sintered fiber felts (SFFs), can contribute to the reduction of aircraft noise by acting as a low-noise trailing edge (TE). A rolling process with a time-varying rolling gap was sucessfully used to tailor the aeroacoustic properties of SFFs. To ensure the suitability of rolled porous materials for application, the mechanical properties after rolling must be investigated. The objective of this study was to clarify the effect of the rolling process on the damage evolution during tensile loading. A SFF consisting of a functional layer and a support grid made of alloy 1.4404 was used for rolling. Interrupted tensile tests in combination with computed tomography (CT) were used to investigate the damage evolution of as-received material, uniformly rolled material and material rolled with a gradient in thickness reduction. Metallographic examination and fracture surface analysis using scanning electron microscopy (SEM) complemented the CT analysis. Uniformly rolled material with a low degree of deformation (−0.74 ≤ φ < 0) failed identically to the as-received material. The functional layer failed first, starting from the center. The support grid subsequently failed due to the incremental failure of individual wires. The material rolled with a gradient in thickness reduction failed accordingly. A significant change in damage evolution occured for material rolled at high degrees of deformation φ ≤ −1.53, where the support grid fails first and the functional layer second. The rolling process using a time-varying rolling gap does not result in a detrimental mechanical behavior under tensile load. The results improve the general understanding of the effects of rolling processes on the properties of porous materials and allow the damage behavior to be taken into account with regard to its application as a TE.

The effect of starch types on extensional, linear and nonlinear rheological properties of starch cracker dough

Cracker is a popular snack, and their quality depends on the rheological properties of the dough during production. This study focused on the impact of different starch types (tapioca, corn, and potato) used in the same amount (30 g) on the rheology of starch cracker dough. Various rheological tests were conducted to assess the dough's properties. Linear viscoelastic properties were determined using oscillatory frequency and temperature sweep tests, while the nonlinear viscoelastic behavior was characterized through stress relaxation and creep recovery tests. Extensional rheological behavior was also examined. Additionally, the textural and thermal properties of the dough were monitored to understand starch gelatinization and its interactions with other components. In the linear viscoelastic region, no significant differences were found between different dough formulations. However, in the nonlinear viscoelastic region, the potato starch-containing formulation exhibited different viscoelastic and textural properties. Biaxial extensional rheological behaviors showed no significant variations between formulations. The temperature sweep test data from differential scanning calorimetry measurements were consistent with temperature sweep data. In summary, this study provides valuable insights into how different starches influence the rheological behavior of starch cracker dough, considering various degrees of deformation and temperature. These findings have implications for cracker production parameters.

Tension anisotropy of rolled AA7075-T6 auminium alloy: Experiments, BP-Neural network modeling and orientation dependent failure mechanisms

This paper presents the investigations on anisotropic tension mechanical responses of AA7075-T6 based on experiments, classical strength theory, BP-neural network modeling and fracture morphology characterization. Results show that the tension strength anisotropy weakens with deformation degree. Compared to the traditional method, the machine learning model exhibits more flexible in solving the anisotropic plastic responses of AA7075-T6 auminium alloy sheet and provides more accurate predictions. Through analyzing the fracture surface of tension specimen at various orientations, the failure mechanism is sensitive to orientation. Specifically, the irregular distribution of dimples zones and cleavage steps can be observed at lower material orientation. As the orientation increases, the alternative occurrence of ductile and brittle features dominates the failure mechanism. The medium-size dimple caused by coalescence of small-size dimples represents a transition between ductile features zone and brittle characteristics region.

Effects of a mattress cover with special airflow technology on the structure and function of the sacral and heel skin during loading: A two-arm exploratory crossover trial.

Prolonged mechanical loading of the skin and underlying soft tissue cause pressure ulceration. The use of special support surfaces are key interventions in pressure ulcer prevention. They modify the degree and duration of soft tissue deformation and have an impact on the skin microclimate. The objective of this randomized cross-over trial was to compare skin responses and comfort after lying for 2.5 h supine on a support surface with and without a coverlet that was intended to assist with heat and moisture removal at the patient/surface interface. In addition, physiological saline solution was administered to simulate an incontinence episode on the mattress next to the participants' skin surface. In total, 12 volunteers (mean age 69 years) with diabetes mellitus participated. After loading, skin surface temperature, stratum corneum hydration and skin surface pH increased, whereas erythema and structural stiffness decreased at the sacral area. At the heel skin area, temperature, erythema, and stratum corneum hydration increased. These results indicate occlusion and soft tissue deformation which was aggravated by the saline solution. The differences in skin response showed only minor differences between the support surface with or without the coverlet.

OPC UA-based Force Control for Deep Rolling with Mechanical Tools

Deep rolling can increase the service life of components under cyclic loads. This is achieved by plastic deformation of the component surface using a roller. The degree of plastic deformation depends on the rolling force. For a maximum increase in service life, the rolling force applied to the roller must stay within defined limits. When performing deep rolling using mechanical deep rolling tools, the rolling force is applied via an elastic element such as a leaf spring. The deep rolling force therefore depends on the deflection of leaf spring. It varies when the workpiece bends or has a varying diameter. These variations in the deep rolling force are not desired. They must be reduced to achieve optimum process results. To achieve this, a novel deep rolling force control for mechanical deep rolling was introduced in this paper. To control the rolling force, the force was measured with a sensory tool and machine tool axes were adjusted accordingly. The adjustment of the axes was implemented using the OPC UA standard. It is shown that this can reduce the force error during mechanical deep rolling by 90%. This ensures a constant process result and improves the mechanical deep rolling process.

Numerical simulation of submarine landslide tsunamis based on the smoothed particle hydrodynamics model

This paper establishes a SPH (Smoothed Particle Hydrodynamics) model for simulating underwater landslides based on the mixture theory. This model requires only one layer of particles, which greatly improves the computational efficiency compared with the traditional two-layer particle simulation for a mixture theory scheme. In the numerical model, based on a mixture theory, submerged landslide flow is regarded as a mixture of water and sediment phases and is discretized into a series of SPH mixed particles employing the volume fraction of the sediment phase. Using this volume fraction, a convection–diffusion term is calculated to represent the material transport between the water phase and the sediment phase. In addition, based on this volume fraction, the SPH mixed particles at any location in the considered domain are classified into three categories: (i) pure water, (ii) low-concentration suspended sediment, and (iii) high-concentration sediment. Pure water is treated as a Newtonian fluid. High-concentration sediment is modeled as a non-Newtonian fluid, and the Herschel–Bulkley–Papanastasiou rheological model is used to describe the viscous forces. The viscosity of the low-concentration suspended sediment, which acts as a transition layer between pure water and high-concentration sediment, is derived from the Chezy relation. A comparison of the numerical and experimental results demonstrates the high accuracy of the present numerical scheme. Using this validated numerical model, underwater landslides are simulated. Specifically, the effects of landslide deformation and compaction degree on the amplitudes of the surge wave crest and trough are investigated.

Исследование влияния термической обработки на структуру и механические свойства полуфабрикатов из сплава NbTa(Zr,Hf,Y), предназначенных для изготовления Nb3Sn сверхпроводников

The influence of the degree of deformation and annealing on the mechanical properties of Nb-based alloy samples of different compositions: Nb-Ta-Zr, Nb-Ta-Hf, Nb-Ta-Zr-Y used in the manufacture of Nb3Sn superconductors is studied. The deformability of Nb-based alloys in the composition of single-fiber composite Nb3Sn superconductors, which were manufactured using the technology of an internal tin source and the «powder – in – tube» method, has been studied. It is shown that the values of the time resistance of samples with a sheath made of Nb alloys 7.5 wt.% Ta–0.5 wt.% Zr and Nb–7.5 wt.% Ta–1 wt. % Zr are at the same level of ~ 650 MPa, and the elongation values are ~ 2%. The structural features of the fracture surface of Nb-based alloy samples with varying degrees of accumulated deformation and single-fiber conductors have been studied. The results of the work will be used in the development of technological modes for manufacturing Nb3Sn-based superconductors.

STUDI KOMPARASI UNTUK AS-BUILT SURVEY DAN PENGAWASAN DEFORMASI DARI GEDUNG: METODE TERESTRIS VS METODE SATELIT DI GEDUNG KULIAH UMUM (GKU) INSTITUT TEKNOLOGI SUMATERA

Infrastructure development is one of the main points of the program by the Indonesian government, outlined in Nawacita. One of the manifestations of this program in 2019 was the construction of the Gedung Kuliah Umum (GKU) at the Institut Teknologi Sumatera (Itera). As an effort to realize sustainable development, Geodetic surveys named 'as-built surveys' and periodic deformation observations need to be conducted. Both surveys can be done by terrestrial method using total station and satellite method using GPS-RTK. In this article, an analysis of the accuracy, precision and efficiency of the terrestrial method and satellite method for as-built survey and deformation observation at GKU Itera is reported along with a comparison between deformation calculation and direct observation. It was found that the terrestrial method produced better accuracy and precision level (19,5 cm compared to 43,3 cm) than the satellite method with 95% confidence level. In addition, the terrestrial method produces 3 times more data than the satellite method, although on the other hand, the total observation time of the terrestrial method is 100% longer than the satellite method. These results show that periodic monitoring is important for detecting the degree of deformation and realizing sustainable development. In addition, the terrestrial method is more suitable for accurate and precise periodic surveillance of a building than the satellite method. These findings could act as a contribution towards better sustainable deformation monitiring of a building and to underline the importance of having such periodic observations.

The coalescence and oscillation of eutectic gallium indium alloy droplets

Gallium-based liquid metal droplets have excellent deformation performance, and their oscillation has huge potential in oscillator and organ-on-chip research. At present, the oscillation of gallium-based liquid metal droplets controlled by external energy (such as the application of electric fields and chemical reactions) has been thoroughly studied, while there are vacancies in the study of the oscillation due to coalescence of droplets without external energy input. A numerical simulation study on the oscillation process after the coalescence of two and three eutectic gallium indium alloy droplets is conducted. The degree of deformation of the droplet is described by the dimensionless length change in the symmetry axis direction of the line connecting the centers of the initial droplets in the top view, that is, in the y direction. The oscillation curve of the droplet is obtained by the fitting method. The results show that the oscillation of coalesced droplets has obvious periodicity and damping attenuation characteristics, and increasing the number of droplets or reducing the droplet radius will increase the damping coefficient. Furthermore, the ratio of droplet sizes and their initial distribution have an impact on the variations in kinetic energy of the three droplets in the y direction, thereby influencing the deformation of the droplets. This research enriches the theory of gallium-based liquid metal droplet deformation and plays a significant role in guiding the application of droplet oscillation in the fields of micromixers and measuring the physical parameters of solutions.

Left atrial myocardial strain, assessed by the method of speckle-tracking echocardiography, as a marker of fibrosis in patients with ischemic stroke

Introduction. Cardioembolic stroke (CE) is one of the main etiopathogenetic subtypes of ischemic stroke and accounts for approximately 17% of all patients with ischemic stroke. Currently, there is a search for widely accessible radiological diagnostic methods that allow for the accurate diagnosis of left atrial (LA) dysfunction. Among these methods is transthoracic strain echocardiography (EchoCG), which provides additional information about the degree of deformation and change in shape of the LA during the cardiac cycle. To date, the association between strain EchoCG parameters and the severity of fibrotic changes in the LA among patients with CE remains unstudied.Objective. To evaluate the relationship between myocardial deformation parameters of the left atrium and the degree of fibrosis in patients with CE, as well as the impact of LA myocardial deformation changes on the prognosis of patients with CE.Materials and Methods. A prospective cross-sectional study included 132 patients who underwent evaluation and treatment in the Department of Emergency Neurology at the N.V. Sklifosovsky Research Institute for Emergency Medicine from 2020 to 2022. Group 1 consisted of 12 patients who died during hospitalization, while Group 2 comprised 120 patients who were discharged from the department after receiving treatment.Results. Deceased patients, compared to survivors, were characterized by the presence of LA myocardial remodeling. Statistically significant differences in LA myocardial deformation parameters were found between the study groups. Correlation analysis revealed statistically significant associations between LA myocardial deformation parameters and the severity of fibrotic changes. In the multifactorial logistic regression model, significant effects on the prognosis of patients were observed for LA strain peak systolic circumferential strain rate (LA-Scs) and LA strain peak systolic longitudinal strain rate (LA-Sls), with each 1% increase in the parameter associated with a 1.128-fold and 1.075-fold increase in the odds of a lethal outcome, respectively (OR: 1.128, 95% CI: 1.021–1.25, p = 0.017, and OR: 1.075, 95% CI: 1.009–1.15, p = 0.025).Conclusions. The conducted study established a strong correlation between LA myocardial deformation and LA fibrosis and the degree of fibrosis in the LA. LA myocardial deformation parameters can be used in risk stratification for the development of a lethal outcome in patients with CE.

Surface Morphology and Formation of Nanocrystals in an Amorphous Zr55Cu30Al10Ni5 Alloy under High-Pressure Torsion

A change in the structure of an amorphous Zr55Cu30Al10Ni5 alloy under deformation by high-pressure torsion (HPT) was studied by X-ray diffraction, high-resolution electron microscopy, scanning electron microscopy, and atomic force microscopy. It was found that the uneven distribution of deformation along the radius of the sample, characteristic of deformation by high-pressure torsion, led to the formation of an inhomogeneous structure. The formation of nanocrystals begins at the periphery of the sample. The threshold value of deformation required for crystallization onset was established; the formation of nanocrystals begins in areas with true deformation e = 4.83 or more. An increase in the deformation degree led to an increase in the height of steps on the deformed sample surface and an increase in the roughness of the surface. The thickness of an elementary step that was formed when one shear band came out to the surface was 10 nm, and its height was about 1 nm. It was found that large steps on the deformed surface of the sample had a complex structure and consisted of a large number of elementary steps. The results obtained are important for analyzing the stress distribution and the concentration of free volume in a deformed material, which affect the parameters of the amorphous-nanocrystalline structure formed.

Comprehensive crashworthiness simulation analysis of a large aircraft fuselage barrel section in various crash scenarios

To utilize computational techniques in investigate and evaluate the crashworthiness of typical fuselage section of a large transport aircraft in various crash scenarios, the finite element model of fuselage section was modeled and validated based on the vertical drop test of fuselage section at 6.02 m/s. The crash simulation analysis in various crash scenarios (such as concrete ground, soft soil grounds and water) were further conducted based on the validated model of fuselage section, and the crash response characteristics (deformation and failure mode, acceleration response and occupant injury risk, energy-absorbing characteristics) were analyzed and compared. The results show that the finite element model can accurately simulate the unrolling failure mode (three plastic hinges failure mode) of fuselage section and the failure of the connections of cargo floor crossbeams and fuselage frames, and it is in good agreement with the test results in terms of impact velocity and acceleration response. In the case of various soft soil grounds impact scenarios, the partial impact energy is absorbed by the soft soil ground, resulting in slightly different failure modes of fuselage section and a reduction in the peak acceleration. The water-entry impact failure mode of fuselage section is consistent with the rigid ground impact failure mode, the overall deformation degree of fuselage section decreases, but the degree of bending and upturning of fuselage frames increases with the increasing of the water-entry impact velocities The safety of occupants can be effectively protected in the soft soil ground and water-entry impact scenarios. The unrolling failure mode of fuselage section can be changed to the flattening failure mode (multiple plastic hinges failure mode) through the reasonable design to avoid the rupture of cargo floor crossbeams, and the more crash energy can be absorbed due to the production of more plastic hinges for the flattening failure mode, and the crashworthiness of fuselage section can be significantly improved.

Direct Melt-Calendaring of Highly Textured (Bi,Sb)2Te3 Thick Films: Superior Thermoelectric and Mechanical Performance via Strain Engineering.

The evolutions of chip thermal management and micro energy harvesting put forward urgent need for micro thermoelectric devices. Nevertheless, low-performance thermoelectric thick films as well as the complicated precision cutting process for hundred-micron thermoelectric legs still remain the bottleneck hindering the advancement of micro thermoelectric devices. In this work, an innovative direct melt-calendaring manufacturing technology is first proposed with specially designed and assembled equipment, that enables direct, rapid, and cost-effective continuous manufacturing of Bi2Te3-based films with thickness of hundred microns. Based on the strain engineering with external glass coating confinement and controlled calendaring deformation degree, enhanced thermoelectric performance has been achieved for (Bi,Sb)2Te3 thick films with highly textured nanocrystals, which can promote carrier mobility over 182.6 cm2 V-1 s-1 and bring out a record-high zT value of 0.96 and 1.16 for n-type and p-type (Bi,Sb)2Te3 thick films, respectively. The nanoscale interfaces also further improve the mechanical strength with excellent elastic modules (over 42.0GPa) and hardness (over 1.7GPa), even superior to the commercial zone-melting ingots and comparable to the hot-extrusion (Bi,Sb)2Te3 alloys. This new fabrication strategy is versatile to a wide range of inorganic thermoelectric thick films, which lays a solid foundation for the development of micro thermoelectric devices.

Effects of precipitation on the stress corrosion crack initiation of alloy 718 in simulated pressurized water reactor primary environment

The effect of precipitation on the stress corrosion cracking (SCC) initiation of Alloy 718 in high temperature hydrogenated water was investigated through slow strain rate tensile (SSRT) test. To clarify the roles of different secondary phases, different heat treatments were applied to separate the precipitation of those phases. There is a tradeoff between the mechanical strength and SCC resistance. Both intergranular δ phase and intragranular γ′/γ′′ phases can enhance the mechanical strength but decrease the SCC resistance of alloy. That is because the precipitates (especially the intergranular δ phase) can be preferentially oxidized due to the high content of active elements. Hence, the grain boundary decorated with δ phase would be significantly degraded. Moreover, both precipitates (especially the intragranular γ′/γ′′ phases) can aggravate the degree of localized deformation. Such enhanced deformation localization can induce stress concentration and promote SCC initiation at grain boundary.