Test Temperature Research Articles

Laser cladding Ni60-SiC/Ti3SiC2 self-lubricating composite coatings on IN718 alloy: Wear mechanisms and oxidation behaviors

To enhance the service performance of IN718 alloy under severe working conditions, the self-lubricating composite coating of Ni60-SiC/Ti3SiC2 was fabricated on its surface using laser cladding. By systematically analyzing the microstructure and properties of composite coatings, the wear mechanism at different temperatures and the oxidation behavior at 800°C of coatings were discussed in depth. The results demonstrate that an increase in coatings’ microhardness by a factor of 1.9 to 3.1 over IN718 was achieved, benefiting from the fine-grained and solid-solution strengthening actions, and the hard phases such as C23C6, Ni3Si, TiC distributed diffusely inside the coatings. The tribological performance of coatings was also significantly improved, in which the coating with 10 wt.% Ti3SiC2 added had the lowest wear rates of 2.13 and 3.57×10-5 mm3/N·m at RT and 600°C, respectively, which were reduced by 82.74% and 87.43% compared to the substrate. When the test temperature changes from RT to 600°C, the main wear form of coatings changes from adhesive and abrasive wear to oxidative wear. With the Ti3SiC2 content increasing, the oxide film is gradually dense and uniform, and the oxidation resistance is significantly improved.

Fractographic analysis on fatigue crack propagation behavior of Inconel 706 at 25, 450 and 650oC

Fatigue crack propagation (FCP) behavior of Inconel 706 (IN706) was examined at two different R ratios of 0.1 and 0.7 and three different testing temperatures of 25, 450 and 650oC. Several points were notable, including the increase in near-threshold ΔK, ΔKth, value with increasing temperature, extremely high starting da/dN values for stage II regime at elevated temperature and the change in Paris' slope, m, at certain test condition. The crack path observation suggested that the increase in ΔKth and high starting da/dN values with increasing temperature was related to the crack blunting at the tip of crack at 450 and 650oC. To understand the reason for the change in m value with different R ratio and temperature, quantitative fractographic analysis was conducted on the FCP-tested IN706 specimens. The fraction of cleavage fracture varied in complex manner, depending on ΔK, testing temperature and R ratio. It was found that intergranular fracture, cleavage fracture competed with one another, determining the shape of da/dN vs ΔK curves of IN706.

Viscous-Layer Compressibility Correction for Two-Equation Reynolds-Averaged Navier–Stokes Models

The baseline two-equation Reynolds-averaged Navier–Stokes (RANS) models include fluid density but lack calibration for compressible flows, making them inadequate for high Mach numbers. Various compressibility corrections have been proposed to integrate the van Driest transformation or the semilocal transformation, i.e., a given compressible law of the wall, into the RANS formulation. Prior work has focused mainly on the logarithmic layer, but upon evaluating these log-layer compressibility corrections, we find that they do not significantly improve skin friction estimates. To overcome this challenge, we develop viscous-layer compressibility corrections. We do that by altering the dissipation terms. These corrections conform the RANS model to the semilocal scaling, resulting in more accurate predictions of mean velocity and temperature in a posteriori tests. Although not the primary focus of this study, we also find that the baseline one-equation Spalart–Allmaras model, which was proposed before the concept of semilocal scaling, produces results consistent with the semilocal scaling in a posteriori tests without requiring any compressibility correction.

Does temperature influence on biomarker responses to copper exposure? The invasive bivalve Limnoperna fortunei (Dunker 1857) as a model

Biomarkers are useful tools for assessing the early warning effects of pollutants. However, their responses can be influenced by confounding factors. In this study, we investigated the influence of temperature on multiple biomarkers in the invasive freshwater bivalve Limnoperna fortunei exposed to copper (Cu). The mussels were exposed to low and high environmental Cu concentrations at two temperatures (15 °C and 25 °C). After 96 h, the oxidative stress, neurotoxicity, and metabolic parameters were assessed. Our results showed that temperature is a key factor influencing biomarker responses in mussels, with higher glutathione S-transferase activity and lower energy reserves at cold temperature. In addition, the effects of Cu were greater at the highest concentration at 15 °C (increased lipid peroxidation and cholinesterase activity). Overall, these findings suggest that cold stress increases the susceptibility of L. fortunei to metal effects and highlight the importance of including temperature in toxicity testing and biomonitoring. In addition, using the invasive bivalve L. fortunei as a model could prove valuable in its role as a sentinel species for other organisms.

Thermomechanical and Viscoelastic Characterization of Continuous GF/PETG Tape for Extreme Environment Applications

The thermomechanical and viscoelastic properties of a glass fiber polyethylene terephthalate glycol (GF/PETG) continuous unidirectional (UD) tape were investigated using differential scanning calorimetry (DSC), thermomechanical analysis (TMA), and dynamic mechanical analysis (DMA). This study identified five operational conditions based on the Army Regulation 70-38 Standard. The DSC results revealed a glass transition temperature of 78.0 ± 0.3 °C, guiding the selection of temperatures for TMA and DMA tests. TMA provided the coefficient of thermal expansion in three principal directions, consistent with known values for PETG and GF materials. DMA tests, including strain sweep, temperature ramp, frequency sweep, creep, and stress relaxation, defined the material’s linear viscoelastic region and temperature-dependent properties. The frequency sweep indicated an increased modulus with rising frequency, identifying several natural frequency modes. Creep and stress relaxation tests showed time-dependent behavior, with strain increasing under higher loads and stress decreasing over time for all tested input values. Viscoelastic models fitted to the data yielded R2 values of 0.99, demonstrating good agreement. The study successfully measured thermomechanical and viscoelastic properties across various conditions, providing insights into how temperature influences the material’s mechanical response under extreme conditions.

Enhancing charpy absorbed energy of aged duplex lightweight steel plates through TRIP and TWIP mechanisms

Ensuring toughness in thick hot-rolled plates remains a challenge for lightweight steels in automotive, shipbuilding, military, and construction industries despite improved tensile properties. This study investigated the Charpy absorbed energy of thick hot-rolled Fe-0.4C-15Mn-6Al duplex lightweight steel plates exhibiting TRIP and TWIP mechanisms, aged at 450–500 °C to precipitate κ-carbides. Fracture initiation and propagation energies measured from instrumented Charpy impact testing were analyzed through microstructural and microfracture analyses. The 500 °C-aged (A500) specimen showed the highest Charpy absorbed energy, composed of the highest fracture initiation and propagation energies across all test temperatures, particularly due to active TWIP and TRIP mechanisms along with significant κ-carbide precipitation strengthening. Despite predominantly ductile fracture modes, regardless of aging temperature and test temperature, deformation mechanisms were influenced by stacking fault energy (SFE). Aging resulted in κ-carbide precipitation, reducing C and Mn contents in austenite and lowering SFE. At 25 °C, the superior energy absorption of the A500 specimen (296 J) was attributed to its high flow stress and extensive roughness in the fracture surface due to crack deflection in the fracture initiation region and zigzag crack propagation. The Charpy absorbed energy decreased significantly at lower temperatures due to limited development of slip line field and less zigzag crack propagation. Despite this, the A500 specimen maintained the highest energy absorption due to its optimized TWIP and TRIP mechanisms and κ-carbide precipitation strengthening.

Comparison of high-temperature friction and wear behaviours of Ti6Al4V produced by additive manufacturing and casting

Additive manufacturing (AM) methods, especially selective laser melting (SLM), have recently attracted attention because they enable the quick and easy production of complex parts that cannot be produced with traditional manufacturing methods. However, residual stresses in the fabricated components impact their mechanical characteristics and may necessitate additional heat treatments. In this study, SLM-produced Ti6Al4V parts were subjected to a stress relief treatment under argon gas at 790°C for 2 h. The microstructure, microhardness and high-temperature tribological properties were examined comparatively with the traditional casting method. Dry sliding tribological experiments were carried out at different temperatures up to 600°C to compare high-temperature performance. It has been determined that the microstructure of samples produced by casting and SLM comprised β and α phases. The casting sample had 66.02% α grains, whereas the SLM sample had 59.02% α grains. The average microhardness in the SLM sample was marginally higher than that in the casting due to the formation of martensitic α. The results showed that wear rates increased with temperature for each sample. SLM samples exhibited slightly higher wear rates at each test temperature compared to the casting sample, which is attributed to the oxidative wear mechanism. The higher percentage of oxygen in the triboxide layers in the casting sample increased the wear resistance. When examining friction coefficients, an increase in average friction coefficients was observed at a test temperature of 300°C, while a decrease was observed at a test temperature of 600°C.

Effect of printing temperature on the mechanical properties of 3D printed polyphenylene sulfide (PPS) during simple and repeated impact tests

AbstractFused filament manufacturing (FFF), also known as 3D printing, is one of the most commonly used additive manufacturing techniques for creating high-quality materials. This process demonstrates the intricacies and challenges involved in choosing appropriate manufacturing parameters to achieve the desired outcomes. Among these critical parameters is the nozzle temperature, which can be adjusted to enhance the mechanical properties of the 3D-printed Polyphenylene Sulfide (PPS) parts. The main objective of this study is to investigate the influence of the printing temperature on the mechanical properties and failure characteristics of 3D printed polyphenylene sulfide (PPS) parts during impact testing. To do this, a series of simple and repeated impact tests were carried out on printed PPS samples in the nozzle temperature range (320–350 °C). CHARPY tests were carried out on the samples manufactured with different sequences for the optimal orientation of the filaments. Furthermore, the impact energy absorption capacity and the induced damage as a function of nozzle temperature were evaluated. CHARPY test results showed that samples with stacking sequence (0/0) had the best impact resistance and specific absorbed energy (SEA). This sequence, printed horizontally, was used to test different print temperatures in single and repeated impact tests. Furthermore, the results indicated that samples printed with a nozzle temperature of 340 °C exhibited higher CHARPY impact resistance and specific absorbed energy (SEA), with a percentage difference of 45.57%, 41.95% and 44.21% compared to samples printed with nozzle temperatures of 320 °C, 330 °C and 350 °C respectively. For repeated impact tests, the results also show that samples printed with a nozzle temperature of 340 °C have a higher initial energy absorption rate and a greater number of impacts before complete failure of the sample. This result proves also that the changing of nozzle temperature does not have a significant effect on the induced damage after CHARPY and repeated impact.

A comparative experimental work on the drop-weight impact responses of thermoplastic polymers produced by additive manufacturing: combined influence of infill rate, test temperature, and filament material

A comparative experimental work on the drop-weight impact responses of thermoplastic polymers produced by additive manufacturing: combined influence of infill rate, test temperature, and filament material

Fracture characteristics of SMA mixtures with hydrated lime through the semi-circular bending approach

Stone Mastic Asphalt (SMA) is a composite mixture made up of high-quality crushed stone, fine aggregates, an asphalt binder, and a significant percentage of mineral filler in contrast to conventional mixtures. Renowned for its durability and rolling resistance, it is predominantly employed as a surface “wearing” course on main roads subjected to heavy traffic, but it can also be used as a binder course under specific project requirements. In this study, we investigated the effect of hydrated lime as a partial replacement of limestone filler at various concentrations on the mechanical and cracking resistance characteristics of 10-mm SMA mixtures. The semi-circular bending (SCB) test, which is pivotal for understanding the cracking mechanism was used to assess the mixtures performance-related response to this distress type. The mixture cores were produced with granite aggregates, limestone filler as natural filler, hydrated lime as natural filler replacement, and a 30/45 penetration asphalt type. Mixtures containing 1.1 %, 2.2 %, and 3.4 % of hydrated lime by weight of aggregates were evaluated, in addition to a control mixture without hydrated lime. The factors considered for comparing the mixtures included: load and deformation curves, stiffness, fracture toughness, fracture energy, and flexibility index of the mixtures. The experimental program also comprised a set of various test temperatures (0°C, 10°C, and 20°C) to better understand the cracking mechanism. Experimental results indicated a significant performance-dependency on the HL concentration and the test temperature. Precisely, it was found that the mixture with the highest hydrated lime content (3.4 %) exhibited the best cracking performance at 0°C and 20°C, making it a suitable filler replacement concentration. However, at 10°C, the mixture containing 2.2 % hydrated lime showed the most consistent performance overall, suggesting and important improvement in asphalt mixtures’ cracking resistance. Overall, these findings obtained from the SCB test approach substantiate the potential benefit of hydrated lime filler replacement in optimizing the cracking performance and durability of SMA mixtures under varying temperature conditions and loading regimes.

A new strategy for developing a Nb microalloyed fire-resistant steel: Effects of boron and cooling rate

This study investigates the correlation among cooling rates, boron addition, and their subsequent effects on the microstructure and mechanical properties of niobium microalloyed steels, specifically with an intent to develop new fire-resistant steels. Slower cooling rates enhanced the ferrite transformation and (Nb,Ti)C precipitation, promoting a shift toward an equilibrium-phase microstructure. A boron addition of 30 ppm was sufficient to increase the fire resistance of niobium microalloyed steels when slowly cooled after thermocontrolled rolling. At rapid cooling rate boron induced the formation of upper bainite. Boron is mainly segregated at the interface of (Nb,Ti)C precipitates, possibly hindering the coarsening kinetics of nanosized carbides and contributing to the maintenance of a high yield strength during fire exposure simulations. The boron addition promoted a ratio between yield strength at 600 °C and room temperature greater than 66%., boron also shifted the strain-temperature curve to higher temperatures in transient tensile tests. These findings contribute to the potential use of boron additions in advancing cost-effective, high-performance, fire-resistant steel development, highlighting the central role of microstructural control and optimized thermomechanical treatment.

Effect of test temperature on deformation microstructure and tensile property of a novel Ni-Co-based superalloy

The tensile behavior, deformation microstructures and failure mechanisms of a novel Ni-Co base precipitation-hardened superalloy, have been investigated at room temperature (RT), 450, 550, 650 and 750 °C. Deformation of the alloy at RT, 450, 550 °C is primarily mediated by dislocation slip and stacking faults while nano-sized deformation twinning is also involved at 650 and 750 °C. The yield and tensile strength decrease with increasing test temperature. In the temperature range of 450–650 °C, however, no obvious reduction in the yield strength and work-hardening rate at low strains is observed, which could be correlated to a high density of stacking faults or deformation twins. Low yield strength and work-hardening at 750 °C, could be related to the softening by thermal activation and the softening of γ′ particles caused by the repeated cutting via stacking faults or twins. However, as the testing temperature is over 450 °C, elongation of the alloy decreases significantly with increasing test temperature, which could be associated with intergranular cracking induced by stress-assisted grain boundary oxidation.

Investigating the effect of MXene reinforcement on the mechanical and vibrational behaviour of honeycomb core sandwich composite structures

Honeycomb core sandwich composite panels are now being employed in various industries and possess huge potential owing to the fact that they provide almost similar properties as that of traditional metallic materials with substantial reduction in weight and are extremely corrosion resistant. MXene nanosheets have caught attention of the scientific community owing their extraordinary physical, chemical and mechanical properties. In the present work, the effect MXene reinforcement on the bending and vibrational behaviour of honeycomb cored sandwich composite structures has been investigated using experimentation and finite element (FE) modeling. The honeycomb cored sandwich plates were fabricated and samples were tested via three-point bending and vibration test under various testing conditions. The SEM images revealed that the MXene nanosheets were well dispersed within the epoxy matrix when their mixture was prepared and the homogenous dispersion was also maintained in the fabricated honeycomb core. Also, the MXene and glass fibres were found to be well bonded with the matrix. As far as bending behaviour is concerned, the sandwich structure containing MXene reinforced honeycomb core displayed superior load bearing capacity and exhibited higher values of core shear strength and face sheet bending strength at all testing temperatures. Furthermore, the reinforcement of MXene resulted in an increase in the natural frequency for all the considered modes irrespective of the end conditions. For instance, the natural frequency of the honeycomb core sandwich composite plate at first mode increased by 5.5 % and 10.2 % under CFFF and CFCF boundary conditions, respectively, upon addition of MXene.

Boron/phosphorus co-doped nitrogen-rich carbon nanofiber with flexible anode for robust sodium-ion battery

Flexible energy storage devices have been paid much attention and adapts to apply in various fields. Benefiting from the active sites of boron (B) and phosphorus (P) doping materials, co-doped carbon materials are widely used in energy storage devices for the enhanced electrochemical performance. Herein, B and P co-doped flexible carbon nanofibers with nitrogen-rich (B-P/NC) are investigated with electrospinning for sodium-ion battery. The flexible of binderless B-P/NC with annealing of 600 °C (B-P/NC-600) exhibits the remarkable performance for the robust capacity of 200 mAh/g at 0.1 A/g after 500 cycles and a durable reversible capacity of 160 mAh/g even at 1 A/g after 12,000 cycles, exhibiting the equally commendable stability of flexible B-P/NC-600. In addition, B-P/NC-600 delivers the reversible capacity of 265 mAh/g with the test temperature of 60 °C. More importantly, the flexible B-P/NC-600 is fabricated as anode for the whole battery, delivering the capacity of 90 mAh/g at 1 A/g after 200 cycles. Meanwhile, theoretical calculation further verified that boron and phosphorus co-doping can improve the adsorption capacity of nitrogen carbon materials. The favorable performance of flexible B-P/NC-600 can be ascribed to the nitrogen-rich carbon nanofibers with three-dimensional network matrix for the more active site of boron and phosphorus co-doping. Our work paves the way for the improvement of flexible anodes and wide-operating temperature of sodium-ion batteries by doping approach of much heteroatom.

Post irradiation examinations of FeCrAl cladding in PWR conditions

FeCrAl alloys have been one of the prominent Accident Tolerant Fuel (ATF) cladding material candidates, primarily due to their excellent oxidation resistance in high-temperature steam conditions when compared to Zr-based alloys. Prototypic irradiation of fueled FeCrAl rods is a fundamental step in confirming the integral performance behavior during in-pile conditions. Early generation C26M cladding, fabricated through wrought metallurgy techniques, was fueled with UO2 fuel pellets and irradiated in a pressurized water loop in the Advanced Test Reactor (ATR) at the Idaho National Lab (INL) to a burnup (BU) of ∼25 GWd/tHM. After irradiation, the rodlets were nondestructively and destructively examined. Nondestructive examinations included visual exams, profilometry, and gamma scanning. These examinations highlight the unique deposits, BU profile of the rodlets as well as the migration path of fission gases within the rodlet, and typical diametrical morphology of fuel rodlets. During handling, brittle failure of one end cap on one pin occurred. Destructive examinations included microscopy and mechanical testing. Radial cross sections of the cladding were analyzed metallographically through light optical microscopy (LOM), scanning electron microscopy (SEM) highlighting a unique corrosion morphology and micro-cracking (∼20–30 μm past the main oxide layer) at the metal-oxide interface. Ring compression testing (RCT) was used to elucidate the mechanical property change of the FeCrAl cladding after neutron irradiation. In contrast to the non-irradiated material, which remained ductile at all test temperatures between 25 °C and 250 °C, the irradiated cladding fractured in a brittle manner at 50 °C and below. The results of the tests show that some challenges remain in the development of FeCrAl cladding for LWR cladding applications including improvement of in-reactor waterside corrosion performance and the retention of ductility after neutron irradiation.

On the use of vibrations and temperatures for the monitoring of plastic chain conveyor systems

In industrial automation, the transportation of unit loads plays a crucial role. This paper addresses the under-explored area of plastic chain conveyors, a versatile and efficient means of transport within production processes. Despite their widespread use, these conveyors suffer from wear and tear due to continuous contact between the chain and guide rails, often leading to unscheduled shutdowns and increased costs. The literature on monitoring solutions for such systems is sparse, particularly for plastic chains. This paper aims to bridge this gap by surveying the most common wear mechanisms for these systems and presenting a physical model that describes the interaction between the chain links and guide rails, based on chain of masses, springs and dampers and the Archard wear model. This model allows to relate the variations due to wear with other physical quantities, such as passage frequencies of the links and heat generated due to friction. The comprehensive model provides analytical formulas to understand the vibrations induced by the chain on the platform and the guide-rail temperatures. To validate the model and evaluate how the measurements are affected by the degradation of the system, an extensive experimental campaign was conducted on a conveyor test rig, acquiring vibration and temperature data. The end goal is to identify and discuss methodologies suitable for estimating the wear mechanisms of conveyor systems, with a focus on the constraints of industrial environments. Hence, this study aims to lay the groundwork for defining monitoring solutions that enhance the maintenance efficiency of plastic chain conveyor systems. The results suggest that the power Spectral Densities (PSD) of the platform’s accelerations are sufficient to estimate the average links pitch, which in turn could be used to assess the chain elongation. Besides, the local temperatures confirmed the model observations, making them suitable for estimating the slide-rail thinning.

Investigating the influence of acid-base/KH550 composite surface modified BF on the properties of fiber-reinforced SBS-modified asphalt mastic

The surface properties of fibers significantly influence fiber-reinforced asphalt mastic (FRAM) performance. However, the impact of composite-modified basalt fiber (BF) on basalt fiber-reinforced asphalt mastic (BFRAM) remains unclear. This study examines the effects of acid-base/KH550 modified BFs on BFRAM performance, providing an experimental basis for further optimization. Tests included SEM and fiber leakage for BFs and separation, physical properties, DSR, and DMA for BFRAMs. The research indicates that (1) Composite modification enhances the fiber’s surface roughness, activity, oil-holding properties, and compatibility with SBS-modified asphalt. (2) Due to differences in acid-base etching, acid etching combined with KH550 promotes a more uniform and extensive coupling reaction with the BFs. In contrast, alkali etching with KH550 facilitates a deeper, localized reaction. (3) Composite modification of the BFs significantly improves the high-temperature rheological properties of the BFRAMs, with acid-base etching making the grafting reaction between the fiber and coupling agent more pronounced. At a test temperature of 82°C, the rutting factor of BFRAMs containing composite-modified (acid-etched + KH550) BFs is 2.7 times that of asphalt mastic without BFs. (4) The glass transition temperature of BFRAMs modified by acid etching and KH550 is 4.9°C lower than that of the original asphalt mastic, proving that composite-modified BFs enhance the low-temperature elastic deformation capacity of the BFRAMs.

Impact of specimen size on mixed mode I and II fracture behavior of asphalt mixture using MMTS criterion

This study investigates how the diameter of specimens impacts the cracking behavior of asphalt mixtures. Testing was conducted on SCB specimens with diameters of 64, 86, and 150 mm under different fracture modes and temperatures. Fracture toughness and fracture energy, crucial fracture parameters, were determined for the tested specimens. The findings revealed that an increase in Me (mode mixity) values led to a decrease in fracture toughness but an increase in fracture energy. By considering all specimen sizes and test temperatures, the fracture toughness for mixed mode I/II and pure mode II was, on average, 13 % and 29 % lower than that for pure mode I loading, respectively. Conversely, the fracture energy for mixed mode I/II and pure mode II was, on average, 19 % and 38 % higher than that for pure mode I loading, respectively. Larger specimens exhibited enhancements in both fracture toughness and fracture energy. Considering all loading modes and test temperatures, the fracture toughness for specimen diameters of 86 mm and 150 mm was, on average, 9 % and 26 % higher than that for a diameter of 64 mm, respectively. The corresponding improvements in fracture energy were 8 % and 14 %, respectively. Additionally, it was observed that fracture toughness increased with decreasing temperature until −20 °C, after which it declined. On the other hand, fracture energy rose with increasing test temperature for all specimen sizes and mode mixities, with a notable increase at 10 °C due to the brittle nature of asphalt concrete. Moreover, the size of the fracture zone (rc) was influenced by temperature and specimen size (R), with larger R resulting in an increase in rc. However, a decrease in temperature initially caused a slight decrease in rc followed by an increase. The study concluded that the MMTS (modified maximum tangential stress) criterion effectively predicted the fracture behavior of SCB specimens across various sizes and loading modes, providing accurate estimations for asphalt mixture fracture behavior. By considering all loading modes and test temperatures, the average error values were 5.9 %, 6.2 %, and 6.5 % for specimen diameters of 64 mm, 86 mm, and 150 mm, respectively.

Ultraviolet curing technology plus chemical copper plating: A novel method for producing highly durable fabric‐based flexible circuit

AbstractThe construction of flexible circuits is a crucial and challenging aspect in the design and fabrication of fabric‐based flexible electronics, which hold significant potential for various applications. In this study, we successfully developed high‐precision and durable fabric‐based flexible circuits by ingeniously combining ultraviolet light (UV)‐curing technology with chemical plating. Specifically, a UV coating containing Ag/Fe3O4 catalysts was applied onto polyester fabric surface, followed by printing the designed circuit structure diagram onto the fabric using UV light‐directed curing of the coating, and fabric‐based flexible circuits were then fabricated through chemical plating process. The fabric‐based flexible circuits exhibit only minimal increases in resistance following durability testing, including bending (8000 times), abrasion (2000 times), high and low temperature stability (−30 to 60°C), and high temperature/humidity stability (65°C, RH = 95%, 48 h), which remains consistently stable. This developed technology holds immense potential across various applications for smart wearable devices.

Investigation of new steel with increased strength for low temperature applications

Abstract The work established the patterns of a structural and phase transformations which occurs in the new steel of the 0,21C-1,0Mn-1,8Ni-0,3Cu-0,3Mo-0,03Ti-0,004B (%, mass) alloying system at different cooling rate. A thermokinetic diagram has been constructed. Laboratory samples of rolled products were manufactured and the mode of hardening of rolled sheets from a temperature of 860 ° C in water was tested to develop the industrial production of new steel using specialized equipment of the laboratory complex of LLC “EC Termodeform-MSTU”. The results of mechanical tests of rolled sheet samples after heat treatment showed that the steel under study in a hardened state has high strength characteristics in complex with increased impact strength at a test temperature of minus 70 °C: tensile strength σUTS = 1500 MPa, yield strength σ0.2 = 1150 MPa, relative elongation A5 = 12.5 %, hardness 429 HBW, impact strength KCV−70 = 50.3 J/cm2. This confirms its high quality and the possibility of using it for the production of heavily loaded mechanical engineering structures operated at low temperatures in the conditions of the Far North and the Arctic zone of the Russian Federation.