JMatPro Software Research Articles

Investigation of the Effect of Alloying Elements on the Density of Titanium-Based Biomedical Materials Using Explainable Artificial Intelligence

Titanium alloys are widely preferred in the healthcare sector as biocompatible materials due to their superior properties such as low density and exceptional mechanical strength. Their low density provides lightweight solutions, and their density is closer to that of human bone compared to other metallic alloys with similar strength. This similarity facilitates a balanced load distribution between the bone and the implant, enhancing biomechanical compatibility. This study investigates the effects of alloying elements on the density of titanium-based biomedical materials using a computational materials science approach. A total of 72 different compositions of Ti-Al-V alloys were modeled using JMatPro software, and their densities were simulated at room temperature (25°C). The simulation produced a comprehensive dataset, which was utilized to train an explainable artificial intelligence (XAI) model. Advanced interpretability techniques, including SHAP (SHapley Additive exPlanations), LIME (Local Interpretable Model-agnostic Explanations), and Partial Dependence Plots (PDP), were employed to elucidate the influence of each alloying element on the density. The dataset was analyzed using an XAI-based regression model implemented with the Artificial Neural Network (ANN) algorithm. The interpretability graphs provided insights into the individual contributions of the alloying elements, revealing their positive or negative effects on the density. The findings offer a deeper understanding of the role of alloying elements in optimizing the performance of titanium-based biomedical materials, particularly in achieving lightweight designs. This study highlights the potential of integrating computational material modeling with explainable AI to advance the design and development of high-performance lightweight materials for biomedical applications.

High-Accuracy Prediction of Mechanical Properties of Ni-Cr-Fe Alloys Using Machine Learning

Artificial intelligence-driven prediction models have emerged as powerful tools for estimating material properties with high accuracy, yet the preparation of training datasets often demands labor-intensive and time-consuming experimental procedures. Leveraging the Computational Materials Science (CMS) approach, this study utilizes phase transformation calculations and thermodynamic data to simulate the mechanical properties of Ni-Cr-Fe alloys. Using JMatPro software, mechanical properties (0.2% Proof Stress, Fracture Stress, and Young's Modulus) of 50 Ni-Cr-Fe alloy compositions were simulated across a temperature range of 540–920°C, generating a dataset of 1000 rows. This dataset was used to train an Artificial Neural Network (ANN) model, with 80% allocated for training and 20% for validation and testing. The trained AI model demonstrated robust predictive capabilities, achieving a 96,61% accuracy rate in forecasting material compositions with the desired thermo-physical properties at specific temperatures. To validate the model's reliability, predicted alloy compositions were re-simulated under identical conditions in JMatPro, confirming the high fidelity of the model's predictions. The results underscore the efficacy of Computational Materials Science (CMS)-generated datasets as a scalable and reliable source for training AI models in materials science. This study highlights the potential of integrating Computational Materials Science (CMS) and Machine Learning approaches to accelerate material design and development processes, delivering significant improvements in prediction speed and accuracy.

Study on the microstructural evolution mechanism of the angular contact ball bearing rings during the quenching and tempering process

Since the rings of the angular contact ball bearings (ACBBs) are typical highly sensitive quenching thin-walled structure, the microstructure and properties variation of the rings during the heat treatment process are often difficult to be controlled precisely, and then the service life of the bearings is reduced. Therefore, in this study, the combination of the numerical simulation and experimental was carried out during the quenching and tempering process of ACBBs (7008C), the phase transformation of the inner and outer ring during the heat treatment process were explored, and the law of the microstructure evolution and the mechanical properties variation were revealed. Firstly, based on the multi-field coupling theory of temperature, microstructure and stress–strain field, the numerical simulation model of the heat treatment process of the bearing rings was established. Secondly, the content of each element of the rings was measured by a direct reading spectrometer (SPECTRO M12), and the thermophysical characteristics parameters of the material were calculated by the JMatPro software. Besides, the numerical simulation of the process was carried out by the Deform software. The evolution process of the temperature, microstructure, and properties during the heat treatment of the rings was investigated. Finally, the microstructure and mechanical properties of the heat-treated rings were obtained by optical microscopy, SEM and hardness tester. The results showed that the microstructure of the inner and outer ring after heat treatment process was cryptocrystalline martensite, and the average sizes of spherical carbides precipitated at grain boundaries were 0.39 μm and 0.38 μm, and corresponding hardnesses were increased to be 62.5 HRC and 62.7 HRC. The evolution of temperature-microstructure-mechanical properties during the heat treatment process of the ACBB rings are revealed, which can provide an important theoretical and technological support for the heat treatment process of the bearing rings for high-quality production.

Design and Optimization of W-Mo-V High-Speed Steel Roll Material and Its Heat-Treatment-Process Parameters Based on Numerical Simulation

W-Mo-V high-speed steel (HSS) is a high-alloy high-carbon steel with a high content of carbon, tungsten, chromium, molybdenum, and vanadium components. This type of high-speed steel has excellent red hardness, wear resistance, and corrosion resistance. In this study, the alloying element ratios were adjusted based on commercial HSS powders. The resulting chemical composition (wt.%) is C 1.9%, W 5.5%, Mo 5.0%, V 5.5%, Cr 4.5%, Si 0.7%, Mn 0.55%, Nb 0.5%, B 0.2%, N 0.06%, and the rest is Fe. This design is distinguished by the inclusion of a high content of molybdenum, vanadium, and trace boron in high-speed steel. When compared to traditional tungsten-based high-speed steel rolls, the addition of these three types of elements effectively improves the wear resistance and red hardness of high-speed steel, thereby increasing the service life of high-speed steel mill-roll covers. JMatPro (version 7.0) simulation software was used to create the composition of W-Mo-V HSS. The phase composition diagrams at various temperatures were examined, as well as the contents of distinct phases within the organization at various temperatures. The influence of austenite content on the martensitic transformation temperature at different temperatures was estimated. The heat treatment parameters for W-Mo-V HSS were optimized. By studying the phase equilibrium of W-Mo-V high-speed steel at different temperatures and drawing CCT diagrams, the starting temperature for the transformation of pearlite to austenite (Ac1 = 796.91 °C) and the ending temperature for the complete dissolution of secondary carbides into austenite (Accm = 819.49 °C) during heating was determined. The changes in carbide content and grain size of W-Mo-V high-speed steel at different tempering temperatures were calculated using JMatPro software. Combined with analysis of Ac1 and Accm temperature points, it was found that the optimal annealing temperatures were 817–827 °C, quenching temperatures were 1150–1160 °C, and tempering temperatures were 550–610 °C. The scanning electron microscopy (SEM) examination of the samples obtained with the aforementioned heat treatment parameters revealed that the martensitic substrate and vanadium carbide grains were finely and evenly scattered, consistent with the simulation results. This suggests that the simulation is a useful reference for guiding actual production.

Target Alloys of Iron-Based Materials through CALPHAD Method

The development of tailored alloys is an important aspect for enhancing efficiency across diverse applications in mechanical engineering. The use of computer-aided modelling offers an opportunity to enable a more efficient and targeted material development. In the present work, new iron-based alloys with specific properties were developed using the CALPHAD method. The alloy design developing process was carried out by using the simulation software JMatPro® and the data evaluation software EDA®. Using a full factorial plan, various alloys were modelled on the basis of the elements iron, nickel, vanadium, carbon, niobium and chromium. Afterwards, the alloys were narrowed down with regard to the criteria of carbide phase content, formability, and corrosion resistance. Subsequently, two final alloys were chosen based on their properties. Afterwards the selected final alloys were produced by mechanically blending different powder alloys and elements. These alloys were welded onto unalloyed steel using Plasma Transferred Arc welding and were characterised by using x-ray diffraction, scanning electron microscopy, hardness measurements, spark spectrometry and metallography. Subsequently, a verification of the welded samples regarding to chemical composition, phases, and corrosion resistance was carried out. The investigations showed that it was possible to simulate alloys with specific properties using computer-based software, which corresponded with the experimental studies.

Chemical Composition Optimization and Isothermal Transformation of δ‐Transformation‐Induced Plasticity Steel for the Third‐Generation Advanced High‐Strength Steel Grade

A new low‐manganese transformation‐induced plasticity steel is designed with optimized nickel content to achieve superior strength and ductility while minimizing the use of expensive nickel. The steel is optimized using JMatPro software, then cast, and hot rolled. To assess the effect of intercritical annealing on austenite (martensite at room temperature) volume fraction and carbon content, hot‐rolled steel samples quenched from different annealing temperatures (680–1100 °C) are used. Additionally, hot‐rolled steel coupons are intercritically annealed at about 50% austenite formation temperature (740 °C) and then subjected to isothermal treatments at 300–425 °C for varying times (10–90 min). After optimizing these treatments to maximize retained austenite (RA), tensile specimens are heat‐treated first at 740 °C and then isothermally at 325 °C. Thermodynamic calculations suggest that aluminum combined with silicon may lead to the δ ferrite formation, and even minimal nickel content can stabilize a considerable amount of austenite. In the experimental studies, it is shown that lower‐temperature bainitic holding enhances austenite stability by enriching the carbon content. Optimized two‐stage heat treatments yield up to 25.8% RA, with a tensile strength of 867.2 MPa and elongation of 40.6%, achieving a strength‐elongation product of 35.2 GPa×%, surpassing the third‐generation advanced high‐strength steel grades minimum requirement of 30 GPa×%.

Recrystallization Behavior of Computationally Optimized Low‐Alloy Steel at Various Temperatures and Strain Rates

The dynamic recrystallization (DRX) behavior of SA508‐III steel, a critical material for reactor pressure vessels (RPVs) normally treated by hot forging, is thoroughly examined in this article. In the investigation, elevated temperatures and the coarsening of metallic phases and carbides are revealed to contribute to the degradation of the steel's strength–toughness relationship. Utilizing computational thermodynamics, the stability of secondary phases, including carbides and brittle inclusions, is simulated to enable precise phase equilibrium calculations and accurate prediction of key mechanical properties such as yield strength, tensile strength, and hardness. These simulations facilitated targeted modifications to the alloy composition to enhance the steel's strength and hardenability under high‐temperature, high‐pressure conditions. In this study, alloy composition and processing parameters within the CALculation of PHAse Diagram framework, utilizing the ThermoCalc and JMatPro software packages, are optimized. In the microstructural investigations conducted under various isothermal deformation conditions (1173–1473 K) and strain rates (0.001–1 s−1), it is demonstrated that DRX mechanisms led to varied grain size developments, with a critical strain rate identified at 0.01 s−1 during high‐temperature deformations. In these findings, significant insights are provided into optimizing the mechanical performance of SA508‐III steel for RPV applications.

Thermodynamic–kinetic calculations and dilatometric verification of the martensitic and bainitic transformations in 4% medium-Mn steel

AbstractThe present study investigated the theoretical and experimental phase transitions phenomena during continuous cooling and isothermal holding above and below Ms temperature in 4 mass. % Mn medium-Mn steel. The thermodynamic–kinetic calculations were performed using JMatPro software, and phase transformations were recorded using a BÄHR high-resolution DIL805A/D dilatometer. The research covered continuous cooling rates from 60 to 0.05 °C s–1 and isothermal holding temperatures in a range between 420 °C and 230 °C. The issues related to both modelling and dilatometric methodology were discussed. The CCT and TTT diagrams were prepared on the basis of dilatometry and compared with the results of light microscopy and hardness tests. The alloy containing about 4 mass.% Mn and 0.22% Mo exhibited very high hardenability as only continuous cooling with rates lower than 1 °C s–1 allowed the bainitic transformation to be initiated. The bainitic transformation is accelerated after passing the Ms temperature. Both the incubation time and the time needed to complete the transformation were significantly reduced (the incubation time from 100 s to below 1 s and the completion time from over 4000 s to below 1000 s). The obtained microstructures were homogeneous and refined.

Thermodynamic approach for designing processing routes of 4Mn quenching and partitioning steel

AbstractThe study addresses the design and optimization of chemical composition and processing routes of new quenching and partitioning medium-Mn alloy using theoretical and experimental approaches. The thermodynamic calculations using Thermo-Calc and JMatPro software were carried out to characterize the influence of Mn, Si and Al contents on cementite formation and precipitation processes. The evolution of individual phases as a function of temperature under thermodynamic equilibrium conditions was estimated. The investigations included the determination of continuous cooling transformation (CCT) and the time–temperature transformation (TTT) diagrams of a model 4Mn alloy. The calculated equilibrium diagrams were compared with the experimental diagrams determined using dilatometric tests. Microstructural observations were carried out to verify the results of dilatometric measurements. The results of thermodynamic calculations and experimental tests showed the moderate agreement. It is related to the inaccuracy of currently available models in the used software and/or non-equilibrium conditions of experimental tests.

Dilatometric study on phase transformations in non-deformed and plastically deformed medium-Mn multiphase steels with increased Al and Si additions

AbstractIn this work, two novel alloys containing 4 and 5 mass.% Mn were subjected to theoretical calculations using JMatPro software and experimental studies using dilatometry in order to determine their critical temperatures and ranges of phase transformations of supercooled austenite in undeformed and deformed states. The differences in the kinetics of phase transformations and final microstructures were observed using a light microscope and compared for both investigated alloys. The Mn addition had a strong effect on reducing the Ac3 and Ms temperatures. The plastic deformation applied prior cooling affected the Ms temperature of investigated alloys and kinetics of phase transformations. Both investigated alloys showed high hardenability in the deformed and non-deformed states; and therefore, they can be used as good candidates for products obtained via the Quenching and Partitioning process. Investigated alloys can be used both for sheets and plates of increased thickness because the homogeneous martensitic microstructure can be obtained in a wide range of cooling rates during quenching. The obtained results show a wide technological window for the investigated alloys in producing sheets and plates via the Quenching and Partitioning process.

Effect of laser energy density on cracking susceptibility and wear resistance of laser-clad tribaloy T-800 coatings on DD5 single-crystal alloys

Effect of laser energy density on cracking susceptibility and wear resistance of laser-clad tribaloy T-800 coatings on DD5 single-crystal alloys

Microstructural study of additively-manufactured carbon steel-stainless steel 316L - Inconel 625 functionally graded material: Simulation and experimental approaches

Microstructural study of additively-manufactured carbon steel-stainless steel 316L - Inconel 625 functionally graded material: Simulation and experimental approaches

Failure analysis and heat treatment process optimization of NOS525 rotary flat binaural hot forging die

Failure analysis and heat treatment process optimization of NOS525 rotary flat binaural hot forging die

Effect of boron on the microstructures and properties of 17-4PH/TiC coatings by laser cladding

The microstructure and properties of 17-4PH/TiC coatings with different boron content have been studied. The calculation result of the JMatPro software is that the addition of B makes the appearance of M2B-type borides in the alloy. The experimental results show that with increasing addition of B, the hardness of the material increases, the friction coefficient and the wear volume decrease first and then increase, and the resistance to corrosion decreases. When the B content was 0.8%, the sample showed a higher hardness (566.3 HV0.3), the smallest wear volume (0.052 mm3), and the highest self-corrosion potential (−0.437 V), which indicated that the composite performance of the composite cladding layer was the best.

Effect of Mo and Cr on the Microstructure and Properties of Low-Alloy Wear-Resistant Steels.

Low-alloy wear-resistant steel often requires the addition of trace alloy elements to enhance its performance while also considering the cost-effectiveness of production. In order to comparatively analyze the strengthening mechanisms of Mo and Cr elements and further explore economically feasible production processes, we designed two types of low-alloy wear-resistant steels, based on C-Mn series wear-resistant steels, with individually added Mo and Cr elements, comparing and investigating the roles of the alloying elements Mo and Cr in low-alloy wear-resistant steels. Utilizing JMatPro software to calculate Continuous Cooling Transformation (CCT) curves, conducting thermal simulation quenching experiments using a Gleeble-3800 thermal simulator, and employing equipment such as a metallographic microscope, transmission electron microscope, and tensile testing machine, this study comparatively investigated the influence of Mo and Cr on the microstructural transformation and mechanical properties of low-alloy wear-resistant steels under different cooling rates. The results indicate that the addition of the Mo element in low-alloy wear-resistant steel can effectively suppress the transformation of ferrite and pearlite, reduce the martensitic transformation temperature, and lower the critical cooling rate for complete martensitic transformation, thereby promoting martensitic transformation. Adding Cr elements can reduce the austenite transformation zone, decrease the rate of austenite formation, and promote the occurrence of low-temperature phase transformation. Additionally, Mo has a better effect on improving the toughness of low-temperature impact, and Cr has a more significant improvement in strength and hardness. The critical cooling rates of C-Mn-Mo steel and C-Mn-Cr steel for complete martensitic transition are 13 °C/s and 24 °C/s, respectively. With the increase in the cooling rate, the martensitic tissues of the two experimental steels gradually refined, and the characteristics of the slats gradually appeared. In comparison, the C-Mn-Mo steel displays a higher dislocation density, accompanied by dislocation entanglement phenomena, and contains a small amount of residual austenite, while granular ε-carbides are clearly precipitated in the C-Mn-Cr steel. The C-Mn-Mo steel achieves its best performance at a cooling rate of 25 °C/s, whereas the C-Mn-Cr steel only needs to increase the cooling rate to 35 °C/s to attain a similar comprehensive performance to the C-Mn-Mo steel.

Microstructural Examination and Thermodynamic Analysis of Sn-1.5Ag-0.5Cu-x mass% Ni Lead-Free Solder Alloys

The diminutive additions of nickel (Ni) element have been fused to Sn-1.5Ag-0.5 mass% Cu (SAC155) lead-free solder alloy. The study was examined experimentally and computationally (using JMatPro software program) the microstructural features, thermal behavior, density, thermal diffusivity, and conductivity as well as tensile stress strain of the Sn-1.5Ag-0.5Cu-x mass %Ni (x = 0.00, 0.05, 0.10, 0.20, and 0.50) solder alloys (SAC155-xNi). The fusing additions of Ni have a little impact on the melting point of SAC155 alloy which increasing from 502 to 504.2K\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$504.2 K$$\\end{document}. The microstructure of SAC155 solder alloy included coarse grains of β-Sn besides, large eutectic regions, and embedded IMCs of Ag3Sn and Cu6Sn5. The computed values of Gibbs free energy (G) during solidification of the β-Sn phase, Ag3Sn, and Sn3Sn4 IMCs show the stability at -130.7×103J.kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$- 130.7 \ imes 10^{3} {\ ext{J}}{\ ext{.kg}}^{ - 1}$$\\end{document}, -157.7×103J.kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$- 157.7 \ imes 10^{3} {\ ext{J}}{\ ext{.kg}}^{ - 1}$$\\end{document}, and -377.13×103J.kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$- 377.13 \ imes 10^{3} {\ ext{J}}{\ ext{.kg}}^{ - 1}$$\\end{document}, respectively. The SAC155-xNi alloys involved finer β-Sn grains, large fibrous eutectic regions, (Cu,Ni)6Sn5 and (Cu,Ni)3Sn4 IMCs. The G of Cu6Sn5 decreased from -233.1×103J.kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$- 233.1 \ imes 10^{3} {\ ext{J}}{\ ext{.kg}}^{ - 1}$$\\end{document} to -317.9×103J.kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$- 317.9 \ imes 10^{3} {\ ext{ J}}{\ ext{.kg}}^{ - 1}$$\\end{document} when Ni content increased up to 0.25 mass %, then stable and steady at -318.4×103J.kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$- 318.4 \ imes 10^{3} {\ ext{J}}{\ ext{.kg}}^{ - 1}$$\\end{document} with more addition of Ni element. The formation of the (Cu, Ni)6Sn5 and (Ni, Cu)3Sn4 IMCs is motivated by the lowest Gibbs free energy, especially when Ni mass% is added to a sufficient level. The measured and computed values of specific heat at constant pressure (Cp) of SAC155-xNi alloys show a good matching especially at lower temperatures and a little mismatch at high temperatures which decreases with increasing Ni content. The activation energy of atomic arrangement (Q) increased from 11.36 to 13.41kJ.mole-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$13.41 {\ ext{kJ}}{\ ext{.mole}}^{ - 1}$$\\end{document} with increasing Ni content in SAC155-xNi alloys. Thermal diffusivity (α) and conductivity (κ) of SAC155-xNi gradually decreased with increasing temperature in the range from 303 to 423 K and/or Ni content in alloys. The measured values of (κ) are slightly lower than the computed value at similar temperatures of the SAC155-xNi alloys. The decrease in (κ) may be assigned to scattering the electrons or reducing the phonon contributions due to the presence of various solute atoms and different IMCs. The results of stress-strain graphs reveal the enhancement of YS and UTS for all Ni-containing alloys. The improvement of the yield stress (YS) and ultimate tensile strength (UTS) of Ni-containing alloys is attributed to the uniform distribution of the IMCs, the reduction of β-Sn grain size, and the smoothed enlargement of the eutectic region.

Improvement of microstructure and mechanical properties of laser welded Al-Si coated 22MnB5 steel joints by austenitic element copper

Improvement of microstructure and mechanical properties of laser welded Al-Si coated 22MnB5 steel joints by austenitic element copper

Effect of Heat Treatment on Magnetic Properties of EN8D Steel Used in Automotive Applications

The present study focuses on achieving the optimum combination of mechanical and magnetic properties for EN8D steel. SAE 1010 and EN8D steels are the candidate materials to manufacture the fixed nucleus of the disk-type electro-mechanical horn. Both materials have either good magnetic or mechanical properties. The main function of fixed nucleus is to get magnetized and pull the mobile nucleus towards it. However, as magnetization and demagnetization take place in the range of 300-500 Hz, fixed and mobile nucleus continuously strikes each other at high frequency. Due to such high frequency working condition, fixed nucleus is prone to failure under wear and tear or under fatigue. For this kind of application, a combination of magnetic and mechanical properties is required in the material used to manufacture fixed nucleus. Thus, in current paper, the effects of chemical composition, microstructure, hardness, strength and toughness of EN8D steel before and after austenizing and tempering heat treatment are evaluated and compared with as-rolled EN8D and SAE 1010 steels, which are mostly used for manufacturing fixed nucleus. Magnetic permeability was evaluated using JMatPro software and compared. Austenizing treatment is performed at 900 °C for 1 hour, followed by water quenching. Tempering treatment of the same was performed at 550 °C for 2.5 hours. The Ultimate Tensile Strength (UTS) and hardness of EN8D after heat treatment decreased from 917 to 781 MPa and 269 to 233 HV0.1 respectively. Charpy V-Notch (CVN) toughness of EN8D steel after heat treatment increased from 12 to 45 joules. It indicates that the decrease in strength and hardness resulted into increase in toughness. Microstructure changes from ferrite and pearlite to combination of tempered martensite, ferrite and bainite. Magnetic permeability evaluated by JMatPro software shows increment from 450 to 564 Gauss/Oersted in EN8D steel after heat treatment.
 Keywords: Electro-mechanical horn, fixed nucleus, magnetic permeability, JMatPro, SAE1010 steel, EN8D steel

Investigating the effect of Cr content on the microstructure and electrochemical measurement of low alloy steel

Investigating the effect of Cr content on the microstructure and electrochemical measurement of low alloy steel

Production and Characterization of an Economical 1100 MPa Advanced High-Strength Silicon-Containing Steel

AbstractIn this investigation, an attempt has been made to identify the metallurgical properties with the change of silicon contents, either theoretically by utilizing Thermo-Calc (the Scheil–Gulliver model implemented in the Thermo-Calc software) or JMatPro software, as a computational prediction technique, in addition to experimental examinations by dilatometer. Microstructures of investigated steels were evaluated optically at low magnification using optical microscopy. Scanning electron microscopy was used to study the observed microstructure at high magnification. ASTM standard specification E-8 was utilized for measuring the tensile property values, while fracture surfaces of the tensile samples were inspected by EDS (point-analyzer) employed in scanning electron microscopy. The investigated steel’s as-polished surface was studied using the experimental results, which revealed that the steel microstructure ranged from full-bainitic to full-pearlitic structures according to the variation of silicon contents. The count of non-metallic inclusions decreased and vice versa by the area occupied by non-metallic inclusions with the rising silicon content. The steel containing silicon of 0.87 wt.% has the best toughness combined with high tensile strength and hardness incomparable with conventional steel. Elongation (16.2%) combined with an ultimate tensile strength (1113 MPa) was achieved for the steel containing 0.87 wt.% Si.