Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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An Alternative Software Benchmarking Dataset: Effort Estimation With Machine Learning
(Elsevier Inc., 2026) Yürüm, O.R.; Ünlü, H.; Demirörs, O.
Effort estimation plays a vital role in software project planning, as accurate estimates of required human resources are essential for success. Traditional estimation models often depend on historical size and effort data, yet organizations frequently struggle to access reliable effort records. Public benchmarking datasets like ISBSG offer useful data but may lack coverage or involve licensing fees. To address this issue, we previously introduced a free, extendable benchmarking dataset that integrates functional size and effort data extracted from 18 studies. In this study, we examine the effectiveness of our dataset for predictive effort estimation and compare it with the widely used ISBSG dataset. Our analysis includes 337 records from our dataset and 732 ISBSG projects, focusing on those with COSMIC size data. We first developed and compared models using linear regression and nine machine learning algorithms — Bayesian Ridge, Ridge Regression, Decision Tree, Random Forest, XGBoost, LightGBM, k-Nearest Neighbors, Multi-Layer Perceptron, and Support Vector Regression. Then, we selected the best-performing models and applied them to an unseen evaluation dataset to assess their generalization performance. The results show that machine learning performance varies based on evaluation method and dataset characteristics. Despite having fewer records, our dataset enabled more accurate predictions than ISBSG in most cases, highlighting its potential for effort estimation. This study demonstrates the viability of our dataset for building predictive models and supports the use of machine learning in improving estimation accuracy. Expanding this dataset could offer a valuable, open-access resource for organizations seeking effective and low-cost estimation solutions. © 2025 Elsevier Inc.
Vibrational Spectroscopy Unveils Distinct Cell Cycle Features of Cancer Stem Cells in Melanoma
(Nature Research, 2025) Uslu, B.R.; Ozdil, B.; Tarhan, E.; Özçelik, S.; Aktuğ, H.; Güler, G.
Cancer stem cells (CSCs) play a central role in melanoma growth, resistance to treatment, and relapse, however, their dynamic regulatory behavior remains poorly understood. Vibrational spectroscopy offers a unique, label-free approach to investigate cellular heterogeneity at the molecular level. Here, we explored the biochemical and regulatory dynamics of CSCs identified by using a time-course design, integrating infrared and Raman spectroscopies with cell cycle analysis and immunocytochemistry targeting the checkpoint proteins p16 and p21. CSCs, non-cancer stem cells (NCSCs), and bulk CHL-1 melanoma cells were monitored at 11, 24, 48, and 72 h. CSCs showed a steady S-phase with an early rise in p16 followed by a subsequent increase in p21 expression, indicating a dynamic state of cell cycle checkpoints. In contrast, NCSCs and CHL-1 cells showed more transient p16/p21 expression and CHL-1 exhibited a marked p16 increase at 24 h. Spectroscopic analysis revealed that CSCs exhibited distinct vibrational profiles, predominantly in the nucleic acid-, protein- and lipid-associated regions. These differences were further supported by principal component and hierarchical clustering analyses, which consistently distinguished CSCs from NCSCs. Our findings underline the potential of vibrational spectroscopy to sensitively detect CSC-specific regulatory patterns and support its use in detecting new therapeutic targets in melanoma. © The Author(s) 2025.
Traditional Water Harvesting Systems in Climate Change Adaptation: Insights From a Semi-Arid Mediterranean Village
(Middle East Technical University, 2025) Gerçek, D.; Yüceer, H.; Özcan Gönülal, Y.; Uştuk, O.; Uzelli, T.; Güler, S.; Baba, A.
Traditional water harvesting systems (WHS), developed over centuries by past civilizations, have long played a crucial role in addressing water scarcity in semi-arid regions. Although these systems have been largely neglected with the expansion of modern water infrastructure, they remain a valuable heritage containing significant knowledge and practices that are still relevant today, particularly in overcoming water management challenges in the face of climate change. Although traditional WHSs have been studied across various regions, their forms and functions vary significantly due to unique climatic, geological, and cultural conditions. In the Mediterranean context, small-scale WHSs have received comparatively limited attention—particularly studies that integrate both their revitalization for contemporary use and their historical and cultural significance. This study aims to help bridge that gap and contribute the existing literature by focusing on the WHSs in Barbaros, a semi-arid village on the Aegean coast of Turkey. Barbaros is particularly unique due to its special geological conditions, as the porous soil makes water retention difficult, which adds to the importance of traditional WHSs. In this context, the main objective of this research is to comprehensively assess these systems, by considering the area’s topography, geological features, WHS construction techniques, and local knowledge transmitted across generations. This multidisciplinary approach, combining a literature review, field observations, expert surveys and interviews with long-time residents, enables a comprehensive analysis of the typologies, current state and socio-cultural evolution of these systems. A thorough understanding of these systems is essential to assess their resilience and relevance for climate change adaptation, especially with regard to drought management. The study concludes that, despite their partial abandonment, the traditional WHSs in Barbaros offer valuable insights into sustainable water management and demonstrate their potential as practical models for addressing today’s water challenges. © 2025 Middle East Technical University. All rights reserved.
Influence of Tapioca, Corn, and Potato Starches on Physical and Textural Characteristics of Puffed Starch Crackers
(Sidas Medya A.S., 2025) Cankal, Y.S.; Berk, B.; Koroglu, E.; Yorulmaz, H.; Çavdaroglu, E.; Unluturk, S.
Puffed products have become increasingly popular, prompting this study to determine how various types of starches such as tapioca, potato, and corn influence the physical, textural, and microstructural properties of starch-based puffed crackers. The physicochemical properties of the starches, including amylose content, water holding capacity (WHC), and oil holding capacity (OHC), as well as the physical properties, texture, and microstructure of the resulting crackers were evaluated. Results indicated that all starches had similar WHC and OHC values. Crackers made with corn starch (FCS) had the lowest oil content (8.65%) and the highest rehydration ratio (1.12). After frying, tapioca and potato starches produced significantly crispier crackers compared to corn starch, with a strong positive correlation (r=0.986) between crispiness and volume expansion. Potato starch-based crackers (FPS) exhibited longer cooling periods due to lower specific heat capacity. Scanning electron microscopy (SEM) images revealed that tapioca starch caused more pronounced changes in microstructure due to its porosity, which explained differences in volume expansion and texture. The study highlighted how different starch sources impacted the texture and microstructure of puffed crackers, providing insights for producing crackers with desired properties. © 2025 Sidas Medya A.S.. All rights reserved.
An Experimental Study on Microplastic Settling Velocities in Different Water Environments: Which Factors Shape the Settling Process
(Elsevier Ltd, 2025) Alpergün, C.; Baycan, N.; Alyürük, N.; Gündüz, O.
Understanding the behavior of microplastics in aquatic environments is crucial, given their widespread presence and potential ecological impact. This study investigated the effects of biofilm formation and weathering processes on the settling rates of microplastics across different water matrices. To this end, nine different polymer types were examined in four distinct conditions—pristine, biofilm-coated, aged, and biofilm-coated after weathering—across three defined size categories. A total of 648 experimental results representing different conditions were analyzed. The results revealed that the settling velocities of microplastics ranging from 0.5 to 4.5 mm varied between 0.012 and 0.154 m/s. Polybutylene terephthalate and polyethylene terephthalate particles exhibited the fastest settling rates (0.154 and 0.145 m/s), whereas acrylonitrile butadiene styrene showed the slowest (0.012 m/s). Although microplastic density and size were found to be significant factors of settling velocity, water matrix, biofilm formation, and weathering processes did not show a statistically significant difference under the conditions of this study. This was related to insufficient time for biofilm growth, limited structural changes due to weathering, and the controlled laboratory environment. Biofilm formation was observed to be more pronounced on rough and matte surfaces, while it was less prominent on shiny and slippery surfaces. Additionally, it was determined that weathering alters surface morphology and potential adsorption capacity, which plays a critical role in the environmental interactions of microplastics. Furthermore, the experimentally determined settling velocities were compared with theoretical estimations obtained using two different models from the literature. A comparison between the experimental settling data and theoretical models demonstrated a strong alignment with the models proposed by Waldschläger and Schüttrumpf (2019) and Akdogan and Guven (2024), particularly for microplastics with irregular shapes. These results suggest that such theoretical approaches can reliably predict the settling behavior of specific polymer types. Overall, the findings underscore the practical applicability of these models for estimating the transport and fate of microplastics in natural aquatic systems, offering a valuable foundation for future environmental assessments. © 2025 Elsevier Ltd
HAPS Assisted Cooperative Offloading for Space–Air–Ground Integrated Networks
(Elsevier GmbH, 2025) Yılmaz, S.S.; Özbek, B.; Erdoğan, E.
Mobile edge computing (MEC) has significantly enhanced computational capabilities at the network edge, enabling computation-intensive applications. However, traditional MEC implementations face significant challenges in areas without reliable terrestrial network infrastructure, such as rural regions or disaster-affected zones. To address this, we present a novel MEC-enabled space–air–ground integrated network (SAGIN) framework that combines high-altitude platform station (HAPS) and low Earth orbit (LEO) satellite to ensure comprehensive coverage and reduce execution delays for ground users (GUs) in areas lacking terrestrial infrastructure. By leveraging the complementary capabilities of HAPS, which provide wide-area coverage and reliable connectivity, and LEO satellites, which offer high-throughput communication, the proposed SAGIN framework enhances computation offloading. We propose a cooperative approach between GUs and the LEO satellite via the HAPS to maximize offloaded data while satisfying stringent delay constraints under a partial offloading mode. A nonlinear optimization problem is formulated to minimize execution delay while increasing offloaded data by jointly optimizing task offloading decisions and resource allocation between the HAPS and LEO satellite. Simulation results show that the proposed cooperative offloading scheme significantly outperforms random and non-cooperative schemes considering execution delay. These results highlight that the proposed cooperative, HAPS-assisted SAGIN framework effectively enables low-delay edge computing in infrastructure-limited regions. © 2025 Elsevier GmbH
Design and Comprehensive Analysis of a Solar-Biomass Hybrid System With Hydrogen Production and Storage: Towards Self-Sufficient Wastewater Treatment Plants
(Elsevier Ltd, 2025) Hajimohammadi Tabriz, Z.; Kasaeian, A.; Mohammadpourfard, M.; Shariaty-Niassar, M.
This paper comprehensively investigates a novel solar-biomass hybrid system designed to produce power, heating, hydrogen, methane, and digestate. The system's design is grounded in regional weather patterns and site-specific resource availability. A comprehensive thermodynamic and exergoeconomic analysis, based on the first and second laws of thermodynamics, is performed alongside parametric studies to evaluate the influence of key parameters on system performance. Multi-objective optimization employs a genetic algorithm facilitated by an artificial neural network to reduce computational time and balance exergy efficiency and total cost. The Pareto front is generated, and the TOPSIS method is employed to identify the optimal trade-off point. The system integrates an auxiliary boiler powered by stored hydrogen and methane to maintain consistent operation during periods of low solar irradiance. Key findings include a base-case overall energy efficiency of 78.67 % and exergy efficiency of 60.41 %. The base-case unit cost of hydrogen is determined to be $3.174/kg, demonstrating competitive viability. Integrating the biomass subsystem with the solar plant resulted in a 40 % increase in exergy efficiency and a 35 % improvement in the total unit cost of products compared to a stand-alone solar system. Optimized system parameters yielded an exergy efficiency of 55.52 % and a total cost rate of 14.98 M$/year. These results confirm the potential of this hybrid system as a promising sustainable solution for developing self-sufficient wastewater treatment plants. © 2025 Elsevier Ltd
Scattering of Water Waves by a Truncated Vertical Cylinder of Arbitrary Cross Section: Asymptotic Analysis
(Elsevier Ltd, 2025) Disibuyuk, N.B.; Yilmaz, O.
Scattering of water waves by a vertical truncated cylinder of arbitrary cross-section is investigated using the linear theory and asymptotic analysis. The flow domain is divided into the exterior and interior regions. The linearized boundary value problem is solved by the method of matched eigenfunctions and in an asymptotic manner that deals with the arbitrary geometry of the cross section. The cross-section shape is expanded in a Fourier series involving a small parameter that represents the deviation of the geometry from a circle. The advantage of this method is that the wave forces on the cylinder are obtained in terms of the coefficients of the Fourier series of the cylinder shape. For the case of a circular cylinder, exact analytical results are recovered. Cylinders with cross-section geometries of cosine-type radial perturbations and of a quasi-ellipse are considered for validation of the present method. Good agreement with the published results is obtained with the first and second-order asymptotic orders. New graphical analyses based on the problem parameters are presented for a vertical elliptical cylinder. Long-wave approximations of wave forces are obtained for cylinders whose cross-sections are not too different from a circle. © 2025 Elsevier Ltd
Semantic Communications in 6G: Coexistence, Multiple Access, and Satellite Networks
(Institute of Electrical and Electronics Engineers Inc., 2025) Ahmed, I.; Sun, Y.; Fu, J.; Köse, A.; Musavian, L.; Xiao, M.; Özbek, B.
The exponential growth of wireless users and bandwidth constraints necessitates innovative communication paradigms for next-generation networks. Semantic Communication (SemCom) emerges as a promising solution by transmitting extracted meaning rather than raw bits, enhancing spectral efficiency and enabling intelligent resource allocation. This paper explores the integration of SemCom with conventional Bit-based Communication (BitCom) in heterogeneous networks, highlighting key challenges and opportunities. We analyze multiple access techniques, including Non-Orthogonal Multiple Access (NOMA), to support coexisting SemCom and BitCom users. Furthermore, we examine multi-modal SemCom frameworks for handling diverse data types and discuss their applications in satellite networks, where semantic techniques mitigate bandwidth limitations and harsh channel conditions. Finally, we identify future directions for deploying semantic-aware systems in 6G and beyond. © 2017 IEEE.
The Role and Potential Sources of Sustainable Plant-Based Foods: a Look to the Future
(Sidas Medya A.S., 2025) Çakıtlı, G.; Nurko, E.
The food industry, influenced by environmental issues such as global warming and climate change, is undergoing significant changes towards establishing a sustainable food system. This system prioritizes reducing the adverse impacts on our natural resources while ensuring sufficient and nutritious foods. Despite animal sources being rich in nutrients, consumer concerns regarding sustainability are increasing the search for alternative sources. With growing consumer interest in sustainable and healthy choices, there is an increasing demand for plant-based food sources. Plant-based protein sources generally include seeds, legumes, nuts, and oilseeds. Plant-based proteins are not only consumed as a food but also valued for their potential for various techno-functional properties in the food industry. Plant-based foods are both good sources for proteins and high in fiber, vitamins, and minerals. This study focuses upon the impact of a developing world and increasing population on plant-based foods, their nutritional value, and potential applications. © 2025 Sidas Medya A.S.. All rights reserved.
In Memoriam Harald Hillebrecht (1960–2024) Editorial On: 22nd International Symposium on Boron, Borides and Related Materials (ISBB 2024)
(Elsevier Masson S.R.L., 2025) Balcı-Çağıran, Ö.; Yücel, O.; Somer, M.
From Work to Leisure: ”Transforming Kitchen Spaces, Technologies, and Practices in Türkiye, 1930s-2020s.”
(Taylor and Francis Ltd., 2025) Emgin, B.; Bektaş Ata, L.; Karaosmanoğlu, D.
Kitchens are more than functional spaces; they reflect and shape cultural values, technologies, and ideals of modern life. Framing the kitchen as an orchestrating concept that brings together images, materials, and competencies, this article examines how idealized settings and tools have produced shifting narratives of modernity and redefined meanings, functions, and everyday practices in Türkiye from the 1930s to the present. It highlights the transformation of the kitchen from a moralizing space to one of entertainment and creativity across three eras: the ordered workshop of the 1930s, the cozy living room of the 1970s, and the technological hub of the 2000s. Drawing on archival research from a larger project on the social history of domestic technologies in Türkiye, the article analyzes newspapers, magazines, TV commercials, social media, and films to reveal how domestic ideals have been negotiated through kitchen spaces. © 2025 Informa UK Limited, trading as Taylor & Francis Group.
Two Key Substitutions in the Chromophore Environment of mKate2 Produce an Enhanced FusionRed-Like Red Fluorescent Protein
(Acta Naturae, 2025) Ruchkin, D.A.; Gavrikov, A.S.; Kolesov, D.V.; Gorokhovatsky, A.Y.; Chepurnykh, T.V.; Mishin, A.S.; Bogdanov, A.M.
Red fluorescent proteins (RFPs) are often probes of choice for living tissue microscopy and whole-body imaging. When choosing a specific RFP variant, the priority may be given to the fluorescence brightness, maturation rate, monomericity, excitation/emission wavelengths, and low toxicity, which are rarely combined in an optimal way in a single protein. If additional requirements such as prolonged fluorescence lifetime and/or blinking ability are applied, the available repertoire of probes could dramatically narrow. Since the entire diversity of conventional single-component RFPs belongs to just a few phylogenetic lines (DsRed-, eqFP578- and eqFP611-derived being the major ones), it is not unexpected that their advantageous properties are split between close homologs. In such cases, a systematic mutagenetic analysis focusing on variant-specific amino acid residues can shed light on the origins of the distinctness between related RFPs and may aid in consolidating their strengths in new RFP variants. For instance, the protein FusionRed, despite being efficient in fluorescence labeling thanks to its good monomericity and low cytotoxicity, has undergone considerable loss in fluorescence brightness/lifetime compared to the parental mKate2. In this contribution, we describe a fast-maturing monomeric RFP designed semi-rationally based on the mKate2 and FusionRed templates that outperforms both its parents in terms of molecular brightness, has extended fluorescence lifetime, and displays a spontaneous blinking pattern that is promising for nanoscopy use. © 2025 National Research University Higher School of Economics.
Development and Evaluation of 177Lu-Imatinib: Radiolabeling and Cell Culture Studies
(Walter de Gruyter GmbH, 2025) Ozgenc, E.; Karpuz, M.; Guler, G.; Burak, Z.; Başpainar, Y.; Gundogdu, E.A.
Targeted radiopharmaceuticals offer promising approaches for cancer diagnosis and therapy. This study developed freeze-dried kit formulations of 177Lu-Imatinib (IMT) and evaluated their potential efficacy through in vitro studies. Four formulations (F1-F4) containing IMT and chelating agents were prepared and characterized via Fourier transform infrared (FTIR), ultraviolet spectrum (UV), and thermogravimetric analysis (TGA) to confirm complex formation. Biocompatibility was assessed in NIH-3T3 cells using the MTT assay. Radiolabeling with 177Lu was optimized by varying pH, incubation time, and reactant ratios. Radiochemical purity and stability were analyzed over 7 days using HPLC. Binding affinity and cytotoxicity were evaluated in MCF-7 and NIH-3T3 cells. Spectroscopic analyses confirm successful complex formation. All formulations exhibited >90% viability in NIH-3T3 cells. Optimal radiolabeling conditions (45mg IMT-chelator, pH 5, 60min incubation) yielded >90% efficiency, with stable radiolabeling for 7 days. The 177Lu-IMT-DOTA (F3) formulation showed significantly higher binding and cytotoxic effects in MCF-7 cells compared to controls. The 177Lu-IMT-DOTA (F3) kit demonstrates high radiolabeling efficiency, stability, and selective in vitro cytotoxicity toward breast cancer cells, supporting its potential as a targeted radiopharmaceutical. © 2025 Walter de Gruyter GmbH, Berlin/Boston 2025.
Dam Body Sediment Movement on Rough Bed Downstream Due to Earthfill Dam Break
(Taylor and Francis Ltd., 2025) Aksoy, A.O.; Dogan, M.; Tayfur, G.
This study investigated movement of flow and sediment due to earthfill dam failure induced by piping and overtopping, using 12.8 m laboratory flume. Dam (60 cm high, 202 cm base width) was built in three zones with two sediment sizes, and downstream channel included a rough bed of cubic blocks. Water levels were monitored with sensors, and final sediment profiles were mapped via laser scanning. Results showed that dam body eventually collapses (in 265 s after the piping, and in 100 s after the overtopping start) while flood flow carries a great portion of its sediment away. Sediment spreading occurred all over downstream area with significant variation in non-uniform thickness (15 cm to 1 cm). In the residential area, the sediment depth variation ranged from 12 cm to 6 cm. The blocks were submerged under muddy flow in both modes of failures. Higher flow levels (22 cm) were observed over smooth bed than rough bed (15 cm), in overtopping break. This was almost the opposite in the piping failure mode (13 cm in smooth, and 15 cm in rough bed case). These findings highlights the dominant role of failure mechanism and bed roughness in sediment transport and flood dynamics. © 2025 Indian Society for Hydraulics.
Aeration Systems for Wastewater Treatments
(Elsevier, 2025) Recepoğlu, Y.K.; Gören, A.Y.
Aeration systems are critical components in wastewater treatment, playing a fundamental role in enhancing oxygen transfer to support microbial activity essential for pollutant breakdown. This chapter provides a comprehensive overview of various aeration techniques, including diffused, mechanical, natural, and jet aeration systems, detailing their operational mechanisms, efficiencies, and energy consumption. The chapter also addresses design considerations, advantages, and limitations, with a focus on optimizing performance and sustainability. Through a detailed analysis, the chapter underscores the indispensable role of aeration systems in advancing wastewater treatment processes and promoting environmental sustainability. © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Advances in Optical Biosensors: Technologies and Trends in Point of Care Applications
(Academic Press Inc., 2025) Sözmen, A.B.; Bayraktar, A.E.; Ülker, Ö.; Arslan-Yildiz, A.
A sensor detects changes in its environment and converts them into readable data using three key components: a receptor to sense changes, a transducer to generate a signal, and a detection system to output the signal. Optical sensors are devices that use a receptor and optical transducer to produce signals corresponding to an analyte, and optical biosensors combine a biological sensing element with an optical transducer to detect and quantify specific analytes. They offer easy-to-read, real-time signals, such as color changes or light emission, sometimes even detectable by the naked eye, reducing the need for external devices and providing versatile Point-of-Care (PoC) applicability. Their portability and rapid response time enable remote testing and monitoring, further improving accessibility. They allow sensitive and selective detection of various analytes, making them utile in areas like glucose monitoring, drug testing, and pathogen detection. Many of these sensors provide label-free and non-invasive detection, further enhancing patient comfort and safety. This chapter provides an overview of optical biosensors; it starts with categorizing them by biorecognition elements, transducers, and detection modes. It investigates biosensors that utilize nanomaterials, polymers, and engineered biorecognition elements are discussed, with examples from literature. Technologies such as miniaturization, multiplexing, and wearable designs, which enhance PoC feasibility, are also examined. Lastly, challenges in development and operation are addressed, and future research directions for advancing optical biosensors in PoC diagnostics are discussed. © 2025
Dynamics of Population Change in Rural Areas of Türkiye: a Spatial Analysis of Villages
(Istanbul Teknik Universitesi, Faculty of Architecture, 2025) Kirdi, Ş.G.; Elburz, Z.
The migration from rural to urban is a critical issue handled by different disciplines. Rural development strategies aim to improve rural areas and reduce inequalities. To formulate the various strategies, it is important to identify the causes of migration. This study aims to analyze the spatial tendency of population change in rural areas in Türkiye and put forward factors that cause this migration. First, LISA analysis is used to reveal spatial patterns of migrations. Then, the causes for migration have been analyzed with aspatial and spatial regression analysis. According to the study results, the change in the rural population in Türkiye shows a spatial autocorrelation. Settlements with high/low populations tend to cluster geographically. According to regression analysis, the presence of primary schools, the presence of the service sector, and the manufacturing sector employment positively affect rural population growth. Contradiction to this, distance to firsttier cities and the presence of a livestock sector have a negative effect. These results can guide policymakers to control and evaluate urban-rural population balance by providing local-scale suggestions for an emerging economy. © 2025, Istanbul Teknik Universitesi, Faculty of Architecture. All rights reserved.
Mixed Finite Element Formulation for Laminated Composite Cylindrical Shells Based on Refined Zigzag Theory
(Scipedia S.L., 2024) Bab, Y.; Kutlu, A.; Dorduncu, M.
This paper presents a mixed finite element formulation to examine the linear static behavior of thin and moderately thick laminated composite cylindrical shells within the framework of the Refined Zigzag Theory (RZT). The RZT is very suitable for modeling thick and highly heterogeneous laminated composite structures without the need for the shear correction factor. The system's stationary condition is expressed by using the HellingerReissner principle. Finite element model employs four-noded quadrilateral elements with bilinear shape functions, meeting the C0 continuity requirements. The mixed finite element equations produce direct nodal displacements and stress resultants simultaneously. Comparisons and convergence analyses are performed by considering various lamination configurations and boundary conditions for validation purposes. © 2024, Scipedia S.L., All rights reserved.
Effect of Partial Austenitization Treatment on Microstructure and Mechanical Properties for Multiphase Steels
(Springer, 2025) Erisir, Ersoy; Sari, Elif; Kocakusakli, Emre; Dulger, Nurten Basak; Oktay, Serkan; Tutuk, Ramazan; Davut, Kemal
In this study, the microstructural evolution and mechanical properties of a 0.15 pct C-2.09 pct Mn multiphase steel was investigated. To produce a multiphase microstructure, a newly developed two-step processing of partial austenitization and quenching (PAQ) treatment was used. In the first step, the steel with initial martensitic microstructure was partially austenitized at 690 degrees C for 8 hours. After cold rolling, a rapid reheating to 840 degrees C and quenching done to simulate hot dip galvanizing conditions. To better understand the PAQ process, thermodynamic and kinetic simulations using ThermoCalc and DICTRA predicted phase transformations and elemental partitioning. Microstructural characterization via LM, SEM, and EBSD revealed an ultrafine-grained multiphase structure consisting of bainite, M/A, and intercritical ferrite. The PAQ840 sample showed an ultimate tensile strength of 740 MPa and excellent ductility with 20 pct total elongation.

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