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Effect of Microalloying Additions on the Microstructure and Mechanical Properties of Low Carbon Steel

Journal of Iron and Steel Research International 2011年第S1期18卷 246-251页

作者： EISSA Mamdouh ABD El-Aziz Ahmed GHALI Saeed halfa hossam SABER Shady Central Metallurgical Research & Development Institute "CMRDI" Faculty of Material Science and Engineering German University in Cairo "GUC"

Low carbon steels are characterized by good weldability,formability and fracture toughness ***,the low strength levels of these steel grades limit their wide *** the other hand,increasing the strength by increasing the carbon content and alloying elements deteriorates the other *** this study,the microalloying technique was used to examine the possibility of attaining low carbon steels with good combination of strength,ductility and impact properties.A low carbon steel microalloyed with single addition of vanadium and another one microalloyed with combined addition of vanadium and titanium were used in this investigation and their properties were compared with non-microalloyed low carbon steel having the same base ***,other two nonmicroalloyed and V-microalloyed steels with higher carbon,silicon and manganese contents were also investigated to reveal the effect of base ***,hardness,room and zero temperature Charpy V-notch impact tests were conducted to evaluate the variations in the mechanical properties of low carbon hot forged steel containing vanadium and combinations of vanadium and *** addition,the microstructures of the different investigated steels were observed using both optical microscope and scanning electron ***,the hardness of the ferrite phase was also determined using micro-hardness *** results showed improvement of the mechanical properties of the investigated steels by both single V-and combined V + ***,hardness and impact tests results indicated that good combinations of strength,ductility and impact properties can be achieved by V-microalloying *** with combination of V and Ti microaddition has much higher hardness,yield strength,ultimate tensile strength and impact energy at both room and zero temperatures compared with non-microalloyed and single Vmicroalloyed *** C,Si and Mn contents result in

关键词： low carbon steels single microalloying combined microalloying strength ductility impact energy grain refinement precipitation strengthening

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Parameters Affecting Energy Consumption for Producing High Carbon Ferromanganese in a Closed Submerged Arc Furnace

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Journal of Iron and Steel Research International 2014年第7期21卷 666-672页

作者： Azza Ahmed hossam halfa Mohamed K.El-Fawakhry Hoda El-Faramawy Mamdouh Eissa Steel Technology Metallurgical Research and Development Institute

The power consumption is considered to be the most important factor affecting the production cost of fer romanganese alloy. Different parameters affecting the energy consumption for industrial production of high carbon ferromanganese HCFeMn were investigated in a closed submerged arc furnace. The analysis of industrial data revealed that the most energy consumed factors were the direct reduction by solid carbon, Boudouard reaction, metal and slag formation, and decomposition of fluxing materials （limestone and dolomite）. To reduce the energy con- sumption and minimize the energy losses in the production process of HCFeMn, it was recommended to use Mn blend with minimum Mn to Fe ratio of 6 and lower SiO2 content or higher basicity. The added coke must be adjusted according to the material balance to prevent the over-coke and to minimize the highly endothermic ＂Boudouard reac tion＂. In addition, it was recommended to work at basic slags with the ratio of （CaO＋MgO） to Si（）2 equal to 1.0- 1.2 instead of much higher slag basicity. Furthermore, the mass losses had to be minimized through adjusting the handling and charging process and to take care of all metal produced.

关键词： high carbon ferromanganese production energy consumption carbonate decomposition Boudouard reaction slag basicity energy loss

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Thermodynamic Calculation for Silicon ModifiedAISI M2 High Speed Tool Steel

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Journal of Minerals and Materials Characterization and Engineering 2013年第5期1卷 257-270页

作者： hossam halfa Steel Technology Department Central Metallurgical R&D Institute (CMRDI) Helwan Egypt

During high speed tool steel production up to 0.2 wt % silicon is added, primarily to react with oxygen e.g. silicon acts as a de-oxidizer. If more than 0.2 wt % silicon is added, it serves to improve the deep hardening properties. An addition up to ~1 wt % silicon provides hardness and improves temper-stability but reduces the ductility. At high concentration, silicon causes embrittlement. Alloying with silicon raises the solubility of carbon in the matrix and hence the as-quenched hardness. It has virtually no influence on the carbide distribution, but it promotes the formation of M6C type carbides. The many essential alloy additions to iron (C, W, Mo, V, Cr, Si) make the high speed tool steel, HSS a complex multi-component system. Its complete experimental investigation would require enormous time and effort. Instead, the CALPHAD method has been successfully used for computation of phase equilibrium the multi-component HSS system. In the present work, the Thermo-Calc program has been applied to the system Fe-C-Cr-W-Mo-V-Si with the thermodynamic information contained in the solid-solution-database of the TCFE. In the present work, some temperature-concentration diagrams for silicon modified AISI M2 steel are presented by calculated quantities (melting and transformation temperatures, amount and compositions of phases). Calculated data are compared with standard AISI M2 high speed tool steel.

关键词： Phase Diagram High Speed Silicon Carbides Thermo-Calc

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Recent Trends in Producing Ultrafine Grained Steels

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Journal of Minerals and Materials Characterization and Engineering 2014年第5期2卷 428-469页

作者： hossam halfa Steel Technology Department Central Metallurgical Research and Development Institute (CMRDI) Helwan Egypt

Ultrafine grained steels with grain sizes below about 1 μm offer the prospect of high strength and high toughness with traditional steel compositions. These materials are currently the subject of extensive research efforts worldwide. Alloy design is one of the first considered issues, while designing new steel with targeted mechanical properties. However, the alloying content of steel does not fully determine the mechanical properties, but manufacturing procedure, hot rolling and cooling parameters, heat treatment parameters etc. are also of vital importance. For instance, same steel with different processing conditions can exhibit rather large variations in properties. To be precise, chemical composition with the processing parameters determines the microstructure, which in turn determines the properties of the steel. Steel is defined as an iron alloy containing C, Mn and Si that are generally used as alloying elements in steel. Micro-alloying elements such as Nb, Ti V, and B, are considered to be effective, causing strengthening as well as microstructural refinement in small quantities below 0.1 wt% (therefore these are called micro-alloy elements) and are quite generally used in ultrafine grain steel. Substitution alloying elements, such as Mo, Ni, Cr and Cu are alloyed to suppress phase transformation temperatures, i.e. for reaching certain level of strengthening, since the strength of steel structures strongly depends on the phase transformation temperature. Accordingly, the alloy design of ultrafine grains steels with different structures generally relies on: i) carbon levels, ii) sufficient alloying to obtain the desired transformation temperature and iii) micro-alloying technology in conjunction with Thermo Mechanical Controlled Processes (TMCP). Also, both advanced thermo-mechanical processes and severe plastic deformation strategies are used to produce ultrafine grained steels. Both approaches are suited to produce submicron grain structures with attractiv

关键词： Ultrafine Thermomechanical Severe Plastic Deformation Structure

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Electroslag Remelting of High Technological Steels

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Journal of Minerals and Materials Characterization and Engineering 2015年第6期3卷 444-457页

作者： hossam halfa A. M. Reda Steel Technology Department Central Metallurgical R&D Institute (CMRDI) Helwan Egypt Department of Physics College of Science & Humanities Shaqra University Al-Dawadme Saudi Arabia Physics Department Faculty of Science Zagazig University Zagazig Egypt

This work aims at the suitability of electroslag process on production of high technological steels such as Maraging steel, modified high speed tool steel (niobium, high nitrogen, and free nitrogen) has been investigated. The experimental results show that high recovery of alloying elements during electroslag remelting of such steels especially high nitrogen tool steel. The previous results are attributed to the slag used in electroslag protect the molten metal from atmospheric oxygen. Also higher recovery of alloying elements during remelting high nitrogen high speed tool steel are due to partial dissolution of nitrides during remelting of such steel which increase nitrogen content above the molten slag which decrease the partial pressure of oxygen leads to protection of molten metal from further oxidation. Also, the results show that, produced ingots are free from internal pipes, porosity and other surface defects. Microstructure obtained for remelted steels is very fine and well distributed for all steel under investigation. In the case of electroslag remelted Maraging steels lower non-metallic inclusions with very fine inclusions and redistribution retained austenite with very fine structure leads to increasing all tensile properties of investigated steels. In the case of high speed tool steels, also the structure is very fine, well distributed, densely and short carbides with lower non-metallic inclusions contents. High cooling rate accompanying with electroslag process has a great effect on type, morphology and content of carbides precipitated in both nitrogen and niobium modified tool steels.

关键词： Electroslag Maraging Cobalt Free Tool-Steel Nitrogen Niobium

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Parameters Affecting the Production of High Carbon Ferromanganese in Closed Submerged Arc Furnace

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Journal of Minerals and Materials Characterization and Engineering 2012年第1期11卷 1-20页

作者： Mamdouh Eissa Hoda El-Faramawy Azza Ahmed Saeed Nabil hossam halfa Steel and Ferroalloys Department Central Metallurgical Research and Development Institute (CMRDI) P. O. Box 87 Helwan Cairo Egypt

This study has been performed to investigate the different parameters affecting on the production of high carbon ferromanganese in closed submerged arc furnace. The analysis of industrial data revealed that using manganese ores with low Mn/Fe ratio necessitates higher amount of Mn-sinter in the charge. Using Mn-blend with higher Mn/Fe ratio reduces the coke consumption and this leads to reducing the electrodes consumption. The recovery of Mn ranges between 70 and 80 %. Much higher basic slag has slight effect on Mn- recovery. However, as slag basicity increases, the MnO- content of slag decreases. The manganese content of produced HCFeMn depends mainly on Mn/Fe ratio of Mn-blend. For obtaining HCFeMn alloy containing minimum 75%Mn, it is necessary to use Mn-blend with Mn/Fe ratio of higher than 6. A model for determination of the amount and composition of off-gases has been derived based on the chemical composition and material balance of the input raw materials and the produced alloy and slag. By using this model, the amount of off-gases was found to increase by increasing both Mn-blend and coke consumption.

关键词： Ferromanganese closed Furnaces carbothermic reduction Slag basicity

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铌对工具钢性能影响有新研究 008

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中国冶金报

作者： hossam halfa 郝鑫

本报讯近日，有学者研究了电渣重熔生产含铌AISI M41超硬高速工具钢的特性，并对比研究了其他3种含铌量不同的钢种。该课题主要研究了电渣重熔过程中铌和强冷却速度对析出碳化物的影响，铌对碳化物形貌、高速工具钢二次硬化温度和磨损...

本报讯近日，有学者研究了电渣重熔生产含铌AISI M41超硬高速工具钢的特性，并对比研究了其他3种含铌量不同的钢种。该课题主要研究了电渣重熔过程中铌和强冷却速度对析出碳化物的影响，铌对碳化物形貌、高速工具钢二次硬化温度和磨损速率的影响。经过研究得出：对于AIS

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Privacy-preserved learning from non-i.i.d data in fog-assisted IoT:A federated learning approach

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Digital Communications and Networks 2024年第2期10卷 404-415页

作者： Mohamed Abdel-Basset hossam Hawash Nour Moustafa Imran Razzak Mohamed Abd Elfattah Faculty of Computers and Informatics Zagazig UniversityZagazigSharqiyah44519Egypt School of Engineering and Information Technology University of New South Wales@ADFACanberraACT2600Australia Deakin University Geelong Waurn Ponds CampusAustralia Computer Science Department Misr Higher Institute for Commerce and ComputersMansoura35511Egypt

With the prevalence of the Internet of Things(IoT)systems,smart cities comprise complex networks,including sensors,actuators,appliances,and cyber *** complexity and heterogeneity of smart cities have become vulnerable to sophisticated cyber-attacks,especially privacy-related attacks such as inference and data poisoning *** Learning(FL)has been regarded as a hopeful method to enable distributed learning with privacypreserved intelligence in IoT *** though the significance of developing privacy-preserving FL has drawn as a great research interest,the current research only concentrates on FL with independent identically distributed(i.i.d)data and few studies have addressed the non-i.i.d *** is known to be vulnerable to Generative Adversarial Network(GAN)attacks,where an adversary can presume to act as a contributor participating in the training process to acquire the private data of other *** paper proposes an innovative Privacy Protection-based Federated Deep Learning(PP-FDL)framework,which accomplishes data protection against privacy-related GAN attacks,along with high classification rates from non-i.i.d ***-FDL is designed to enable fog nodes to cooperate to train the FDL model in a way that ensures contributors have no access to the data of each other,where class probabilities are protected utilizing a private identifier generated for each *** PP-FDL framework is evaluated for image classification using simple convolutional networks which are trained using MNIST and CIFAR-10 *** empirical results have revealed that PF-DFL can achieve data protection and the framework outperforms the other three state-of-the-art models with 3%–8%as accuracy improvements.

关键词： Privacy preservation Federated learning Deep learning Fog computing Smart cities

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Erosion control of Chinese loess using polymer SH and ryegrass

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Journal of Mountain Science 2024年第6期21卷 2043-2058页

作者： YING Chunye LI Lanxing MAKEEN Gehad Mohamed hossam LIU Yabin School of Geological Engineering Qinghai UniversityXining 810016China Key Laboratory of Genozoic Resource&Environment in North Margin of the Tibetan Plateau Xining 810016China Faculty of Engineering China University of GeosciencesWuhan 430074China Faculty of Science Ain Shams UniversityCairo 11566Egypt

The China Loess Plateau is subjected to severe soil erosion triggered by intense rainfall,resulting in significant harm and losses to both human society and the natural *** this study,a novel technique for managing loess erosion is introduced,which involves the utilization of a combined polymer SH and ryegrass.A comprehensive series of tests were undertaken,including rainfall erosion tests,disintegration experiments,and scanning electron microscopy examinations,to assess the accumulative sediment yield(ASY),disintegration ratio,and microstructural features of both untreated and treated loess *** results showed a significant reduction in ASY with increased dry density of untreated ***,the combined technique effectively controlled erosion,limiting ASY to 266.2 g/cm^(2)in 60 *** was approximately one-sixth,one-ninth,and one-fifteenth of the ASY in SH-treated loess(L-SH),ryegrass-treated loess(L-R),and untreated loess,*** resisted disintegration better than ryegrass alone but slightly less than *** improvement was due to the combined effect of SH and ryegrass,which reduced raindrop impact,improved loess microstructure,and boosted ryegrass *** innovative technique holds the potential to be applied as a field-scale technique in the Loess Plateau region of China.

关键词： Loess Plateau Loess erosion Ryegrass Polymer SH Erosion control Microstructure

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Hepatic recompensation according to Baveno VII criteria via transjugular intrahepatic portosystemic shunt

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World Journal of Gastroenterology 2024年第12期30卷 1777-1779页

作者： hossam Eldin Shaaban Abeer Abdellatef Hussein Hassan Okasha Department of Internal Medicine and Gastroenterology NHTMRICairo 11796Egypt Department of Internal Medicine Division of Gastroenterology and HepatologyKasr Al-Aini School of MedicineCairo UniversityCairo 11562Egypt

Transjugular intrahepatic portosystemic shunt is a therapeutic modality done through interventional *** is aimed to decrease portal pressure in special situations for patients with decompensated liver disease with portal *** represents a potential addition to the therapeutic modalities that could achieve hepatic recompensation in those patients based on Baveno VII criteria.

关键词： Decompensated liver cirrhosis Hepatic recompensation Baveno VII Portal hypertension

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