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

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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

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

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

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

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

Role of pancreatic juice cytology in diagnosis of high-grade pancreatic intraepithelial neoplasia

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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World Journal of Clinical Cases 2025年第10期13卷 59-61页

作者： Hussein Hassan Okasha Mohammed Tag-Adeen hossam Eldin Shaaban Division of Gastroenterology and Hepatology Department of Internal MedicineKasr Al-Aini School of MedicineCairo UniversityCairo 11562Egypt Division of Gastroenterology and Hepatology Department of Internal MedicineQena Faculty of MedicineSouth Valley UniversityQena 83523Egypt Department of Internal Medicine and Gastroenterology National Hepatology and Tropical Medicine Research InstituteCairo 11796Egypt

High-grade pancreatic intraepithelial neoplasia is a challenging diagnosis and itdoes not exhibit mass lesions. It is suspected based on changes in the mainpancreatic duct in magnetic resonance cholangiopancreatography. Sometimesonly an unclear duct shows in magnetic resonance cholangiopancreatographywith no focal strictures and upstream dilatation of the main pancreatic duct. Serialpancreatic juice cytology is valuable in diagnosis of those patients.

关键词： High-grade pancreatic intraepithelial neoplasia Pancreatic cancer Magnetic resonance cholangiopancreatography Endoscopic retrograde pancreatography Pancreatic juice cytology Pancreatic ductal adenocarcinoma

Layered Software Patterns for Data Analysis in Big Data Environment

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International Journal of Automation and computing 2017年第6期14卷 650-660页

作者： hossam Hakeem Faculty of Computing and Information Technology King Abdulaziz University JeddahSaudi Arabia

The proliferation of textual data in society currently is overwhelming, in particular, unstructured textual data is being constantly generated via call centre logs, emails, documents on the web, blogs, tweets, customer comments, customer reviews, *** the amount of textual data is increasing rapidly, users ability to summarise, understand, and make sense of such data for making better business/living decisions remains challenging. This paper studies how to analyse textual data, based on layered software patterns, for extracting insightful user intelligence from a large collection of documents and for using such information to improve user operations and performance.

关键词： Big data data analysis patterns layered structure data modelling

Analytical Approach to Exact Solutions for the Wick-Type Stochastic Space-Time Fractional KdV Equation

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Chinese Physics Letters 2014年第6期31卷 29-33页

作者： hossam A. Ghany Department of Mathematics Faculty of Industrial Education Ameria (11282) Helwan University Cairo Egypt Department of Mathematics Faculty of Science Taif University Hawea(888) Tail Saudi Arabia

This study is devoted to giving an analytical approach to exact solutions for the Wick-type stochastic spacetime fractional KdV equation. By means of Hermite transform, white noise theory, and the fractional Riccati equation method, we derive white noise functional solutions for the Wick-type stochastic space-time fractional KdV equations. Exact traveling wave solutions for the variable coefficients space-time fractional KdV equations are given by using the fractional Riccati equation method. The obtained results include soliton-like, periodic, and rational solutions.

关键词： FUNCTIONAL equations RICCATI equation -- Numerical solutions STOCHASTIC processes PROBABILITY theory ENERGY storage