International Conference on “Frontiers in Basic and Applied Science for Sustainability and Innovation, 2025
Tool steels are crucial for machining materials like plastics, rubber, wood, and metals due to th... more Tool steels are crucial for machining materials like plastics, rubber, wood, and metals due to their durability, which relies on hardness, strength, and wear resistance. They typically contain over 0.5% carbon (except mold steels) to achieve a martensite hardness of 55-65 HRc. Higher carbon content increases wear resistance through undissolved carbides. Alloying elements such as chromium, vanadium, molybdenum, tungsten, and cobalt enhance specific properties and overall durability. This work examines tool steel grades and their grading systems, emphasizing the metallurgical concepts that influence their properties, particularly in production and heat treatment. AISI M2 high-speed tool steel is highlighted for its versatility in high-speed applications that require hardness, toughness, and wear resistance. Achieving optimal properties involves precise control of cleanliness, structure, and microstructure during heat treatment, which is essential for AISI M2 tool steel. AISI M2 high-speed tool steel was produced through induction melting and electroslag refining (ESR) to reduce nonmetallic inclusions. Various characterization experiments were conducted to investigate phase transformation, microstructure, and dilatation. The study utilized JMatPro software for phase equilibria and solidification analysis. Precipitated carbides were examined using optical microscopy and X-ray diffraction, identified through wavelength dispersive X-ray, scanning electron microscopy, and energy-dispersive X-ray techniques. Image analysis with Image J software assessed the count and size distribution of precipitated carbides and inclusions. The critical transformation temperature was measured using dilatometry.
Metallography, Microstructure, and Analysis, Jan 9, 2024
In this investigation, an attempt has been made to identify the metallurgical properties with the... more In 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.
International Journal of Materials Technology and Innovation (Online), Jun 1, 2023
The effect of heat input on the microstructure and mechanical properties of low nickel-high manga... more The effect of heat input on the microstructure and mechanical properties of low nickel-high manganese stainless steel welded using a shielded metal arc was investigated. Six samples divided equally into two groups that represented the two distinct degrees of heat input were conducted: low heat (128 J/mm-139 J/mm-165 J/mm) and high heat (182 J/mm-207 J/mm-225 J/mm), respectively. These groups were subjected to microstructural analyses and tensile tests to see how heat input affected their joints' mechanical characteristics and microstructure evolution. In the second group, the high value of the ultimate tensile strength (UTS) was found in the case of the high-heat input (182 J/mm) sample. Macrostructure observations were made at the melting zone for each sample. In the case of low heat input formation, partial penetration was observed. However, in the case of high heat input formation, full penetration was observed in all samples treated to the various heat inputs. No defects, such as cracks or voids, were found. In addition, it was observed by increasing heat inputs that the average inter-dendritic spacing in the weld zone increased, which plays a significant role in the observed changes in the tensile characteristics of the welded samples.
Journal of Minerals and Materials Characterization and Engineering, 2014
Ultrafine grained steels with grain sizes below about 1 µm offer the prospect of high strength an... more 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 attractive mechanical properties. This overview describes the various techniques to fabricate ultrafine grained steels.
Metallography, Microstructure, and Analysis, Jun 1, 2022
Aluminium matrix composites containing 15, 30 and 50 vol.% of pulverized Al 62 Cu 25.5 Fe 12.5 (i... more Aluminium matrix composites containing 15, 30 and 50 vol.% of pulverized Al 62 Cu 25.5 Fe 12.5 (in at.%) melt spun ribbons have been prepared by a vacuum hot pressing (T = 673 K, P = 600 MPa). The microstructure of the initial ribbon and the composites was investigated using X-ray, scanning and transmission electron microscopy. In the as-spun ribbon the quasicrystalline icosahedral phase (i-phase) coexisted with the cubic copper rich β-Al(Cu, Fe) intermetallic compound. The phase composition of Al-Cu-Fe particles changed after consolidation process and the i-phase transformed partially to the ω-Al 70 Cu 20 Fe 10 phase. Additionally, the Θ-Al 2 Cu phase formed at the α(Al)/Al-Cu-Fe particle interfaces. With an increase in volume fraction of the reinforcement the hardness of the composites increased up to HV = 180 for the highest amount of added particles. The ultimate compression strength of the same sample reached the value of 545 MPa.
Modeling of the phase-structural state in a hybrid multicomponent alloy with a high boron content
Physics and Chemistry of Solid State
The present work is focused on analyzing the thermodynamically equilibrium path of structure form... more The present work is focused on analyzing the thermodynamically equilibrium path of structure formation in a multi-component Fe-W-Mo-Cr-Ti-Mn-Si alloy of tribotechnical purpose, containing 0.72 wt. % C and 2.75 wt. % B is analyzed. Computer simulation of the crystallization process was performed using the program “Thermo-Calc Software”. It was found that the alloy belongs to the hyper-eutectic compositions, since its crystallization begins at 1472 oC with the formation of primary boride WB and carbide TiC. After a series of subsequent eutectic reactions (in the range of 1126-923 oC) and solid-phase transformations, a set of equilibrium phases is formed in the alloy, which at room temperature consists of borides WB, MoV, Fe2B, Cr4B, Mn4B, carbides TiC, M7C3, and ferrite. The total volume fraction of borides and carbides is 45.05 vol. %. A comparison of the obtained data with the results of the study of the manufactured alloy showed that the simulation with “Thermo-Calc Software” provi...
The novel hybrid concept on designing advanced multi-component cast irons: Effect of boron and titanium (Thermodynamic modelling, microstructure and mechanical property evaluation)
Journal of Environmental Chemical Engineering, 2018
The present work attempts to increase the benefit of using calcium fluoride based slag, which con... more The present work attempts to increase the benefit of using calcium fluoride based slag, which considers as waste material after remelting of advanced steel by an electro slag remelting (ESR) process, as one of innovative material for nuclear shielding applications. This work differentiates between the neutron shielding properties of different types of steel slag waste, types of stainless steel and ordinary concrete. The total and partial neutron interactions have been done in the energy range of 10 −5 eV-20 MeV using Monte Carlo program. The dependence of total and partial neutron macroscopic cross sections (MaCSs) on incident neutron energy and elemental composition has been evaluated. Besides, the total and partial microscopic cross sections (MiCSs) were determined via the total and partial MaCSs. It was found that the rutile has higher total MaCSs and MiCSs than the other investigated materials. This study should be useful for potential application of these materials in the field of nuclear radiation for choice of neutron shielding materials.
Study on Equilibrium and Non-equilibrium Solidification of Boron-Containing High-Speed Tool Steel: Effect of Cooling Rate and Microstructure Investigation
The effect of changing the time of immersion and temperature on the electrochemical corrosion beh... more The effect of changing the time of immersion and temperature on the electrochemical corrosion behavior of C-250 maraging steel grade in 1.0 M H2SO4 pickling solution was reported. The study was carried out using potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) investigations. It was found that the increase of immersion time from 10 min to 1 h, 2 h, and 24 h increases the corrosion of the C-250 maraging steel in the acid solution through increasing the corrosion current and corrosion rate, while decreasing the corrosion resistance as was indicated by the polarization measurements. This effect was found to further increase with increasing the temperature of the sulfuric acid solution from 20º to 50 ºC due to the increase of surface reactivity with temperature. The results obtained by EIS measurements confirmed those ones obtained by potentiodynamic polarization that C-250 maraging steel suffers sever uniform corrosion increases with elongating the immersi...
This paper is devoted to the evaluation of the “three-body-abrasion” wear behaviour of (wt.%) 5W–... more This paper is devoted to the evaluation of the “three-body-abrasion” wear behaviour of (wt.%) 5W–5Mo–5V–10Cr-2.5Ti-Fe (balance) multi-component (C + B)-added alloys in the as-cast condition. The carbon (0.3 wt.%, 0.7 wt.%, 1.1 wt.%) and boron (1.5 wt.%, 2.5 wt.%, 3.5 wt.%) contents were selected using a full factorial (32) design method. The alloys had a near-eutectic (at 1.5 wt.% B) or hyper-eutectic (at 2.5–3.5 wt.% B) structure. The structural micro-constituents were (in different combinations): (a) (W, Mo, and V)-rich borocarbide M2(B,C)5 as the coarse primary prismatoids or as the fibres of a “Chinese-script” eutectic, (b) Ti-rich carboboride M(C,B) with a dispersed equiaxed shape, (c) Cr-rich carboboride M7(C,B)3 as the plates of a “rosette”-like eutectic, and (d) Fe-rich boroncementite (M3(C,B)) as the plates of “coarse-net” and ledeburite eutectics. The metallic matrix was ferrite (at 0.3–1.1 wt.% C and 1.5 wt.% B) and “ferrite + pearlite” or martensite (at 0.7–1.1 wt.% C an...
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Papers by Hossam Halfa
This work examines tool steel grades and their grading systems, emphasizing the metallurgical concepts that influence their properties, particularly in production and heat treatment. AISI M2 high-speed tool steel is highlighted for its versatility in high-speed applications that require hardness, toughness, and wear resistance. Achieving optimal properties involves precise control of cleanliness, structure, and microstructure during heat treatment, which is essential for AISI M2 tool steel.
AISI M2 high-speed tool steel was produced through induction melting and electroslag refining (ESR) to reduce nonmetallic inclusions. Various characterization experiments were conducted to investigate phase transformation, microstructure, and dilatation. The study utilized JMatPro software for phase equilibria and solidification analysis. Precipitated carbides were examined using optical microscopy and X-ray diffraction, identified through wavelength dispersive X-ray, scanning electron microscopy, and energy-dispersive X-ray techniques. Image analysis with Image J software assessed the count and size distribution of precipitated carbides and inclusions. The critical transformation temperature was measured using dilatometry.