ISRN Metallurgy http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Influence of the Slag Density on the Splashing Process in a Steelmaking Converter Thu, 13 Feb 2014 11:21:32 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2014/525706/ The way in which slag density influences the slag splashing phenomenon in an oxygen steelmaking converter is numerically analyzed in this work. Several values of the density of the slag are considered, and their effect on the global mass balance and slag average volume fraction on the sidewalls of the converter is studied using isothermal, two-dimensional transient computational fluid dynamics simulations. Diameter of the slag drops is determined from the slag density and the impact velocity of the nitrogen jet. Besides, the effect of the nitrogen jet Mach number on the slag splashing is simulated and discussed. A qualitative comparison between the computer simulations and results from the literature is made. Miguel A. Barron, Dulce Y. Medina, Isaias Hilerio, and Gabriel Plascencia Copyright © 2014 Miguel A. Barron et al. All rights reserved. CFD Model Study of a New Four-Port Submerged Entry Nozzle for Decreasing the Turbulence in Slab Casting Mold Thu, 28 Nov 2013 15:38:50 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2013/981597/ In recent years, the continuous casting process in which molten metal is constantly cast into semifinished shapes has been widely adopted in the steel and nonferrous metal producing industry, mainly due to its economic advantages associated with increased yields and the elimination of intermediate processing steps. Turbulent flow in submerged entrance nozzle and mold of continuous casting is associated with costly failure such as the entrainment of slag inclusions and the formation of surface defects. A number of previously studies have analyzed the flow. A CFD model study has done to decrease the turbulence within the mold by developing a 4-port submerged entry nozzle in comparison with conventional 2-port submerged entry nozzle. VOF (volume of fluid) simulation study has been done to find out the effect of turbulence within mold on slag metal interaction, level fluctuation, and risk of breakout. In all the cases the performance of new 4-port SEN over 2-port SEN has been compared by plotting graph. Debasish Chatterjee Copyright © 2013 Debasish Chatterjee. All rights reserved. Drain Rate and Liquid Level Simulation in Blast Furnace Hearth Using Plant Data Tue, 30 Jul 2013 13:30:31 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2013/960210/ Proper understanding and control of drainage of hot metal and slag from hearth are essential for a stable and efficient blast furnace operation. Various operational problems like irregular casting intervals, damage to lining, low blast intake, furnace pressurization, and so forth are normally encountered when liquid levels in the hearth exceed a critical limit where hearth coke and deadman start to float. Estimation of drain rate and liquid level in hearth needs to be simulated based on the operating parameters available as carrying out any direct measurement is extremely difficult due to the hostile conditions. Here, a mathematical model has been developed to simulate real-time liquid level and drainage behavior of the furnace hearth. Based on the computed drainage rate, production rate, and mass balance, the model is able to predict occurrence of slag-out time and cast close time which are in good agreement with the plant data. Hemant Upadhyay and T. K. Kundu Copyright © 2013 Hemant Upadhyay and T. K. Kundu. All rights reserved. High-Temperature (1700–1800°C) Electrochemical Preparation of Metallic Ti from Rutile: A Pathway of Step-by-Step Electrodeoxidization Wed, 27 Mar 2013 14:31:37 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2013/808413/ The mechanism of producing metallic titanium by electrochemically reducing rutile (TiO2) at high temperatures was studied. First, the oxygen was successfully electroremoved from TiO2 at temperatures 1700, 1750, and 1800°C in molten CaF2 under a stable electrolytic potential of 2.5 V. Second, the electrodeoxidization process was studied with cyclic voltammetry (CV) tests at 1750°C. It was found that the electrochemical reduction for preparing metallic Ti from TiO2 at the high temperatures can be divided into several steps. In other words, the oxygen in TiO2 was electro-removed as a step-by-step pathway (TiO2→Ti4O7→Ti3O5/Ti2O3→TiO→Ti) at different electrolytic potentials. It unraveled the mechanism of electrochemical reduction of TiO2 at the high temperatures, which is helpful for monitoring the reduction procedure. Fanke Meng and Huimin Lu Copyright © 2013 Fanke Meng and Huimin Lu. All rights reserved. Electrochemical Fabrication of Niobium Silicon Alloys from Oxide Powder Mixtures Mon, 11 Mar 2013 09:00:39 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2013/429818/ NbSi alloys were prepared by direct electrochemically reducing four mixed Nb2O5 and SiO2 powders (Nb-10Si, Nb-20Si, Nb-30Si, and Nb-37.5Si) in molten CaCl2 electrolyte at 900°C. The samples were characterized with scanning electron microscope (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). No oxidized phases were remained by XRD tests. Under SEM, Nb phase was scattered in Nb5Si3 phase for the samples of Nb-10Si, Nb-20Si, and Nb-30Si. For the sample of Nb-37.5Si, only Nb5Si3 was obtained after electrolysis. Fanke Meng and Huimin Lu Copyright © 2013 Fanke Meng and Huimin Lu. All rights reserved. Aluminising of Mild Steel Plates Wed, 20 Feb 2013 08:36:24 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2013/191723/ Hot dip aluminising of low carbon steel was done at temperatures 690°C and 750°C for dipping time ranging from 300 to 2400 seconds. During aluminising a mixture of ZnCl2 and NH4Cl was used as flux. During aluminising components of the flux decomposed and zinc formed interacted with the Fe and Al. The aluminised samples were characterised for iron-aluminium intermetallic layer formation, morphology, and local composition. It was observed that intermetallic layer was predominantly Fe2Al5 and FeAl3 at 690°C and at 750°C coating consisted of FeAl3 layer and a layer with Al/Fe ratio greater than 3.26. For both temperatures, coating thickness increased with increase in time. For a given dipping time, deposition was less at higher temperature and this is attributed to changes in the kinetics of growth of individual layers due to dissolved zinc in the aluminium, at 750°C. Also, spalling of intermetallic layers was observed at elevated temperatures and longer dipping times. Udaya Bhat Kuruveri, Prashanth Huilgol, and Jithin Joseph Copyright © 2013 Udaya Bhat Kuruveri et al. All rights reserved. Effects of Added Chloride Ion on Electrodeposition of Copper from a Simulated Acidic Sulfate Bath Containing Cobalt Ions Tue, 12 Feb 2013 08:39:20 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2013/930890/ The effects of added chloride ion on copper electrodeposition was studied using Pb-Sb anode and a stainless steel cathode in an acidic sulfate bath containing added Co2+ ion. The presence of added chloride ion in the electrolyte solution containing 150 ppm of Co2+ ion was found to increase the anode and the cell potentials and decrease the cathode potential. Linear sweep voltammetry (LSV) was used to study the effects of added chloride ion on the anodic process during the electrodeposition of copper in the presence of added  ppm; the oxygen evolution potential is polarised by adding 10 ppm chloride ion at current densities (≥150 A/m2), and further increase in chloride ion concentration increases the polarisation of oxygen evolution reaction more at higher current densities. X-ray diffraction (XRD) showed that added chloride ion and added Co2+ ion changed the preferred crystal orientations of the copper deposits differently. Scanning electron microscopy (SEM) indicated that the surface morphology of the copper deposited in the presence of added chloride ion and added Co2+ ion has well-defined grains. Bijayalaxmi Panda Copyright © 2013 Bijayalaxmi Panda. All rights reserved. Optimization of GMAW Process Parameters Using Particle Swarm Optimization Tue, 22 Jan 2013 09:02:54 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2013/460651/ To improve the corrosion-resistant properties of carbon steel cladding process is usually used. It is a process of depositing a thick layer of corrosion resistant material-over carbon steel plate. Most of the engineering applications require high strength and corrosion resistant materials for long-term reliability and performance. By cladding, these properties can be achieved with minimum cost. The main problem faced in cladding is the selection of optimum combinations of process parameters for achieving quality clad and hence good clad bead geometry. This paper highlights an experimental study to optimize various input process parameters (welding current, welding speed, gun angle, contact tip to work distance, and pinch) to get optimum dilution in stainless steel cladding of low-carbon structural steel plates using gas metal arc welding (GMAW). Experiments were conducted based on central composite rotatable design with full-replication technique and mathematical models were developed using multiple regression method. The developed models have been checked for adequacy and significance. Using particle swarm optimization (PSO) the parameters were optimized to get minimal dilution. P. Sreeraj, T. Kannan, and Subhashis Maji Copyright © 2013 P. Sreeraj et al. All rights reserved. Thermal Conductivity of Cu-Cr-Zr-Ti Alloy in the Temperature Range of 300–873 K Sun, 30 Dec 2012 14:22:14 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/580659/ In the present investigation, thermal conductivity of Cu-Cr-Zr-Ti alloy was determined as the product of the specific heat (), thermal diffusivity (), and density () in the temperature range of 300–873 K. The experimental results showed that the thermal conductivity of the alloy increased with increase in temperature up to 873 K and the data was accurately modeled by a linear equation. For comparison, thermal conductivity was also evaluated for OFHC copper in the same temperature range. The results obtained were discussed using electrical conductivity and hardness measurements made at room temperature. Transmission electron microscopy (TEM) was done to understand the microstructural changes occurring in the sample after the test. Wiedemann-Franz-Lorenz law was employed for calculating electronic and phonon thermal conductivity using electrical conductivity. On the basis of studies conducted it was deduced that in situ aging may be one of the reasons for the increase in thermal conductivity with temperature for Cu-Cr-Zr-Ti alloy. S. Chenna Krishna, N. Supriya, Abhay K. Jha, Bhanu Pant, S. C. Sharma, and Koshy M. George Copyright © 2012 S. Chenna Krishna et al. All rights reserved. Sweet Corrosion Inhibition on API 5L-B Pipeline Steel Tue, 25 Dec 2012 09:30:00 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/892385/ Corrosion inhibition and adsorption behavior of two triazole derivatives on API 5L-B carbon steel in CO2-saturated 3.5% NaCl solutions was investigated using potentiodynamic polarization, EIS, and EFM techniques. Specimen surfaces were characterized using SEM, EDX, and XRD. Results show that the two compounds are mixed-type inhibitors and inhibition efficiency increases with increasing concentrations. Adsorption of the two compounds chemisorption and obeys Langmuir adsorption isotherm. Activation energy and thermodynamic parameters were calculated. Surface analyses confirm the formation of iron nitrides on the metal surface which supports results obtained from previous techniques. Mahmoud Abbas Ibraheem, Abd El Aziz El Sayed Fouda, Mohamed Talaat Rashad, and Fawzy Nagy Sabbahy Copyright © 2012 Mahmoud Abbas Ibraheem et al. All rights reserved. Structural and Electronic Properties of Pure Ta, TaNO, and TaZrNO with Ab Initio Calculations Mon, 17 Dec 2012 15:56:10 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/456762/ This paper presents the results of self-consistent first-principle calculations for the crystal structure and electronic structure of pure tantalum, TaNO, and TaZrNO within density functional theory (DFT) for the sake of comparison and shows the influence of allowing elements on the interatomic distance and the Fermi level. The large total densities of states (TDOS) value for TaZrNO implies the highest electronic conductivity. The difference in values is due to the Zr metallic atoms presence in TaZrNO compound. There is a strong interaction between Ta and (N, O) (, ) in TaON compound, and Zr presence increases this interaction (, ) in TaZrON compound. T. Chihi, M. Fatmi, M. Guemmaz, and J. C. Parlebas Copyright © 2012 T. Chihi et al. All rights reserved. A Kinetic Study of the Emerging of Grains and Block of Grains from the Inner Volume to the Free Surface of a Cd-Zn Alloy Superplastically Deformed Thu, 06 Dec 2012 15:29:22 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/286765/ A local measurement technique for the study of the kinetic processes of emerging of grains or blocks of grains from the inner volume to the free surface of superplastic materials during deformation is presented and used for the case of the Cd-Zn eutectic alloy deformed at room temperature. This technique could be used to evaluate the approximate time of fracture due to fissure or cavitation growth in samples under superplastic deformation. In principle, this technique will be useful for the development of physical procedures, which allows retarding the process of formation of low mismatch angle, , between neighboring grains, process which gives place to blocks of grains which dynamically behave as units under the shear stress action. For materials with nanocrystalline structures, such processes are expected to be higher than those of the case of microcrystalline materials. J. A. Montemayor-Aldrete, R. Mendez-Olvera, P. Ugalde-Velez, G. Torres-Villaseñor, and M. del Castillo-Mussot Copyright © 2012 J. A. Montemayor-Aldrete et al. All rights reserved. Densification Behaviour in the Fabrication of Al-Fe Metal Matrix Composite Using Powder Metallurgy Route Wed, 28 Nov 2012 09:23:33 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/195654/ Densification behaviour of the powder particles in two- and/or multicomponent system is unpredictable. The present work deals with the densification behaviour of Al-Fe powder particles during compaction and sintering in order to fabricate the Al-Fe metal matrix composites by powder metallurgy route. Green compacts of Al-6.23 wt.% Fe powder particles were fabricated under varying compaction pressures, and these fabricated green compacts were sintered over a series of temperatures (430°C–590°C). The sintered products have been characterised with the help of X-ray diffraction (XRD) and scanning electron microscope attached with energy dispersive spectroscopy (EDS). It has been found that the green density of the compacts increases with increase in compaction pressure. The rate of change in green density is found to be lower at higher compaction pressures. Sintered density increases with increasing sintering temperature up to 550°C whereas a drop in sintered density is perceived at 590°C. This decrease in sintered density is considered to occur due to swelling which has been explained on the basis of the Kirkendall effect. The XRD and EDS analyses of sintered products indicated the presence of Al and Fe particles with the trace amount of intermetallics. Siddhartha Tiwari, Priyanka Rajput, and Sanjay Srivastava Copyright © 2012 Siddhartha Tiwari et al. All rights reserved. Nickel-Containing Alloys for Medical Application Obtained by Methods of Mechanochemistry and Powder Metallurgy Wed, 14 Nov 2012 11:03:23 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/464089/ The methods of mechanochemistry, in combination with cold pressing and pressureless sintering, were used to obtain the most popular nickel-based and nickel-containing alloys used in dentistry and implantology. It was shown that the intense mechanical treatment of Ni, Ti, and Cr powders used as reagents, and the application of the above-mentioned simple powder metallurgical technique for densification allows obtaining NiCr and NiTi alloys with controlled structural properties. The nickel-based dental alloys obtained by mechanically activated sintering possess excellent mechanical, technological, and aesthetic properties. These alloys are suitable as dental restorative materials and for production of porcelain veneered constructions like crowns and bridges using the so-called metal-to-ceramic dental technique. It was shown that the method of mechanically assisted synthesis allows obtaining nanosized NiTi alloy at significantly lower temperature in comparison with the traditional high-temperature alloying. It was also shown that after 40 hours intense mechanical treatment of reagents, a direct synthesis of NiTi alloy proceeds. The product has excellent sinterability which enables to produce bodies with controlled porosity appropriate for application in implantology. D. D. Radev Copyright © 2012 D. D. Radev. All rights reserved. Synthesis of PVP-Capped Au-CdSe Hybrid Nanoparticles Mon, 05 Nov 2012 10:32:50 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/824179/ We report the synthesis of PVP-capped Au-CdSe hybrid nanostructures synthesized using the UV-irradiation method. The high resolution transmission electron microscopy (HRTEM) and powder X-ray diffraction (XRD) studies confirm the presence of the hybrid gold and CdSe nanoparticles. M. M. Chili, V. S. R. Rajasekhar Pullabhotla, and N. Revaprasadu Copyright © 2012 M. M. Chili et al. All rights reserved. A Kinetic Model for Tribological Surface Transformations Occuring on the Railroads: Irreversible Near-Surface Metallurgical Transformations Thu, 01 Nov 2012 13:24:16 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/590792/ During the manufacturing processes or the operational phases, some materials are liable to undergo metallurgical phenomena known as irreversible solid-solid phase transformations or Tribological Surface Transformations (TSTs). The treads of several rails in the French railroad network have been affected by TSTs. The kinetic model presented in this paper describes the initiation of TSTs and their development near the rail surface. G. Antoni Copyright © 2012 G. Antoni. All rights reserved. Thermal Expansion Behaviour of Ternary Nickel-Based, Cobalt-Based, and Iron-Based Alloys Containing Very High Fractions of Carbides Wed, 31 Oct 2012 08:46:21 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/750914/ Some of the wear-resistant pieces or coatings, constituted of a metallic matrix and of carbides present in high fractions, are a mix, in similar quantities, of two materials displaying greatly different levels of hardness but also of thermal expansion coefficient. When temperature increases, the second difference of property may lead to particular geometrical behaviours. To study these differences, nine nickel-based, cobalt-based, and iron-based alloys containing very high quantities of carbides were elaborated by foundry. In their as-cast conditions, the microstructures of these alloys were characterized; their hardness and thermal expansion until 1200°C were measured and analysed, with regard to the evolution of the structures predicted by thermodynamic calculations. The hardness of the alloys is high (nickel alloys) or very high (cobalt and iron alloys, 600 Hv and more) while the thermal expansion is greatly influenced by carbides, notably when temperature has become very high. Some of the variations of thickness at the end of heating or during an isothermal stage at 1200°C, essentially contraction, directly result from the mechanical interaction between matrix and carbides which was accumulated during the heating. Patrice Berthod and Lionel Aranda Copyright © 2012 Patrice Berthod and Lionel Aranda. All rights reserved. Aluminium Alloy-Based Metal Matrix Composites: A Potential Material for Wear Resistant Applications Wed, 17 Oct 2012 13:51:29 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/594573/ Aluminium alloy-based metal matrix composites (AMMCs) have been by now established themselves as a suitable wear resistant material especially for sliding wear applications. However, in actual practice engineering components usually encounter combination of wear types. An attempt has been made in the present paper to highlight the effect of dispersing SiC in 2014 base alloy adopting the liquid metallurgy route on different wear modes like sliding, abrasion, erosion, and combinations of wear modes like cavitation erosion, erosion abrasion, sliding abrasion, and the results obtained compared with the base alloy. It is found that there are a number of contributing factors for the resulting wear and all are not necessarily derogatory in nature. The limits within which the AMMCs can exhibit superior performance over the base alloy have been discussed. Worn surface and subsurface studies have been carried out to understand the mechanism of material removal and the role of the different contributing factors to material removal. Wear mechanisms that have been prevalent have been suggested and the possibility of making wear resistant components from the MMCs is discussed based on the experimental results obtained. Rupa Dasgupta Copyright © 2012 Rupa Dasgupta. All rights reserved. Study of Amorphous-Crystalline Phase Transformations by DSC and Dilatometer in the Case of Al-Based Amorphous Alloys Mon, 15 Oct 2012 08:48:41 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/602108/ The amorphous-crystalline transformation is studied by DSC and dilatometer. From the DSC signal the characteristic temperatures and the heat evolved during each transformation step can be determined. The dilatometer depicts the thermal contractions accompanying the changes in topological short range order. Although the characteristics temperatures determined by DSC and dilatometer, two methods are slightly different their dependences on the heating rate are very similar, where from the activation energies of each transformation steps can be determined using the Kissinger plots. As an example, two aluminum-based amorphous ribbon samples (Al88Mm5Ni5Co2 and Al85Y8Ni5Co2) will be measured and compared. Éva Fazakas, Béla Varga, and Lajos Károly Varga Copyright © 2012 Éva Fazakas et al. All rights reserved. Development of MoSi2-SiC Component for Satellite Launch Vehicle Sun, 14 Oct 2012 18:46:03 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/670389/ Intermetallic base MoSi2-SiC composite, an excellent high temperature oxidation-resistant material meant for the aerospace structural applications between 1600°C and 1700°C under oxidizing environment, has been developed successfully using powder metallurgy techniques. Mechanically milled (MM) MoSi2 powder, blended with SiC particulate was consolidated by vacuum hot pressing, yielded about 98.5% theoretical density. The composite has been characterized for physical, mechanical, and thermal properties. Properties were found satisfactory. Machining of semis to intricate shape was possible through electro-discharge machining (EDM) process. Plasma arc jet test (PAJT) under argon and argon + oxygen environment has proved its excellent high temperature oxidation resistance properties as it could sustain high heat flux up to 250 W/cm2 under oxidizing environment. The component realized has full potential to be used in critical aerospace application. This paper highlights the details of experimental work carried out and its characteristic properties attained. G. P. Khanra, Abhay K. Jha, S. GiriKumar, D. K. Mishra, T. T. Sarvanan, and S. C. Sharma Copyright © 2012 G. P. Khanra et al. All rights reserved. A Model for Conjoint Shape Memory and Pseudo-Elastic Effects during Martensitic Transformation Thu, 27 Sep 2012 19:17:19 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/612891/ Shape memory alloys (SMA) are metals which can restore their initial shape after having been subjected to a deformation. They exhibit in general both nonlinear shape memory and pseudoelastic effects. In this paper, shape memory alloy (SMA) and its constitutive model with an empirical kinetics equation are investigated. A new formulation to the martensite fraction-dependent Young modulus has been adopted and the plastic deformation was taken into account. To simulate the variations, a one-dimensional constitutive model was constructed based on the uniaxial tension features. K. Boubaker Copyright © 2012 K. Boubaker. All rights reserved. Electrochemical Study of the Corrosion Behavior of Zinc Surface Treated with a New Organic Chelating Inhibitor Tue, 04 Sep 2012 11:23:01 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/940107/ The effect of a new organic compound (N-[(1E)-(4 methoxy phenyl)methylene]hydrazinecarbothioamide), called ATSC, with chelating groups, on the corrosion behavior of zinc was investigated. Electrochemical study of the zinc specimens was carried out in aqueous electrolyte containing 0.2 M Na2SO4 and 0.2 M NaCl maintained at pH 5 using galvanostatic polarization curves. The surface treatment of zinc was achieved by immersion in solutions of different concentrations of ATSC and for different immersion time and bath temperatures. The zinc metal treated with ATSC at 5% has showed good corrosion resistance and maximum protection efficiency of about 84% at 300 K. Moreover, the treatment induced a basic modification of the cathodic nature of zinc and controls the corrosion by decreasing the electron transfer rate. The corrosion protection could be explained by the formation of a protective organometallic layer on the zinc surface due to the chelation reaction between zinc and inhibitor molecules. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) were applied to study the protective layer. R. A. Prabhu, T. V. Venkatesha, and B. M. Praveen Copyright © 2012 R. A. Prabhu et al. All rights reserved. Effect of Isothermal Holding on Semisolid Microstructure of Al–Mg2Si Composites Thu, 14 Jun 2012 11:01:22 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/631096/ Effect of heat treatment and isothermal holding has been investigated on the microstructure and degree of globularity of Al–Mg2Si composites. Different contents of reinforcement, 15, 20, and 25% have been used in this study. Isothermal holding experiments were conducted at 585 °C for 140 min. Results showed that, upon heat treatment, grain size of dendrites was reduced while the degree of nodularity was increased. Results of nodularity were obtained using an image-analyzing software which gives the distribution of radius of curvature for different phases of particles. According to the results, in contrast to Al–15 and 25% Mg2Si, isothermal holding significantly influenced the microstructure of Al–20% Mg2Si composites. Two companion mechanisms have been proposed for the generation of globular grains. SEM investigations were also employed to confirm the optical observations. A. Malekan, M. Emamy, J. Rassizadehghani, and M. Malekan Copyright © 2012 A. Malekan et al. All rights reserved. Alloy Designation, Processing, and Use of AA6XXX Series Aluminium Alloys Mon, 09 Apr 2012 09:48:06 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/165082/ The strength-to-weight ratio offered by AA6XXX alloys and their enhanced mechanical properties have become crucial criteria for their use in light weight military vehicles, rockets, missiles, aircrafts, and cars, used for both defence and civil purpose. The focus of this review paper is to put together the latest knowledge available from various sources on alloy design, industrial processing, development of properties, and potential use of AA6XXX alloys. The direct chill (DC) cast AA6XXX wrought alloys which are subsequently processed by fabrication process like hot working, cold working, process annealing, and age hardening heat treatments are the foci of this review though designation section also contains the designations of cast alloys to provide the reader a broad overview on designation. World-wide accepted designations are briefly tabled along with their alloying elements. The effects of the alloying elements which are generally used for AA6XXX wrought alloys are discussed incorporating their interactions during wrought AA6XXX alloy fabrication. The significance of the alloying and also the processing to develop the certain properties and the underlying strengthening mechanisms are discussed. The frequent and versatile uses of these AA6XXX alloys for the structural applications both in defence and civil purpose are put forth. Prantik Mukhopadhyay Copyright © 2012 Prantik Mukhopadhyay. All rights reserved. Defect Studies in bcc and fcc Iron Mon, 26 Mar 2012 16:59:50 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/431742/ Variation of vacancy formation energy (𝐸𝐹1𝑣) with π‘Ÿπ‘ of Ashcroft's empty core model potential (AECMP) model for different exchange and correlation functions (ECFs) show almost independent nature but slight variation with ECF for both bcc 𝛼 iron and fcc 𝛾 iron. A. Ghorai and Arjun Das Copyright © 2012 A. Ghorai and Arjun Das. All rights reserved. Overview of Intermetallic Sigma (𝜎) Phase Precipitation in Stainless Steels Thu, 08 Mar 2012 15:08:59 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/732471/ The 𝜎 phase which exists in various series of stainless steels is a significant subject in steels science and engineering. The precipitation of the 𝜎 phase is also a widely discussed aspect of the science and technology of stainless steels. The microstructural variation, precipitation mechanism, prediction method, and effects of properties of 𝜎 phase are also of importance in academic discussions. In the first section, a brief introduction to the development and the precipitation characteristics (including morphologies and precipitation sites) of 𝜎 phase in stainless steels is presented. In the second section, the properties effect, prediction method, processing effect, elemental addition, retardation method and Thermo-Calc simulation of the 𝜎 phase in stainless steels are highlighted. Chih-Chun Hsieh and Weite Wu Copyright Β© 2012 Chih-Chun Hsieh and Weite Wu. All rights reserved. Effect of Artificial Aging on Plane Anisotropy of 6063 Aluminium Alloy Wed, 15 Feb 2012 09:50:16 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/639319/ Most aluminum profiles’ production by deep-drawing and extrusion processes require certain degree of structural homogeneity because of the segregated second-phase particles in the as-cast structure. Rolled texture and directionality in properties often give rise to excessive earring, breakout, and tears. This study investigates the effect of heat treatment (artificial aging) on the anisotropic behavior of AA6063 alloy between rolling direction (0°) through 90° directions. The results show significant reduction in property variability in the aged samples along the rolling direction 0°, and 90° directions compared with the as-cast samples. This gave rise to improved % elongation, impact toughness, and substantial reduction (33.3%) in hardness. These results are capable of achieving huge savings in die conditioning and replacement with improved quality and sale of deep-drawn AA6063 alloy profiles for sustained profitability. S. O. Adeosun, O. I. Sekunowo, M. A. Bodude, A. A. Agbeleye, S. A. Balogun, and H. O. Onovo Copyright © 2012 S. O. Adeosun et al. All rights reserved. Modeling to Study the Effect of Environmental Parameters on Corrosion of Mild Steel in Seawater Using Neural Network Mon, 30 Jan 2012 12:10:20 +0000 http://www.hindawi.com/journals/isrn.metallurgy/2012/487351/ Prediction of corrosion rate of steel structure in seawater is a challenging task for design and corrosion engineers for existing as well as new structures, due to wide variation of its composition across the global marine environment. The major parameters influencing the rate are salinity, sulphate, dissolved oxygen, pH, and temperature. While the individual effects of these parameters on corrosion are known, the conjoint effect of the parameters together is complex and unpredictable. Endeavors have been made to model the corrosion rate from laboratory experimental data, using Artificial Neural Network to predict corrosion rate at any combinations of the above five parameters and to better understand the effects of these parameters jointly on corrosion behavior. 3D mappings clearly reveal the complex interrelationship between the variables and importance of conjoint effect of the variables rather than single variable on the corrosion rate of steel in seawater. Subir Paul Copyright © 2012 Subir Paul. All rights reserved.