Solidification

Phase change materials (PCMs) are classified according to their phase change process, temperature, and composition. The utilization of PCMs lies mainly in the field of solar energy and building applications as well as in industrial processes. The main advantage of such materials is the use of latent heat, which allows the storage of a large amount of thermal energy with small temperature variation, improving the energy efficiency of the system. The study of PCMs using computational fluid dynamics (CFD) is widespread and has been documented in several papers, following the tendency that CFD nowadays tends to become increasingly widespread. Numerical studies of solidification and melting processes use a combination of formulations to describe the physical phenomena related to such processes, these being mainly the latent heat and the velocity transition between the liquid and the solid phases. The methods used to describe the latent heat are divided into three main groups: source term...

A highly repeatable solidification test was developed. It was designed to study the effect of process parameters on solidified micro and macrostructures. Different cooling rates were used for solidification and cooling of S 355 J2 construction steel. It was observed that cooling rate has a substantial influence on final grain size and on columnar-to-equiaxed transition zone (CET). Within the interval of constant thermal gradient, different macroand micro-structural features have been provided, which consequently enables the study of dynamics of precipitation dependence on solidification processing parameters. Izvleček: Razvit je bil visoko ponovljiv test strjevanja. Razvit je bil kot orodje, za preučevanje vpliva procesnih parametrov na lito mikro in makrostrukturo. Za strjevanje konstrukcijskega jekla S 355 J2 so bile uporabljene različne ohlajevalne hitrosti. Opažen je bil močan vpliv ohlajevalne hitrosti tako na končno velikost zrn, kot tudi na mejno plast med stebričastimi in ek...

Dendritic structures are one of the most frequent patterns in nature, that appear in crystalline systems (such as metals), advanced ceramics and neural systems of the living organisms. Embedded in the core of many industrially important processes such as casting, there is a strong relationship between the material properties and the solidified dendritic microstructures.

In our proposed study microstructural simulations were performed using MICRESS® code, which implements a multi-phase-field approach and essentially provides a mathematical solution to the coupled partial differential equations of phase-field and diffusion. In the context of the study, MICRESS® was used to simulate the morphological transitions and the solute segregations during directional solidification under a wide spectrum of temperature gradients, solidification rates and chemical compositions. The proposed model is integrated with an in-situ experimental study of solidification in a high-temperature laser-scanning confocal microscope. Such in-situ studies are able to provide an experimental mean to measure some of the crucial physical properties of the studied alloys, resulting in more refined microstructural simulations of such phenomena. For instance we demonstrated a real-time method for the calculation of Gibbs-Thomson coefficient and the solid-liquid interfacial energy of the studied alloys by analysing the shape of the grain-boundary grooves at the solid-liquid interface. The interface mobility parameter was calibrated so to achieve a realistic interface velocity aligned with the regime experimentally observed in real-time in the confocal microscopy.

Hydrogen embrittlement in 304L austenitic stainless steel fabricated by laser powder-bed-fusion (LPBF) was investigated and compared to conventionally produced 304L samples with two different processing histories; casting plus annealing (CA) and CA plus thermomechanical treatment (CA-TMT). Interestingly, no significant difference in the amount of deformation-induced α ′ martensite between the LPBF and CA-TMT samples was observed, suggesting that the solidification substructure in the LPBF sample enhanced the strength without promoting the harmful hydrogen embrittlement effect. These results are discussed in terms of the chemical in-homogeneity, hydrogen-assisted cracking behavior, and hydrogen diffusion and trapping in the present 304L samples.

Thank you very much; I am bharat sharma founder of steady die casting solutions. This time I have found one more solution for biscuit thickness validation in high pressure die casting. In this paper we will discuss, what is biscuit thickness?, why we need to identify right biscuit thickness?, how we can validate right biscuit thickness? and effect of biscuit thickness variation. This paper is all about to clear all myth to calculate biscuit thickness in high pressure die casting. This is very serious business when we are calculating biscuit thickness to avoid casting defect. Through this paper I would like to share this knowledge and I hope it will helpful to others. "Keep learning till death ".

Alumno: Ramón Eduardo Lopez Vilamil 1. Vibraciones de la red cuadrada. Consideremos vibraciones transversales de una red cuadrada plana de filas y columnas dé atomos idénticos y designemos por u l,m el desplazamiento normal al plano de la red eí atomo de la columna l y de la fila m. La masa de cadá atomo es M. Suponer que las constantes de fuerza son tales que la ecuación del movimiento es: M d 2 u l,m dt 2 = C[(u l+1,m + u l−1,m − 2u l,m) + (u l,m+1 + u l,m−1 − 2u l,m)] (1) Se ha descubierto que esta ecuación, planteada como problema en las primeras ediciones de este libro, solo resulta de una hipótesis no realista respecto a las fuerzas interatomicas. No obstante ,puede continuarse el problema en la forma ahora expuesta. (a)Suponer soluciones de la forma: u l,m = u(0)exp[i(lK x a + mK y a − ωt)] (2) En donde a es la separación entre losátomoslosátomos vecinos mas próximos. Demostrar que se satisface la ecuación de movimiento si: ω 2 M = 2C[2 − cos(K x a) − cos(K y a)] (3) Esta es la relación de dispersión para el problema.(b) Demostrar que la región del espacio K, para la cual existen soluciones independientes, puede considerarse como un cuadrado de arista 2π/a. Esta es la primera zona de Brillouin de la red cuadrada. Solución: Note que du l,m dt = −iωu(0)exp[i(lK x a + mK y a − ωt)] (4) d 2 u l,m dt 2 = −ω 2 u(0)exp[i(lK x a + mK y a − ωt)] (5) Sustituyendo d 2 u l,m dt 2 en (1) M d 2 u l,m dt 2 = −M ω 2 u(0)exp[i(lK x a + mK y a − ωt)] (6) Donde (3) también se puede escribir como ω 2 M = −4C + C[exp(iK x a) + exp(−iK x a)] + C[exp(iK y a) + exp(−iK y a)] (7) 1

The control of the metallurgy of steels is now highly developed. This is in contrast to the casting techniques for steels. Although continuous casting is generally conducted well, current ingot casting techniques are poor, unnecessarily introducing masses of oxides. For some steel compositions, double oxide films, bifilms, are entrained. This mechanism, occurring naturally during pouring, but till now generally overlooked, appears to be capable of explaining most of the features of steel defects in all their forms. For most Ni alloys and some steels it appears capable of generating a dense population of cracks, greatly impairing subsequent mechanical working and even final properties. In other steels the effects are much less severe. The techniques to avoid this damage to liquid steels and Ni alloys are described, including contact pouring, and naturally pressurized filling system designs. An ultimate system is counter gravity casting. For remelting processes, the risks of unreliability because of cracks intrinsic to VIM and VAR are discussed for both shop floor production and laboratory research. The potential crack-free properties of ESR when correctly made are recommended. Even so, remelting processes might constitute an unnecessary luxury if steels and Ni alloys were cast to avoid the entrainment of oxides.

Today, a large number of different steels are being processed by Additive Manufacturing (AM) methods. The different matrix microstructure components and phases (austenite, ferrite, martensite) and the various precipitation phases (intermetallic precipitates, carbides) lend a huge variability in microstructure and properties to this class of alloys. This is true for AM-produced steels just as it is for conventionally-produced steels. However, steels are subjected during AM processing to time-temperature profiles which are very different from the ones encountered in conventional process routes, and hence the resulting microstructures differ strongly as well. This includes a very fine and highly morphologically and crystallographically textured microstructure as a result of high solidification rates as well as non-equilibrium phases in the as-processed state. Such a microstructure, in turn, necessitates additional or adapted post-AM heat treatments and alloy design adjustments. In this review, we give an overview over the different kinds of steels in use in fusion-based AM processes and present their mi-crostructures, their mechanical and corrosion properties, their heat treatments and their intended applications. This includes austenitic, duplex, martensitic and precipitation-hardening stainless steels, TRIP/TWIP steels, maraging and carbon-bearing tool steels and ODS steels. We identify areas with missing information in the literature and assess which properties of AM steels exceed those of conventionally-produced ones, or, conversely, which properties fall behind. We close our review with a short summary of iron-base alloys with functional properties and their application perspectives in Additive Manufacturing.
The main advantages of additive manufacturing (AM) technologies
of metallic parts compared to conventional synthesis and shaping pro-
cesses lie in their ability to produce complex and/or customized parts
with a short lead time, albeit in relatively low numbers. These advan-
tages are exploited for example when patient-specific implants are
produced, when complex, structurally optimized parts lead to
performance-critical weight savings, or when AM is used for the repair
of expensive metallic jet engine parts. The alloys usually envisaged in
these applications are biocompatible, high temperature and lightweight
materials such as Ti-, Ni-, Al- and Mg-based alloys. Consequently, re-
views of alloys in AM have typically focussed on these materials [1–3],
with two notable exceptions which do discuss steels, however with a
different focus than the present review [4,5]. Yet, the most successful of
all alloy families since the dawn of the iron-age 3000 years ago, namely
steel, has received relatively little attention with respect to providing a holistic view of the interplay of alloy design, microstructure, properties
and AM processing.

Earlier research carried out on the ductility of Al-Si-Cu-Mg alloys have showed that the ductility of Al-Si-Cu-Mg alloys with high levels of Fe (0.5 wt. %) and Cu (4.0 wt. %) is increased at high (7~9%) concentrations of Si. Quantitative metallographic analysis performed on these alloys suggested that the refinement of both Fe-rich β-Al5FeSi and Curich θ-Al2Cu intermetallics, arose from the shorter solidification path accounting for the increased ductility. More recent studies on the effect of Si concentration on the size and shape of iron-rich (Al5FeSi) intermetallic phase of ternary Al-Si-0.8Fe alloys showed that the size of β-Al5FeSi plates increased with increasing silicon content. It was then proposed that the presence of Cu was adamant to the refining effect of Si, presumably through the introduction of low melting point pools of Cu-Al eutectic. It was proposed that Fe remained in solution in the Cu-rich liquid, whereas the liquid pools were dispersed by the high volume fraction of Al-Si eutectic, thus resulting in a finely dispersed and highly refined distribution of Fe- and Cu- rich intermetallics.

Hence, this project has conducted a systematic study across a range of Al-Si-Cu-Mg alloys to elucidate the mechanisms by which increased Si refines and disperses the Fe- and Curich phases, increasing the material’s ductility. Limits to the effect have been determined, and the optimum content of the alloy components have been identified. This is supplemented by an optimisation of composition, providing the basis for improved property-processing alloy selection.

Thermal information of various Al-Si-Cu-Mg-Fe alloys were obtained during solidification, using computer controlled data acquisition device and the LabView-Signal Express® software, and the corresponding SDAS were also measured on optical microscope images followed by intermetallic particle size distributions that were measured using image analysis software, Image-Pro® software, on the BSE SEM images in order to compare the size refining effect of Si and Cu content on the Fe-rich and Cu-rich intermetallic phase particles for different SDAS, i.e. different cooling rate. EBSD and EDS mapping and point analysis were used to identify the Fe-containing intermetallic phases. Sample prepared using FIB was also used to further confirm elements, by EDS in TEM, on the script-like Fecontaining intermetallic phase.

Si and/or Cu content showed a considerable decrease in the size of SDAS for a constant average solidification rate which should only be calculated between the liquidus and  solidus temperatures; not between the liquidus and eutectic temperatures, especially when having many solute elements, for the range of experimental Al-Si-Cu-Mg- Fe) alloys  studied here. The relationship between cooling rate and the SDAS for the alloys was determined in the form of λ2 = a R −n where a and n are composition-  ependent fitting parameters, that also depend on the cooling rate calculation method. The combined presence of high levels of Cu, Si and Fe which produces intermetallics  throughout the entire solidification period, but particularly in the latter stages, hinders the SDAS coarsening, refining the SDAS for given cooling rate. 

Fe intermetallics exist as two different phases depending on the SDAS and Si concentration: (1) script-like α-Al8Fe2Si; (2) plate-like β-Al5FeSi. A preferential formation of  α-phase particles is observed at high cooling rates, leading to an overall decrease in the size of the intermetallics. Modification with Sr increases the size of pre-eutectically (Al-Si)  formed β- l5FeSi intermetallic plates whereas it reduces the co-eutectic and post eutectic β-Al5FeSi plates (observed as curved-shape), especially at low cooling rates. i.e. there are two different distributions of Fe-bearing intermetallics that form in Sr-modified Al-Si-Fe alloys.

High levels of Si and/or Cu decreased the amount and size of the β-Al5FeSi  platelets in Al-Si-Cu-Mg-Fe casting alloys, especially at small SDAS if the Fe level is below the Si dependent critical level for the formation of the pre-eutectic platelets (for the Fe-bearing  phases precipitation in the post eutectic stage). At small SDAS, in the low Si (4.5%) alloys, Cu leads to decreased size of the intermetallics whereas in the Cu-free, high-Si alloy, the  plates are replaced by a mixture of the irregular alpha-Al8Fe2Si and β-Al5FeSi platelets, i.e. in the Cu containing alloys, plates are  formed even at small SDAS.

High levels of Si decrease the size of the Fe-bearing intermetallics in Al-Si-Fe alloys at 0.2  and 0.5 Fe level. This effect is accompanied by the formation of script-like phases,  possibly α-Al8Fe2Si or branched β-Al5FeSi plates, isolated or clustered together. Thescript-like Fe-intermetallics are formed, in high Si  alloys, at low and high solidification rates for the 0.2 and 0.5 Fe alloys. In the low Si alloys, this only occurs at high solidification rates. The number density of script-like particles is higher in the high Si and low Fe alloys,  suggesting that the eutectic Si provides additional nucleation sites. A high level of Cu refines the intermetallic particles in  the low Si alloys, but it may have the opposite effect when the Si level is high. The optimal composition for a strong and ductile casting using secondary Al-Si-Cu alloys  appears to be 9Si and 1 Cu, for the alloys Fe<0.5, and for the alloy with Fe >0.5 a high Si (>9 mass %) with a maximum SDAS of 30 μm. The SDAS  should not exceed 30  μm for Cu >1%, for both low and high Si, in order to obtain a wellrefined population of intermetallic particles.

We present a brief overview on recent developments in the field of strong and ductile non-equiatomic high-entropy alloys (HEAs). The materials reviewed are mainly based on massive transition-metal solute solutions and exhibit a broad spectrum of microstructures and mechanical properties. Three relevant aspects of such non-equiatomic HEAs with excellent strength–ductility combination are addressed in detail, namely phase stability-guided design, controlled and inexpensive bulk metallurgical processing routes for appropriate microstructure and compositional homogeneity, and the resultant microstructure–property relations. In addition to the multiple principal sub-stitutional elements used in these alloys, minor interstitial alloying elements are also considered. We show that various groups of strong and ductile HEAs can be obtained by shifting the alloy design strategy from single-phase equiatomic to dual-or multiphase non-equiatomic compositional configurations with carefully designed phase instability. This design direction provides ample possibilities for joint activation of a number of strengthening and toughening mechanisms. Some potential research efforts which can be conducted in the future are also proposed.

La représentation des propriétés et des phénomènes du monde physique existe dès le début de la vie, comme une donnée première de la réalité. Dans plusieurs recherches centrées sur les représentations des enfants on trouve que ces représentations jouent un rôle décisif à l’enseignement et sont souvent incompatibles au modèle scientifique. Cet article présente les résultats d’une recherche empirique sur les représentations des petits enfants  pour la fusion et la solidification du sel. L’échantillon de l'étude est composé de 359 élèves grecs de 5 à 14 ans, partagés en quatre groupes d’âge. Les données ont été recueillies dans le cadre élargi, de type ouvert, semi-structurés conversations individuelles entre d’enfants de l'échantillon et d'un chercheur. Les résultats des entretiens montrent que ces enfants utilisent différentes catégories des représentations, dominées pour la majorité par la nature de la substance que nous étudions.

The representation of the properties and phenomena of the physical world exists from the beginning of life, as a first datum of reality. In several studies focused on children's representations, we find that these representations are critical to education and are often incompatible with the scientific model. This article presents the results of an empirical research on the representations of children for melting and solidification of salt. The research sample consisted of 359 Greek students 5 to 14 years, divided into four age groups. Data were collected through expanded, open type, semi-structured individual conversations between a child of the sample and one researcher. The results of the interviews show that these children use different types of representations, the majority dominated by the nature of the substance under study.

Due to its influence on the heat transfer between cast part and mould the air gap formation is an important problem for many casting processes. The general explanation for the gap formation is that as a result of stresses and distortions that are created from inhomogeneous cooling, shrinkage of the casting and expansion of the mould occurs. In this paper we apply different thermomechanical approaches by using three commercial and one in-house code to a well defined casting process and compare their predictions with experimental findings. The experimental facts were gained from the solidification and subsequent cooling of cylindrical castings of eutectic Al-13%Si and ternary Al-7%Si-0.3%Mg alloys. Based on these findings, the major differences between the predictions of the models and the actual formation of the air gap are discussed.

Hot tearing is a major defect in castings or semifinished cast products. It corresponds to the opening of cracks in the mushy zone and, more precisely, in the areas with high fraction of solid (typically 0.9 and beyond) when the material is subjected to deformations leading to local tensile stress. Various kinds of criteria have been developed to highlight a risk of formation of hot tears. The aim of this study is to evaluate their capability to predict the occurrence of hot tears correctly. In order to do so, two kinds of tests have been analyzed with the use of a thermomechanical finite element model.

The purpose of this study is to investigate the influence of the aspect ratio and Grashof number on the convection diffusion phenomena associated with solid liquid phase transition processes during PCM solidification within a rectangular cavity. The applied two-dimensional physical model is based on the enthalpy method approach. The numerical solutions are obtained with finite volume method and validated with existing numerical and experimental studies of natural convection in phase change material. Numerical analysis are performed using water as phase change material, for an aspect ratio range 0.5 to 4. The left and right walls of the cavity are maintained at hot and cold temperatures, respectively, while the upper and lower surfaces are considered adiabatic. From this study, it is found that PCM initially liquid evolves to thermal stationary regime where solid and liquid regions are present. The solidification phase change process depends considerably on the thermal and geometrical parameters of the system. Additionally, it is demonstrated that the physical approach based on a purely conductive model remains valid to cases of low values of Grashof number and aspect ratio. The findings of this research may contribute to the elaboration of an efficient modeling of PCM heat storage systems.

Solidification patterns in crystalline systems are one the most aesthetically pleasing examples of pattern formation in nature. During solidification when a planar solid/liquid interface becomes unstable, it reorganizes itself into cellular and dendritic micro arrangements. These interfacial patterns appear as fractal features and their level of complexity is characterized by their fractal dimension or by their primary and secondary arms spacing. In metallic systems, because solidification microstructure is a defining link between production techniques and the mechanical properties, it is technologically crucial and economically favored to achieve desired properties of the final product through a controlled solidification process.
One of the major obstacles for the solidification studies in metallic systems is its occurrence at high temperatures and the lack of experimental techniques to observe this phenomenon in real-time. Hence all the previous in-situ research was carried out on substitute transparent materials, which mimic the forms of solidification in metallic systems. The real-time technologies and adequate techniques to observe patterning in metallic-systems-themselves were only introduced in the recent years eventually proving the possibility to answer the fundamental question: to what extend the substitute transparent materials can mimic the forms of solidification in metallic systems?
Our proposed study uses a high-temperature Laser-Scanning Confocal Microscopy (LSCM) combined with in-house technological advancements to make real-time observations of phase transformations at high temperatures and such system was used to observe pattern formations during steel solidification. Using the Concentric Solidification technique, pattern formations during solidification of steel were observed in real-time and subsequently the effect of cooling rate and alloy composition on the cellular spacing were discussed morphologically and analytically.

"Al–Cu-based MMCs reinforced by Al–Fe intermetallics are investigated for their wear behaviour. The composite (Al–4.5 mass% Cu–3.4 mass% Fe) was produced by solidification processing where the Al–Fe-based intermetallic formed in situ in a matrix of mainly Al–Cu alloy. The effects of thermal and mechanical processing, viz., as-cast condition, solution treatment, aging and hot rolling on the wear behaviour of the composites were examined. The composites were characterized by optical microscopy, SEM, microhardness measurements and X-ray diffraction. The wear behaviour of the composites was studied in a pin-on-disc type wear apparatus.

The as-cast in situ composite exhibited the highest wear rate. The wear rate of the (cast + solution treated + aged) composite was about 4.5 times and that of the (rolled + solution treated + aged) composite about 9.5 times lower than the wear rate of the as-cast composite. Hot-rolling + solution treatment + ageing of the MMC was found to yield the lowest wear rate among all processing conditions investigated. Worn surface revealed that mainly abrasive wear took place in all cases. The extent of abrasive wear was largest in the as-cast MMC as evidenced by deep groves on the worn surface as well as by the highest weight loss. Dark patches of presumably transfer layer were found in some cases, particularly on the (rolled + solution treated + aged) samples. Attempt has been made to relate the wear behaviour of the in situ MMC to their microstructures and to the microhardness of the matrix and the reinforcing phase."

The work is devoted to improvement of mechanical properties of iron castings via adjusting of the cooling rate without introduction of alloying additives. The new technological solution is suggested; it can be easily adapted to a casting technology. This solution is based on variation of the cooling rate of iron castings within structurally sensitive solidification intervals. For this purpose, the casting mould was initially cooled after pouring, then heated and cooled again. Cooling of the mould during the period of primary austenite crystal forming led to increase of dendrite crystallization rate and was executed using compressed air. Retarding of the cooling rate during the period of eutectic transformation was provided by the mould heating via burning of exothermic carbon-containing additives introduced in a facing layer of sand-clay moulding mix. Burning reaction is accompanied by heat extraction, what steeply retarded the cooling rate within the interval of eutectic transformation. Consequent acceleration of castings cooling within the interval of eutectoid transformation was achieved via repeated air blowing through a worked reaction layer. Adjusted cooling of iron castings allowed to provide the most favourable solidification conditions, taking into account strictly individual requirements for each structurally sensitive temperature intervals. It led to increase of a volumetric part of primary austenite dendrite crystals, to decrease of eutectic transformation overcooling degree, to forming of graphite eutectics and enlargement of dispersity of pearlite component in iron. Consequently, lowering of widespread iron castings rejects takes place, among them chilling, with simultaneous improvement of metal mechanical properties. As a result, the primary and real structures were varied, what had a positive effect on mechanical properties of casting metal. It is shown that use of solidification rate adjustment led to essential increase of metal tensile strength for the experimental casting.

Sand casting technologies have now emerged as practical and commercial ways of manufacturing high integrity near net shape castings. A variety of castings have found their way into general engineering applications. Castings that serve these specific applications have to achieve the quality requirements of superior mechanical properties and zero-porosity. To achieve these objectives within a limited time frame in a product development process, CAD technologies with numerical analysis combined with process simulation tools are increasingly used to optimize form filling and solidification of the cast parts. In this process the molten aluminum is introduced in the mold at 800 0 C, the ambient temperature and mold are at 30 0 C. The top and side faces of the mold exchange heat with the environment by free convection. 2D Axi-symmetric behavior is assumed for sand mold and aluminum casting. Transient thermal analysis is considered for 1500 sec.

A busca pela melhoria das propriedades metalúrgicas do depósito soldado e de suas características geométricas aguça a realização de pesquisas voltadas para o desenvolvimento e o aperfeiçoamento da gama de aplicação da soldagem a arco elétrico. Nos processos MIG/MAG e TIG, a implementação de complexas técnicas de controle do processo de pulsação de corrente possibilita o seu uso na união de
estruturas metálicas com espessura de parede cada vez mais fina, além de permitir a atuação sobre a agitação da poça de fusão, o tamanho e a forma dos grãos e as frações volumétricas dos microconstituintes. Com justificativa nesses benefícios, este trabalho revisa e discute as pesquisas realizadas no campo da pulsação, convencional e térmica, da corrente de soldagem.

Fonte: Revista Corte & Conformação de Metais, pp. 98-125. Outubro 2008.
Research Interests: Welding Technology, Solidification, Welding Metallurgy, Grain size, Soldagem, Pulsed Current, Solidificação, and Zona fundida

In this paper an arbitrary Lagrangian–Eulerian (ALE) formulation has been developed for the simulation of casting processes. The method is applied both to mould filling simulation, where it can provide accurate free surface description, and to the study of thermo-mechanical phenomena occurring in the subsequent cooling down of cast parts: prediction of solute transport and of distortions and stresses. In the first three sections, all governing equations (constitutive equations, momentum, energy, solute transport) are given. Then the ALE formulation is presented: mesh updating with evolving free surfaces, using ''conservative'' normal vectors to enforce mass conservation; treatment of advection terms, using an original nodal upwind method; definition of Lagrangian and Eulerian–Lagrangian regions. Finally, examples of applications are given.

Solidification of molten metal after being poured into a mould cavity is an important phenomenon in casting and is of great interest to physicists, metallurgist, casting engineers and software developers. A molten metal is poured at a very high temperature into refractory material sand at room temperature. During the solidification of casting in a mould, the heat transfer between casting and sand mould plays a vital role. It is a nonlinear transient phenomenon, posing a challenge in terms of modeling and analysis. It has been identified that the solidification process mainly governed by three parameters such as conductivity of sand, pouring temperature of molten metal and initial temperature of sand. Thus it becomes necessary to identify the most prominent parameter affecting the solidification out of the above mentioned. Experiments were conducted by simulation using ANSYS software to study the effect of these parameters on the heat transfer during solidification of casting. Thus experiments were planned using the strategy of design of experiments (DOE). Levels and ranges of input parameters were selected and then experiments were conducted. The results obtained with permutation and combinations of these parameters were analyzed by using Analysis of Variance (ANOVA), a statistical method to investigate the critical parameter affecting the heat transfer during the solidification process and their contribution.

Beam blank casting is a mature process born in 1968 [1]. Around 60 casters has been installed since. In this paper a thorough review of the literature on defects in beam blanks is carried out. The focus is on the formation mechanism and the solutions proposed to decrease their occurrence. Surface defects included are longitudinal cracks and transverse cracks. Internal defects are blowholes and solidification cracks. The review includes the techniques used to investigate the defects: metallographical characterizations, CFD, thermodynamical and thermomechanical modelling, etc. The measures taken have to do with changes in casting system (i.e. SEN design), mold design, secondary cooling modifications and regulation, strand support. Casting of beam blanks may be carried out with open casting, semisubmerged casting and submerged casting. The three casting possibilities are presented in figure 1. Each one has advantages and drawbacks (table 1). Open casting tends to concentrate in the sma...

Beam blank casting is a mature process born in 1968 [1]. Around 60 casters has been installed since. In this paper a thorough review of the literature on defects in beam blanks is carried out. The focus is on the formation mechanism and the solutions proposed to decrease their occurrence. Surface defects included are longitudinal cracks and transverse cracks. Internal defects are blowholes and solidification cracks. The review includes the techniques used to investigate the defects: metallographical
characterizations, CFD, thermodynamical and thermomechanical modelling, etc. The measures taken have to do with changes in casting system (i.e. SEN design), mold design, secondary cooling modifications and regulation, strand support. Casting of beam blanks may be carried out with open casting, semisubmerged casting and submerged casting. The three casting possibilities are presented in figure 1. Each one has advantages and drawbacks (table 1). Open casting tends to concentrate in the smaller sizes. Usually two metering nozzles are used for a given strand, although use of one has been practiced, too. Automatic nozzle changer has been developed for open beam blank casting [2]. Deoxidation is with Si and Mn, at times completed with aluminum injection in the mold. The quality issues mentioned in table 1 conspire against open casting, despite of its inherent simplicity and productivity. Semi-submerged casting is the most used casting mode, as it combines the advantages of the other two casting ways. Here two funnels conduct the liquid steel flow to the mold, allowing for casting powder addition. Straight, vertical entrance to the mold is usually carried out, although lateral ports has been tested [3]. Stopper or slide gate / SEN casting is the choice when the beam blank dimension is large and Al killed steel grades have to be cast. Due to the space constraints, one SEN casting has been tested [4, 5].