Wyniki wyszukiwania - BazTech

1

Study of Casting and Solidification of Slab Ingot from Tool Steel Using Numerical Modelling

Tkadlečková M., Michalek K., Machovčák P., Kováč M., Socha L.

Archives of Metallurgy and Materials

|

2015

|

Vol. 60, iss. 4

2879--2886

EN

The main problem in the production of forgings from tool steels, especially thick plates, blocks, pulleys and rods which are used for special machine components for demanding applications, it is the inhomogeneous structure with segregations, cracks in segregations or complex type of non-metallic inclusions MnS and TiCN. These forgings are actually produced from conventional forging ingots. Due to the size of forgings, it would be interesting the production of these forgings from slab ingots. It is possible that the production of forgings from slab ingots (which are distinguished by a characteristic aspect ratio A/B), it would reduce the occurrence of segregations. The paper presents the verification of the production process of slab steel ingots in particular by means of numerical modelling using finite element method. The paper describes the pre-processing, processing and post-processing phases of numerical modelling. The attention was focused on the prediction of behavior of hot metal during the mold filling, on the verification of the final porosity, of the final segregation and on the prediction of risk of cracks depending on the actual geometry of the mold.

PL

Głównym problemem w produkcji odkuwek ze stali narzędziowych, szczególnie grubych płyt, bloków, kół pasowych i prętów, używanych do specjalnych elementów maszyn dla żądanych zastosowań, jest niejednorodna struktura z segregacją, pęknięciami w segregacji lub złożonego typu niemetaliczne wtrącenia MnS i TiCN. Te odkuwki są rzeczywiście produkowane z konwencjonalnych wlewków przeznaczonych do kucia. Ze względu na wielkość odkuwek, można by produkować te odkuwki z wlewków płaskich. Możliwe, że produkcja odkuwki z wlewków płaskich (które wyróżniają się charakterystycznym stosunkiem A/B), pozwoli zmniejszyć występowanie segregacji. W pracy przedstawiono weryfikację procesu produkcji wlewków płaskich za pomocą modelowania numerycznego z wykorzystaniem metody elementów skończonych. Artykuł opisuje fazy modelowania numerycznego: wstępną fazę przetwarzania, obróbkę i przetwarzanie końcowe. Zwrócono uwagę na zachowanie się ciekłego metalu podczas napełniania wlewnic, na weryfikację końcowej porowatości, końcowej segregacji i przewidywania ryzyka pęknięcia w zależności od rzeczywistej geometrii wlewnic.

2

Numerical modelling of macrosegregation in heavy steel ingot

Tkadlečková M., Machovčák P., Gryc K., Michalek K., Klus P.

Archives of Metallurgy and Materials

|

2013

|

Vol. 58, iss. 1

171-177

EN

The paper presents new knowledge and experience from numerical modelling of macrosegregation in heavy steel ingot using ProCAST software. The main aim of numerical modelling realized under the conditions of the Department of Metallurgy and Foundry and Regional Materials Science and Technology Centre at VSB-TU Ostrava is the optimization of the production of heavy steel ingots produced in V´ITKOVICE HEAVY MACHINERY a.s. Input parameters of computation were determined by the real conditions of parallel experimental casting of a 90-ton steel ingot. The input data were also verified by thermal analysis and thermography measurement. The numerical results of macrosegregation were compared with the chemical analysis evaluated in a real ingot section. According to the comparison, attention will be focused next on determination of the effect of boundary conditions of filling and solidification of the ingot on the size of macrosegregation.

PL

W artykule przedstawiono doswiadczenia i nowe informacje uzyskane o procesie makrosegregacji w wielkogabarytowym wlewku stalowym przy pomocy modelowania numerycznego z uzyciem oprogramowania ProCast. Głównym celem badan o charakterze modelowania numerycznego prowadzonych na Wydziale Metalurgii i Odlewnictwa oraz w Regionalnym Centrum Technologii i Inzynierii Materiałowej VSB-TU Ostrava jest optymalizacja produkcji wielkogabarytowych wlewków stalowych produkowanych w VITKOVICE HEAVY MACHINERY a.s. Dane wejsciowe do obliczen zostały wyznaczone w oparciu o opracowana analize rzeczywistych warunków odlewania stacjonarnego 90-tonowego wlewka stalowego. Zostały one dodatkowo zweryfikowane poprzez analize termiczna i pomiary termograficzne. Wyniki obliczen numerycznych porównano z wynikami analizy chemicznej przeprowadzonej dla wlewka rzeczywistego. Uzyskane rezultaty upowazniaja do podjecia w dalszej czesci badan problematyki dotyczacej okreslenia wpływu warunków brzegowych napełniania wlewnicy i krzepniecia wlewka na wielkosc procesu makrosegregacji.

3

Segregation of alloying elements in thermomechanically rolled medium-Mn multiphase steels

Grajcar A., Kamińska M., Opiela M., Skrzypczyk P., Grzegorczyk B., Kalinowska-Ozgowicz E.

Journal of Achievements in Materials and Manufacturing Engineering

|

2012

|

Vol. 55, nr 2

256--264

EN

Purpose: The aim of the paper is to assess the tendency of alloying elements to macro- and microsegregation during hot-forging and successive thermomechanical rolling of medium-Mn Al-bearing steel sheets. Design/methodology/approach: The macro- and microsegregation of alloying elements was assessed by EDS and WDS measurements across the thickness of the roughly-forged flats and thermomechanically processed 3.3 mm sheets. The microstructure was revealed using combined methods of optical microscopy (OM) and scanning electron microscopy (SEM). Morphological features of microstructural constituents were discussed with focusing on retained austenite. Findings: It was found that the final multiphase microstructure is mainly dependent on the Mn content and the effect of Nb microaddition is relatively low. The 3Mn steels possess very fine bainite-based microstructures whereas the steels containing 5% Mn are characterized by lath bainitic-martensitic microstructures. All the steels contain retained austenite as fine granules or layers located between bainitic ferrite laths. Some fraction of martensite-austenite (M-A) islands was also identified. The tendency of Mn and Al to macrosegregation was found after the initial hot-forging. It disappears after successive rough and thermomechanical rolling whereas thin martensite and martensite-austenite microbands as a result of Mn microsegregation locally occur. Research limitations/implications: Further investigations are required to quantify the local changes of chemical composition especially in formed microbands and X-ray quantitative phase analysis should be applied to assess a fraction of retained austenite. Practical implications: The knowledge of the macro- and microsegregation of alloying elements in advanced medium-Mn steels containing retained austenite can be useful in designing the thermomechanical rolling procedures of multiphase steel sheets. Originality/value: A problem of macro- and microsegregation of Mn and Al in advanced high strength steels, which belong to the third generation of automotive steels was discussed with concentrating on Mn and Nb microaddition effects.

4

Weryfikacja eksperymentalna algorytmu odtworzenie współczynnika wnikania ciepła w zagadnieniu krzepnięcia stopu dwuskładnikowego

Słota D.

Hutnik, Wiadomości Hutnicze

|

2012

|

Vol. 79, nr 3

163--166

PL

W pracy przedstawiono wyniki weryfikacji eksperymentalnej algorytmu rozwiązania zagadnienia odwrotnego polegającego na wyznaczeniu współczynnika wnikania ciepła podczas krzepnięcia stopu dwuskładnikowego, gdy znane są pomiary temperatury w wybranych punktach odlewu. W rozważanym modelu rozkład temperatury opisany został zagadnieniem Stefana ze zmienną temperaturą początku krzepnięcia zależną od stężenia składnika stopowego, natomiast do opisu stężenia wykorzystano model linii łamanej.

EN

The paper presents the results of experimental verification of the algorithm of solving the inverse problem consisted in determination of the heat transfer coefficient in solidification of the binary alloy when the measurements of temperature in selected points of the cast are known. In considered model the distribution of temperature is described by means of the Stefan problem with varying temperature at the beginning of solidification process depending on the alloy component concentration, whereas for description of the concentration the broken line model is used.

5

Evaluation of chemical heterogeneity of a 90-ton forging ingot

Machovcak P., Opler A., Carbol Z., Trefil A., Merta K., Tkadleckova M., Michalek K.

Archives of Materials Science and Engineering

|

2012

|

Vol. 58, nr 1

22--27

EN

Purpose: This article describes performance of the experimental 90-ton forging ingot casting, the way of cutting, the methodology of chemical analysis and the results of that investigation. Design/methodology/approach: The experimental ingot 8K91SF weighing almost 90 tons was cast due the performance a detailed analysis of the current state of casting and solidification. The ingot was cut and macrostructure and chemical heterogeneity of the ingot was evaluated in detail. The standard method used in metallurgical analytics - analyses using optical emission spectrometers - was not applicable due to the large number of required analyzes. Thus, the mobile optical spectrometer SPECRTOTEST was used. Sulfur prints and fluid penetration tests were performed due to detect macroscopic distribution of sulfur and to locate surface-breaking defects. Findings: Current level of segregations of selected elements in real 90-ton steel ingot was detected. Also mutual mixing of two heats needed for the production of this ingot was verified. Research limitations/implications: Future research is focused on determination of inclusion content in selected parts of experimental ingot and on the level of micro-segregations. We are limited by the accuracy of chosen analytical method, which is also discussed in the paper. Practical implications: The gained knowledge is used to specification of the setting of boundary conditions of the numerical simulations, which should help to optimize the production technology of casting heavy forging ingots and minimize the level of segregation in ingots. Originality/value: New knowledge concerning mutual mixing of two heats needed for bottom casting of heavy forging ingot are presented in this paper. Distribution of segregation in so heavy ingot was detected. Results are the base for further investigations in macro-segregations and for the improving the accuracy of results of numerical simulations.

6

Segregation behaviour of third generation advanced high-strength Mn-Al steels

Grajcar A.

Archives of Foundry Engineering

|

2012

|

Vol. 12, iss. 2

123-128

EN

The paper addresses the macro- and microsegregation of alloying elements in the new-developed Mn-Al TRIP steels, which belong to the third generation of advanced high-strength steels (AHSS) used in the automotive industry. The segregation behaviour both in the as-cast state and after hot forging was assessed in the macro scale by OES and by EDS measurements in different structural constituents. The structural investigations were carried out using light and scanning electron microscopy. A special attention was paid to the effect of Nb microaddition on the structure and the segregation of alloying elements. The tendency of Mn and Al to macrosegregation was found. It is difficult to remove in Nb-free steels. Microsegregation of Mn and Al between austenite and ferritic structural constituents can be removed.

7

Reconstruction of the boundary condition in the problem of the binary alloy solidification

Słota D.

Archives of Metallurgy and Materials

|

2011

|

Vol. 56, iss. 2

278-285

EN

The solution of the inverse problem involving the designation of the boundary condition in the problem of the binary alloy solidification for known temperature measurements at a selected point of the cast is presented. In the discussed model, the temperature distribution is described by means of the Stefan problem with varying in time temperature corresponding to the beginning of solidification and depending on the concentration of the alloy component. Whereas to describe the concentration, the Scheil model was used.

PL

W pracy przedstawiono rozwiązanie zagadnienia odwrotnego polegającego na określeniu warunku brzegowego w zagadnieniu krzepnięcia stopu dwuskładnikowego, gdy znane są pomiary temperatury w wybranym punkcie odlewu. W rozważanym modelu rozkład temperatury opisany został zagadnieniem Stefana ze zmienną w czasie temperaturą odpowiadającą początkowi procesu krzepnięcia, zależną od stężenia składnika stopowego. Do opisu stężenia wykorzystano model Scheila.

8

Effects of Mn and Nb on the macro- and microsegregation in high-Mn high-Al TRIP steels

Grajcar A., Kalinowska-Ozgowicz E., Opiela M., Grzegorczyk B., Gołombek K.

Archives of Materials Science and Engineering

|

2011

|

Vol. 49, nr 1

5-14

EN

Purpose: The aim of the paper is to determine the effects of Mn and Nb on the macro- and microsegregation of new-developed (3-5)Mn 1.5Al TRIP steels in the as-cast state and after hot forging. Design/methodology/approach: To assess possible macro- and microsegregation the chemical composition was investigated in the macro scale by OES and by the use of EDS in microregions. To reveal the macrostructure the ingots were etched by Oberhoffer’s reagent. The chemical composition along a diameter of the ingots was tested as well as in different regions of the plastically deformed flats. Metallographic investigations were carried out using optical (OM) and scanning electron microscopy (SEM). Findings: The Mn and Nb contents have significant effects on the obtained bainitic-martensitic structures and the morphology of retained austenite. The tendency to macrosegregation of Mn and Al between middle and external parts of the as-cast ingots and hot forged flats was detected. The Nb micoalloying results in the overall refinement of obtained microstructures and reduces the identified segregation of Al and Mn. A little microsegregation of these alloying elements between structural constituents was also detected. Research limitations/implications: Further investigations to describe in detail the identified structural constituents and the tendency of alloying elements to segregation in the thermomechanically rolled sheets are in progress. Practical implications: The knowledge of the macro- and microsegregation of Mn and Al in the TRIP steels with a high fraction of retained austenite is of primary importance for the manufacturing paths of these multiphase structure steels. Originality/value: A problem of segregation of Al and Mn in advanced high strength steels with and without Nb microaddition was described and interesting types of bainitic structures were identified.

9

Reconstruction of the heat transfer coefficient in the problem of binary alloy solidification with application of the broken line model

Słota D., Hetmaniok E., Wituła R.

Archives of Foundry Engineering

|

2011

|

Vol. 11, iss. 4

137-140

EN

In the paper, solution of the inverse problem is presented, which consists in determination of the heat transfer coefficient during the process of binary alloy solidification for the known temperature measurements in the selected points of the cast. In the cons idered model distribution of temperature is described with the aid of Stefan problem with the varying liquidus temperature depending on the concentration of alloy component. Whereas, for description of the concentration the broken line model is used.

10

Numerical modeling of macrosegregation and stress-strain state distribution in slab during continue casting with soft reduction

Rec T., Milenin A.

Archives of Metallurgy and Materials

|

2010

|

Vol. 55, iss. 3

915-919

EN

The center segregation is forming in the slab during continuous casting process. The segregation of elements in the slab is negative influences on mechanical, chemical and microstructure of final product. One of the methods of decrease the center segregation is mechanical soft reduction process. The efficiency of soft reduction is dependent on value and localization of soft reduction and parameters of continuous casting process. Moreover, the soft reduction process to change the stress-strain state in the slab and it can cause formation cracks on slab surface. The purpose of this paper is to develop a numerical FEM model of continuous casting process with soft reduction process and optimization of parameters of soft reduction for industrial example. The proposed numerical model of slabs casting with soft reduction technology takes into ac-count the processes of crystallization, thermal stress, diffusion, macrosegregation and mechanical deformation.

PL

W procesie krzepnięcia wlewków odlewanych w sposób ciagły zachodzi zjawisko segregacji pierwiastków. Zjawisko to powoduje powstawanie niejednorodnej struktury we wlewku co niekorzystnie wpływa na własności mechaniczne chemiczne i mikrostrukturalne wyrobów finalnych. Jedna z metod obniżenia segregacji we wlewkach ciągłych jest zastosowanie odkształcenie wlewka w stanie półciekłym w końcowym etapie odlewania. Efektywność tej metody zależy od momentu i wielkości przyłożenia odkształcenia, prędkości odlewania czy składu chemicznego odlewanej stali. Ponad to, zadany gniot zmienia stan naprężenia i odkształcenia we wlewku co może prowadzić do powstawania pęknięć na powierzchni wlewka. W pracy przedstawiono model numeryczny procesu ciągłego odlewania stali uwzględniający zjawisko krzepnięcia wlewka, segregacji pierwiastków oraz stanu odkształcenia i naprężenia w stanie półciekłym. W oparciu o opracowany model numeryczny podjęto próbę optymalizacji parametrów procesu odkształcenia w stanie półciekłym w celu zmniejszenia segregacji pierwiastków dla warunków przemysłowych.Wykonano porównanie wyników modelowania rozkładu segregacji w przekroju wlewku z danymi doświadczalnymi.

11

Interplay between temperature gradients field and C → E transformation in solidifying rolls

Wołczyński W., Guzik E., Kania B., Wajda W.

Archives of Foundry Engineering

|

2009

|

Vol. 9, iss. 4

254-260

EN

At first step of simulation a temperature field for solidifying cast steel and cast iron roll has been performed. The calculation does not take into account the convection in the liquid since convection has no influence on the proposed model for the localization of the C → E (columnar to equiaxed grains) transformation. However, it allows to study the dynamics of temperature field temporal behavior in the middle of a mould. It is postulated that for the C → E transition a full accumulation of the heat in the mould has been observed (plateau at the T(t) curve). The temporal range of plateau existence corresponds to the incubation time for the full equiaxed grains formation. At the second step of simulation temporal behavior of the temperature gradient field has been studied. Three ranges within temperature gradients field have been distinguished for the operating point situated at the middle of mould: a/ for the formation of columnar grains zone, ([...] and high temperature gradient [...]), b/ for incubation of the liquid to the C → E transformation, ([...] no temperature gradient changes [...]), c/ for equiaxed grains growth, ([...] and moderate temperature gradient [...]). T - temperature, r - roll radius. It is evident that the heat transfer across the mould decides on the temporal appearance of incubation during which the solidification is significantly arrested and competition between columnar and equiaxed growth occurs. Moreover solidification with positive temperature gradient transforms into solidification with negative temperature gradient (locally) after the incubation. A simulation has been performed for the cast steel and cast iron rolls solidifying as in industry condition. Since the incubation divides the roll into to parts (first with columnar structure, second with equiaxed structure) some experiments dealing with solidification have been made in laboratory scale. Finally, observations of the macrosegregation or microsegregation and phase or structure appearance in the cast iron ingot / roll (made in laboratory) has also been done in order to confront them with theoretical predictions. An equation for macrosegregation identification is suggested. Additionally, a new equation for redistribution studied across a given grain and its surrounding (precipitates) is also delivered. The role of the back-diffusion parameter is emphasized as a factor responsible for homogenization of the massive roll ingots.

12

Numeryczne modelowanie segregacji pierwiastków we wlewku COS z uwzględnieniem odkształcenia wlewka w stanie półciekłym

Milenin A., Rec T.

Hutnik, Wiadomości Hutnicze

|

2008

|

Vol. 75, nr 10

597-601

PL

W pracy przedstawiono wyniki numerycznego modelowania zjawiska segregacji pierwiastków oraz stanu odkształcenia i naprężenia we wlewku COS z ciekłym rdzeniem. W symulacjach analizowano wpływ parametrów procesu odkształcenia wlewka w stanie półciekłym (wielkość gniotu, moment przyłożenia odkształcenia) na proces segregacji pierwiastków oraz stan odkształcenia we wlewku COS.

EN

In present paper the result of numerical modelling of macrosegregation phenomena and stress-strain stand in continuous casting ingot with semi-solid core was presented. The influence of soft reduction parameters (reduction value, distribution of SR in time) on elements segregation and strain distribution in CC ingot was shown.

13

Simplified models of macrosegregation

Mochnacki B., Suchy J. S.

Journal of Theoretical and Applied Mechanics

|

2006

|

Vol. 44 nr 2

367-379

EN

The macrosegregation process takes place during typical solidification of alloys. Fractions of alloy components in a liquid and solid sub-domains are time-dependent and determined by the course of border lines on the equilibrium diagram. From the mathematical point of view, the process is described by a system of partial differential equations (diffusion equations) and boundary-initial conditions. The process is coupled with the solidification one. In this paper, simplified models of macrosegregation are discussed. The volumetric solidification and the 'sharp' solid-liquid interface are considered. Examples of computations are also shown. It seems that for practical applications, the methods proposed are sufficiently exact. Additionally, they are very simple for numerical realization.

PL

W pracy przedstawiono opis matematyczny procesu segregacji składników stopowych w objętości krzepnącego odlewu. Wskazano na trudności związane z rozwiązaniem odpowiedniego problemu brzegowo-początkowego, a w dalszej części artykułu przedstawiono propozycje rozwiązań przybliżonych. Rozpatrywano zarówno problem krzepnięcia objętościowego, jak i klasyczne zadanie Stefana. Rozważania teoretyczne zilustrowano przykładami obliczeń numerycznych.

14

Sensitivity analysis of macrosegregation process

Mochnacki B., Majchrzak E., Suchy J. S.

Prace Naukowe Instytutu Matematyki i Informatyki Politechniki Częstochowskiej

|

2004

|

Vol. 3, nr 1

161--164

EN

Heat transfer in the domain of solidifying and cooling metal is accompanied by the process of mass diffusion. Connected with this phenomena changes of alloy component concentration are called the macrosegregation process. In the paper the sensitivity analysis is applied in order to find the mutual connections between the perturbations of partition coefficient value and the course of macrosegregation. On the stage of numerical computations the boundary element method has been used. In the final part of the paper the results obtained are shown.

15

Simplified model of macrosegregation

Lara S., Pawlak E., Prażmowski M.

Archiwum Odlewnictwa

|

2004

|

R. 4, nr 14

259-266

EN

In the paper the simplified model of macrosegregation using the broken line approach [1, 2] is discussed. The considerations presented in quoted papers are generalized on the problems of cylindrical and spherical geometry of the casting. In the final part of the paper the example of numerical computations is shown.

PL

W pracy rozpatruje się uproszczony model makrosegregacji z wykorzystaniem metody linii łamanej [1, 2]. Rozważania prezentowane w artykule dotyczą odlewów o geometriach walcowych i sferycznych. W końcowej części zaprezentowano przykład obliczeń numerycznych.

16

Control Volume Method in Numerical Modelling of Macrosegregation

Suchy J., Mochnacki B., Prażmowski M.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

|

2003

|

z. 76

275-278

17

Analysis of segregation process using the broken line model. Numerical realization

Suchy J. S., Mochnacki B., Prażmowski M.

Archiwum Odlewnictwa

|

2003

|

R. 3, nr 10

235--240

EN

In the paper [1] the basic idea of simplified model of macro-segregation process called 'a broken line model' is presented. Here, the details concerning the algorithm realizing the numerical simulation of the process are discussed. The examples of computations concern both the constant solidification rate and the time-dependent one.

PL

W pracy [1] omówiono istotę uproszczonego modelu makrosegregacji nazwaną przez autorów metodą linii łamanej. W niniejszym artykule przedstawione zostaną niektóre szczegóły dotyczące algorytmu realizującego obliczenia numeryczne. Przykłady obliczeń dotyczą zarówno zadań, dla których założono stałą szybkość krzepnięcia, jak i zadań, dla których szybkość krzepnięcia zmienia się w czasie.

18

Analysis of segregation process using the broken line model. Theoretical base

Suchy J. S., Mochnacki B.

Archiwum Odlewnictwa

|

2003

|

R. 3, nr 10

229--234

EN

In the paper the mathematical description of the macrosegregation process proceeding in the casting domain is discussed. Because the solution of the task formulated in such way is rather complicated we present the simplified models in particular the considerations resulting from the lever arm rule and the Scheil assumption and also the model worked out by the authors of this paper called 'a broken line model'. The considerations presented concern the problems for which the solidification rate is assumed to be known (the mutual connections between solidification model and segregation one are omitted).

PL

W pracy przedstawiono opis matematyczny procesu makrosegregacji w obszarze krzepnącego odlewu. Ponieważ konstrukcja efektywnego algorytmu numerycznego na bazie takiego opisu jest raczej skomplikowana, więc rozpatruje się również modele uproszczone. Autorzy prezentują własne podejście do modelu wynikającego z reguły dźwigni oraz modelu wynikającego z założeń Scheila. W dalszej części artykułu omówiony jest nowy sposób opisu procesu segregacji, w którym rozkład stężenia w fazie ciekłej przybliża się linią łamaną. Prezentowane w tej części rozważania dotyczą przypadku, gdy szybkość narastania warstwy zakrzepłej jest znana, co umożliwia rozprzężenie modelu krzepnięcia z modelem ruchu masy.

19

Symulacja krzepnięcia odlewu z uwzględnieniem procesu segregacji

Mochnacki B., Suchy J. S., Prażmowski M.

Przegląd Odlewnictwa

|

2001

|

Vol. 51, nr 4

144-149

PL

Typowe programy narzędziowe stosowane do symulacji numerycznej krzepnięcia odlewu w formie opierają się na modelach matematycznych, z reguły nie uwzględniających zjawiska makrosegregacji. Zaniedbanie tego zjawiska powoduje, że pewne ważne z cieplnego punktu widzenia procesy nie będą uwzględnione. W artykule przedstawiono wyniki badań w postaci procedur numerycznych uzupełniających model przepływu ciepła w układzie odlew-forma-otoczenie podczas krzepnięcia objętościowego. Podano prosty model makrosegregacji, zbliżający opis matematyczny do realnych warunków fizycznych. Zaprezentowano również model krzepnięcia na poziomie pojedynczego ziarna.

EN

Typical software programmes utilized in the numerical simulation of the casting solidification in a mould are based on mathematical models which as a rule do not take into consideration the macrosegregation effect. To neglect this effect causes that some important from the thermal point of view processes will not be taken into account. In the article the investigation results in the form of numerical procedures, which complete the model of heat transfer in a casting-mould-environment system during the solidification in volume, are presented. A simple model of macrosegregation, bringing the mathematical description closer to real physical conditions, was given. The solidification model developed for a single grain was also proposed.