Setting a numerical simulation of filling and solidification of heavy steel ingots based on real casting conditions: Postavitev numerične simulacije polnjenja in strjevanja velikih jeklenih ingotov na podlagi realnih razmer pri ulivanju

The paper is devoted to new experiences with the setting of a numerical simulation of filling and solidification of a 90-ton steel ingot in the ProCAST simulation programme. The aim of the numerical modelling realized under the conditions of the Department of Metallurgy and Regional Materials Science and Technology Centre (RMSTC) at VSB-TU Ostrava is the verification and optimization of the production technology for the heavy-steel ingots produced in VÍTKOVICE HEAVY MACHINERY a.s. The input parameters of the computation were determined with the real conditions of casting a 90-ton steel ingot. The ingot geometry was created in the CAD system SolidWorks. Before the computational grid generation of finite elements in the Visual-Meshmodule, the geometry was subjected to an analysis of the topology. The material properties of the individual components of the ingot-casting system were defined with the Computherm calculating module selecting the materials from its own database of ProCast. In addition, the thermodynamic properties were determined by using the datasheets of the refractory materials of the manufacturer, and finally checked with the equations generally used to determine liquidus and solidus temperatures, density and enthalpy, etc. The boundary conditions and the heat transfer were also defined. In parallel with the numerical simulation, the operational experimental casting of a 90-ton ingot was carried out. To obtain more complete information about the temperature fields of the ingot-casting system and of the data about the values of the heat flow, the process of filling and solidification was monitored by using thermal imaging cameras. The conclusion summarizes the main knowledge obtained on the basis of the primary results of the computation and gives a guideline for further research. Članek obravnava nove izkušnje z numerično simulacijo polnjenja in strjevanja 90-tonskega jeklenega ingota s ProCAST-programom za simulacijo. Namen izvršenega numeričnega modeliranja v Department of Metallurgy in Regional Materials Science and Technology Centre (RMSTC) na VSB-TU Ostrava je preverjanje in optimiranje proizvodne tehnologije težkih jeklenih ingotov, proizvedenih v Vítkovice Heavy Machinery, a. s. Vhodni parametri za izračun sobili določeni v realnih razmerah pri ulivanju 90-tonskega jeklenega ingota. Geometrija ingota je bila postavljena v CAD-sistemu SolidWorks. Pred postavitvijo mreže končnih elementov z Visual-Mesh-modulom je bila geometrija obdelana s topološko analizo. Lastnosti materiala posameznih komponent livnega sistema ingota so bile določene z računskim modulom Computherm in z izbiro materiala iz datoteke ProCast. Termodinamske lastnosti so bile določene z uporabo datotek proizvajalcev ognjevzdržnih materialov ter končno preverjene z izračunom po enačbah, ki se uporabljajo za določanje temperature likvidusa in solidusa, gostote, entalpije itd. Določeni so bili robni pogoji in prenos toplote. Vzporedno z numerično simulacijo je bilo izvršeno eksperimentalno ulivanje 90-tonskega ingota. Da bi dobili bolj popolno informacijo o temperaturnih poljih ulivnega sistema ingota in podatke o vrednostih toplotnega toka, je bil postopek polnjenja in strjevanja posnet tudi s termovizijsko kamero. Sklepi povzemajo glavne ugotovitve primarnih rezultatov izračunov in dajejo napotke za nadaljnje raziskave.