Thermal Processes While Pouring into Ceramic Shells and their Numerical Simulation

Abstract

In the thermal regime of ceramic shell moulds the role of heat transfer by radiation and convection into the surrounding environment is most significant. In shells the walls are mutually irradiated and non-symmetrical heat flows in individual directions. Experimental measuring enabled establishing the heat relations during casting and solidification of a model system of cylindrical castings of different diameters placed on a ring gate. The N155 alloy (Cr-Ni-Co alloy steel) was cast. Thermocouples were used to measure temperature in the castings and in the shell walls. The experimentally established data used was significant in the subsequent numerical simulation. The boundary conditions of heat transfer were calculated using FLUENT software. The actual thermo-physical and boundary conditions of the system were determined via inverse modelling by means of the ProCAST software. Using the CAFE module of the ProCast program the numerical simulation of the alloy structure was performed; simulated structures were compared with the metallographically established structure.