Numerický a experimentální výzkum teplotního pole tuhnoucího masivního válce z tvárné litiny

Numerical and experimental investigation of temperature field of solidifying massive ductile-cast-iron roller

článek v časopise - ostatní, Jost

en

The quality of the working rollers used for rolling rails of different profiles is determined by the chemical and structural composition of the material of the rollers and the production technology The requirements of the quality cannot be ensured without perfect knowledge of the course of solidification, cooling and heat treatment of the cast rollers as well as the kinetics of the temperature field of the casting and mould. The solidification and cooling of ductile-cast-iron roller in metal and non metal mold is a very complicated problem of heat and mass transfer with a phase and structural changes described by the Fourier equation. An original application of ANSYS simulated the forming of the temperature field of the entire system comprising the casting, the mold and ambient. The simulation of the release of the latent heats of phase or structural changes is carried out by introducing the thermodynamic enthalpy function. In the experimental investigation of temperature field, an original methodology for the measurement of the distribution of temperatures and heat flows in the roller-mould system had been developed and verified in the operation. In the design of the original procedure, there were a number of problems connected with the great size of the roller and mould, uneven dilatation of the solidifying roller and mould, the installation and insulation of the thermocouples, the wiring of the thermocouple system, etc. The findings regarding the kinetics of the temperature field of the roller and mould, obtained from experimental research, were used for determining the boundary conditions and for the verification of the numerical simulation program. The calculation of the temperature field focused on the analysis of the effect of the mould separator on the course of solidification of the roller. The results of the mathematical modelling indicate that the distribution of temperatures and the solidification in the vertical direction is significantly uneven, this has an effect on the internal quality of the casting.

Kvalita pracovních válců pro válcovácí tratě různých profilů je určena chemickým a strukturálním složením materiálu válců a výrobní technologií. Originální aplikace software ANSYS na numerický model tuhnutí simuluje tvorbu teplotního pole celého systému. Výpočet teplotního pole byl věnován anylýze vlivu separátoru odlitku na průběh tuhnutí válce. Výsledky matematického modelování prokazují, že rozložení teploty a tuhnutí ve vertikálním směru je významně nerovnoměrné, což má vliv na vnitřní kvalitu odlitku.

The quality of the working rollers used for rolling rails of different profiles is determined by the chemical and structural composition of the material of the rollers and the production technology The requirements of the quality cannot be ensured without perfect knowledge of the course of solidification, cooling and heat treatment of the cast rollers as well as the kinetics of the temperature field of the casting and mould. The solidification and cooling of ductile-cast-iron roller in metal and non metal mold is a very complicated problem of heat and mass transfer with a phase and structural changes described by the Fourier equation. An original application of ANSYS simulated the forming of the temperature field of the entire system comprising the casting, the mold and ambient. The simulation of the release of the latent heats of phase or structural changes is carried out by introducing the thermodynamic enthalpy function. In the experimental investigation of temperature field, an original methodology for the measurement of the distribution of temperatures and heat flows in the roller-mould system had been developed and verified in the operation. In the design of the original procedure, there were a number of problems connected with the great size of the roller and mould, uneven dilatation of the solidifying roller and mould, the installation and insulation of the thermocouples, the wiring of the thermocouple system, etc. The findings regarding the kinetics of the temperature field of the roller and mould, obtained from experimental research, were used for determining the boundary conditions and for the verification of the numerical simulation program. The calculation of the temperature field focused on the analysis of the effect of the mould separator on the course of solidification of the roller. The results of the mathematical modelling indicate that the distribution of temperatures and the solidification in the vertical direction is significantly uneven, this has an effect on the internal quality of the casting.

Tvárná litina, masivní válec, teplotní pole, numerický model

Ductile cast iron, massive roller, solidification, temperature field, numerical model

2012

15.05.2012

IMT Ljubljana

Ljubljana Slovinsko

1580-2949

46 (2012)

4

321–324

4