The calculations are made with the sole help of the material and transformation dependent parameter - Apparent Activation Energy.
The target parameters are more specifically calculated using the well known Arrhenius equation (isothermal, non-isothermal and combined). The basic model is also known as Hollomon & Jaffe. While the Lite version of the App can calculate isothermal parameters the Pro version can perform isothermal, non-isothermal and combined, without Ads.
The application calculates one of the parameters by imposing the others. Only the first from the following four main options is available (each of them having another 2 options) for the LITE version :
1) Isothermal Conversion - TIME versus TEMPERATURE. Isothermal heat treatment time can be decreased by increasing the temperature. Conversely, the temperature can be decreased by increasing the heat treatment (soaking) time;
2) Heating Ramp Conversion. In this case it is possible to modify the start and end temperature (target parameters) in order to obtain the HEATING RATE or the start temperature and heating rate to calculate the END TEMPERATURE;
3) Isothermal to Heating Ramp. If the Isothermal heat treatment parameters are known for the desired properties, equivalent parameters can be calculated for a Heating Ramp, i.e. by imposing a start temperature and a heating rate it is possible to calculate the END TEMPERATURE or by choosing the start and end temperatures the software can calculate the HEATING RATE;
4) Heating Ramp to Isothermal. If the Heating Ramp heat treatment parameters are know for the desired properties, equivalent parameters can be calculated for an Isothermal, i.e. by imposing the temperature it is possible to calculate the TIME or by choosing time the software can
calculate the TEMPERATURE.
The Apparent Activation Energy is the sole material and transformation dependent parameter of the model. Apparent Activation Energy can extensively be found in the literature for the most of the phase transformations or diffusion reactions. Nevertheless his value can differ depending on desired property, chemical composition, thermo-mechanical history of the material and the model by which it was assessed. For improved precision it can be determined experimentally on the material that should be heat treated, as described in the literature.
The Heat Treatment Kinetics software can be a powerful tool for the reduction of costs and heat treatment optimisation. The purpose of the software is not to be a precision tool but rather an aide for laboratory research or process development.
As any mathematical model the current computation came with some limitations. It is strongly recommended to read the Caution section before any use of the application.
In the same time the input and output parameters were limited particularly for options implying heating ramps in order to reduce the risk of erroneous calculations as following :
- temperatures : -273.15 to 2000 °C;
- heating rates : 0.001 to 1000 °C/min.
If you want to help improving the software you can send by e-mail screenshot/s of parameters that did or did not work for you. In the same time please provide a full description of the material and temperature range of the transformation. The values of the material dependent apparent activation energies could be used for the integration in the future versions of the software.