About the TTT Diagram Property Model

The TTT Diagram Property Model, available with the Property Model Calculator and the Steel Model Library, can be used to calculate a Time-Temperature-Transformation (TTT) diagram, with a One Axis calculation on temperature. The Model calculates the isothermal kinetics of concurrent transformation of austenite into ferrite, pearlite, bainite, and martensite. The algorithms and parameters for ferrite, pearlite, bainite, and martensite are the same as in the individual Property Models (Ferrite, Pearlite, Bainite, Martensite Temperatures, and Martensite Fractions), but the competitive occupation of prior austenite grain boundaries and bulk volume is handled in the TTT Diagram Property Model.

If the reaction temperature is below martensite-start temperature (Ms), it is assumed that a fraction of (athermal) martensite according to the calculation forms instantaneously at time zero, prior to the formation of ferrite, pearlite, and bainite. Otherwise austenite transforms to ferrite, pearlite, and/or bainite.

To run calculations with the Steel Models requires a valid maintenance license plus licenses for both the TCFE (version 9 and newer) and MOBFE (version 4 and newer) databases. Also see our website to learn more about the Steel Model Library and other related examples.

The input parameters are entered on the Configuration window for the Property Model Calculator. There are also settings on the Plot Renderer where you can choose from the available and relevant axis variables.

See TTT Diagram Property Model Settings.

For an example see PM_Fe_06: TTT Diagram for Fe-C-Mn-Si-Cr-V.