The pre-built steel models currently include the Martensite Fractions, Martensite Temperatures and Pearlite models. A bainite model will also soon be available.
The Steel Model Library is available for free to all users who have, or upgrade to, the thermodynamic and mobility steel databases TCFE9 and MOBFE4, plus have a valid Maintenance and Support Subscription.
The Martensite Fractions property model calculates fraction of athermal martensite based on an analytical equation derived in Huyan et al. (2016). It is assumed that the first forming martensite morphology is the only forming one. The first morphology is determined based on the Ms-temperatures of all morphologies.
See below for more information about the example (PM_Fe_01) demonstrating this model.
The transformation curves plot showing Fe-Cr-C martensite with intercritical annealing.
The Martensite Temperatures property model calculates the martensite start temperature (Ms) based on modeling the transformation barrier with fitted analytical equations. The model is based on Stormvinter et al. (2012) with subsequent update and extension by Gulapura Hanumantharaju (2018) and Thermo-Calc internal assessment. The partitionless equilibrium temperature T0 is calculated using the thermodynamic database. The model also gives temperatures corresponding to 50%, 90%, and 99% transformations. Martensite fractions are calculated with the same algorithm as in the Martensite Fractions property model.
See below for more information about the examples (PM_Fe_01 and PM_Fe_02) demonstrating this model.
A diagram showing all the Ms temperatures of different types of martensite morphologies (lath, plate and epsilon (hcp)) compared with experimental epsilon Ms values.
The Pearlite property model describes the thermodynamics and kinetics of pearlite formation from austenite during isothermal heat treatment. It is assumed that the overall composition of pearlite is the same as the austenite composition (system composition), and growth rate is constant over time. Growth rate and lamellar spacing of pearlite are determined by a criterion where either growth rate or Gibbs energy dissipation rate is maximized. The model considers Gibbs energy dissipation due to formation of ferrite-cementite interface in pearlite, finite austenite-pearlite interfacial mobility, solute drag, and diffusion of elements within austenite and along austenite-pearlite interface.
See below for more information about the example (PM_Fe_03) demonstrating this model.
The TTT (time-temperature-transformation) diagram showing times of start (2% transformation) and finish (98% transformation) as functions of isothermal heat treating temperature in an Fe-0.69C-1.80Mn alloy (mass %).
The Steel Model Library makes it easy to set up time-temperature-transition calculations using a TTT template that is accessed directly from the homescreen of Thermo-Calc. The template has several preconfigured settings to help you set up and calculate the TTT diagram using the Martensite temperatures and Pearlite property models.
The template also includes a plotting mode called TTT mode, which is used to define the Temperature on the y-axis and Time on the x-axis for all selected quantities. For example, as shown in the image below, Pearlite will show transformation times for 2%, 50% and 98% Pearlite, and time independent results, like the Ms temperature, will be drawn a horizontal line.
A time-temperature-transformation (TTT) diagram in a basic Fe-10Cr-1C alloy (mass %) made using the TTT-template and the TTT plotting mode which shows transformation times for 2%, 50% and 98% Pearlite and time independent results, like the Ms temperature, which are drawn as a horizontal line.
The Steel Model Library includes examples to help get you started. These particular examples are available from within the software starting with Thermo-Calc 2019a: From the menu, choose Help > Example Files > Property models > Steel.
Tip! Search the Thermo-Calc Help
You can find more information about the examples and property models (and all the Thermo-Calc features) in the Help, which is also available with DEMO and Academic versions of the software.
From within Thermo-Calc, press F1 or from the menu select Help > Online Help and then search for Property Model Calculator or any other search term relevant to your query.
The Steel Model Library is available for free to all users who have, or upgrade to, the thermodynamic (TCFE9) and mobility (MOBFE4) steel databases plus have a valid Maintenance and Support Subscription.
Thermo-Calc Software is also developing Property Model Libraries for nickel, aluminium and titanium-based alloys. A bainite model is also soon available with the Steel Model Library.
Fill out the form belowy to find out more about the Steel Model Library or to inquire about getting a license.