The Austenite Decomposition, Kirkaldy–Venugopalan interface () is found under the Heat Transfer > Metal Processing () branch when adding a physics interface. The physics interface is intended for studying metallurgical phase transformations. The interface specifically uses the phase transformation modeling framework of Kirkaldy and Venugopalan, in which austenite decomposition into different destination phases is expressed in terms of, for example, grain size and chemical composition. Physical phenomena, such as latent heat of phase transformation and transformation strains can be computed and used in Heat Transfer in Solids and Solid Mechanics. With the Nonlinear Structural Materials Module or the Geomechanics Module, plastic strains and hardening behavior of each metallurgical phase can be used in Solid Mechanics.

When the Austenite Decomposition, Kirkaldy–Venugopalan interface is added, ten nodes are added to the Model Builder — five Metallurgical Phase nodes, four Phase Transformation nodes, and one Steel Composition node. The interface is tailored specifically to the decomposition of austenite into a combination of ferrite, pearlite, and bainite, using the phase transformation framework of Kirkaldy and Venugopalan. The displacive martensitic phase transformation is modeled using the Koistinen–Marburger phase transformation model. The Steel Composition node is added to the interface, and it is configured to compute:

You need to supply the chemical composition and the ASTM grain size number to the Steel Composition node.

The Initial Phase Fraction is set to one in the Austenite node, and zero in the other metallurgical phase nodes. Four Phase Transformation nodes are also created to define the relevant phase transformations:

The source and destination phases in each phase transformation are set to the corresponding phases that have been created. The Phase transformation model is set to Microstructure based, except in Austenite to Martensite, where it is set to Koistinen–Marburger. The phase transformation nodes are automatically configured to use temperature limits and phase transformation functions, as computed by the Steel Composition node.

From the Physics toolbar, you can delete or disable metallurgical phases and phase transformations that are irrelevant in a given situation, and you can add additional metallurgical phases and phase transformations. You can also right-click Austenite Decomposition, Kirkaldy–Venugopalan to select physics features from the context menu.

The Label is the default physics interface name.

The Name is used primarily as a scope prefix for variables defined by the physics interface. Refer to such physics interface variables in expressions using the pattern <name>.<variable_name>. In order to distinguish between variables belonging to different physics interfaces, the name string must be unique. Only letters, numbers, and underscores (_) are permitted in the Name field. The first character must be a letter.

The default Name (for the first physics interface in the model) is audc.