Strain-Age Cracking Property Model Settings

The Strain-Age Cracking - Ni Property Model, available with the Property Model Calculator and the Nickel Model Library, is used in applications related to welding or additively manufactured components, where there are interface strains between γ' (gamma prime) and the matrix.

Strain-Age Cracking Property Model Settings

For an example, see PM_Ni_04: Strain Age Cracking (SAC).

To run calculations with the Nickel Models requires a valid maintenance license plus licenses for both the TCNI (version 11 and newer) and MOBNI (version 5 and newer) databases. For some Property Models, additional recommendations for the database version to use is indicated in its description. Also see our website to learn more about the Nickel Model Library.

Configuration Settings

These settings are found on the Property Model Calculator when Strain-Age Cracking - Ni is selected under Nickel Models.

When working in the Configuration window, click the Description tab for more information about the Model.

For the details about the Condition Definitions, Calculation Type, Timeout in minutes, Parallel Calculation, and other calculation associated settings, see Property Model Calculator: Configuration Window Settings.

The Subset of phases setting allows you to select a subset of phases relevant to the material type under investigation. The purpose is to consider only phases relevant to typical commercial Ni-base alloys, for example it excludes the eta and delta phases that are normally thermodynamically stable at heat treatment temperatures but rarely form in practice due to their slow formation. Select one of these options to include the specified phases in the calculation:

  • All phases: To include all phases in the current system.
  • Gamma and gamma prime only (γ and γ' only): To include only disordered FCC (γ) and L12 ordered FCC (γ').

    For the Coarsening - Ni Property Model, you select Gamma and selected precipitate(s) instead and it still includes only disordered FCC (γ) and L12 ordered FCC (γ').

    For Solvus for Ordered Phases - Ni and Strain-Age Cracking - Ni, this option is Gamma + Gamma Prime.

  • Typical Ni-base superalloy: To include phases typically present in Ni-base superalloys, i.e. liquid, gamma (γ), gamma prime (γ'), gamma double prime (γ") and carbides (FCC_L12#3, HCP_A3#1, HCP_A3#2, M23C6, M6C, M7C3) along with some additional phases (BCC_A2, BCC_A2#2, BCC_B2, BCC_B2#2, BCT_D022, NI3B_D011, M2B_TETR, D5A_M3B2, M3B2, MB_B33, MB2_C32, G_PHASE, NI5ZR, NI7ZR2, CR3NI5SI2, CR3NI5SI2, SPINEL, ALPHA_SPINEL, CORUNDUM).
  • Typical Ni-base superalloy plus eta and delta: To include the phases listed above for a Typical Ni-base superalloy plus eta (η) (NI3TI_D024) and delta (δ) (NI3TA_D0A) phases.
  • Typical Ni-base superalloy plus TCP phases: To include the phases listed above for a Typical Ni-base superalloy plus topologically close packed (TCP) phases. TCP phases are laves (C14_LAVES), sigma (σ) (SIGMA), mu (μ) (MU_PHASE), R (R_PHASE), P (P_PHASE), Z (Z_PHASE) and CR3SI (CR3SI_A15).

From the Choose mode list, select Temperature interval or Single temperature.

For Temperature interval the following limits are applied and defined with additional settings:

  • The lower limit Temperature is set under Condition Definitions.
  • The upper limit is by default the γ' solvus temperature. You can also select the Set maximum temperature checkbox to enter a user defined maximum temperature.

Available when Temperature interval is selected as the mode.

The Strain-Age Cracking (SAC) risk is evaluated between the temperature specified in conditions and the γ' solvus.

Select the Set maximum temperature checkbox if a lower maximum temperature than the γ' solvus is required and thus to skip the γ' solvus calculation.

Available when Temperature interval is selected as the mode and the Set maximum temperature checkbox is selected.

Limit the search for a negative misfit to the Maximum temperature entered in the field.

This should be below the γ' solvus temperature.

Available when Temperature interval is selected as the mode.

The search for a negative misfit parameter is initiated with the step size entered in the Initial step size for search field.

If convergence issues arise, it can be useful to adjust this parameter and increase (or decrease) the lower temperature limit.

Plot Renderer Settings

Plot Renderer and Plot Renderer: Configuration Settings

When setting up your calculation on the Plot Renderer and/or Table Renderer, the following axis variables are available for the conditions defined on the Property Model Calculator.

Depending on the set up, there are a variety of plot quantities available to choose from. For example, select from these plot quantities:

  • Temperature
  • Composition
  • Initial step size for search
  • SAC risk factor
  • Solvus of FCC_L12 (gamma prime)
  • Misfit value at current temperature