Here is an example to follow, note that the command to perform stepping of variables are unfortunatly different than those used in MULTIPHASE

• We define the system using the database for solutions and for pure substances (to get NbC):

  APPLICATION OPTION ? def sy 'Fe,Cr,Ni,Nb,C' sou plus sub_sgte ! [Ret]
  APPLICATION OPTION ? cl ab p(*) no p(FCC_A1,CNb,M23C6) ! [Ret]
  

• We call the macro:

  APPLICATION OPTION ? '/opt/mtdata/bin/isopleth.mac' [Ret]
  

• You should read the description when prompted, use the default values proposed by MTDATA (composition tolerance and temperature intervals). The application actually provides the list of settings that you need to do:
  • Setting the composition at the origin:

    APPLICATION OPTION ? range t 973 1473 0.1 ! [Ret]
    APPLICATION OPTION ? set w 1 ! [Ret]
    APPLICATION OPTION ? set 'start' [Ret]
    ENTER AMOUNT IN COMPOSITION GROUP start FOR COMPONENT Fe :0.699 [Ret]
    ENTER AMOUNT IN COMPOSITION GROUP start FOR COMPONENT Cr :0.18 [Ret]
    ENTER AMOUNT IN COMPOSITION GROUP start FOR COMPONENT Ni :0.12 [Ret]
    ENTER AMOUNT IN COMPOSITION GROUP start FOR COMPONENT Nb :0.001 [Ret]
    ENTER AMOUNT IN COMPOSITION GROUP start FOR COMPONENT C :0.0 [Ret]
    SET WHAT ? !
    

    Note the exclamation mark to finish the command.

  • Setting the composition at the end (here 0.1 wt% C), here the alternative way to input the compositions is shown:

    APPLICATION OPTION ? set 'end' 0.698 0.18 0.12 0.001 0.001 ! [Ret]
    

  • Setting the number of steps between the starting and end point:

    APPLICATION OPTION ? range 'start' 'end' 30 ! [Ret]
    

• Start the calculation, depending on how many phases you have allowed to be present, and how many components you have, this may take anything between 10 seconds and a few hours:

  APPLICATION OPTION ? compute !

• Label the different areas if you wish, then close the diagram using a [Ret] twice. If you then type plot go, the diagram is shown again with lines instead of points. See this page for more about the graphical interface.

Result for this example: