> L ! -------------------------R >pl63 âThe Use of Phase Diagrams by K S Dahl and C J van Tyneâ This set of programs is supplied on Š floppy disk for IBM-compatible computers Š running MS-DOS or PC-DOS. The minimum Š hardware configuration is 256K with CGA. Š The programs will run with EGA and will Š be useable with a monochrome monitor. You are advised to make a backup copy of Š the program disk immediately. Consult Š your DOS manual for instructions on how Š to do this. The package consists of one disk and this Š user manual. To run the package insert Š the disk into the default drive (probably Š a:) and from your DOS prompt type MENU Š followed by the RETURN key. After a few Š seconds you will see the main menu, which Š offers a choice of four routines 1. Simple diagrams 2. Eutectics 3. Solidification 4. Heat treatment To run one of these programs simply press Š the appropriate number key (1 to 4). To Š quit the package entirely press Q. At any time pressing F10 (function key Š 10) will return you to the main menu. At Š certain points in the routines it may Š also be necessary to make the response Š requested by the program before the menu Š will be loaded. >pa The four routines which comprise this Š package deal with the use of equilibrium Š binary phase diagrams. In the first two Š routines the user can explore Š (quantitatively) the amount and Š composition of each phase at a chosen Š temperature and overall composition. In Š the third and fourth routines the Š development of microstructure on cooling Š is simulated. Throughout, real phase Š diagrams are used. Each program is now described in detail. â1. Simple diagramsâ, and â2. Eutecticsâ These two routines are similar and will Š be considered together: When keys 1 or 2 are pressed a logo Š similar to that on the next page will Š appear within a few seconds. A similar Š logo will appear as each routine is run. Š As indicated on the screen, pressing any Š key will cause the program to continue. Opposite is the menu for the âsimple Š diagramsâ routine. It lists all the phase Š diagrams available for analysis. To work Š with a particular diagram, type in the Š appropriate letter, followed by the Š RETURN key. >pa Above is the menu for the âeutectics⠊ routine. Nine eutectic diagrams are Š available for use. The choice of diagram Š is again made by entering the Š appropriate letter followed by the RETURN Š key. As an example we will examine the Fe-C Š system so letter e is entered from the Š first menu. After the phase diagram is chosen the Š type of analysis to be performed must be Š indicated. Phase Analysis (choice 1) Š produces a tie-line and lever law Š calculation for a given temperature and Š composition. Fraction Charts (choices 2 Š or 3) will plot the amount of each phase Š present as a function of either Š temperature or composition. In these Š charts the other variable is held Š constant. In the above example, a Phase Š Analysis is chosen by entering the number Š 1. When the phase diagram appears the Š temperature and composition of the alloy Š to be examined must be given. Examples Š of these entries appear on the next page. >pa The temperature, phases present, Š composition of phases and amount of each Š phase are tabulated to the right of the Š phase diagram. An X is placed on the Š phase diagram itself, to mark the alloy Š being analysed. At this point another Š temperature and composition can be Š specified (as shown above) or an e can be Š entered to exit from this diagram. Multiple analyses can be made to fill the Š table as shown above. Each set of data Š will correspond to one of the X 's which Š appear on the diagram. If a Phase Fraction Chart is needed, the Š appropriate choice must be made in the Š menu which appears just after an alloy Š system is chosen. In the example below, Š a Fraction Chart vs Composition is to be Š selected and the number 2 is therefore Š entered. A specific temperature for this phase Š fraction chart must be specified. In the Š example above a choice of 800 C is made. A constant temperature line is drawn Š across the phase diagram and the Fraction Š Chart is drawn below the diagram. The Š amounts of each phase are given in Š percentages and the scale to be used is Š indicated by the arrows which appear just Š below the phase label. In the above Š example the amount of alpha and the Š amount of cementite (C) are read from the Š left side of the chart. The amount of Š gamma is read from the right side scale. >pa If a Phase Fraction Chart vs. Temperature Š for a constant composition is desired, Š then the choice is made in the menu which Š appears immediately after the phase Š diagram is chosen. The number entered is Š 3, as shown above. The alloy composition is then Š requested. In the example below, a value Š of 1 percent carbon is entered. The Š phase fraction chart will appear to the Š right of the phase diagram. The resulting phase fraction chart is Š shown above. The alloy composition is Š indicated on the phase diagram. The Š amounts of the individual phases are Š given in percentages on the top or bottom Š scales. The arrows which appear to the Š right of the phase label indicate which Š scale to use. In the above example the Š amount of liquid (L) and cementite (C) Š are read from the upper scale and the Š amount of gamma and alpha are read from Š the lower scale. â3. Solidificationâ An example of the Solidification program Š is shown on the following pages. Š Selection of option 3 from the main menu Š produces the logo below. Pressing any Š key at this point brings you to the menu Š for this routine. >pa The above is the menu for the Š solidification program, from which an Š alloy must be chosen. In the above Š example the solidification of a hyper- Š eutectic alloy will be observed by typing Š the number 4. The program will Š simultaneously display the phase diagram, Š the cooling curve and the microstructure Š of the material. The dynamics of the Š process are illustrated on the computer. Š Several 'snap-shots' of this program Š appear on the next two pages. When the solidification process is Š complete the entire cooling curve and Š microstructure of the solidified alloy Š are shown. The microstructure is Š labelled. To run another solidification Š simulation, just press any key. If you Š wish to quit the program type the letter Š q, as indicated on the screen. >pa â4. Heat treatmentâ When the Heat Treatment program is run, Š by pressing 4 from the main menu, the Š usual logo appears (as below). By Š pressing any key the menu for this Š routine will be displayed and a choice of Š heat treatment can be made. The above is the menu from which choice Š number 7, spheroidizing a 1080 steel Š steel, has been selected. When the Š choice is made the phase diagram, the Š time-temperature plot associated with the Š heat treatment and the microstructure of Š the alloy are displayed simultaneously. Š The next five pages illustrate the Š screens which would appear for the Š spheroidizing heat treatment. >pa ‹ The final screen displays the final Š microstructure, with the structures Š labelled, and the time-temperature Š profile for the particular heat treatment Š which was chosen. The user can examine Š another heat treatment by pressing any Š key at this point or can quit the program Š by typing the letter q . âPhotographing the screenâ It is quite simple to prepare slides for Š projection by photographing the screen. Š Use a transparency film, of speed 100 or Š 200 asa. Mount the camera on a tripod Š and use a cable release. An exposure of Š at least a quarter of a second is needed Š to avoid synchronisation problems. We Š have found that, for many screens, an Š aperture of f8 or f11 is then about right Š for 200 asa film. A less distorted image Š is obtained from most display screens if Š a telephoto lens is used. ************ âWarranty, Copyright and Licensingâ The program disks are warranted to be Š defect free, assuming a normal use, for Š a period of 90 days. No other Š warranty, expressed or implied, is given. Š The programs are for educational use and Š are not intended for other purposes. Š The programs are copyrighted. Copying Š of any program, except for backup Š purposes only, is prohibited. Site Š Licenses are available. The Site Š License entitles the school or Š organization to make copies for all Š members of their organization (i.e. Š faculty, staff and students.)Œ