Heavyforgings
There are no simple programs for this because of the effect of alloying elements on the liquidus temperature for pure iron. Here are some web sites that may help you get started;
Will at least give you an idea but be aware of what the program is doing in the background to give you the numbers...it may be way off if you use the wrong database (for example)..
I have found the formula below to be accurate in estimating the liquidus temperature of steel alloys to better than plus or minus 20 degrees Fahrenheit. Be sure to use weight percents in the following equation, and not volume percents. You can easily perform this calculation with a hand calculator.
TL is the liquidus temperature in degrees Fahrenheit and the asterisks in the equation stand for the following:
* Use only when carbon content is 0.51% or less
** Use only when carbon content is greater than 0.51%
*** Use only when nickel content is 6.2% or less
**** Use only when nickel content is greater than 6.2%
The accuracy of this formula may not hold to plus or minus 20 degrees Fahrenheit for carbon contents in excess of 1.22%, or for vanadium, tungsten, or silicon contents exceeding 5%.
When I was a young student of metallurgy ( > 40years ago ) , I knew the following formula and I presumed this one were only a theoretical info in order to have an idea.
During my metallurgical life ( steelmaking, forging , extrusion ,ndt and so on ) , I found how this formula were " honest" to calculate the liquidus line.
Liquidus = 65C+5Mn+8Si+25S+30P+1,5Cr+4Ni+5Cu+0,8Co+2Mo+18Ti+10Nb+w+2V
and temperature t° ( C) is :
t° = 1528 - Liquidus
Temperature of forging = t° - 270° C (+10 /- 20 )
Pay attention on : NOT applicable for Ni alloys and high levels of low meting elements.
You know how much it's important for Steelmaker to know the Super Heat for the continous casting process and ingot pouring as well.Consequentely, this temperature is important in order to know the max t° of hot forging or rolling. During the last years , this formula was a little bit modified but the results were not so different compared to the old ones.
However, there is a more easy way to know this temperature.
Because all Steelmakers have a operative practice for every kind of grade and parameters of each heat , you could simply ask the temperature of liquidus of heat number "XYZ" and the low melting elements that usually do not appears on mill certificate.
This info, if avaible, is the best way to know liquidus line of specific heat and is a good help to avoid overheating that is the main "bad habit "of all forging people. Just to say that if the ingot ( bloom or billet )come out from furnace at 1200 °C and and liquidus is 1450 °C ,if you will apply a strong reduction at first step, temperature could be reach > 1450 at centerline/inside of piece causing the typical bursts.
Finally, I had rarely seen failure of forging piece caused by low temperature of hot process. Therefore, better lower than higher temperature !
Based on my 10-year experience with Thermo-Calc, the software does an excellent job when it comes to calculating not just the liquidus temperature, but also the solidus and all other important transition temperatures (e.g., A1, A3, Acm temperatures in carbon steels -- see for example
