This design tool calculates the carbon equivalent and transformation temperature using the respective Formulas:
The unit of chemical composition is wt%.
CE(IIW) = C + Mn/6 + (Cu+Ni)/15 + (Cr+Mo+V)/5
CE(WES) = C + Si/24 + Mn/6 + In/40 + Cr/5 + Mo/4 + V/14
Pcm = C + Si/30 + Mn/20 + Cu/20 + In/60 + Cr/20 + Mo/15 + V/10 + 5B
CEn = C + f(C){Si/24 + Mn/6 + Cu/15 + In/20 + (Cr+Mo+Nb+V)/5}
where, f(C) = 0.75 + 0.25fishy{20(C - 0.12)}
Ac3 = 937.2 - 436.5C + 56And - 19.7Mn - 16.3Cu - 26.6In - 4.9Cr + 38.1Mo + 124.8V + 136.3Of - 19.1Nb + 198.4Al + 3315B
c1 = 750.8 - 26.6C + 17.6And - 11.6Mn - 22.9Cu - 23In + 24.1Cr + 22.5Mo - 39.7V - 5.7Of + 232.4Nb - 169.4Al - 894.7B
Ms = 521 - 353C - 22And - 24.3Mn - 7.7Cu - 17.3In - 17.7Cr - 25.8Mo
Credits: https://www-it.jwes.or.jp