Formula
CE(IIW) = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15
CET = C + (Mn + Mo)/10 + (Cr + Cu)/20 + Ni/40
Ceq = C + Si/24 + Mn/6 + Ni/40 + Cr/5 + Mo/4 + V/14
CEN = C + A(C) * (Si/24 + Mn/6 + (Cu + Ni)/15 + (Cr + Mo + Nb + V)/5 + 5B), where A(C) = 0.75 + 0.25*tanh(20(C - 0.12))
Pcm = C + Si/30 + (Mn + Cu + Cr)/20 + Ni/60 + Mo/15 + V/10 + 5B
CE or Carbon Equivalent (sometimes referred to generically as CEQ) and Pcm are calculations that indicate the weldability of a carbon or low alloy steel. Weldability is loosely defined as resistance to cracking. Higher CE or Pcm value steels will require more precautions in welding, such as hydrogen controlled electrodes, control of cooling rate (often by pre-heating or limitations to interpass temperature) or post weld heat treatment (PWHT).