Carbon equivalents

CET · CE · PCM · CEM · CEN from one analysis

Material analysis

Alloying element content in percent by weight.

%
%
%
%
%
%
%
%
%
%

Calculated carbon equivalents

CET within its range of validity 0.28
CE no range of validity documented 0.37
PCM no range of validity documented 0.22
CEM within its range of validity 0.22
CEN no range of validity documented 0.34

CET is the input value of the preheat calculator.

The five formulas
CET C + (Mn + Mo)/10 + (Cr + Cu)/20 + Ni/40
CE C + Mn/6 + (Cr + Mo + V)/5 + (Cu + Ni)/15
PCM C + Si/30 + (Mn + Cu + Cr)/20 + Mo/15 + Ni/60 + V/10 + 5·B
CEM C + Si/25 + (Mn + Cu)/20 + (Cr + V)/10 + Mo/15 + Ni/40
CEN C + A(C) · [Si/24 + Mn/6 + Cu/15 + Ni/20 + (Cr + Mo + V + Nb)/5 + 5·B]
A(C) = 0,75 + 0,25 · tanh[20 · (C − 0,12)]

CET — The basis of the preheat temperature to EN 1011-2, Method B. Source: Uwer/Höhne 1991 · EN 1011-2 Gl. C.2

CE — Widely used for assessing weldability. Less suitable for cold cracking questions and short cooling times. Source: IIW

PCM — For short cooling times and root runs. Source: Ito/Bessyo 1969

CEM — Only for short cooling times (2 to 6 s) and a narrow range of composition. Source: not attributed to a source

CEN — Brings CE and PCM together: the accommodation factor shifts the weighting with the carbon content. Source: Yurioka

Ranges of validity

The five equivalents have different ranges of validity. Two are documented: CET through the concentration ranges of EN 1011-2, CEM through a narrower range of its own together with a cooling time of 2 to 6 s. For CE, PCM and CEN no range is available; they are calculated without claiming a limit.

The input limits of the fields are the union of all documented ranges — whoever has an analysis should be able to enter it. Which formula carries it is for the formula to decide.

What has changed against the previous calculator
  • Each formula checks its own range of validity. Previously one check was made against the ranges of CET and the outcome applied to all five: too high a niobium content also wiped out CET, CE, PCM and CEM, although niobium appears only in CEN.
  • Boron is carried to three decimal places. It previously appeared with two and therefore as “0.00” — its entire range lies below 0.01, and it enters PCM and CEN with a factor of 5.
  • Analyses valid for CEM (carbon from 0.02, manganese from 0.40, nickel up to 3.50) are accepted. Previously they blocked the whole calculator.
  • Faulty entries are named field by field; empty fields no longer break the page.

CET to EN 1011-2 eq. C.2 (Uwer/Höhne 1991) · CE to IIW · PCM to Ito/Bessyo 1969 · CEN to Yurioka