Carbon Equivalent (CE)

Calculate the Carbon Equivalent to determine the weldability of steel alloys and evaluate the risk of Hydrogen-Induced Cracking (HIC). Enter the material composition in weight percentages (wt%).

Fills the fields with typical nominal chemistry for standard grades.
Chemical Composition (wt%)
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Carbon Equivalent (CE)
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Why Measure CE?

Carbon and other alloying elements increase the hardenability of steel. If the steel hardens too much during the rapid cooling of the welding process, it becomes brittle and is highly susceptible to Cold Cracking (Hydrogen-Induced Cracking).

The IIW Formula
$CE = C + \frac{Mn}{6} + \frac{Cr+Mo+V}{5} + \frac{Ni+Cu}{15}$
International Institute of Welding Standard Formula
Weldability Zones
CE Range Weldability Pre-heat Req.
Up to 0.35 Excellent None
0.36 - 0.40 Very Good Thick sections only
0.41 - 0.45 Good Usually required
0.46 - 0.50 Fair Mandatory
Over 0.50 Poor Preheat + PWHT
Note: Even with a low CE, high-restraint joints or highly humid environments may still require pre-heating and low-hydrogen (e.g., 7018) electrodes.