Carbon Equivalent CE/Pcm

Calculates the IIW Carbon Equivalent (CE) and Japanese Pcm from chemical composition, with a simple weldability indication for each.

Engineering calculator — results require technical review before production use.

Source & assumptions

IWE Module 2 – Materials and Their Behavior during Welding, Chapter 5, Section 6 (Carbon Equivalent) and Chapter 9, Section 1 (Carbon Equivalent)

CE (IIW) = C + Mn/6 + (Cr+Mo+V)/5 + (Cu+Ni)/15, with all element values in weight percent.
Pcm (Japanese) = C + Si/30 + (Mn+Cu+Cr)/20 + Ni/60 + Mo/15 + V/10 + 5*B, with all element values in weight percent.
CE below 0.45 is taken as an indication of good weldability, per the source.
Pcm below 0.22 is taken as an indication of good weldability, per the source.
An element absent from the input is treated as 0 (not reported / negligible).

CE and Pcm are weldability indicators, not a complete welding procedure approval — they do not replace WPS qualification.
The thresholds (0.45 for CE, 0.22 for Pcm) are simple guidance values from the source, not a full preheat or hydrogen-cracking-risk assessment.
Results must not replace engineering judgement, or applicable project- or standard-specific requirements.
The 'unusually high' composition warnings are an implementation-level sanity check for likely data-entry errors — they are not sourced from IWE Module 2 and are not a compositional specification limit.