Carbon Equivalent and Preheat Screen
Carbon equivalent CE = C + (Mn + Si)/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15...
Example
You enter
- Carbon C (wt %) 0.25
- Manganese Mn (wt %) 0.8
You get
- Carbon equivalent (AWS D1.1; IIW when Si = 0) 0.383333
Checked against published worked examples from: IIW / AWS D1.1 carbon-equivalent formula.
Details, formula, and sources
ScopeCarbon equivalent CE = C + (Mn + Si)/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15 (AWS D1.1 Annex XI; leave Si at 0 for the IIW formula) from the steel chemistry, with a plain-English weldability / preheat band (a screen, not a welding procedure).
Formula or tableCE = C + (Mn + Si)/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15 (AWS D1.1 Annex XI; Si = 0 gives the IIW form). Bands: < 0.35 readily weldable; 0.35-0.55 preheat advised; > 0.55 high hardenability.
Source and editionAWS D1.1 Structural Welding Code (2000) Annex XI carbon equivalent, which adds Si to the IIW formula, by name; published formula.
Free accessPublished weighted-sum formula; the output is a screening band, not a qualified welding procedure.
What governsEstimate. AHJ and licensed professional govern.
API field namesc, mn, carbon_equivalent
- Composition the steel chemistry (weight percent of C, Mn, Si, Cr, Mo, V, Ni, Cu) is user-supplied from the mill certificateAWS D1.1