Exit console
Welding — Schaeffler / DeLong diagram

Predict weld microstructure from composition

Cr_eq + Ni_eq plot the alloy on the canonical weld-microstructure map (Schaeffler 1949 / DeLong 1974). Reveals austenite / ferrite / martensite zones, FN ferrite-number contour, and σ-phase formation risk.

Inputs

wt%
wt%
wt%
wt%
wt%
wt%
wt%
Nitrogen included in DeLong Ni-equivalent — critical for nitrogen-strengthened duplex.
wt%

Results

Schaeffler diagram — predicted weld microstructure
FN=5FN=10AusteniteMartensiteA + MFerriteA + FF + MA + M + F0510152025303540051015202530Cr-equivalent (wt%)Ni-equivalent (wt%)(19.3, 13.0)Schaeffler 1949 / DeLong 1974 · ANSI/AWS A4.2 · weld-metal microstructure prediction
Cr_eq=19.3 · Ni_eq=13.0 → A + M + F
Cr-equivalent (Schaeffler)19.25wt%
Ni-equivalent (Schaeffler)11.50wt%
Ni-equivalent (DeLong, w/ N)13.00wt%
Predicted regionDuplex (A + F)
Ferrite Number FN (WRC-1992 est.)13.5FN
σ-phase formation riskno
For thermodynamically rigorous prediction, run the calphad_weld_microstructure agent tool — it cross-checks Schaeffler against CALPHAD equilibrium and flags σ-phase under HAZ exposure (550-900 °C).
Download all inputs + calculations + outputs as a single PDF.