Calculate ferrite content in austenitic stainless steel weld metal using the DeLong diagram with nitrogen correction for Cr/Ni equivalents
Input Parameters
Results
--
Cr Equivalent
--
Ni Equivalent
--
Ferrite Number (FN)
FN
--
Ferrite Percent (approx)
%
Note: DeLong improved the Schaeffler diagram by adding nitrogen to the Ni equivalent. This is important for GTAW/GMAW welds where nitrogen pickup shifts the microstructure. DeLong is less accurate above 18 FN - use WRC-1992 instead.
Reference
DeLong Diagram Equivalents (1974):
Creq = Cr + Mo + 1.5×Si + 0.5×Nb
Nieq = Ni + 30×C + 0.5×Mn + 30×N
Key improvement over Schaeffler: includes nitrogen (N) in Nieq
FN and ferrite % are NOT identical - FN is based on magnetic measurement.