Schaeffler Diagram Calculator

The Schaeffler diagram predicts the weld metal microstructure of stainless steel and dissimilar metal welds based on Chromium Equivalent (Creq) and Nickel Equivalent (Nieq). It helps identify risk of hot cracking, martensite formation, or lack of ferrite.

Formulas (Schaeffler)

Creq = Cr + Mo + 1.5Si + 0.5Nb
Nieq = Ni + 30C + 0.5Mn

🔬 Schaeffler Diagram Calculator

Enter weld deposit chemistry (wt %). Use 0 for absent elements.

Cr %

Ni %

C %

Mo %

Si %

Mn %

Nb (Cb) %

N %

Cu %

Schaeffler Results

Creq (Chromium Equivalent)–

Nieq (Nickel Equivalent)–

Predicted Microstructure–

Hot Cracking Risk–

Ferrite Number (approx)–

Recommendation–

Schaeffler Diagram Regions

Region	Microstructure	Properties
High Nieq, Low Creq	Fully Austenitic	Hot cracking risk, no ferrite
High Creq, Low Nieq	Ferrite	Brittle at high %, magnetic
Mid-range both	Austenite + Ferrite	Optimal — 4-10 FN ideal
Low Creq, Low Nieq	Martensite	Hard, brittle, cracking risk
Medium Creq + Nieq	Duplex	High strength + corrosion resistance