Welding — heat input
q = (V × I × η) / v · per AWS / IIW
Computes welding heat input + verifies it sits in the material's qualified window. Drives HAZ microstructure (sensitization, ferrite balance, σ-phase) and pre/inter-pass temperature decisions.
Inputs
V
A
mm/min
Robot ~100-300 mm/min · manual SMAW ~150-250 · sub-arc ~400-1000
—
Default for GTAW (TIG): 0.65 · high-quality, lower thermal coupling
Per AWS A4.5 / IIW Doc IX-1330. Heat-input affects HAZ cooling rate, sensitization (austenitic SS), σ-phase precipitation (duplex), and martensite formation (low-alloy steels).
Results
Heat input q0.94kJ/mm
Material window0.5 – 2.5 kJ/mm
VerdictIN RANGE
Cooling Δt₈/₅ estimate1.0s
Material note: similar to 304L; lower for thin sections
heat-input window (kJ/mm)
0.94
Download all inputs + calculations + outputs as a single PDF.