Hydrogen Diffusion Coefficient Calculator

Calculate hydrogen diffusion coefficient in steel as a function of temperature using Arrhenius-type relationship for ferritic and austenitic structures

Input Parameters

Results

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Diffusion Coefficient D
cm²/s
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Diffusion Half-Time
hours
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HIC Risk Level
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Time to Safe Level
hours
Note: Hydrogen in steel causes HIC (hydrogen-induced cracking), HICC, and delayed cracking. BCC structures (ferrite, martensite) allow fast H diffusion but have low solubility. FCC (austenite) has high solubility but slow diffusion. Martensite is most susceptible to H cracking.

Reference

Hydrogen Diffusion (Arrhenius): D = D0 × exp(-Q/RT) Ferrite (BCC): D0=1.4×10⁻³ cm²/s, Q=13,400 J/mol Austenite (FCC): D0=5.9×10⁻³ cm²/s, Q=53,900 J/mol H diffuses ~10⁴× faster in BCC than FCC at room temperature Diffusion half-time: t½ ≈ 0.049 × L²/D