The permeation data for 2.25Cr-1wt%Mo steel could be described by the expression:

P (cm2/cm s Pa½) = 0.00037 exp[-54.5(kJ/mol)/RT]

while the H diffusivity could be described by:

D (cm2/s) = 0.00032 exp[-9.2(kJ/mol)/RT]

On the Effective Hydrogen Permeability in Metastable Beta Titanium Alloy, Niobium and 2.25CM Mo Ferritic Steel. T.P.Perng, C.J.Altstetter: Metallurgical Transactions A, 1986, 17[11], 2086-90

 

Table 58

Permeation and Diffusion of H in 18Cr-8%Ni Steel

 

Thickness (cm)

T (C)

H2 (atm)

P (cm3/min atm½)

D (cm2/s)

0.1011

603

1.03

1.3 x 10-3

3.3 x 10-4

0.1011

603

10.9

1.2 x 10-2

3.3 x 10-4

0.1011

395

1.01

2.0 x 10-4

3.6 x 10-5

0.1011

395

10.2

7.5 x 10-4

3.6 x 10-5

0.1011

395

29.1

2.0 x 10-3

3.6 x 10-5

0.2475

398

1.04

5.9 x 10-5

3.6 x 10-5

0.2475

398

10.1

2.4 x 10-4

3.6 x 10-5

0.2475

398

30.4

9.1 x 10-4

3.6 x 10-5

0.1003

302

1.04

5.0 x 10-5

7.9 x 10-6

0.1003

302

30.1

8.0 x 10-5

7.9 x 10-6