The permeability and diffusivity of H in the stainless steels were measured by using a gaseous permeation technique at between 200 and 430C. The results indicated that the permeability and diffusivity obeyed Arrhenius relationships:

AISI316L:     D (m2/s) = 4.79 x 10-7 exp[-51.59(kJ/mol)/RT]

AISI316LN:     D (m2/s) = 4.33 x 10-7 exp[-50.99(kJ/mol)/RT]

AISI316L:     P (molH2/msMPa½) = 3.90 x 10-4 exp[-64.06(kJ/mol)/RT]

AISI316LN:     P (molH2/msMPa½) = 1.85 x 10-4 exp[-60.66(kJ/mol)/RT]

and were not affected by cold-working or heat-treatment. The values were affected by the alloy composition.

X.Sun, J.Xu, Y.Li: Materials Science and Engineering, 1989, A114, 179-87

 

Table 101

Permeation of D through AISI 316

 

Temperature (K)

Pb-Li Layer

P (m3[STP]/smbar½)

518

yes

3.9 x 10-13

526

yes

4.1 x 10-13

526

no

6.8 x 10-13

540

no

2.7 x 10-13

547

no

1.0 x 10-12

548

yes

5.4 x 10-13

556

yes

6.0 x 10-13

556

no

1.2 x 10-12

570

yes

7.4 x 10-13

584

yes

1.1 x 10-12

586

yes

7.0 x 10-13

589

yes

9.0 x 10-13

589

no

2.3 x 10-12

600

no

3.0 x 10-12

625

yes

1.3 x 10-12

626

yes

1.3 x 10-12

626

no

4.2 x 10-12

629

yes

1.2 x 10-12

632

no

4.8 x 10-12

652

no

6.9 x 10-12

665

yes

2.0 x 10-12

667

yes

2.0 x 10-12

667

no

7.8 x 10-12

680

no

9.0 x 10-12