The Gruzin method was used to study the bulk and grain-boundary diffusion of 63Ni (tables 94 to 96) in steels which contained 0.3Mn, 0.2Si, 0.004S and 0.007wt%P in addition to major concentrations of Cr and Ni. Mathematical analysis showed that the energy of the grain boundary was a function of the difference between the activation energies for volume and grain-boundary diffusion.

P.Guiraldenq, P.Poyet: Mémoires Scientifiques de la Revue de Métallurgie, 1973, 70[10], 715-23

 

Table 93

Bulk and Grain-Boundary 63Ni Diffusion in Fe-17Cr-12wt%Ni

 

Temperature (C)

Dv (cm2/s)

Dgb (cm3/s)

603

7.081 x 10-18

4.416 x 10-17

650

4.747 x 10-17

1.401 x 10-16

702

5.725 x 10-16

4.430 x 10-16

748

8.950 x 10-16

6.510 x 10-16

799

7.984 x 10-15

7.688 x 10-16

851

1.049 x 10-14

2.588 x 10-15

898

9.619 x 10-14

4.477 x 10-15

949

2.240 x 10-13

8.436 x 10-15

1000

3.333 x 10-13

2.624 x 10-14

1002

4.403 x 10-13

2.183 x 10-14

1051

1.350 x 10-12

1.908 x 10-14

1098

1.216 x 10-12

5.186 x 10-14

1099

4.659 x 10-12

2.412 x 10-14

1149

4.166 x 10-12

7.004 x 10-14

1200

1.344 x 10-11

6.422 x 10-14

1248

5.433 x 10-11

7.822 x 10-14

1250

2.607 x 10-11

1.091 x 10-13

1253

4.078 x 10-11

-

 

 

Table 94

Bulk Diffusion Parameters for 63Ni in

Fe-Ni-19wt%Cr Alloys at 900 to 1200C

 

Ni (wt%)

Do (cm2/s)

E (kcal/g-atom)

10

1.4 x 100

72

30

1.4 x 100

72

45

2.0 x 104

96

55

2.8 x 100

71

65

2.6 x 100

71

75

7.2 x 10-2

60.5