The diffusion of 14C in the ferrite phase of the 9.8Co-5.7W-0.9wt%C alloy steel was studied by using a radio-isotope method. The results for 590 to 710C could be described by:

D (cm2/s) = 8.9 x 102 exp[-46.5(kcal/mol)/RT]

 

The diffusion parameters depended upon whether or not allowance was made for the carbide phase.

I.K.Kupalova, S.V.Zemskii: Izvestia Akademii Nauk, 1974, 4, 123-5

 

 

Table 56

Bulk Diffusivity of 51Cr in Fe-Cr Alloys

 

Temperature (K)

AlloyMethod

D (m2/s)

1043

1R

2.56 x 10-16

1043

1S

2.59 x 10-16

983

1R

1.60 x 10-17

983

1S

4.07 x 10-18

923

1R

3.04 x 10-19

923

2R

1.51 x 10-19

923

3R

2.92 x 10-19

923

1S

2.10 x 10-19

923

2S

1.86 x 10-19

923

3S

2.34 x 10-19

863

1R

9.84 x 10-20

863

2R

6.36 x 10-20

863

3R

6.19 x 10-20

863

1S

1.07 x 10-19

863

2S

8.05 x 10-20

863

3S

5.69 x 10-20

1: Fe-10.18Cr; 2: Fe-8.03Cr-0.17C;

3: Fe-8.36Cr-0.09C-0.56Mn-0.20Si-0.46Ni-0.89wt%Mo

R: residual activity; S: serial sectioning

 

Table 57

Grain Boundary Diffusivity of 51Cr in Fe-Cr Alloys

 

Temperature (K)

AlloyMethod

D (m3/s)

1043

1R

3.70 x 10-21

1043

1S

5.07 x 10-21

983

1R

5.73 x 10-22

983

2R

2.00 x 10-22

983

3R

5.97 x 10-23

983

2S

2.04 x 10-22

983

3S

6.75 x 10-23

983

1S

8.73 x 10-22

923

3R

6.49 x 10-24

923

3S

7.20 x 10-24

923

1R

1.90 x 10-23

923

2R

4.14 x 10-23

923

1S

2.68 x 10-23

923

2S

4.17 x 10-23

863

3R

2.47 x 10-25

863

3S

3.17 x 10-25

803

1R

9.05 x 10-26

803

2R

5.07 x 10-25

803

3R

2.35 x 10-26

743

1R

4.49 x 10-26

743

2R

4.32 x 10-26

743

3R

3.79 x 10-27

743

1S

4.46 x 10-26

743

2S

4.32 x 10-26

743

3S

4.81 x 10-27

Fe-10.18Cr; 2: Fe-8.03Cr-0.17C;

3: Fe-8.36Cr-0.09C-0.56Mn-0.20Si-0.46Ni-0.89wt%Mo

R: residual activity; S: serial sectioning