The lattice and grain boundary diffusion coefficients of 22P were determined at between 932 and 1155K (tables 126 and 127) by using tracer/sectioning techniques. The Arrhenius plots for lattice diffusion exhibited discontinuities at temperatures close to the Curie temperature. This was also true of the grain boundary diffusion data, but the temperatures at which the discontinuities occurred were lower by some 100K. It was suggested that the discontinuities were caused by magnetic transformations in the bulk and at the grain

boundaries. The addition of Mo was found to decrease both the lattice and grain boundary diffusion of P.

T.Matsuyama, H.Hosokawa, H.Suto: Transactions of the Japan Institute of Metals, 1983, 24[8], 589-94

 

Table 124

Self-Diffusion of 59Fe in Fe-Mo Alloys

 

Mo (wt%)

Temperature (C)

D (cm2/s)

0.54

680

2.00 x 10-14

1.06

680

3.61 x 10-14

1.50

680

3.51 x 10-14

2.50

680

1.08 x 10-14

1.06

700

9.83 x 10-14

1.50

700

1.01 x 10-13

0.54

720

5.62 x 10-14

1.06

720

6.33 x 10-14

1.50

720

5.51 x 10-14

2.50

720

6.26 x 10-14

0.54

740

2.39 x 10-13

1.06

740

1.91 x 10-13

1.50

740

3.95 x 10-13

2.50

740

1.60 x 10-13

0.54

760

5.09 x 10-13

1.06

760

6.11 x 10-13

1.50

760

4.19 x 10-13

2.50

760

3.25 x 10-13

0.54

780

1.07 x 10-12

1.06

780

1.45 x 10-12

1.50

780

1.82 x 10-12

2.50

780

7.85 x 10-13

0.54

810

3.18 x 10-12

1.06

810

4.96 x 10-12

1.50

810

3.68 x 10-12

2.50

810

2.52 x 10-12

0.54

840

6.34 x 10-12

continued

Table 124 (continued)

Self-Diffusion of 59Fe in Fe-Mo Alloys

 

Mo (wt%)

Temperature (C)

D (cm2/s)

1.06

840

6.69 x 10-12

1.50

840

1.04 x 10-11

2.50

840

6.36 x 10-12

0.54

870

1.44 x 10-11

1.06

870

1.65 x 10-11

1.50

870

1.78 x 10-11

2.50

870

1.13 x 10-11

0.54

900

2.35 x 10-11

1.06

900

3.70 x 10-11

1.50

900

4.23 x 10-11

2.50

900

2.83 x 10-11

 

 

Table 125

Diffusivity of H in Fe-Mo at 300 to 800C

 

Mo (wt%)

Do (cm2/s)

E (kcal/g-atom)

0.93

8.9 x 10-4

2.82

2.17

1.59 x 10-3

3.52

3.11

1.53 x 10-3

3.70