Fe-Cr: Mo, V, W Grain Boundary Diffusion

The diffusivities of 99Mo, 48V and 181W in ferritic Fe-Cr and Fe-Cr-C alloys, and in 2 commercial 8%Cr ferritic steels, were determined by using serial sectioning methods at temperatures ranging from 743 to 1123K (tables 55 to 58). It was found that the coefficients for volume diffusion exhibited a theoretically predicted magnetic anomaly. The diffusivities along high-diffusivity paths were explained in terms of the basis of interactions of the diffusant with carbide particles.

J.Cermák, J.Ruzicková, A.Pokorná: Acta Materialia, 1996, 44[12], 5007-19

Table 55

Bulk Diffusion of 99Mo in Fe-Cr Alloys

Cr (wt%)	Ni (wt%)	Mo (wt%)	V (wt%)	Temperature (K)	D (m2/s)
8.07	0.01	-	-	1103	2.01 x 10-15
8.07	0.01	-	-	1043	2.80 x 10-16
8.07	0.01	-	-	983	7.23 x 10-17
8.07	0.01	-	-	923	4.69 x 10-18
8.07	0.01	-	-	863	3.63 x 10-19
8.07	0.01	-	-	803	3.38 x 10-20
10.18	0.01	-	-	1103	2.28 x 10-15
10.18	0.01	-	-	1043	3.77 x 10-16
10.18	0.01	-	-	983	4.00 x 10-17
10.18	0.01	-	-	923	2.80 x 10-18
10.18	0.01	-	-	863	6.26 x 10-20
10.18	0.01	-	-	803	3.22 x 10-20
12.25	0.01	-	-	1103	1.96 x 10-15
12.25	0.01	-	-	1043	4.64 x 10-16
12.25	0.01	-	-	983	4.80 x 10-17
12.25	0.01	-	-	923	4.50 x 10-18
12.25	0.01	-	-	863	7.09 x 10-20
12.25	0.01	-	-	803	3.15 x 10-20
8.03	0.01	-	-	983	5.37 x 10-17
8.03	0.01	-	-	923	1.03 x 10-18
8.03	0.01	-	-	863	1.20 x 10-19
8.03	0.01	-	-	803	4.55 x 10-20
8.36	0.46	0.89	0.20	983	6.95 x 10-17
8.36	0.46	0.89	0.20	923	1.35 x 10-18
8.36	0.46	0.89	0.20	863	3.38 x 10-20
8.36	0.46	0.89	0.20	803	1.44 x 10-20
8.50	0.10	0.88	0.23	983	6.84 x 10-17
8.50	0.10	0.88	0.23	923	2.62 x 10-18
8.50	0.10	0.88	0.23	863	2.93 x 10-20
8.50	0.10	0.88	0.23	803	1.74 x 10-20

Table 56

Grain Boundary Diffusion of 99Mo in Fe-Cr Alloys

Cr (wt%)	Ni (wt%)	Mo (wt%)	V (wt%)	Temperature (K)	D (m3/s)
8.07	0.01	-	-	1103	1.82 x 10-21
8.07	0.01	-	-	1043	3.08 x 10-22
8.07	0.01	-	-	983	1.28 x 10-22
8.07	0.01	-	-	923	3.74 x 10-23
8.07	0.01	-	-	863	2.24 x 10-24
8.07	0.01	-	-	803	1.72 x 10-25
10.18	0.01	-	-	1103	1.15 x 10-21
10.18	0.01	-	-	1043	3.28 x 10-22
10.18	0.01	-	-	983	1.10 x 10-22
10.18	0.01	-	-	923	6.47 x 10-23
10.18	0.01	-	-	863	1.87 x 10-24
10.18	0.01	-	-	803	7.72 x 10-26
12.25	0.01	-	-	1103	1.10 x 10-21
12.25	0.01	-	-	1043	5.29 x 10-22
12.25	0.01	-	-	983	8.44 x 10-23
12.25	0.01	-	-	923	2.56 x 10-23
12.25	0.01	-	-	863	1.83 x 10-24
12.25	0.01	-	-	803	1.93 x 10-25
8.03	0.01	-	-	983	2.27 x 10-22
8.03	0.01	-	-	923	5.26 x 10-23
8.03	0.01	-	-	863	4.52 x 10-24
8.03	0.01	-	-	803	2.43 x 10-25
8.36	0.46	0.89	0.20	983	5.39 x 10-23
8.36	0.46	0.89	0.20	923	1.33 x 10-23
8.36	0.46	0.89	0.20	863	6.96 x 10-25
8.36	0.46	0.89	0.20	803	5.09 x 10-26
8.50	0.10	0.88	0.23	983	1.86 x 10-23
8.50	0.10	0.88	0.23	923	7.93 x 10-24
8.50	0.10	0.88	0.23	863	8.68 x 10-25
8.50	0.10	0.88	0.23	803	9.54 x 10-26

Table 57

Grain Boundary Diffusion of 48V in Fe-Cr Alloys

Cr (wt%)	Ni (wt%)	Mo (wt%)	V (wt%)	Temperature (K)	D (m3/s)
8.07	0.01	-	-	1103	1.18 x 10-20
8.07	0.01	-	-	1043	1.79 x 10-21
8.07	0.01	-	-	983	3.80 x 10-22
8.07	0.01	-	-	923	1.68 x 10-23
8.07	0.01	-	-	863	1.70 x 10-24
8.07	0.01	-	-	803	8.20 x 10-26
8.07	0.01	-	-	743	4.09 x 10-26
10.18	0.01	-	-	1103	6.99 x 10-21
10.18	0.01	-	-	1043	7.36 x 10-22
10.18	0.01	-	-	983	4.04 x 10-22
10.18	0.01	-	-	923	1.89 x 10-23
10.18	0.01	-	-	863	3.71 x 10-24
10.18	0.01	-	-	803	1.59 x 10-25
10.18	0.01	-	-	743	2.83 x 10-26
12.25	0.01	-	-	1103	3.58 x 10-21
12.25	0.01	-	-	1043	8.57 x 10-22
12.25	0.01	-	-	983	4.15 x 10-22
12.25	0.01	-	-	923	5.98 x 10-24
12.25	0.01	-	-	863	1.28 x 10-24
12.25	0.01	-	-	803	8.66 x 10-26
12.25	0.01	-	-	743	1.91 x 10-26
8.03	0.01	-	-	983	1.89 x 10-22
8.03	0.01	-	-	923	2.97 x 10-23
8.03	0.01	-	-	863	4.44 x 10-24
8.03	0.01	-	-	803	1.25 x 10-25
8.03	0.01	-	-	743	1.95 x 10-26
8.36	0.46	0.89	0.20	983	5.55 x 10-23
8.36	0.46	0.89	0.20	923	7.68 x 10-24
8.36	0.46	0.89	0.20	863	4.78 x 10-25
8.36	0.46	0.89	0.20	803	7.48 x 10-26
8.50	0.10	0.88	0.23	983	5.14 x 10-23
8.50	0.10	0.88	0.23	923	5.71 x 10-24
8.50	0.10	0.88	0.23	863	9.14 x 10-25
8.50	0.10	0.88	0.23	803	4.30 x 10-26

Table 58

Grain Boundary Diffusion of 181W in Fe-Cr Alloys

Cr (wt%)	Ni (wt%)	Mo (wt%)	V (wt%)	Temperature (K)	D (m3/s)
8.07	0.01	-	-	1123	2.97 x 10-20
8.07	0.01	-	-	1063	5.00 x 10-21
8.07	0.01	-	-	1003	6.05 x 10-22
8.07	0.01	-	-	943	4.79 x 10-22
8.07	0.01	-	-	883	4.93 x 10-23
8.07	0.01	-	-	823	5.91 x 10-25
8.07	0.01	-	-	773	9.15 x 10-26
10.18	0.01	-	-	1123	3.29 x 10-20
10.18	0.01	-	-	1063	4.06 x 10-21
10.18	0.01	-	-	1003	6.21 x 10-22
10.18	0.01	-	-	943	3.55 x 10-22
10.18	0.01	-	-	883	5.05 x 10-23
10.18	0.01	-	-	823	3.95 x 10-25
10.18	0.01	-	-	773	2.52 x 10-26
12.25	0.01	-	-	1123	2.26 x 10-20
12.25	0.01	-	-	1063	3.01 x 10-21
12.25	0.01	-	-	1003	1.08 x 10-21
12.25	0.01	-	-	943	4.08 x 10-22
12.25	0.01	-	-	883	5.97 x 10-23
12.25	0.01	-	-	823	2.66 x 10-25
12.25	0.01	-	-	773	6.40 x 10-26
8.03	0.01	-	-	983	7.47 x 10-23
8.03	0.01	-	-	943	2.46 x 10-23
8.03	0.01	-	-	903	8.47 x 10-24
8.03	0.01	-	-	863	1.88 x 10-24
8.03	0.01	-	-	823	4.29 x 10-25
8.03	0.01	-	-	773	1.91 x 10-26
8.36	0.46	0.89	0.20	983	1.87 x 10-23
8.36	0.46	0.89	0.20	943	8.89 x 10-24
8.36	0.46	0.89	0.20	903	1.37 x 10-24
8.36	0.46	0.89	0.20	863	9.60 x 10-26
8.36	0.46	0.89	0.20	823	5.45 x 10-26
8.36	0.46	0.89	0.20	773	6.58 x 10-27
8.50	0.10	0.88	0.23	983	1.88 x 10-23
8.50	0.10	0.88	0.23	943	1.20 x 10-23
8.50	0.10	0.88	0.23	903	2.49 x 10-24
8.50	0.10	0.88	0.23	863	5.23 x 10-25
8.50	0.10	0.88	0.23	823	6.59 x 10-26
8.50	0.10	0.88	0.23	773	6.95 x 10-27