Need diffusion coefficient in ferritic stainless steel (12%Cr) 1

[PhysMet]

Hi there
I require chromium and carbon's diffusion coefficient in ferritic stainless steel.
Any references?
Thanx

 

[NickE]

All I could find right now is the variation of diffusion coef. w/ temp. for Carbon in bcc-Fe.

D=2x10^-6 exp(-84300/RT)

Units m^2/s

Nick

 

[kenvlach]

From “Diffusion Data of various Element in the Matrix with Iron or Iron Alloys,” data from Technology Reports of the Tohoku University, vol.47~48,

http://dfw.nims.go.jp/diffus2/

you can find diffusion data for Cr in Fe & Fe-Cr alloys at

http://144.213.7.21/cgi-bin/diffus_search?Cr

and diffusion data for C in Fe and a number of Fe alloys at

http://144.213.7.21/cgi-bin/diffus_search?C

Note: the data are presented in tabular form such that you can select which data to use, then enter the temperature (^oK) at the bottom, and the diffusion coefficient will be calculated for you. Log D vs. 1/T can also be plotted. The closest alloy listed is Fe-13%Cr for which D = 3.32 x 10^-16 m²/s at 1073K.

Note: there doesn’t seem to be much diffusion data for C in Fe-Cr alloys, but it appears that the diffusion rate for C in Cr-1%Fe is about 10% that for C in bcc-Fe, so it would be reasonable to reduce the diffusion coefficient for Fe-12%Cr by about 1% from that for bcc-Fe.

You might also be interested in another on-line resource:
“Review on Lattice Diffusion of Substitutional Impurities in Iron. A Summary Report”
Hiroshi OIKAWA ( 1982)

http://inaba.nims.go.jp/diff/DIF_Oikawa/DIF2/oikawa2.html

For diffusion coefficient of Cr in bcc-Fe at 1048-1971K, D_o = 2.33 x 10^-4 m²/s, E_a = 238.8 KJ/mole.