ASTM 800, Ferrite content (CF8M)

[valveman52]

Three questions:

1. If have worked our the "Volume percent Ferrite" of material ASTM A351 Gr CF8M according to ASTM A800 at 16%. Is there a method of transfering this percentage into a Ferrite number according to ASTM A800? FN?

2. What is the minimum Ferrite percent / FN number possible using the calculation within ASTM A800? for ASTM A351 Gr CF8M?

3. Is it possible to have a ferrite content of 8% or less for ASTM A351 Gr CF8M using the calculation within ASTM A800?

Thanks for any help

 

[metengr]

Here is some light reading regarding correlations between ferrite number and % volume fraction of ferrite in stainless steel castings or weldments.

http://eagar.mit.edu/EagarPapers/Eagar085.pdf

http://www.osti.gov/bridge/purl.cover.jsp?purl=/14577-l1268K/webviewable/

 

[bruv]

Answer 1) No

Answer 2) 0% ferrite percent.

Answer 3) Yes, see answer 2).

Regarding 2) and 3), you need to know the niobium and nitrogen content of your steel before you carry out the calculation.