ferrite calculations 5

[NBROWN]

Is their such a thing to Calucalate the amount of Ferrite in a material?
My Specification calls for 15-45% Ferrite.
We are getting differant answers from the european community and the USA community.
Is their differant calculations/formulas?
Composition:
C 0.08
SI 1.50
Mn 1.50
P 0.04
S 0.04
Cr 18-22.0
Ni 9 - 13.0
Mo 3 - 4.0

Mecahnical
YS min 359MPa
TS min 650 MPA
Elongation Min 33%

Ferrite content 15-45%

Can this be done?

 

[Rich2001]

Online Ferrite Calculator can found here-

http://engm01.ms.ornl.gov/FNPLots.HTML

Nueral Net Model online

http://engm01.ms.ornl.gov/FNPLotNeural.HTML

Simple calculation method presented by Avesta Sheffield. The formula for Avesta Ferrite Number FNA assumes parallel lines of constant ferrite numbers.
Creq = Cr + 1.5 Si + Mo + 2 Ti + 0.5 Nb
Nieq = Ni + 30 (C + N) + 0.5 Mn + 0.5 Cu + 0.5 Co
FNA = 3.34 Creq - 2.46 Nieq - 28.6

Algorithim & Fortan Source code

http://www.msm.cam.ac.uk/map/steel/subs/fparam-b.html

 

[bruv]

You might also want to ave a look at a copy of ASTM A800/A800M-01 Standard Practice for Steel Casting, Austenitic Alloy, Estimating Ferrite Content Thereof, which contains a different formula to the one given by Rich2001

 

[ijzer]

If your spec calls for a certain amount of ferrite content it should also specify either per Schaeffler or by Delong or by WRC because they all use different formula 's

 

[rd400guy]

I use Schaeffler-DeLong diagram and corresponding formulas. It takes the most elements into consideration. A very simple spreadsheet can do all the calcs if you just input the element percentages, that is if you run ferrite calculations a lot. Outokumpu (AvestaPolarit) is a good link:

http://www.outokumpu.com/template/Page____5781.asp

Hope it helps.

 

[mcguire]

You will need to know your nitrogen level. It's very important.