ASTM A800

[bruv]

Appendix section X1.5 of this spec gives a formula for calculating the composition ration CR from the ferrite content F

CR = 0.9 + (3.38883x10^-2 F)-(5.58175x10^-4 F^2)+(4.22861x10^-6 F^3)

Has anybody got a version where F is the unknown?

Thanks

 

[metengr]

In ASTM A800-97 under X1. NOTES TO SCHOEFER DIAGRAM, the specification contains the equation for the solid line (central curve), which you have above, and actual graph of CR and volume percent ferrite. You also have tables containing volume fractions of ferrite and CR (Table X1.1)and vice versa (TAble X.1.2) with upper and lower limit ranges.

Why do you need to re-arrange the central line equation to solve for F in terms of CR?

 

[bruv]

So that I can plug the chemistry into a spreadsheet and get an answer out quickly, rather than looking up the standard each time.

I have to do a lot of these.

 

[cloa]

What happen when you run solver on it in the spreadsheet? Suggest repost in Engineering spreadsheets forum