Ferrite test

what is the use of measuring ferrite number in ass family?? we know pmi for knowing the material composition but what about ferrite number…i am new for ss.please anyone clarify?

FERRITE RATIO

Ferrite test to measure of ferrite number (FN) or ferrite percentage (%Fe).
Ferrite test are most applied for duplex/ superduplex stainless steels, stainless steel P-No. 6, 7, 8.

Convert % Fe to FN, see API RP 582 2016 para. 11.3.4.3.

Read more: ferrite test for duplex stainless steel.

PMI

Positive Material Identification of low-alloy steel, stainless steel.
Note to you: PMI measurement of carbon content and without content.

  1. PMI with reading %C such for type 316L, 304L, …
  2. PMI without reading %C such for type 316, 304, …