Ferrite Testing

Ferrite content analysis is a non-destructive testing method which provides critical data for austenitic stainless steel and duplex materials. The delta ferrite percentage or number allows a technical assessment of material corrosion susceptibility, mechanical properties, service suitability, and service reliability. 

To perform properly ferrite testing, both a minimum material thickness and a minimum specimen size are required. Test results are interpreted in accordance with current specifications and/or customer requirements. Reports issued are accompanied when necessary by drawings to identify locations tested.


  1. Austenitic stainless steel/Duplex stainless steels
  2. Welds (tubing, etc.)
  3. Normal construction steel with Austenitic chrome alloy steel   welded cladding (Ex. Boilers, vessels, etc.)
  4. Weldments, Castings, Forgings, Weld Overlays, Wrought materials
  5. Weld materials
  6. Butt/fillet welds
  7. Category A-D welds
  8. Stainless weld overlays on non-ferrous interfaces
  9. In-service and in-construction components


  1. Rapid and accurate analysis
  2. Highly portable digital technology
  3. Variable calibration in both Ferrite Number (FN) and % Ferrite (FN) using AWS Standards
  4. Testing instrument meets all requirements of ANSI/AWS A4.2 and DIN EN ISO 8249
  5. Calibration is traceable to internationally approved IIW secondary calibration standards


  1. Not recommended where the material is at temperatures greater than approximately 125 °F
  2. Surface preparation is very important for result accuracy
  3. Both a minimum material thickness and a minimum specimen size are required
  4. Shape of the specimen may have a negative effect on the results obtained. Correction calculations can be performed in some instances