3. Conclusion

The "ferrite rate" is a convenient intermediary for understanding the properties of molten metal and controlling the risk of hot cracking.

The problems involved in measuring ferrite in austenitic stainless steel deposits can be overcome. They do, however, call for rigorous application of the measurement technique, while taking care not to be too rigorous in assessing the results.

Various methods can be used to measure "ferrite content". They differ in :

• the physical principle involved ;

• whether they are destructive or non-destructive;

• the volume of material to be measured (local or global measurement) ;

• sensitivity to variations in ferrite characteristics (which depend, among other things,...