Author : Baker Rahmetallah, Hassan
Engineering and Technology Journal,
2010, Volume 28, Issue 1, Pages 84-102
Factors affecting on formability of austenitic stainless steel AISI321 and two
duplex stainless steels GOST A917, and SAF2205, have been studied in the asreceived
condition at different strain rates, testing temperatures, and directions.
The mechanical properties obtained from tensile testing (strength, ductility, strain
hardening index, and strain rate sensitivity), have been chosen as criteria to detect
the formability. The values of these criteria are compared with stretching behavior
obtained from Olsen test (peak height, maximum stretching force, and total work
done). Strain hardening index, elongation, and tensile: yield ratio, were found
good criteria which represent formability. Results from tensile and stretching tests
of these alloys in the as-received condition, showed that the austenitic stainless
steel had the best formability due to its higher ductility and work hardenability.
Formability was found to be dependent on strain rate, testing temperature, and
rolling direction due to the anisotropy. Stretching tests for the three alloys in the
as-received condition, showed that 321 austenitic stainless steel had higher (hvalue)
, followed by 2205 duplex. Lubrication was found to improve formability
by increasing the (h-value) for the three alloys.