Author/Authors :
Abbasi، S. M. نويسنده Faculty of Mechanical Engineering, Khajenasir Toosi University of Technology, Tehran, Iran , , Shokuhfar، A. نويسنده Faculty of Mechanical Engineering, Khajenasir Toosi University of Technology, Tehran, Iran , , Ehsani، N. نويسنده Faculty of Materials Engineering, MUT, Tehran, Iran ,
Abstract :
In this study the hot deformation behaviour of a precipitation hardened (PH) stainless
steel at high strain rates has been predicted through hot compression testing. Stress–strain curves
were obtained for a range of strain rates from 10-3 to 10+1 s-1 and temperatures from 850 to
1150°C. Results obtained by microstructure and stress-strain curves show that at low temperatures
and high strain rates, where the Zener-Holman parameter (Z) is high, work hardening and
dynamic recovery occure. By increasing temperature and decreasing strain rate, the Z parameter
is decreased, so that dynamic recrystallization is the dominant softening mechanism. The results
were fitted using a Log Z versus Log (sinh (? ?p) diagram allowing an assessment of the behavior
of the stresses measured at strain rates closer to those related to the industrial hot rolling
schedules. It is clearly shown that the data collected from low strain rate testing can be fairly
reasonably extrapolated to higher orders of magnitude of strain rate.
