Influence of temperature and strain rate on tensile properties of 15Cr–2·2Mo–15Ni–Ti modified austenitic stainless steel

The influence of temperature and strain rate on the tensile properties of 15Cr–2·2Mo–15Ni–Ti modified austenitic stainless steel (conforming to ASTM A-771/UNS S 38660 and commonly referred to as alloy D9) has been examined in the temperature range 300–1023 K and in the strain rate range 6·3×10⁻⁵ to 26×10·2 s⁻¹. At intermediate temperatures (573–823 K), the various manifestations of dynamic strain aging (DSA) were observed, such as serrated flow, ductility minima, and peaks and plateaus in the variations of yield strength, ultimate tensile strength, flow stress, and work hardening rate with temperature. At temperatures above the DSA range the strength decreased rapidly owing to the onset of recovery. The influence of strain rate on the strength and ductility of the alloy was found to be controlled by DSA at intermediate temperatures and by recovery at higher temperatures.

MST/1676