High temperature work hardening stages, dynamic strain aging and related dislocation structure in tensile deformed AISI 301 stainless steel

Abstract

The development of dislocation structures associated with work hardening stages and dynamic strain aging (DSA) is investigated in an AISI 301 austenitic stainless steel plastically deformed in tension at 500 and 600°C. In the first work hardening stage, up to 22% of plastic strain at 500°C and 18% at 600°C, incipient dislocation cells begin to be formed and are observed in association with {100} TEM diffraction pattern. At the transition point from first to second stage, the cells are well consolidated with a maximum dislocation density typical of DSA in stainless steels. The sharp decrease in work hardening rate after the transition point discloses a reduction in cell size together with evidence of dynamic recovery without sub-boundaries formation due to DSA.