Investigating solute interactions in V–4Cr–4Ti based on tensile deformation behavior of vanadium

Tensile tests were carried out on annealed, unalloyed vanadium from 200 to 500 °C at strain rates ranging from 10−1 to 10−5 s−1 to investigate the interaction between Ti and interstitial O, C, and N solutes in the V–4Cr–4Ti alloy. Dynamic strain aging (DSA) is manifested in unalloyed vanadium at 300 and 400 °C as serrations (continuous) and discontinuous yielding in the Lüders strain and work hardening regimes of stress–strain curves with a concomitant negative value in strain rate sensitivity (SRS) for flow stresses. Diffusion data indicate that the DSA phenomenon at temperatures below 400 °C is related to the migration of carbon and oxygen while at higher temperatures nitrogen becomes increasingly important. DSA occurs in V–4Cr–4Ti within the temperature range from 300 to 750 °C (J. Nucl. Mater 283–287 (2000) 508). The data shows that alloying with Ti and Cr solutes shifts the maximum negative SRS from 300 °C in vanadium to ∼600 °C in the alloy.