The effect of pre-straining at intermediate temperatures on the mechanical behavior of high-bainite dual phase (HBDP) steels

摘要: Abstract High-bainite dual phase (HBDP) steels with 34 vol.% ferrite were subjected to tensile strains of 1%, 3%, and 5% at intermediate temperatures (150–450 °C). Mechanical behavior pre-deformed was then investigated room temperature. A maximum value for both yield stress ultimate strength observed steels. minimum elongation also found in the same specimens range 250–350 °C. It that dynamic strain aging (DSA) plays major role mechanical properties pre-strained HBDP The DSA indicator parameter (DSAP) introduced evaluate mechanism. Maxima DSAP likewise At higher pre-deformation retarded as a result, decreased. In order shed more light on this matter, response surface methodology (RSM) employed evaluation important factors (temperature pre-strain) DSA. results showed statistically significant effects first term well second However, there no interaction between these two factors. optimization achieving revealed is 47.5 under following conditions: temperature 312 °C; pre-strain 5%. Moreover, fatigue tests conducted 312 °C. demonstrated would lead limit.