Recovery and recrystallization of carbon steel between intervals of hot working

Abstract

AbstractInterrupted compression tests were used to study the static softening of austenite at temperatures from 780 to 1040°C. Prior straining was carried out at strain rates in the range 10−3 to 10−1 s−1 and interruption strains of up to 0.41 were applied to 0.06% C, 0.42% C and 0.68% C steels, as well as to a modified 0.07% C steel containing niobium.The results indicate that a critical strain is required for the initiation of static, i.e., classical, recrystallization after prior hot deformation. For strains inferior to this critical amount, recrystallization does not occur at all, even after holding intervals of 105 s or more, and softening takes place instead entirely by static recovery. Evidence is presented for the existence of a second critical strain, about twice as large as the first, which corresponds to a point just before the peak in the flow curve. This is the critical strain for the initiation of post-dynamic (metadynamic) recrystallization. The latter process, unlike the mechanism of class...