Static Recrystallization of Tool Steels

Abstract:

Double-twist torsion tests were used to determine static softening in the hot working range of three tool steels – W1, a carbon steel (1.03% C - 0.8% other elements), A2 and D2, a medium and a high alloy steel, containing 8.45% and 14.82% alloying elements. The carbon steel, that was single-phase austenite in the hot-working range, experienced rapid static recrystallization due to increased diffusion rate caused by C in hot austenite, very little alloying solute and no carbides. Carbides in alloy tool steels, which exist throughout the hot-working range, have a retarding effect on the progress of recrystallization but are responsible for enhancing initiation due to formation of nuclei at the strain concentration near the particle/matrix interface. Static recrystallization (SRX) of the alloy tool steels was compared with austenitic stainless steels, with similar strengths but much greater alloying content, and with microalloyed steels, as well as with the dynamic recrystallization kinetics.