Mechanism by which cold-hardened iron softens during high-speed heating

Conclusions

• 1. Removal of the distortions in the crystal structure and the microrecrystallization processes develop independently of one another. Under our experimental conditions (a high heating rate), recrystallized iron inherited most of the hardening effect and distortions introduced by preliminary cold-hardening.

• 2. The sequence in recovery and recrystallization observed when cold-hardened metal is heated is governed by kinetic factors and is a function of temperature. The sequence in completion of these processes is reversed in the experimental conditions; this indicates that recovery and microrecrystallization are different in nature and independent.