Abstract: The hot sizing is a technology that enables sheet metal part using, high elastic material to eliminate spring-back and distortion. The paper expounds and proves the principle of fixing shape of hot sizing, that is, they re synthetic effects of material softening and stress relaxation in shot time. Then the theoretical rule of hot sizing for beading spring-back is established by this principle. They show quantitatively effects of main factors, such as material property, part geometry, temperature and time, for the rule of hot sizing. The theoretical values of spring-back in the process of hot sizing are in good agreement with that of experiments, They may be used to estimate technological parameters of hot sizing. In addition thermo-mechanical characteristics under standard temperatures of forming or sizing and the experimental curves of hot sizing for Ti-6Al-4V and Ti-2Al-1.5Mn are given.

Key words: 回弹, 矫正, 钛合金, 弯曲