Abstract: The stretching process of 300 MW generator rotor is taken as an example, three different forging manipulator motion trajectories are established based on the scheme 1(anvil offset is zero), scheme 2(anvil offset is half of feed) and scheme 3(anvil offset is according to the need of practice process). The effects of different stretching processing at the same process parameters on effective strain in longitudinal center line of forging are studied. The results show that the scheme 3 is better than scheme 1 and 2. By comparison, the minimum effective strains in longitudinal center line of forging after all passes is increased by 15% and 22%, and the average effective strains in intermediate parts are increased by 5.6% and 6.2%, respectively. Furthermore, the axial effective strain distribution is the most even one. Therefore, anvil offset should be considered based on the most uniform deformation principle in planning the forging manipulator motion trajectory.

Key words: Effective strain, Forging manipulator, Generator rotor, Stretching