The retaining ring is an important component of turbogenerator. The high deformation stress-strain curves of three  kind  of  retaining  ring  steel-0.53C- 16.98Mn-3. 17Cr(1)

0. 12C- 19.57Mn- 19.27Cr-0.60N(2)and  0.06C- 18.58Mn- 19. 15Cr-0.69N(3)and the high temperature plasticity- reduction of area of containing nitrogen retaining ring steel at temperature 800~1200 ℃ have been studied by Gleeble- 1500 thermal simulation machine. The results showed that with increasing nitrogen content in steel

the critical deformation value for dynamic recrystallization increased in order to gradually  increase corresponding deformation force; the maximum reduction of area of containing nitrogen steel was at 1050 ℃

and  the high plastic deformation region shrunk with increasing nitrogen content in steel. Therefore modifying deformation model to  increase process plasticity is an available way to increase the quality of retaining ring.