Abstract: Central bending analysis of a 600 MW thermal power generating unit’s HP-IP combined casing rotor is conducted and it concludes that high temperature creep and residual stress is the main reason leading to permanent plastic deformation. First, they build the fine three-dimensional solid model with the FEA software ANSYS according to the rotor structure. It carries out finite element analysis of temperature field and stress field. On this basis, heat-solid coupling analysis is proceed, by dealing with the experiment data, they get the parameters of Norton creep model and implement finite element analysis of high temperature creep and residual stress in ANSYS. The research show that simply high temperature creep is not sufficient to cause the rotor bending during start-up process, but rotor bending will happen in short time if coupled with the residual stress. Using Norton three-parameter model and generating residual stress method are proved more effectively. The conclusion drawn can be referenced and guided for analysing the HP-IP combined casing rotor’s central bending.

Key words: rotor bending;high temperature creep;residual stress;ANSYS