Abstract
The calculation and assessment method for the crack propagation life under low cycle fatigue and high cycle fatigue of nuclear steam turbine rotors is presented. The loads and fatigue cycle stress amplitude, the threshold and material constants of the fatigue crack growth as well as the crack propagation life calculation methods for low cycle fatigue and high cycle fatigue of nuclear steam turbine rotors are introduced. The calculation and assessment method for the crack propagation calendar life under low cycle fatigue and high cycle fatigue of nuclear steam turbine rotors are given together with an application example for calculation and improvement of the fatigue crack propagation calendar life of a low pressure rotor for 1000MW nuclear steam turbines. The analysis results indicate that effect of the high cycle fatigue on the fatigue crack propagation calendar life of nuclear steam turbine rotors can not be ignored. It is necessary to evaluate the crack propagation life under LCF and HCF interactions, both for new designed nuclear steam turbine rotors and defect nuclear steam turbine rotors in service.
