汽轮机转子初始裂纹高周疲劳安全性分析方法及其在焊接转子中的应用

High Cycle Fatigue Safety Analysis for Steam Turbine Rotors with Initial Cracks and Its Application to a Welded Rotor

介绍了汽轮机转子高周疲劳寿命的设计方法.提出了汽轮机转子初始裂纹高周疲劳安全性的分析方法,转子高周疲劳的平均应力σm、应力幅σA和应力强度因子范围ΔKI的计算方法以及转子钢疲劳裂纹扩展门槛值ΔKtRh的经验计算公式.给出了汽轮机转子初始裂纹高周疲劳安全性的分析思路、分析方法、评价判据以及半转速1 000MW核电汽轮机焊接低压转子的高周疲劳安全性分析应用实例.结果表明:转子初始裂纹高周疲劳分析方法能够应用于汽轮机转子的安全性评价,并可以为汽轮机转子的结构优化和长周期安全运行提供依据.

An introduction is being presented to the design method of high cycle fatigue life of steam turbine rotors, together with descriptions to analytical methods for high cycle fatigue safety of turbine rotors with initial cracks, and to calculation methods for the mean stress am, stress amplitude aa and the range △KthR of stress intensity factors as well as to an experience formula for the fatigue crack growth threshold △KthR of the rotor material. Meanwhile, an analysis method and the assessment criteria for high cycle fatigue safety of steam turbine rotors with initial cracks are given, with an application example listed for high cycle fa- tigue safety analysis of a welded low-pressure rotor for a half-speed steam turbine in a 1 000 MW nuclear power station. Results show that the analytical methods may be used for safety evaluation and structural optimization of steam turbine rotors, so as to guarantee safety operation of relevant power plants.