重型燃机压气机盘淬火应力场的计算机模拟

Computer Simulation of Quenching Stress Field during Gas Turbine Compressor Disk Quenching Process

利用有限元法研究了某重型燃机压气机盘在淬火过程中的应力场分布。模拟计算中,采用等效热容法处理相变潜热对淬火温度场的影响,采用等效线胀系数法处理相变引起的组织应力,同时考虑了材料热物性参数和力学性能参数的温度相关性。模拟结果表明,在淬火初期,由于热应力的作用使工件表面受拉而心部受压,随着相变的发生,应力发生了多次转向,最后形成了表面受压心部受拉的残余应力分布。在油淬过程中,工件内持续承受较高的拉应力,而空冷时承受的内应力较小,从而避免了工件的变形和开裂。

The quenching process of gas turbine compressor disk was simulated to study the stress field by finite element method. In this model, the equivalent thermal capacity method was used to deal with the influence of latent heat on the temperature field and the transformation stress resulted from phase transformation was taken into account using the equivalent linear expansion coefficient method. The temperature dependency of thermal and mechanical properties of materials was considered. The results show that the axial stress in workpiece surface is tensile, whereas the center is subjected to compressive stress due to the effect of thermal stress in the early period of quenching process. During the phase transformation, the stress orientation changes. At last, the residual stress in surface is compressive and the central residual stress is tensile. In the oil quenching process, the tensile stress in the workpiece is too large to ensure the workpiece properties. Nevertheless, the workpiece is subjected to less internal stress in the air cooling process, which can protect the workpiece from distortion and cracking .