加工表面完整性对GH33A高低周疲劳寿命的影响

 <正> 切削加工表面完整性,如表面粗糙度、表面残余应力和表面加工硬化,对高温合金零构件的疲劳性能有很大影响。以往主要集中于对高周应力控制疲劳影响的研究,然而,实际应用中许多零构件都需要有关应变控制低周疲劳性能的试验数据。“在航空发动机结构完整性研究”中就提出了加工表面完整性对涡轮盘低周疲劳寿命影响的研究。为此,本文研究了GH33A高温合金在常、高温条件下,不同加工表面质量对其高周和低周疲劳寿命的影响,以便为新型发动机涡轮盘的设计提供依据。

EFFECT OF SURFACE INTEGRITY ON LOW-CYCLE AND HIGH-CYCLE FATIGUE LIFE OF NICKEL-BASE SUPERALLOY GH33A

The effect of the surface roughness, the residual stresses and surface hardening created by cutting and grinding on high-cycle and low-cycle fatigue life of nickel-base superalloy GH33A at room and elevated temperature are studied. It is shown that under the condition of low-cycle fatigue, surface roughness is a main affecting factor and surface hardening has an unfavorable influence on fatigue life, while residual stresses can be neglected due to their relaxation under applied loads. The effect of surface integrity on low cycle fatigue is different from that on high-cycle fatigue.