摘要
通过对 GH33A 合金在蠕变与疲劳复合加载条件下的系列试验,发现拉伸保时使蠕变与疲劳发生了交互作用,加快了疲劳裂纹扩展速率,加速裂纹早期进入失稳扩展,大大降低了疲劳寿命。GH33A 合金具有良好的抗蠕变裂纹扩展能力,但疲劳裂纹扩展阻力较低。由此讨论了拉伸保时对裂纹扩展的影响,并对在蠕变-疲劳交互作用下的裂纹扩展模型作了探讨。
Based on the tests of tensile-holding under creep and fatigue complex load-ing,the results show that the creep-fatigue interaction takes place.Tensile-hiding acceler-ates the rate of crack propagation(da/dN)and reduces the fatigue life(N_f)greatly.GH33Aalloy possesses good creep crack resistance but low fatigue crack propagation resistance.Effects of tensile-holding on creep-fatigue crack propagation have been discussed and amodel of creep-fatigue crack propagation has been set up for GH33A alloy.
基金
国家自然科学基金
5860316
关键词
GH33A合金
蠕变
疲劳
裂纹
creep-fatigue interaction
tensile-holding time
crack propagation
