GH132合金疲劳蠕变交互作用下裂纹扩展速率研究
The Investigation of Crack Crowth Rate under the Condition of Fatigue-Creep Interaction for GH132 Disc
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摘要: 通过对650℃、不同应力条件下GH132合金的裂纹扩展速率的测定结果表明:
(1)由于GH132合金的蠕变与疲劳裂纹的扩展机构不同,使得前者有更大的环境敏感性。
(2)在疲劳蠕变交互作用条件下,裂纹的扩展过程受Kmax及ΔK共同控制(Keq=Kmax+αΔK)。通常的ΔK描述法已不能全面解释裂纹扩展速率与寿命之间的对应关系。Abstract: The crack growth rates under the condition of fatigue-creep interaction at 650℃ were measured. The results of mesurement indicated that the crack growth rate was controlled by both Kmax and AK. In this case the effective stress indensity factor (Keq) is a suitable parametes describing the behaviour of crack propagation.Keq is equal to the sum of kmax and α'△k, Where α' was assumed as a parameter represented the effect of crack closure, and α' is a function of crack length.