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研究了不同固溶温度和稳定化处理工艺后GH864合金的裂纹扩展情况.通过分析合金的微观组织,断口形貌以及lga--lgNi/Nf、da/dN--a及da/dN--N曲线特征,定量计算了裂纹萌生期、稳态扩展期及失稳瞬断期在整个疲劳断裂过程中所占比例,并进一步分析影响各自比例的微观组织因素.结果表明:随着固溶温度的升高,晶粒尺寸增加,合金的裂纹扩展速率降低,同时裂纹的萌生期的比例降低,而裂纹的扩展期比例则会增加;随稳定化时间的延长和温度的升高,晶界碳化物析出量增加,降低了合金的裂纹扩展速率,但是裂纹萌生期的比例在逐渐增加.
The crack growth of GH864 alloy after different solution treatment temperature and stabilization treatment was studied. The microstructure and fracture morphology of the alloy were studied by means of the analysis of the microstructures and fracture morphology of lug - lgNi / Nf, da / dN - a and da / dN - N Curve characteristics of the crack initiation, steady-state expansion and instability instantaneous fracture in the whole process of fatigue fracture, and further analysis of the microstructure factors affecting their respective proportions.The results show that: with the solution temperature Increased, the grain size increased, the alloy crack growth rate decreased, while the crack initiation rate decreased, while the proportion of crack growth period will increase; with the stabilization time and temperature, the grain boundary carbide The amount of precipitation increased, the crack growth rate decreased, but the crack initiation rate gradually increased.