直接时效GH4169高温合金疲劳裂纹扩展性能试验

对直接时效GH 4169高温合金的疲劳裂纹扩展性能进行了试验研究。分别研究了厚度、温度、应力比等因素对直接时效GH 4169高温合金疲劳裂纹扩展性能的影响。结果表明,在410 mm的厚度范围内,厚度对直接时效GH 4169高温合金疲劳裂纹扩展性能几乎没有影响,但厚度为2 mm且应力比为0.1时其裂纹扩展速率稍有下降;应力比对直接时效GH 4169高温合金疲劳裂纹扩展的影响随着应力比的提高逐渐减小;温度的提高对直接时效GH 4169的裂纹扩展速率有明显的加速作用,但是随着应力强度因子范围的增加,其影响逐渐减小,氧化作用是加速其裂纹扩展的主要机理。 

Experimental Study on Fatigue Crack Growth Behavior of Direct Aging GH4169 Superalloy

Fatigue crack growth tests were conducted on a CT specimen of a nickel base superalloy direct aging GH4169.The effects of thickness,temperature and stress ratio on fatigue crack growth behavior were studied separately.The key results are as follows:thickness has no effect on fatigue crack growth behavior in the thickness range from 4 mm to 10 mm,but as thickness is decreased to 2 mm,the fatigue crack growth rate decreases when stress ratio is 0.1;the effect of stress ratio on fatigue crack growth rate diminishes as stress ratio increases;increasing temperature accelerates fatigue crack growth rate,but the effect of temperature diminishes with the increase of stress intensity factor and the main mechanism for accelerating fatigue crack growth is oxidation.