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本文根据舰船功力装置运行周期较长的特点,着重研究了在较长保载停留时间(不短于0.5小时)下,以不同温度和应力组合的循环加载对GH33、GH37和GH49三种变形高温合金持久断裂寿命的影响。研究结果表明,循环加载一般都降低试验合金的持久断裂寿命,最严重的约降低寿命的一半。随着保载停留时间的延长,这种有害作用随之减小,但二者之间没有明显的线性关系。提高温度、降低应力一般都降低寿命的损伤率,但单纯降低应力却没有收到同样的效果。三种合金表现出三种完全不同的行为。 本文在分析试样断口和金相结果的基础上,根据循环加载可能对不同的损伤机制产生影响的观点,定性地解释了试验中出现的主要现象,并得出了一些初步的结论。
In this paper, according to the characteristics of long ship operation period, this paper focuses on three kinds of deformation of GH33, GH37 and GH49 with cyclic loading of different temperature and stress under the condition of long dwell time (not less than 0.5 hour) Effect of Long-term Rupture Life of Superalloy. The results show that cyclic loading generally reduces the ductile fracture life of the test alloy and, in the worst case, reduces the life expectancy by half. As the dwell time increases, this detrimental effect decreases, but there is no obvious linear relationship between the two. Increasing the temperature and reducing the stress generally reduce the damage rate of life, but merely reducing the stress but not receiving the same effect. Three alloys show three completely different behaviors. Based on the analysis of the fracture surface and the metallographic results, this paper qualitatively explains the main phenomena in the experiment and gives some preliminary conclusions according to the viewpoint that cyclic loading may affect different damage mechanisms.