EFFECT OF TEMPERATURE ON THE FATIGUE‐CRACK PROPAGATION BEHAVIOUR OF INCONEL X‐750
EFFECT OF TEMPERATURE ON THE FATIGUE‐CRACK PROPAGATION BEHAVIOUR OF INCONEL X‐750
复制标题
温度对 INCONEL X-750 疲劳裂纹扩展行为的影响
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
L. James
中科院分区：
文献类型：
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作者：
W. Mills;L. James
采用线弹性断裂力学方法研究了温度对沉淀热处理疲劳裂纹扩展行为的影响。Inconel X-750在24至649°C的空气环境中，通常发现裂纹扩展速率随温度的升高而增加，特别是在最高试验温度(649°C)下。在538℃下研究了应力比对Inconel X-750合金疲劳裂纹扩展行为的影响，结果表明，在所研究的生长速率水平下，这种镍基高温合金的高温疲劳响应对应力比水平相对不敏感。对Inconel X-750疲劳断口的金相和电子断口分析表明，裂纹扩展机制是温度和主要应力强度因子的函数。在室温和中温条件下(高达538°C)，所有疲劳断口表面在低裂纹扩展速率下都表现出多面晶体形貌，然后在较高扩展速率区域出现条纹。在最高试验温度(649℃)下，疲劳裂纹以沿晶机制扩展。
— Linear-elastic fracture mechanics techniques were used to characterize the effect of temperature on the fatigue-crack propagation behaviour of precipitation heat-treated. Inconel X-750 in an air environment over the temperature range 24 to 649°C. In general, crack growth rates were found to increase with increasing temperature, particularly at the highest test temperature (649°C). The effect of stress ratio on the fatigue-crack growth behaviour of Inconel X-750 was examined at 538°C, and results indicated that the elevated temperature fatigue response of this nickel-base superalloy was relatively insensitive to stress ratio level at the growth rate levels studied. Metallographic and electron fractographic examination of Inconel X-750 fatigue fracture surfaces revealed operative crack growth mechanisms to be a function of temperature and prevailing stress intensity factor. Under room temperature and intermediate temperature conditions (up to 538°C), all fatigue fracture surfaces exhibited a faceted crystallographic morphology at low crack growth rates followed by striations in the higher growth rate regime. At the highest test temperature (649°C), the fatigue crack was found to propagate by an intergranular mechanism.