粉末高温合金FGH97疲劳裂纹扩展行为的研究

Study on Fatigue Crack Growth Behavior of FGH97 P/M Superalloy

摘要:

本文研究了氩气雾化制粉+热等静压工艺成型所制备的粉末高温合金FGH97在650℃下的疲劳裂纹扩展性能,并与俄制旋转电极制粉+热等静压工艺成型的EP741NP合金盘件进行对比；重点分析了不同制粉工艺、氧含量、晶粒度、γ"尺寸等因素对裂纹扩展速率的影响。结果表明：氩气雾化制粉+热等静压工艺制备的FGH97合金试验盘具有比俄制旋转电极制粉+热等静压工艺制备的EP741NP合金盘件更好的疲劳裂纹扩展抗力；分析发现晶粒度对氩气雾化制粉+热等静压工艺制备的试验盘裂纹扩展性能影响较为明显,晶粒度越大,疲劳裂纹扩展速率越低；γ"相尺寸的影响次之,在一定范围内γ"相尺寸增大,疲劳裂纹扩展速率略为降低；而氧含量在100~150ppm范围内对疲劳裂纹扩展性能无显著影响。

Abstract:

Fatigue crack growth behavior at 650℃ of a P/M superalloy FGH97, which was made by Argon Atomization (AA) + Hot Isostatic Pressing (HIP)process, was investigated. Comparison tests were conducted using a Russian EP741NP disk made of Plasma Rotating Electrode Process (PREP) + HIP process. The effects of different powder making methods, oxygen content, grain size and gamma prime size on the fatigue crack growth rate were evaluated. The results revealed that the fatigue crack growth behavior of AA + HIP processed FGH97 test disk has a lower crack growth rate compared with EP741NP disk, and disks with larger grain size, larger gamma prime size have lower crack growth rates, the oxygen content between 100~150 ppm range has no significant effect on the crack growth rate.