析出相在 GH907 低膨胀合金中的作用

Effects of Precipitates in the Low Expansion Superalloy GH907

研究了析出相对Ｇ９０７合金持久性能的影响。采用特定的热处理制度得到以某一析出相为主的显微组织。经性能测试后发现，γ′为合金提供良好的瞬时强度，但单一γ′强化相不能使合金得到满意的持久性能；Ｌａｖｅｓ相对合金的性能没有明显的益处；ε相使合金持久寿命大幅度提高，并消除了缺口敏感性。本文在应用主平面应力法的基础上，提出了一种模型对此做了满意的分析。

The effects of precipitates on stress rupture properties of GH907 superalloy was studied in this paper Special heat treatments were employed to obtain microstructures with ideal strengthening precipitate It was determined that the single γ′ could not provide satisfying rupture properties though excellent tensile strength could be reached;obvious profit could not be observed by the appearance of Laves in the microstructure;however,ε was beneficial to the rupture life of the alloy,specially to eliminating the notch sensitivity The reason is also explained by means of a model based on the principal facet stress method