【摘要】 研究了Ni－Al－Ti细化剂对K4169高温合金铸态组织及性能的影响．结果表明，合金液不经过均匀化处理，在1420℃下加入细化剂浇注可显著细化晶粒和提高断面等轴晶的比例细晶组织的室温拉伸性能明显优于普通铸造组织在中温下，细晶组织的强度高于普通铸造组织，但二者的拉伸塑性相差不大细晶组织的中温持久寿命显著高于普通铸造组织，但二者的持久塑性差别不大利用扫描电镜对拉伸和持久断口进行了分析更多还原

【Abstract】 The samples of superalloy K4169 used in testing mechanical property were cast under conventional and fine-grained cast conditions. The effects of refiner Ni-Al-Ti on grain structures and mechanical properties were investigated. Fracture surfaces of the test bars were examined by scanning electron microscopy (SEM). The results indicate that the fine-grained cast process can obviously refine the grains of K4169 alloy, the yield and tensile strength, and the tensile plasticity at room temperature are also improved. Especially, the stress rupture life of the fine-grained sample is doubled compared with that of the convelltional cast sample under the test conditions of 760℃ and 480 MPa stress, whereas there is no obvious difference in permanent plasticity.更多还原