Creep-fatigue crack growth behavior in GH4169 superalloy  

作　　者：Dianyin HU Xiyuan WANG Jianxing MAO Rongqiao WANG 

机构地区：[1]School of Energy and Power Engineering, Beihang University, Beijing 100191, China [2]Collaborative Innovation Center of Advanced Aero-Engine, Beijing 100191, China [3]Beijing Key Laboratory of Aero-Engine Structure and Strength, Beijing 100191, China

出　　处：《Frontiers of Mechanical Engineering》2019年第3期369-376,共8页机械工程前沿（英文版）

基　　金：National Natural Science Foundation of China (Grant Nos. 51675024, 51305012, and 51375031).

摘　　要：This study aims to examine the crack growth behavior of turbine disc GH4169 superalloy under creepfatigue loading. Crack growth experiments were performed on compact tension specimens using trapezoidal waveform with dwell time at the maximum load at 650℃. The crack growth rate of GH4169 superalloy significantly increased with dwell time. The grain boundaries oxidize during the dwell process, thereby inducing an intergranular creep-fhtigue fracture mode. In addition, testing data under the same dwell time showed scattering at the crack growth rate. Consequently, a modified model based on the Saxena equation was proposed by introducing a distribution factor for the crack growth rate. Microstructural observation confirmed that the small grain size and high volume fraction of the δ phase led to a fast creep-fatigue crack growth rate at 650℃, thus indicating that two factors, namely, fine grain and presence of the δ phase at the grain boundary, increased the amount of weakened interface at high temperature, in which intergranular cracks may form and propagate.

关 键 词：crack growth rate creep-fhtigue GH4169 SUPERALLOY CT SPECIMEN DWELL time 

分 类 号：TH[机械工程]