航空学报 > 2022, Vol. 43 Issue (2): 625004-625004   doi: 10.7527/S1000-6893.2021.25004

高温合金线性摩擦焊接头疲劳裂纹扩展有限元分析

杨夏炜1, 彭冲1, 马铁军1, 温国栋2, 王艳莹1, 柴小霞1, 徐雅欣1, 李文亚1   

  1. 1. 西北工业大学 凝固技术国家重点实验室 陕西省摩擦焊接工程技术重点实验室, 西安 710072;
    2. 中煤科工集团西安研究院有限公司, 西安 710077
  • 收稿日期:2020-11-24 修回日期:2020-12-14 发布日期:2022-03-04
  • 通讯作者: 马铁军 E-mail:matiejun@nwpu.edu.cn
  • 基金资助:
    国家自然科学基金(51875470,52074228,52075551);凝固技术国家重点实验室自主研究课题(2021-TS-07)

Finite element analysis of fatigue crack growth of linear friction welded superalloy joints

YANG Xiawei1, PENG Chong1, MA Tiejun1, WEN Guodong2, WANG Yanying1, CHAI Xiaoxia1, XU Yaxin1, LI Wenya1   

  1. 1. State Key Laboratory of Solidification Processing, Shaanxi Key Laboratory of Friction Welding Technologies, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China;
    2. Xi'an Research Institute of China Coal Technology & Engineering Group Corp., Xi'an 710077, China
  • Received:2020-11-24 Revised:2020-12-14 Published:2022-03-04
  • Supported by:
    National Natural Science Foundation of China (51875470, 52074228, 52075551);State Key Laboratory of Solidification Processing (2021-TS-07)

摘要: 为了表征高温合金线性摩擦焊接头疲劳服役环境下疲劳裂纹的萌生及扩展行为,揭示裂纹扩展对接头失效的影响机制,基于有限元法研究高温合金线性摩擦焊接头疲劳裂纹扩展的行为及其重要影响因素。以接头失效内因(孔洞、硬质夹杂、残余应力)为研究对象,建立不同几何和位置特征的含有初始孔洞及夹杂的疲劳接头有限元模型,研究不同特征下疲劳接头裂纹萌生及扩展的先后顺序,划分裂纹扩展重要因素等级。结果表明:含有初始孔洞及夹杂的疲劳接头裂纹萌生于孔洞及夹杂所在位置,初始夹杂接头试样裂纹均以"绕过"方式扩展,初始孔洞接头试样裂纹均以"横穿"方式扩展,孔洞及夹杂的位置特征对裂纹萌生位置及扩展方式影响较小,裂纹萌生、扩展及试样断裂的时间随着孔洞及夹杂尺寸的增大而提前。接头的残余拉应力加速裂纹的萌生及扩展,裂纹的萌生及扩展时间与拉应力呈正相关。

关键词: 接头, 有限元分析, 微结构, 残余拉应力, 裂纹扩展

Abstract: To characterize the fatigue crack initiation and growth of linear friction welded superalloy joints in the fatigue environment and reveal the effect of crack growth on joint failure, this study investigates the fatigue crack growth behavior of the linear friction welded superalloy joint and its important influencing factors based on the finite element method. To study the internal causes of joint failure (holes, hard inclusions, and residual stresses), finite element models for the fatigue joints containing initial holes and inclusions with different geometric and location characteristics were established to study the sequence of crack initiation and propagation of the joints and classify important factors of crack growth. The results show that for the fatigue joints with initial holes and inclusions, cracks were initiated at the locations of the holes and inclusions. For the specimens with initial inclusions, the cracks grew in a "bypass" manner. For the joints with initial holes, the cracks were all propagated in a "crossing" manner. The locations of holes and inclusions had little effect on the crack initiation position and propagation mode. Crack initiation, propagation and specimen fracture occurred earlier with the increase of the size of holes and inclusions. The residual tensile stress of the joint accelerates the initiation and propagation of cracks, and the initiation and propagation time of cracks is positively correlated with the tensile stress.

Key words: joint, finite element analysis, microstructure, residual tensile stress, crack propagation

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