Prediction of threshold value for FGA formation

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:528

Article

Zhao, Aiguo¹  Xie, Jijia¹  Sun, Chengqi¹  Lei, Zhengqiang¹  Hong, Youshi¹ 

[1] Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China

关键词: Very high cycle fatigue;    FGA;    Crack growth threshold;    Frequency effect;    Stress intensity factor;   

DOI  :  10.1016/j.msea.2011.05.070

来源: Elsevier

【 摘 要 】

This paper studies the formation mechanism of fine granular area (FGA) in high-strength steels and predicts the threshold value of its formation. Fatigue experiments are carried out by using rotating bending and ultrasonic fatigue testing machines on a high carbon chromium steel (GCr15) with three different heat treatments. The results show that the range of stress intensity factor at the periphery of FGA (Delta K-FGA) keeps constant with an average value of 5.2 MPa m(1/2), which is close to the traditional crack growth threshold (Delta K-th,K-0), 5.0 MPa m(1/2). A theoretical model based on the plastic zone at crack tip is proposed to predict the value of Delta K-FGA and the predictions are in good agreement with experimental data. (C) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

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