Effect of Shot Peening on Fatigue Limit Stress Concentration Sensitivity of 3 Kinds of Typical Materials for Aeroengine

• Main Authors: WANG Xin, LI Xudong, SONG Yinggang, WANG Qiang, LUO Xuekun, AI Yingjun, TANG Zhihui, ZHAO Zhenye
• Format: Article
• Language: zho
• Published: Journal of Aeronautical Materials 2017-12-01
• Series: Journal of Aeronautical Materials
• Subjects: typical materials for aeroengine; fatigue limit; stress concentration sensitivity; shot peening
• Online Access: http://jam.biam.ac.cn/CN/Y2017/V37/I6/102
• ISSN: 1005-5053; 1005-5053

Fatigue curves of C250 steel, TA29 titanium alloy and FGH96 powder metallurgy (PM) superalloy with stress concentration coefficients <i>K</i>_t=1 and <i>K</i>_t=1.7were investigated, and the effect of shot peening on the fatigue curve under the stress concentration condition was also studied. The results show that the 10⁷ conditional fatigue limits of C250 steel, TA29 titanium alloy and FGH96 PM superalloy decrease from 757 MPa, 366 MPa and 566 MPa to 526 MPa, 240 MPa and 465 MPa respectively while the stress concentration coefficients increase from <i>K</i>_t=1 to <i>K</i>_t=1.7, indicating that the three kinds of high-strength materials have the stress concentration sensitivity of fatigue limit obviously. Moreover, after shot peening, fatigue limits rise to 597 MPa, 297 MPa and 530 MPa respectively when the Kt is 1.7, which indicates that shot peening can mitigate fatigue limit stress concentration sensitivity of high-strength alloys from a technological point of view. On the other hand, the 10⁵-cycle and 10⁷-cycle strength difference of titanium alloy and PM superalloy is reduced with the increase of stress concentration coefficient, showing that shot peening can reduce the dispersion of fatigue test data.