Effect of Shot Peening on Fatigue Performance Stress-Concentration Sensitivity of FGH96 Powder Metallurgy Superalloy
WANG Xin1,2, HU Yunhui3, WANG Xiaofeng4,5, TANG Zhihui1,2, ZOU Jinwen4,5
( 1. Surface Engineering Institution, AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China;
2. Aviation Key Laboratory of Advanced Corrosion and Protection on Aviation Materials, AECC Beijing Institute of
Aeronautical Materials, Beijing 100095, China;
3. R & D Center, AECC Xi’an Aero-Engine Ltd., Xi’an 710021, China;
4. Superalloy Institution, AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China;
5. National Key Laboratory of Advanced High Temperature Structural Materials, AECC Beijing Institute of Aeronautical
Materials, Beijing 100095, China )
Ceramic shot peening using different intensities was applied on grinded surface of FGH96 powder metallurgy
superalloy to research its effect on fatigue performance stress-concentration sensitivity. The fatigue tests and surface
integrity statues were characterized. The results show that fatigue limit of grinding declines from 583MPa to 465MPa at
650 ℃ when the stress concentration factor increases from Kt=1 to Kt=1.7. Shot peening using high intensity makes the
Kt=1.7 fatigue limit edge up to 530MPa while low intensity has no gain for the Kt=1.7 fatigue limit. High intensity leads to
the elimination of grinding marks, an increscent average roughness and an 100μm-depth residual stress profile, therefore
the 600MPa fatigue cracks are initiated at the subsurface in a single source fatigue model. By contrast, low intensity hardly
makes marks eliminated and the fatigue cracks are initiated at the surface in multiple sources fatigue model. The research
proves that the suitable shot peening method can minish the weaken effect to fatigue performance by structural stress-concentration.
2017, 
