Ultrasonic fatigue lives of 40CrNiMoA steel with different microstructures

作者：Shao Hong Hong^*; Jiang Xiao Yan; Zhang Dao Jun

来源：Journal of Materials Engineering, 2008, (5): 24-28.

• Different microstructures
• Fatigue life
• High strength
• S/N curves
• Two types
• Ultrasonic fatigues
• Ultrasonic vibrations

Fatigue lives of 40CrNiMoA steel with different microstructures were studied by the ultrasonic fatigue technique at 20 kHz and R = -1. The results showed that the ultrasonic fatigue life of the specimen with microstructure of combined high strength and good toughness had higher fatigue life under ultrasonic vibration. Different microstructure of 40CrNiMoA had two types of S-N curves, stepwise and continually decreasing curves, and the specimen would be failing over 107 stress cycles, SEM fractograph of the fatigue specimens showed that, under ultrasonic vibration conditions, fatigue crack initiated at the surface of the specimens. The fracture mechanism of the super high cycle fatigue was discussed.

• 出版日期2008