Foreign object damage tolerance and fatigue analysis of induction hardened S38C axles

Materials & Design

Jing Han¹  Ming-Hua Yu²  Ding Liao³  Jie-Wei Gao⁴  Shun-Peng Zhu⁴  Zhen-Yu Zhu⁴ 

[1] Center for System Reliability &State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, China;School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China;School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China;

关键词: Foreign object damage;    S38C;    Railway axle;    Fatigue strength;    Kitagawa–Takahashi diagram;   

DOI  :  

来源: DOAJ

【 摘 要 】

Flying ballast impact damage on railway axles poses a threat to structural integrity and safety of high-speed trains. A comprehensive evaluation on the fatigue strength debit of axles with foreign object damage (FOD) is vital for their safe operation and maintenance under damage tolerance philosophy. In this study, FODs were simulated by shooting tungsten steel balls to the specimens extracted from surface induction hardened S38C axles. Specifically, tests were performed under three impact velocities, i.e. 200, 300 and 400 m/s, and five incident angles for each impact velocity. Morphologies of impact damage were observed by scanning electron microscope (SEM) as well as the cross-sections. Fatigue strength of impacted specimens were then evaluated. Results show that depth and volume of damaged zone increases with the incident angle at the velocity of 200 m/s. Fatigue strength losses of specimens impacted at velocities of 300 and 400 m/s is around 50% compared with that of smooth ones. Fatigue crack originated from the exit rim for 200 m/s glanced impacted specimens, while multiple cracks propagated from both exit rim and bottom of crater impacted at 300 and 400 m/s. Finally, fatigue strength of damaged specimens was evaluated based on the defect depth concept and Kitagawa–Takahashi (K–T) diagram.

【 授权许可】

Unknown