Citation

Yan S, Wang Q, Chen X, Zhang C, Cui G. J. Fail. Anal. Prev. 2019; 19(2): 361-368.

Copyright

(Copyright © 2019, ASM International, Publisher Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s11668-019-00607-z

PMID

unavailable

Abstract

The present work details a study for the determination of causes of a prematurely failed automobile spring. Several tools consisting of visual observation, optical microscope, scanning electron microscope (SEM), energy-dispersive spectrometer (EDS) analysis, etc., were used on the failed product to investigate the underlying causes. Photographs of the failed spring showed large wear marks and machinery indentations on the surface. These wear marks indicated an improper installation which could cause additional stresses under service loads. SEM images of one of the indentations showed radiating ridges emanating from the indentation tip which indicated that it served as the fatigue initiation. EDS results showed foreign elements in the fatigue origin implying the existence of microcracks. Under the effect of service and additional load, a stress concentration point was formed and fatigue crack originated from the indentation tip resulting in the final rupture.

Language: en

Keywords

Automobile spring; Crack initiation; Fatigue failure; Fatigue striations; High-level stress