Failure Investigation of a Diesel Engine Gear-Shaft

  • Xiaolei Xu
  • Zhiwei Yu
Technical Article---Peer-Reviewed


A diesel engine gear-shaft used in a truck fractured in service. Fracture occurred at the root fillet region of the upper groove and the platform. The fractographic study shows that the failure of the gear-shaft was initiated by fatigue. The small fillet radius of the upper groove provided a stress concentration level in root fillet region and created the conditions responsible for the fracture of the gear-shaft. Absence of the induction-hardening layer on the surfaces of the cylinder and the platform led to further problems at the root fillet region in terms of operation of the gear-shaft. Both the geometry of the gear-shaft and incorrect induction-hardening process are responsible for the failure of the gear-shaft.


Gear-shaft Fatigue initiation Fillet radius Induction-hardening Failure analysis 


  1. 1.
    Determination of effective depth of hardening after induction or flame hardening steel, China Standard, GB5617-85 (2000) (in Chinese)Google Scholar
  2. 2.
    ASM Metals Handbook. Failure Analysis Prevention, 10th edn., vol. 11. ASM International (1993)Google Scholar
  3. 3.
    Peterson, R.E.: Stress Concentration Factors. Wiley, New York (1974)Google Scholar

Copyright information

© ASM International 2009

Authors and Affiliations

  1. 1.College of Electromechanics and Material EngineeringDalian Maritime UniversityDalianPeople’s Republic of China

Personalised recommendations