Journal of Failure Analysis and Prevention

, Volume 8, Issue 5, pp 426–430 | Cite as

Failure of a Fusion Welded Ball Joint as a Result of Modification in MnS Direction

Case History---Peer-Reviewed

Abstract

A failure investigation was performed on a ball joint from an ATV front suspension system. The location of the fracture was the bearing ball/stud interface, which is a fusion-welded joint, and occurred after approximately 20 h of field-testing. The two parts are made out of carbon steel and were previously heat-treated. Many elongated MnS inclusions were found in the stud material, and these inclusions were parallel to the symmetry axis. Even though these inclusions were not significantly sized, their number was important. Macroscopic evidence showed that the joint failed in a ductile mode under centered tensile overload. Microscopic examination showed that MnS orientation changed in the fusion joint area. The inclusions had been redirected during the welding process and laid parallel to the fracture surface. This reorientation caused a significant decrease in the effective cross section of the joint and overload fracture occurred.

Keywords

Ball joint Elongated MnS Fusion welding Failure analysis 

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Copyright information

© ASM International 2008

Authors and Affiliations

  • Marina Banuta
    • 1
  • Isabelle Tarquini
    • 1
  • Benoit Gauvin
    • 1
  1. 1.SGS CanadaMontreal Canada

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