Practical Failure Analysis

, Volume 2, Issue 4, pp 77–80 | Cite as

Hydrogen induced cracking of a tappet adjusting screw

  • B. V. Krishna
Peer Reviewed Articles

Abstract

The electroplated tappet adjusting screws used in diesel engines failed during initial bend testing. The analysis of the failure showed that the fracture was nucleated from the subsurface of the screw. The fracture surface was intergranular at the ID and OD region and microvoid coalesence in the center. The improper baking after electroplating of the screw led to H2-induced blistering/cracking. The high strength of the threaded region of the adjusting screw increased the failure propensity.

Keywords

electroplating failure analysis hydrogen damage hydrogen embrittlement hydrogen induced cracking 

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Copyright information

© ASM International - The Materials Information Society 2002

Authors and Affiliations

  • B. V. Krishna
    • 1
  1. 1.Materials Science & Technology Division, Thapar Centre for Industrial Research and DevelopmentThapar Technology CampusPatialaIndia

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