Skip to Main Content
ASM Failure Analysis Case Histories

Handbook of Case Histories in Failure Analysis

Edited by
Khlefa A. Esaklul
Khlefa A. Esaklul
Search for other works by this author on:
ASM International
Volume
2
ISBN electronic:
978-1-62708-215-0
Publication date:
1993
Book Chapter

Failed Bolts From an Army Tank Recoil Mechanism

By
Victor K. Champagne
Victor K. Champagne
United States Army Research Laboratory, Materials Directorate
Search for other works by this author on:
Published:
1993
Page range:
384 - 387

Abstract

The heads of two AISI 8740 steel bolts severed while being installed into an Army tank recoil mechanism. Both broke into two pieces at the head-to-shank radius and the required torque value had not been attained nor exceeded prior to the failure. A total of 69 bolts from inventory and the field were tested by magnetic particle inspection. One inventory bolt failed because of a transverse crack near the head-to-shank radius. It was deduced that either a 100% magnetic particle inspection had not been conducted during bolt manufacturing, or the crack went undetected during the original inspection. Optical and electron microscopy of the broken bolts revealed topographies and the presence of black oxide consistent with quench cracking. The two bolts failed during installation due to the presence of pre-existing quench cracks. Recommendations to prevent future failures include: ensuring that 100% magnetic particle inspections are conducted after bolts are tempered; using dull cadmium plate or an alternative to the electrode position process, such as vacuum cadmium plate or ion-plate or ion-plated aluminum, to mitigate the potential for delayed failures due to hydrogen embrittlement or stress-corrosion cracking; ensuring that the radius at the shoulder/shank interface conforms to specifications; and replacing all existing bolts with new or reinspected inventory bolts.

You do not currently have access to this content.
Don't already have an account? Register

Victor K. Champagne, 1993. "Failed Bolts From an Army Tank Recoil Mechanism", Handbook of Case Histories in Failure Analysis, Khlefa A. Esaklul

Download citation file:


Close
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal