Accession Number:

ADA220858

Title:

Brittle Torsional Fatigue Crack Initiation in an Otherwise Ductile Environment

Descriptive Note:

Final technical rept.

Corporate Author:

ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS

Personal Author(s):

Report Date:

1990-03-01

Pagination or Media Count:

20.0

Abstract:

The results of a torsional fatigue test program on marage 250 steel indicate that the usual fatigue failure mechanism occurs as a flat ductile fracture along the cross section of the test specimens. However, a small number of specimens displayed a small penny-shaped crack on the outer surface at a 45-degree helix, typical of brittle torsional failure, before the final ductile failure. Scanning electron microscope examination showed that the brittle failure was caused by a brittle inclusion on the outside surface of the specimen. Keywords Titanium.

Subject Categories:

  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE