Accession Number:

ADA027025

Title:

Fracture Mechanics Study on 155 mm M107E1 Projectile Made from Isothermally Transformed HF-1 Steel

Descriptive Note:

Technical research rept.

Corporate Author:

FRANKFORD ARSENAL PHILADELPHIA PA

Personal Author(s):

• Mulherin, Joseph H.
• Steward, William B.
• Corrie, John D.

Report Date:

1976-02-01

Pagination or Media Count:

53.0

Abstract:

A linear elastic fracture mechanics approach is used to describe critical flaw sizes in the 155 mm M107E1 HE projectile as manufactured from isothermally transformed HF-1 steel. Based on dynamic fracture toughness determinations and both experimental and analytical determinations of stress, critical crack sizes are calculated for each of the major sources of stress encountered during rough handling drop testing and launch. Drop tests of intentionally pre-flawed projectiles are used to check the validity of the approach. The low fracture toughness of isothermally transformed HF-1 at -65 degrees F and the relatively high stresses encountered by the projectile Particularly under drop test conditions result in critical crack depths as small as 0.010 inch. A recommendation is made that isothermally transformed HF-1 not be considered for use in an HE projectile of the M107 configuration.

Descriptors:

• *PROJECTILES
• *FRAGMENTATION AMMUNITION
• STRESS ANALYSIS
• FRACTURE(MECHANICS)
• ARTILLERY AMMUNITION
• HEAT TREATMENT
• CRACK PROPAGATION
• BRITTLENESS

Subject Categories:

• Metallurgy and Metallography
• Ammunition and Explosives

Distribution Statement:

APPROVED FOR PUBLIC RELEASE