Accession Number:

AD0774828

Title:

Wear, Friction and Thermal Fatigue of Gun Barrel Materials

Descriptive Note:

Final rept. 23 May-31 Dec 1973

Corporate Author:

ROCKWELL INTERNATIONAL CORP THOUSAND OAKS CA SCIENCE CENTER

Personal Author(s):

• Robertson, W. M.

Report Date:

1973-12-21

Pagination or Media Count:

171.0

Abstract:

Thermal fatigue tests were performed on the following materials gun steel 4340 steel chromium plated gun steel gun steel plated with a composite plate of chromium over alumina dispersion hardened cobalt 4340 steel plated with the composite chromium-cobalt plate and tantalum-10 tungsten. Temperatures were cycled over various ranges from a minimum of 350F to a maximum of 1535F. The tubular test specimens were heated by induction and cooled by passing air through the tube center. Diametral strain was measured and constrained to follow a preset temperature strain relation which provided either 0.2 or 0.8 plastic compressive strain in the specimen at the maximum temperature of the cycle. Loads required to maintain the preset strain were measured and time to specimen failure was determined. The application of these results to the optimization of wear resistant coatings on gun barrels is discussed.

Descriptors:

• *GUN BARRELS
• *COATINGS
• *WEAR
• *THERMAL FATIGUE
• COMPOSITE MATERIALS
• LOADS(FORCES)
• STRAIN(MECHANICS)
• STEEL
• CHROMIUM
• TUNGSTEN ALLOYS
• COBALT
• TANTALUM ALLOYS

Subject Categories:

• Metallurgy and Metallography
• Guns

Distribution Statement:

APPROVED FOR PUBLIC RELEASE