Accession Number:

AD0737276

Title:

The Effects of Surface Layer on Plastic Deformation and Crack Propagation

Descriptive Note:

Semiannual rept. Jul-Dec 1971

Corporate Author:

MARTIN MARIETTA AEROSPACE DENVER CO

Personal Author(s):

Report Date:

1972-01-01

Pagination or Media Count:

22.0

Abstract:

A change in proportional limit after cycling was observed for aluminum 2014-T6. Cycling below the endurance limit increases the proportional limit. The etch pit distribution of dislocations in Fe-3Si steel was investigated. The threshold stress for the appearance of slip steps in untreated and SSLE treated specimens of aluminum 2014-T6 was determined. The percentage of grains deformed in specimens of aluminum 2014-T6 which are stressed to various values was observed. The effect of SSLE treatment on the threshold stress intensity for 4130 steel was established. A diametral gage to measure the surface layer stress of notched specimens was manufactured.

Subject Categories:

  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE