Accession Number : AD0284750

Title :   AN INVESTIGATION OF THE CRACK-PROPAGATION RESISTANCE OF HIGH-STRENGTH ALLOYS AND HEAT-RESISTANT ALLOYS

Corporate Author : SOUTHERN RESEARCH INST BIRMINGHAM ALA

Personal Author(s) : JENKINS,P.C. ; MORRISON,J.D.

Report Date : 19 SEP 1962

Pagination or Media Count : 1

Abstract : Experiments with a compliance gage for measuring slow crack extension are described. It was found that at a temperature of 400 F a greater amount of slow crack growth occurs in the low-alloy steel--300M--than at other temperatures from 75 F to 800 F. At this same temperature (400 F) a minimum in net fracture strength and a maximum in ultimate tensile strength occur. Similar behavior at 350 F was noted for another low-alloy steel-AISI 4340. Replicate determinations of the fracture-toughness parameter, K sub c, from compliance-gage measurements of critical crack length indicate that a fair degree of reproducibility of K sub c values can be obtained by this method. Experiments with specimens of AISI 4340 steel have shown that crack lengths calculated from compliance-gage measurements agree well with actual measured crack lengths in the same specimens. (Author)

Descriptors :   *STEEL, MECHANICAL PROPERTIES, MEASURING INSTRUMENTS, RELIABILITY, SHEETS, TENSILE PROPERTIES, TEST METHODS

Distribution Statement : APPROVED FOR PUBLIC RELEASE