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

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)

Document Details

Document Type
Technical Report
Publication Date
Sep 19, 1962
Accession Number
AD0284750

Entities

People

  • J.d. Morrison
  • P.c. Jenkins

Organizations

  • Southern Research

Tags

DTIC Thesaurus Topics

  • Alloys
  • Crack Propagation
  • Cracks
  • Heat Resistant Alloys
  • High Strength Alloys
  • Low Alloy Steels
  • Measurement
  • Resistance
  • Steel
  • Tensile Strength

Readers

  • Marine Hydrodynamics
  • Materials Science and Engineering.
  • Metallurgy