Effects of Nonmetallic Inclusions on Stage II Fatigue Crack Propagation in a Low Alloy Steel.

Abstract

The dependence of fatigue crack growth rate on stress intensity factor range was shown to be more sensitive to the morphology and distribution of inclusions than to the total quantity of nonmetallistics present. Higher crack growth rates were obtained in specimens containing relatively small sulphides that were irregularly shaped and clustered or aligned. Conversely, the lowest crack growth rates were obtained in specimens containing well distributed, spherical oxides. Fractographic examination accompanied by energy dispersive x-ray analysis of inclusions 'in situ' on fracture surfaces illustrated the involvement of inclusions in the fracture process. Also, these inspections verified the metallographic observations. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1972
Accession Number
AD0746950

Entities

People

  • Peter A. Thornton

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Alloys
  • Crack Propagation
  • Cracks
  • Inclusions
  • Inspection
  • Intensity
  • Low Alloy Steels
  • Observation
  • Steel
  • Stress Intensity Factors
  • Stresses
  • Sulfides
  • X Rays

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).