NOTCH BRITTLENESS AFTER FRACTURE

Notched plates and bars prestrained in compression or extension, before or after notching, at 70 deg F or 550 deg F were tested to fracture in tension at -16 deg F. It was found that a catastrophic reduction of ductility could be caused by small prestrains. Uniform longitudinal or transverse prestraining by as little as 0.05 at 70 deg F reduced the initial ductility of notched bars by a factor of 4 or more. Hot prestraining was even more damaging: the greatest drop in the ductility at -16 deg F was caused by prestrains of only 0.025 at 550 deg F. These tests indicate that the "brittle" behavior of mild steel structures results from some damaging prior history of straining. Therefore, the proper selection of steels should be based on their resistance to embrittlement by suitable straining rather than on their properties in the initial undamaged state. The presented testing methods offer a great control over the steel ductility. They would be useful both in steel assessment and in the investigations of the factors influencing the resistance of steel to fracture.

  • Supplemental Notes:
    • Sponsored by the Naval Sea Systems Command, Washington, D.C. 20362. (A Ship Structure Committee Project.)
  • Corporate Authors:

    Brown University

    Providence, RI  United States  02912
  • Authors:
    • Mylonas, C
    • Kobayashi, S
  • Publication Date: 1968-12

Media Info

  • Features: References;
  • Pagination: 40 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00164218
  • Record Type: Publication
  • Source Agency: Ship Structure Committee
  • Report/Paper Numbers: SSC-192 Final Rpt.
  • Contract Numbers: NObs-88294
  • Files: TRIS
  • Created Date: Oct 29 1977 12:00AM