RESTORATION OF DUCTILITY OF HOT OR COLD STRAINED ABS-B STEEL BY HEAT TREATMENT AT 700 TO 1150F

The severe embrittlement caused by a suitable history of strain and temperature has been confirmed also for steel conforming to ABS-B classification. Steel prestrained in compression by about 50% at 70F and subsequently tested in tension fractures at an extensional strain of the order of 1%. Prestraining at 550F by even 25% can cause brittleness in extension at -16F. Local severe embrittlement of this nature has been shown to be the basic cause of the static initiation of brittle failure of structures at low average stress. This is confirmed by service failures, whose origin is frequently traced to cold worked areas, or to the hot strained regions of defects close to welds. It is shown that a suitable heat treatment can restore appreciable ductility to steel embrittled by hot or cold straining. The duration of heating decreases with the temperature, but increases very rapidly with the amount of prestrain. To each temperature corresponds a limiting prestrain for which heat treatment becomes impractically long. Cold strained steel requires considerably longer heat treatment and higher temperatures (1000-1200F) than hot strained steel (700-1000F). Approximate time-temperature-prestrain curves have been experimentally determined. The results confirm that a major beneficial effect of the so-called 'thermal stress-relieving' treatment is a restoration of the ductility of locally embrittled steel. (Author)

  • Supplemental Notes:
    • Rept. on Manufacture Fundamentals.
  • Corporate Authors:

    Brown University

    Providence, RI  USA  02912
  • Authors:
    • Mylonas, C
    • Beaulieu, R J
  • Publication Date: 1965-4

Media Info

  • Pagination: 32 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00327726
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: SSC-167
  • Contract Numbers: NObs-88294
  • Files: TRIS
  • Created Date: Feb 18 1981 12:00AM