The influence of substructure on the cleavage transition temperature in iron single crystals was investigated. Substructure was introduced by prestraining up to 10% and annealing, with the dislocation density increasing correspondingly from an initial value of about 10 to the 7th power to about 10 to the 10th power per sq cm. The yield properties of the crystals with substructure were somewhat higher while the brittle transition temperature was raised about 40 C. Twinning preceded cleavage in these tests, and all the cleavage microcracks observed were associated with twins. The microcracks were located either along the twin/matrix interfaces or within the twins, but not in the matrix itself nor at intersecting twins. Cleavage appears to be initiated by the action of twinning, rather than by the role of twins as barriers to slip. (Author)

  • Supplemental Notes:
    • Prepared in cooperation with Washington Univ., Seattle and Massachusetts Inst. of Technology, Cambridge.
  • Corporate Authors:

    Ship Structure Committee

    National Academy of Science, 2101 Constitution Avenue, NW
    Washington, DC  United States  20418
  • Authors:
    • Flanagan, W F
    • Averbach, B L
    • Cohen, M
  • Publication Date: 1962

Media Info

  • Pagination: 22 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00327724
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: SSC-133, Progress rept. no. 5
  • Contract Numbers: NOBS-78541, NOBS-84321
  • Files: TRIS
  • Created Date: Feb 18 1981 12:00AM