FAILURE BY STRESS CORROSION CRACKING - CURRENT APPROACHES TOWARD FAILURE PREDICTION

Stress corrosion cracking (SCC) produces failures in a material when it is subjected to the combined effects of mechanical stress and reaction with an environment. All proposed mechanisms of SCC seek to explain how the combination of a given level of stress, a particular material, and a given environment can lead to the initiation and propagation of cracks. The three major categories of mechanisms that are generally proposed are (1) active path dissolution, (2) stress-sorption, and (3) embrittlement. From chemistry have come two main currents; (a) increased awareness of the importance of characterizing the altered environment inside a growing crack, and (b) a recognition of the importance of the regrowth rate of a protective film on a bare surface exposed when that film is broken by stress. The main emphasis in the metallurgy of SCC has been on the crucial role played by structure in general, and particularly at the tip of a crack. Aiding this objective has been the use of the high voltage electron microscope which can directly look at the interaction of the environment with structural defects, e.g., dislocations. Finally, major thrust in the mechanics of SCC has been the application of the concepts and techniques of fracture mechanics. The impact of these new concepts and measurement techniques on predicting and preventing SCC failure is discussed.

  • Supplemental Notes:
    • Presented at the 20th Meeting of the NBS Mechanical Failure Prevention Group, Gaithersburg, Maryland, May 8-10 1975.
  • Corporate Authors:

    National Bureau of Standards

    Technical Analysis Division
    Washington, DC  USA  20234
  • Authors:
    • Kruger, J
  • Publication Date: 1976-4

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Subject/Index Terms

Filing Info

  • Accession Number: 00142537
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Report/Paper Numbers: Spec. Pub. 423 Proceeding
  • Files: TRIS
  • Created Date: Dec 15 1976 12:00AM