The Effects of the Surface Layer on Plastic Deformation and Crack Propagation

Abstract

The report describes the effect of a surface layer on the rate of crack propagation and, based on this knowledge, the author proposes to improve the crack propagation resistance of metals used in pressure vessels. The qualification of pressure vessel hardware is usually achieved by the proof test method. The maximum size of the flaw that is present can be predicted from fracture mechanics. However, cracks can grow below the critical stress intensity K(c) and can cause leak failure. Therefore, the subcritical crack growth characteristics of metals are important in pressure vessel material selection. An evaluation of the crack growth rate under sustained or cyclic loading under the service stress gives a measure of reliability of the hardware.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1971
Accession Number
AD0721292

Entities

People

  • Irvin R. Kramer

Organizations

  • Martin Marietta

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Aluminum
  • Continuum Mechanics
  • Corporations
  • Crack Propagation
  • Cracks
  • Fatigue Life
  • Fracture (Mechanics)
  • Intensity
  • Massachusetts
  • Materials
  • Mechanics
  • Metals
  • Plastic Deformation
  • Pressure Vessels
  • Reliability
  • Test And Evaluation
  • Test Methods

Fields of Study

  • Engineering

Readers

  • Materials Science (Mechanical Engineering).
  • Software Engineering